@INPROCEEDINGS{0410:Quality,
TITLE="Quality Effects of wireless {VoIP} using security solutions",
BOOKTITLE="MILCOM",
ORGANIZATION="IEEE",
ADDRESS=1,
DAYS=20,
MONTH=oct,
YEAR=2004
}

@INPROCEEDINGS{0410:Quality,
TITLE="Quality Effects of wireless {VoIP} using security solutions",
BOOKTITLE="MILCOM",
ORGANIZATION="IEEE",
ADDRESS=1,
PAGES="1352-1357",
DAYS=31,
MONTH=oct,
YEAR=2004,
ABSTRACT="The challenge for wireless voice-over-IP (VoIP) is to achieve both voice
quality and efficient use of spectrum. VoIP over wireless network (VoWLAN)
has higher security vulnerabilities. Secured wireless VoIP presents many
challenges to providing quality voice communication. This paper presents
the results of an experimental analysis of the transmission of voice over a
secure communication wireless network implementing various security
solutions. The experimental results demonstrate how choices in voice-packet
security and IP security influence the overall design decisions. This study
raised an awareness of the effects of the various security solutions on
voice qualities that must be considered when deploying VoIP in the wireless
networks."
}

@INPROCEEDINGS{Aad0409:Denial,
AUTHOR="Imad Aad and Jean-Pierre Hubaux and Edward Knightly",
TITLE="Denial of Service Resilience in Ad Hoc Networks",
BOOKTITLE="10th ACM MobiCom Conference 2004",
ADDRESS="Philadelphia, Pennsylvania",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="Significant progress has been made towards making ad hoc networks secure
and DoS resilient. However, little attention has focused on quantifying DoS
resilience: do ad hoc networks have sufficiently redundant paths and
counter-DoS mechanisms to make DoS attacks largely ineffective? Or are
there attack and system factors that can lead to devastating effects? In
this paper, we design and study DoS attacks in order to assess the damage
that difficultto- detect attackers can cause. The first attack we study,
called the JellyFish, is targeted against closed-loop flows such as TCP;
although protocol compliant, it has devastating effects. The second attack
is the Black Hole, which has effects similar to the JellyFish, but on
open-loop flows. We quantify via simulations and analytical modeling the
scalability of DoS attacks as a function of key performance parameters such
as mobility, system size, node density, and counter-DoS strategy. One
perhaps surprising result is that such DoS attacks can increase the
capacity of ad hoc networks, as they starve multi-hop flows and only allow
one-hop communication, a capacity-maximizing, yet clearly undesirable
situation."
}

@INPROCEEDINGS{Aage0404:Dynamic,
AUTHOR="Fin Arve Aagesen and Chutiporn Anutariya and Mazen Malek Shiaa and Bjarne
Helvik and Paramai Supadulchai",
TITLE="A Dynamic Configuration Architecture",
BOOKTITLE="IEEE/IFIP Network Operations and Management Symposium",
ADDRESS="Seoul, Korea",
DAYS=19,
MONTH=apr,
YEAR=2004,
ABSTRACT="The paper presents a formal framework for dynamic configuration and
reconfiguration of services in TAPAS (Telematics Architecture for
Plug-and-Play Systems). TAPAS shall meet the requirements of the dynamic
changes in both time and position related to resources, users and changed
service requirements. The framework presented in this paper, provides
representation, computation and reasoning mechanisms for semantic
description and matching of required and offered capabilities and status
which are required by a particular service system. It employs CIM schema
and recently developed languages for the Semantic Web -- RDF, RDF Schema
and DAML languages -- in order to provide a mechanism for human-readable
and machine-comprehensible descriptions of status, capabilities, system
(re)configuration plans as well as the exchanging messages. It exploits XDD
theory -- an expressive XML rule-based, knowledge representation -- to
seamlessly unify such various languages into a single uniform formalism,
hence allowing the integration, extraction, computation of and reasoning
with instances/objects of those different languages. It permits formal
definitions of application-specific configuration requirements and
constraints as well as reconfiguration policies for handling particular
events in terms of XML clauses. Reasoning about these definitions and the
available capabilities and status of nodes in the system yields appropriate
(re)configuration plans for composition of new services to be installed and
for adaptation of the currently executing services. A prototype reasoning
engine has already been developed and is demonstrated in the paper. The
proposed architecture is applicable for configuration management
functionality, which is based on the matching of required and offered
status and capabilities."
}

@INPROCEEDINGS{Aawa0412:Access,
AUTHOR="Aawatif Hayar and Illia Racunica and Christian Bonnet",
TITLE="Access Control, code allocation, and adaptive scheduling for {UMTS} {TDD}",
BOOKTITLE="IEEE Workshop on Adaptive Wireless Networks",
ADDRESS="Dallas, Texas, USA",
DAYS=3,
MONTH=dec,
YEAR=2004,
ABSTRACT="In UMTS-TDD (Universal Mobile Telecommunications System - Time Division
Duplex) the data rates and the service quality (bit error rate, delays) are
provided by the Radio Resource Management (RRM). The RRM manages the
transmission power, the spreading factor and the orthogonal code
assignment. The specifications leave open the choice of the RRM strategy.
This work proposes a scheme suitable for mixed traffic consisting of Real
Time (RT) services and Non Real Time (NRT) services in downlink. The access
to the RT services is controlled by the Call Admission Control (CAC) using
a Power-based algorithm. This algorithm determines the OVSF (Orthogonal
Variable Spreading Factor) codes of a user in order to optimize the sharing
of the transmitted power in the downlink in the most uniform manner over
the assigned slots in the frame. The OVSF codes given by this algorithm are
attributed to a Dedicated Channel. For NRT services, in presence of RT
services, a channel allocation power-based strategy is combined at the
physical layer with an adaptive scheduling at the Medium Access Control
(MAC) layer to minimize Node-B transmitting power and schedule mixed
traffic that benefits of a good radio channel and respects Quality of
Service (QoS) constraints and fairness rules. The overall RRM strategy
minimizes the number of RT rejected calls and the Block Error Rate (BLER)
of NRT services. RT services are usually mapped on Dedicated Channel (DCH)
and NRT services are mapped on Downlink Shared Channel. The DCH are
configured at the connection of the RT services then NRT services are
mapped on already configured DSCH. The algorithm allows the RT traffic to
use DSCH in certain circumstances."
}

@INPROCEEDINGS{Abar0405:Performance,
AUTHOR="Jaime Abarca",
TITLE="Performance evaluation of the downlink {CDMA} cellular system supporting
integrated voice/data traffic",
BOOKTITLE="Vehicular Technology Conference Spring 2005 Mobile Applications and
Services",
ADDRESS="Stockholm, Sweden",
DAYS=29,
MONTH=may,
YEAR=2004,
ABSTRACT="In this work, we evaluate the performance of the downlink in CDMA cellular
system with a services mix (voice and high data-rate packet). The users
that arrive to the system follow a Poisson process. The data service is WWW
traffic and the transmission is made through code aggregation in burst
mode. The focus of this work is not only in the performance of data users,
but also in the impact on voice users sharing the CDMA band. Call admission
control is used to regulate the traffic load in the system. To maintain QoS
requirements and to avoid excessive interference power control is
considered. We use a mix of static and dynamic simulations to evaluate the
performance of the system (call blocking and dropout probabilities,
capacity, coverage, packets delay and performance of burst admission).In
the dynamic simulation we considered: mobility, soft handoff events and
correlated shadowing."
}

@INPROCEEDINGS{Abaw0411:Interactive,
AUTHOR="Daniel Abawi and Joachim Bienwald and Ralf Doerner",
TITLE="Interactive Specification of Virtual Objects Poses in an {AR} System Using
{Multi-Marker} Tracking",
BOOKTITLE="ISMAR'04",
ADDRESS="Arlington, VA,",
DAYS=2,
MONTH=nov,
YEAR=2004,
ABSTRACT="This paper presents an authoring process and authoring tools that support
authors in associating virtual objects with multi-markers. With this,
author can efficiently specify how virtual objects should be located and
oriented in an Augmented Reality (AR) where the underlying AR system relies
on optical tracking with multiple markers. For this, a multi-marker based
tracking algorithm has been conceived that takes the accuracy of each
single marker into account. The results of extensive accuracy experiments
with single markers are reported and made operational by the definition of
an accuracy function. The results show a specific distribution of tracking
accuracy dependent on distance as well as angle between camera and marker.
This insight is applicable for designing the set-up of AR applications in
general that rely on optical tracking."
}

@INPROCEEDINGS{Abba0403:Interleaver,
AUTHOR="Aliazam Abbasfar",
TITLE="Interleaver Design For High Speed Turbo Decoders",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="Recently some efficient parallel architectures for turbo decoder have been
proposed. In these architectures the bottleneck for the parallelization of
the decoder is the interleaver. On the other hand, turbo codes achieve a
very impressive near Shannon-capacity performance in which the interleaver
plays a crucial role. Therefore, it is of great interest to design
interleavers that are good from both performance and parallelization point
of views. In this paper we propose an interleaver structure that is very
suitable for parallelization of turbo decoders. It is shown that such an
interleaver can be designed to have good BER performance as well. By this
structure not only fast decoders with very low latency can be built, but
also the regularity of the decoder and the simplicity of the interleaver
structure make them very promising for VLSI implementation. We also present
a fast algorithm to design such an interleaver, which can be used to design
S-random interleavers as well. Such interleavers have been designed and the
performances are compared to that of S-random interleavers by simulations."
}

@INPROCEEDINGS{Abba0403:Interleaver,
AUTHOR="Aliazam Abbasfar",
TITLE="Interleaver design for turbo codes by distance spectrum shaping",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="Interleaver plays a critical role in the performance of turbo codes. It can
be best designed given the structure of the code. In this paper a new
methodology for systematically designing the interleaver for a
parallel-concatenated convolutional code (PCCC) is presented that exploits
the structure of the code. Some novel approaches that result from this
methodology are introduced. This methodology can be a basis for
constructing algorithms to design very good interleavers for Turbo-like
codes. This algorithm tries to maximize the minimum distance of the code.
The performance of the interleavers designed with this methodology is
compared with previous methods and its superiority is illustrated by
simulation results."
}

@INPROCEEDINGS{Abba0411:Accumulate,
AUTHOR="Aliazam Abbasfar and Dariush Divsalar and Kung Yao",
TITLE="Accumulate Repeat Accumulate Codes",
BOOKTITLE="IEEE Globecom 2004 - Communication Theory",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT={We propose a new channel coding called {"}Accumulate Repeat Accumulate
codes{"} (ARA). These codes are subclass of Low Density Parity Check (LDPC)
codes, with fast encoder structure. Using density evolution for ARA codes,
we show that for maximum variable node degree 5 a minimum bit SNR as low as
0.08 dB from channel capacity for rate 1/2 can be achieved as the block
size goes to infinity . Thus based on fixed low maximum variable node
degree, its threshold outperforms the best known LDPC codes with the same
maximum node degree. Furthermore by puncturing the accumulators any desired
high rate codes close to code rate 1 can be obtained with thresholds that
stay close to the channel capacity thresholds uniformly. Iterative decoding
simulation results are provided. The ARA codes also have projected graph or
protograph representation, that allows for high speed decoder
implementation.}
}

@INPROCEEDINGS{Abba0411:Maximum,
AUTHOR="Aliazam Abbasfar and Dariush Divsalar and Kung Yao",
TITLE="Maximum Likelihood Decoding Analysis of {Accumulate-Repeat-Accumulate}
Codes",
BOOKTITLE="IEEE Globecom 2004 - Communication Theory",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="Repeat-Accumulate (RA) codes are the simplest turbo-like codes that achieve
good performance. However, they cannot compete with Turbo codes or
low-density parity-check codes (LDPC) as far as performance is concerned.
The Accumulate-Repeat-Accumulate (ARA) codes, as a subclass of LDPC codes,
are obtained by adding a pre-coder in front of RA codes with puncturing,
where an accumulator is chosen as a precoder. These codes not only are very
simple, but also achieve excellent performance with iterative decoding. In
this paper, the performance of these codes with (ML) decoding are analyzed
and compared to random codes by very tight bounds. The weight distribution
of some simple ARA codes is obtained, and through existing tightest bounds
we have shown the ML SNR threshold of ARA codes approaches very closely to
the performance of random codes. We have shown that the use of precoder
improves the SNR threshold but interleaving gain remains unchanged with
respect to RA code with puncturing."
}

@INPROCEEDINGS{Abba0412:Data,
AUTHOR="Kaja Abbas and Ram Dantu and Martin O'Neill and Armin Mikler",
TITLE="Data Centric Modeling of Environmental Sensor Networks",
BOOKTITLE="IEEE Workshop on Adaptive Wireless Networks",
ADDRESS="Dallas, Texas, USA",
DAYS=3,
MONTH=dec,
YEAR=2004,
ABSTRACT="Meteorological and hydrological sensors deployed over several hundred
kilometers of geographical area comprise an environmental sensor network.
Large amounts of data need to be processed in minimal time and transmitted
over the available low speed and low bandwidth links. This paper describes
algorithms for optimal data collection and data fusion. An inductive model
using exponential back-off policy is used to collect optimal amount of
data. The data measurements for temperature, pH and specific conductance
collected for a year from the sensors deployed at Lake Lewisville are used
to test the inductive model. Energy savings of 90\% are achieved even with
1\% of degree of tolerance. The problem of data fusion is addressed by the
introduction of a novel concept of a super-sensor, based on
self-organization and collaboration among sensors. A histogram application
is described that uses recursive doubling for global collaboration between
sensors. The performance of the networked super-sensor in comparison to a
centralized polling approach is analyzed for optimality on two different
geographical areas."
}

@INPROCEEDINGS{Abbe0405:Doubly,
AUTHOR="Chad Abbey and Geza Joos",
TITLE="A {Doubly-Fed} Induction Machine and Energy Storage System for Wind Power
Generation",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Renewable energy sources have recently received increased attention due to
concerns about the environment and the search for alternate energy sources.
Wind power has become the most important source of renewable energy in many
countries, and has been shown to effectively complement central generation.
However, good power quality of distributed generators is of vital
importance, and for this reason independent control of the real and
reactive power is desirable. In addition, there has been an increasing
demand for alternative energy sources to behave like conventional
generators, whereby their output power is deterministic. Wind energy is an
inherently stochastic system since the output power of the generator is
proportional to the wind speed. Therefore, external measures must be used
to overcome the fluctuations in the generators energy production as a
result of the winds dynamics. This presentation deals with the modeling and
simulation of a doubly-fed induction machine as a wind power generator. The
ability of the system to track the peak power points and provide
independent control of the real and reactive power is demonstrated. The
incorporation of a battery or other energy storage device in the dc link
enables temporary storage of energy and therefore, the ability to provide
smooth output power, which is both deterministic and resistant to wind
speed fluctuations. The power electronic converters directly control the
machine and act as the interface between the storage system and the grid.
This allows full control over voltage characteristics as well as real power
generation. Simulations of the system in EMTP-RV show that the design is
feasible."
}

@INPROCEEDINGS{Abbo0405:Extraction,
AUTHOR="Samir Hakim Abbou and Marcel Gabrea and Christian Gargour",
TITLE="Extraction des caractéristiques pour la reconnaissance de mots isolés
par la méthode des paquets dondelettes",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="EXTRACTION DES CARACTÉRISTIQUES POUR LA RECONNAISSANCE DE MOTS
ISOLÉS PAR LA MÉTHODE DES PAQUETS DONDELETTES S.H. Abbou, M. Gabrea
and C.S. Gargour Electrical Engineering Department École de technologie
supérieure (ETS), University of Québec 1100 Notre-Dame West,
Montréal, Québec, Canada H3C 1K3 Plusieurs méthodes utilisées
dans le domaine de la reconnaissance des mots isolés par segmentation
font usage dun nombre variable de segments pour chaque mot [1] ceci, selon
la longueur du mot considéré. Nous présenterons ici une méthode
basée sur la segmentation de chaque mot en un nombre fixe de segments de
tailles variables ayant un certain degré de chevauchement. Après un
fenêtrage de Hamming, les paramètres de chaque segment sont extraits
en utilisant le paquet dondelettes admissible (Admissible Wavelet Packet
AWP) [2] selon une décomposition adéquate du signal en vingt quatre
bandes fréquentielles. Cette décomposition se rapproche de
léchelle de Mel dont les avantages sont reconnus dans la littérature
[2,3]. Les paramètres utilisés sont lénergie normalisée de
chacun des vingt quatre nuds de la décomposition [4]. La transformée
discrète en cosinus (DCT ) est ensuite appliqué aux logarithme des
vingt quatre valeurs dénergie pour obtenir de nouveaux paramètres. Un
certain nombre des paramètres ainsi obtenus sont utilisés pour la
reconnaissance du mot. Pour évaluer la méthode proposée, nous
avons utilisé la base de données TIDIGITS qui contient des chiffres
prononcés deux fois par chaque locuteur. Les résultats obtenus
donnent un taux élevé de reconnaissance. [1] L. R. Rabiner and B. H.
Juang, Fundamentals of speech recognition, Englewood Cliffs, N.J.,
Prentice-Hall , 1993. [2] O. Farooq and S. Datta., Mel Filter-Like
Admissible Wavelet Packet Structure for Speech Recognition, IEEE Signal
Processing Letters, vol. 8, No. 7, July 2001, pp. 196-198 [3] J.W. Picone,
Signal Modeling Techniques in Speech Recognition, Proceedings of the IEEE,
vol. 81, No. 9, September 1993, pp. 1215 1247. [4] S.Chang, Y.Kwon, S.Yang,
Speech feature extracted from adaptive wavelet for speech recognition,
Electronics Letters. vol. 34, No. 23, November 1998, pp. 2211 2213."
}

@INPROCEEDINGS{Abde0405:Bayesian,
AUTHOR="Wegdan Abdelsalam and Yasser Ebrahim",
TITLE="A {Bayesian-Networks-Based} Approach to Managing Uncertainty in
{Location-Tracking} Applications",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Location tracking systems are discrete in nature. They provide information
in the form of location-time pairs that show the location of the moving
object (MO) at certain points in time. Due to technological limitations,
these points in time could be minutes or even hours apart. If we want to
know the location of an MO between location reports or sometime in the
future, we have to estimate the location at that point in time using the
location reports we already have. Estimation leads to uncertainty;
something all location-tracking applications try to minimize. In this paper
we present a probabilistic model for managing uncertainty in
location-tracking applications. Our technique tries to capitalize on the
fact that humans are creatures of habit, which makes it possible to predict
how a person would react in a certain situation, based on his/her history.
Since the MOs we are interested in here are humans whose location could
somehow be tracked, we refer to this subset of MOs as Roving Users or RUs.
Our approach is based on using Bayesian Networks to model the RU behavior
and preferences. This user model is then used to predict his/her actions
allowing the system to more accurately determine his/her location between
location reports. The idea is not to improve on the accuracy of the users
position as reported by a device such as a GPS. Rather, our technique
improves on the accuracy of location estimation based on the last location
reported and knowledge about the current state of affairs. We present the
results of a simulation we performed comparing the accuracy of location
estimation of a popular technique to that of our proposed probabilistic
technique."
}

@INPROCEEDINGS{Abde0405:Novel,
AUTHOR="Amr Abdel-Dayem and Mahmoud El-Sakka",
TITLE="A Novel Morphologial-based Carotid Artery Contour Extraction",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Early detection of plaque buildup on the walls of the carotid artery plays
an important role in preventing serious heart problems. Currently,
ultrasound imaging provides an inexpensive means for monitoring the blood
flow within the carotid artery. Manual extraction of carotid artery walls
from ultrasound images is a tedious and time-consuming task. In this paper,
we propose a novel carotid artery contour extraction scheme. First, the
image is histogram equalized as a pre-processing step. Second, a median
filter is used to reduce the effect of speckle noise. Third, the image is
uniformly quantized using three quantization levels. The effect of the
quantization step is to cluster the image pixels into three virtual
objects. These three objects approximate the area inside the artery, the
artery wall, and the plaque layers. Fourth, a morphological edge detector
is applied. Finally, a morphological opening operation is applied to smooth
the resulting contour and fill any gaps that may be present in the contour.
The resulting contour can be projected on the original image. This contour
represents an initial reproducible estimate of the carotid artery walls.
Experimental results over a set of training samples showed that the
proposed scheme is an effective tool in monitoring and detecting plaque
precipitation on the walls of the carotid artery."
}

@INPROCEEDINGS{Abde0405:Temperature,
AUTHOR="Mohammad Abdeen",
TITLE="A Temperature dependent {Large-Signal} Drain Current Neural Model for the
{Dual-Gate} {MESFET}",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="The Field Effect Transistor (FET) is an essential building component in
todays analogue and digital communication systems. Having efficient and
accurate FET models is crucial so that the performance of its applications
is predictable within a minimal error. The dual gate MESFET (DGFET) has
many attractive non-linear applications such as mixers, frequency
multipliers, and power combiners and splitters. The development of
efficient models of such a device, including thermal effects, is important
to assure accurate electrical performance and reliable operation [1].
Moreover, modeling of the drain current is the focus of the majority of the
existing nonlinear transistor models, e.g. Curtice, Statz, and Materka [2],
since it is the prime cause of the nonlinear transistor behavior. While
there exist a number of works on large-signal DGFET models [3][4], no model
we know of accounts for the effect of device temperature. Neural modeling
of devices and circuits is recently used in microwave CAD. Fast, accurate
and reliable neural network models can be trained from measured or
simulated data. Once developed, these neural models can be used to replace
CPU-intensive physics/EM models of devices to speed up microwave design.
Neural network (NN) techniques have been used to model a wide variety of
microwave devices with significant successes. In this paper, we present a
temperature dependent large-signal drain current model for the dual-gate
MESFET using neural networks. We have modeled an on-wafer symmetric 6x100
\m dual gate MESFET manufactured by Nortel Networks. The
measurements of the drain current were taken in the ranges: gate voltages,
Vgs1 is -1.6 0.6 (step of 0.2) Volts, Vgs2 is -1.6 0.6 (step of 0.2) Volts,
and drain voltage, Vds is 0.0 6.0 (step of 0.1) Volts. The measurements are
repeated for various device temperatures (T = 15, 25, 45, and 65 oC) by
mounting the wafer on a temperature controlled thermal chuck. The generated
optimal neural DGFET model is of five-layers. One input, one-output and
three hidden layers. The total number of model neurons is 25. The number of
measurement data points used in this model is 34,652. About 70\% of them
are used to train the model while the remaining 30\% were used in
testing/verification. The five-layer model showed an excellent fit to the
measurement data. The model error is less than \%1."
}

@INPROCEEDINGS{Abde0405:Tool,
AUTHOR="Amr Abdel-Hamid and Mohamed Zaki and Sofiene Tahar",
TITLE="A tool for Converting Finite State Machine to {VHDL}",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Finite state machines (FSM) are a basic component of hardware designs, they
repre- sent the transformation between inputs and outputs for sequential
designs. FSMs can be represented graphically, which would help the designer
to visualize and design in a more e±cient way. The designer requires a
fast direct way to convert the visualized design to high description
languages (HDL) code directly in order to simulate and implement it."
}

@INPROCEEDINGS{Abde0406:Analysis,
AUTHOR="Raja Abdelmoumen and Chadi Barakat",
TITLE="Analysis of {TCP} Latency over Wireless Links Supporting {FEC/ARQ-SR} for
Error Recovery",
BOOKTITLE="Wireless Networking Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="We study in this paper the performance of TCP over a wireless link
implementing hybrid FEC/ARQ-SQ at the link layer. The study is done by
simulating a large number of TCP transfers over a wireless link showing
Bernoulli errors. We are motivated by how to tune link-level error
recovery, e.g. amount of FEC, persistency of ARQ, so as to minimize the
latency of TCP. We provide results for different physical characteristics
of the wireless link (delay, error rate), different traffic loads and
different file sizes. Our main finding is that the latency of TCP always
improves with the persistency of ARQ, except for some extreme cases where
the delay is large, files are small, and the loss rate is low. When adding
FEC, the latency of TCP improves then deteriorates, and the deterioration
is more pronounced in the case of large files, high loss rate and small
delay. Another finding of our study is that with the hybrid mechanism, the
wireless link is able to carry more traffic than when FEC and ARQ-SR are
separately used."
}

@INPROCEEDINGS{Abde0409:Robust,
AUTHOR="Ayman Abdel-Samad and Alex Gershman and Timothy Davidson",
TITLE="Robust Transmit {Eigen-Beamforming} Based on Imperfect Channel State
Information",
BOOKTITLE="VTC'F04 Transmission Technology",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="Transmit beamforming is a powerful approach to enhance the performance of
wireless communication systems employing multiple antennas at the
transmitter. A major drawback of existing transmit beamforming techniques
is that most of them require a nearly perfect knowledge of the channel at
the transmitter, which is not available in practice. Transmitter designs
that address the imperfect channel state information (CSI) problem commonly
use statistical models for the channel and/or the mismatch between the
presumed and actual transmitter CSI. Since these approaches are
model-based, they can suffer from mismodeling. In this paper, we propose a
more robust framework in which we make no statistical assumptions about the
channel or the CSI mismatch. Our robust transmit beamformer is designed to
have the best performance under the worst-case CSI mismatch. It turns out
to be an eigen-beamformer along the eigenvectors of the spatial channel
correlation matrix. Power loading across the beams is achieved by a spatial
water-filling-type strategy in which the water level is determined in a
closed form."
}

@INPROCEEDINGS{Abde0409:Using,
AUTHOR="Fatma Abdelkefi and Jaouhar Ayadi",
TITLE="Using Pilot Tones Distribution For Maximal Correction Capacity Of Impulse
Noise in {OFDM} Systems",
BOOKTITLE="VTC'F04 Wireless Access",
DAYS=27,
MONTH=sep,
YEAR=2004,
ABSTRACT="We present an efficient algorithm for the impulse noise correction in the
context of OFDM systems. This correction algorithm is based on the use of
an appropriate pilot tones distribtion in order to cancel the impulse
additive noise. We proove the effeciency of the presented algorithm and we
derive a necessary and (sufficient) condition that guarantees a maximal
correction capacity. Simulation results are given to support our claims."
}

@INPROCEEDINGS{Abe0405:Effective,
AUTHOR="Atsushi Abe and Fumio Nakase and Ryusuke Fukui and Hiroaki Inoue and Hiromi
Okada",
TITLE="Effective Reflect-transmission Schemes for {Vehicle-PEdestrian}
Communications {(VPEC)}",
BOOKTITLE="Transportation",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="The Inter-Vehicle Communications (IVC) is one of the most important
technologies to realize the advanced Intelligent Transport Systems (ITS).
We deal with Vehicle-PEdestrian Communications (VPEC) as the communications
between vehicles and pedestrians. The objective of VPEC is to defend
pedestrians from traffic accidents. In VPEC without any controls,
pedestrians (p-nodes) transmit a lot of packets to vehicles (v-nodes) to
inform the positioning information of p-nodes. But, the battery capacity of
p-nodes is small. It is necessary to suppress the transmission of p-nodes
to obtain proper information exchanges. In this paper, we present effective
Reflect-transmission schemes which can reduce useless transmissions from
p-nodes. In addition, we present Silent Control Protocol, Mask Control
Protocol and Distance-based Priority Control Protocol as more effective
protocols for Reflect-transmission scheme. The proposal protocols can
operate Reflect-transmission scheme more efficiently."
}

@INPROCEEDINGS{Abe0409:Practical,
AUTHOR="Tetsushi Abe",
TITLE="A Practical Throughput Comparison between {MIMO-CDMA} and {MIMO-OFDM}",
BOOKTITLE="VTC'F04 Transmission Technology",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="Since several papers have indicated the great theoretical potential of MIMO
(Multiple Input and Multiple Output) transmission (e.g., [1]), MIMO
techniques are now being discussed for deployment in various air
interfaces, such as W-CDMA (3GPP) and OFDM. Although MIMO techniques can
obviously be applied to any air-interface, we first need a comprehensive
comparison of the effectiveness of the MIMO techniques on various
air-interfaces using practical conditions (e.g., frame structure and
propagation model). This paper conducts a comprehensive comparison and
analysis of link level throughput performance of MIMO transmission over
W-CDMA and OFDM air-interfaces; practical conditions are used in the
comparison. As for W-CDMA, specifications similar to HSDPA [2] are used,
while for OFDM, we consider a frame structure similar to HSDPA. For MIMO
transmission, PARC (Per Antenna Rate Control) [3] and [4] based on MMSE
detection with successive interference cancellation is employed both for
CDMA and OFDM. Along with the extensive comparison, we introduce a novel
pilot and control signal cancellation scheme in order to improve link
adaptation quality and signal detection performance in MIMO-CDMA. The
computer simulations assume perfect channel estimation, same total
bandwidth, frame length, and fractional data power per transmit frame for
both CDMA and OFDM, and the main results are the following, -MIMO-CDMA
outperforms MIMO-OFDM in flat fading channels in high SNR region,
-MIMO-OFDM outperforms MIMO-CDMA in frequency selective channels in high
SNR region, -The newly introduced pilot and control signal canceling scheme
effectively enhances the throughput of MIMO/CDMA."
}

@INPROCEEDINGS{Abed0406:Improved,
AUTHOR="Saied Abedi",
TITLE="Improved Stability of {QoS} Provisioning for {3G} Systems and beyond:
Optimum and Automatic Strategy Selection for Packet Schedulers",
BOOKTITLE="QoS and Performance Modeling Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="Wireless all-IP multimedia communications systems promise wide range of
services with differ-ent Quality of Service (QoS) requirements and diverse
ranges of supported bit rates. This implies that the nature of input
traffic load at base station is expected to vary significantly in time.
When radio channels are shared by the existing mixed services (say for
example real-time and non-real time services), packet scheduler and channel
assignment faces a number of parallel input data pipes which are varied in
terms of bit rate. The weights, assigned to different involved aspects in
the packet scheduling process, outline the strategy in terms of importance
given to different aspects of packet scheduling. Schedulers with fixed
weighting parameters are unable to cope with variable traffic load and
radio channel conditions effi-ciently. The weights assigned to specific
traffic or radio channel conditions, might not be suitable for others. In
this paper, we propose an optimization and automation algorithm for
selection and adaptation of packet scheduling weights. It is shown that the
proposed algorithm is capable of improving different aspects involved in a
successful QoS provisioning, such as fairness, stability, delivered delay,
bit rate and throughput, simultaneously."
}

@INPROCEEDINGS{Abhy0407:Characterization,
AUTHOR="Aditya Abhyankar and Stephanie Schuckers",
TITLE="Characterization, similarity score and uniqueness associated with
perspiration pattern",
BOOKTITLE="Audio- and Video-based Biometric Person Authentication",
ADDRESS="Rye, New York, USA",
DAYS=20,
MONTH=jul,
YEAR=2004,
ABSTRACT="Vulnerabilities in biometric systems including spoofing has emerged as an
important issue. The focus of this work is on characterization of
'perspiration pattern' in a time-series of fingerprint images for liveness
detection. By using information in the high pass bands of the images the
similarity score for the two images is calculated to determine the
uniqueness of the perspiration pattern. In this wavelet-based approach, the
perspiration pattern is characterized by its energy distribution in the
decomposed wavelet sub bands. We develop a similarity matching technique
that is based on quantifying marginal distribution of the wavelet
coefficients. The similarity match technique is based on Kullback-Leibler
distance, which is used to decide 'uniqueness' associated with the
perspiration pattern. Experimental results show good separation resolution
in similarity scores of inter (43 subjects) and intra (12 subjects over 5
months) class comparisons. This may be considered as a robust liveness test
for biometric devices."
}

@INPROCEEDINGS{Abie0405:Low,
AUTHOR="Rami Abielmona and Voicu Groza and Nizar Sakr and Jonathan Ho",
TITLE="{Low-Level} {Run-Time} Reconfiguration of {FPGAs} for Dynamic Environments",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="In this paper, we build on the ongoing project of reconfigurable learning
techniques in autonomous agents [1], by taking a look at the run-time
reconfiguration of on-board digital hardware resources, such as a
field-programmable gate array (FPGA). The advent of such reconfigurable
devices has allowed for a revolutionary type of computing, mainly
reconfigurable computing (RC). This work extends the research first
presented in [2]. The main goal of this project is to abstract the physical
resources in order to provide the higher-level tasks with a consistent
application programming interface (API), that can be utilized to run-time
reconfigure (RTR) the FPGA. It follows from [3] that there are limited
hardware resources on-board a mobile autonomous agent, faced with real-time
contraints and a dynamic environment. Henceforth, a RTR-based methodology
will be imperative for the computational requirements of the system, as (a)
various tasks will have to be dynamically loaded to meet unforeseen changes
in the environment and (b) multiple real-time tasks will have to be
alternated to meet the limited (and remote) hardware resources constraint.
The outlined goal is broken into the three following objectives: modeling
the FPGA resources, running a placement algorithm for the various hardware
blocks (HBs) and managing the physical resources of the FPGA. The
aforementioned have been implemented and tested using the Xilinx JBits API,
which is a development framework for Xilinx FPGAs based on the Java
language. The API provides low-level access to the configuration of
resources of a Xilinx FPGA (currently the Virtex device). Using JBits, a
RTR API was developed that provides the following functionalities:
insert/remove a HB, re-route input-output block (IOB) and block RAM (BRAM)
connections, defragment the FPGA, clear the FPGA, and test a HB. A
graphical user interface (GUI), which hooks into the JBits BoardScope
class, has been designed and realized, showcasing the entire RTR API
functionality."
}

@INPROCEEDINGS{Aboe0405:Call,
AUTHOR="Mokhtar Aboelaze",
TITLE="A Call Admission Protocol for Cellular Networks that Supports
Differentiated Fairness",
BOOKTITLE="Wireless Access",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="In this paper, we introduce a new protocol for call admission in cellular
networks. Our protocol supports differentiated fairness in call admission
and works well under both Poisson and clustered call arrival pattern. In
the full paper, the protocol will be presented, the performance of the
protocol will be assessed using both simulation and Markov chain analysis,
and a comparison with the existing protocols will be presented."
}

@INPROCEEDINGS{Aboe0409:Priority,
AUTHOR="Mokhtar Aboelaze and Ayman Elnaggar",
TITLE="A Priority Based Call Admission Control Protocol with Call Degradation for
Cellular Networks.",
BOOKTITLE="International Symposium on Wireless Communication Systems",
ADDRESS="MAURITIUS",
DAYS=20,
MONTH=sep,
YEAR=2004,
ABSTRACT="Call Admission Control (CAC) plays a very important role in the performance
of wireless networks. In this paper, we present a call admission control
protocol for cellular wireless networks. Our protocol depends on degrading
the existing calls by reducing the bandwidth allocated to them in order to
admit important calls. Our protocol assign priorities for the incoming
calls, and in the same time assign priorities to the existing calls, both
admitted calls are admitted according to their priorities and the existing
calls are degraded according to their priorities. In the full paper, we
will present our results and compare it to the previously known call
admission protocols. We introduce a measure for customer satisfaction that
depends on the average bandwidth assigned to the call and the frequency of
changes in that bandwidth. We also show results for the relation between
customer satisfaction for the different priorities, rejection ratio for the
different priorities, and the network throughput"
}

@INPROCEEDINGS{Aboe0411:Parallel,
AUTHOR="Emad Aboelela",
TITLE="A Parallel {IP-Address} Forwarding Approach Based on Partitioned Lookup
Table Techniques",
BOOKTITLE="The 29th Annual IEEE Conference on Local Computer Networks",
ADDRESS="Tampa, Florida",
DAYS=16,
MONTH=nov,
YEAR=2004,
ABSTRACT="As the traffic on the Internet has exponentially increased, it is vital
that the Internet routers handle the received packets faster. When a router
receives a packet, it has to make a decision where to send it next. To
forward an IP packet, the routers need to lookup the destination address of
the received packet in the forwarding table, implement forwarding
algorithms, then forward the packet to the appropriate next hop or outgoing
port. In this paper we introduce a parallel approach that combines an IP
packet forwarding technique based on partitioned lookup table with linear
search on prefix lengths, binary search on prefix lengths and LC trie.
Simulation results show that the proposed partition schemes speeds up the
IP address lookup process."
}

@INPROCEEDINGS{Abol0401:GPS,
AUTHOR="Mehran Abolhasan",
TITLE="{GPS-based} Route Discovery Algorithms for On-demand Routing protocols in
{MANETs}",
BOOKTITLE="Wireless On-demand Network Systems 2004",
ADDRESS="Madonna di Campiglio, Trento, Italy",
DAYS=21,
MONTH=jan,
YEAR=2004,
ABSTRACT="This papers presents new Global Positioning System (GPS)-based route
discovery algorithms for on-demand routing in MANETs, called
Position-based Selective
Flooding (PSF). We applied our route discovery algorithm to our previous
routing protocol, which is
called Location-based Point-to-point Adaptive routing (LPAR) protocol and
investigated its performance
by simulation. Simulation results show that our position based flooding
algorithm produce fewer routing
overheads than the pure flooding, expanding ring search (used in AODV),
LAR1 and our existing LPAR
strategy, as network traffic and density is increased. Furthermore, we
propose a number of improvements and
variations which can be used instead of, or to further improve the
performance of PSF under different
network conditions."
}

@INPROCEEDINGS{Abol0405:Routing,
AUTHOR="Mehran Abolhasan",
TITLE="A Routing Strategy for Heterogeneous Mobile Ad Hoc Networks",
BOOKTITLE="IEEE 6th CAS Symposium on Emerging Technologies: Frontiers of Mobile and
Wireless Communication",
ADDRESS="Shanghai, China",
DAYS=1,
MONTH=may,
YEAR=2004,
ABSTRACT="This paper presents a new routing strategy for heterogeneous Mobile Ad Hoc
Networks. We refer to this strategy as On-demand Utility-Based Routing
Protocol (OUBRP). This protocol introduces a Utility-Based route discovery
strategy, which aims to minimise the number of control packets disseminated
into the network during route discovery by efficiently using available
resources at each node. Furthermore, we propose a new strategy to eliminate
uni-directional links during the route discovery phase. We refer to this
strategy as Uni-directional Link Elimination (ULE). We performed a
simulation study to compare the performance of OUBRP with a number of
different routing protocols proposed for MANETs. Our results show that
OUBRP compared to other routing strategies produces significantly fewer
control packets and achieves higher levels of successful packet delivery
with increasing number of nodes. Furthermore, we propose a number of
alternative Uni-directional Link Elimination strategies."
}

@INPROCEEDINGS{Abol0411:Design,
AUTHOR="Mehrdad Abolbashari and Hassan Aghaeinia",
TITLE="Design and Analysis of New Methods for Generating Spreading Sequences by
Chaotic Dynamic Systems",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="In this paper, some methods for generating binary sequences, derived from
chaotic dynamic systems, are presented. Generated sequences possess large
family size and high security. These sequence generation methods are
applied to proposed chaotic dynamic systems and application and performance
of derived sequences are assessed in asynchronous DS-CDMA systems. It is
shown that generated sequences with proposed methods, that possess large
family size and high security, have better performance than Gold sequences
according to W-index."
}

@INPROCEEDINGS{Aboo0405:Automated,
AUTHOR="Mohammad Aboofazeli and Zahra Moussavi",
TITLE="Automated Classification Between Swallowing and Breath Sounds",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="The purpose of this study was development of an automated and objective
method to separate swallowing sounds from breath sounds. Swallowing sound
detection can be utilized as part of a system for the swallowing mechanism
assessment and diagnosis of disordered oropharyngeal swallowing (dysphagia)
by acoustical means. In this study, an algorithm based on multilayer feed
forward neural networks was investigated for decomposition of tracheal
sound into swallowing and respiratory segments. Among many features
examined, root-mean-square (RMS) of the time domain signal, the average
power of the signal over 150-450 Hz frequency band and waveform fractal
dimension were selected features to be applied to neural network as inputs.
Findings from previous studies about temporal and durational patterns of
swallowing and respiration were used in a smart algorithm for further
locating the swallow and breath segments. The proposed method was applied
to 18 tracheal sound recordings of healthy subjects (ages 13-30 years).
Average number of swallows in each recording was 14. All subjects were fed
5 ml bolus of juice. The results were validated manually by visual
inspection using air flow measurement and spectrogram of the sounds, and
auditory means. Since the number of subjects was not large enough for
randomly dividing to training and testing data sets, leave-one-out approach
was utilized in a way such that each subject's data was used as a test data
once and the accuracy of the algorithm was then averaged between the
subjects. The algorithm was able to detect 91.7\% of swallows correctly.
The average of missed swallows and average of false detection were 8.3\%
and 9.5\%, respectively. With additional preprocessing and post processing,
the proposed method may be used for automated swallowing and respiratory
sound detection from tracheal sound recordings of dysphagic subjects."
}

@INPROCEEDINGS{Aboo0405:Wavelet,
AUTHOR="Mohammad Aboofazeli and Gabriel Thomas and Zahra Moussavi",
TITLE="A Wavelet Transform Based Digital Image Watermarking Scheme",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Digital image watermarking techniques have been proposed to prevent
unauthorized distribution of multimedia data. A digital watermark encodes
the owner's license information and embeds it into the image. Several
discrete wavelet transform (DWT) based techniques are used for watermarking
digital images. In this paper, a digital image watermarking scheme is
proposed, in which image is decomposed into wavelet coefficients and a
visual recognizable logo is embedded as a watermark pattern by modifying
high and middle frequency bands of the image's wavelet coefficients. This
logo can be a binary, gray-scale or color image. The embedded watermark is
hard to detect by human visual perceptivity. As watermarking techniques
should be robust to some attacks such as smoothing, sharpening and
compression, watermark pixels are embedded in wavelet coefficients
corresponding to the points located in a neighborhood that have maximum
entropy. These points can survive a variety of attacks and be used as
reference points for watermark embedding and detection. In order to
evaluate the performance of the method, the similarity of original
watermark and extracted watermark was measured by the standard correlation
coefficient between them in each band. A higher correlation indicates the
existence of the watermark in that band. The robustness of the technique
was tested after different attacks. The attacks were sharpening using
linear high pass filter, smoothing by linear low pass and median filters,
adding Gaussian noise, and JPEG compression with different compression
ratios. The results confirmed that the technique is robust to these
attacks. Based on the experimental results, the proposed algorithm achieves
two important desirable watermarking characteristics, invisibility and
robustness and therefore may be used as a technique for encoding
information for owner's verification."
}

@INPROCEEDINGS{Aboo0409:Computer,
AUTHOR="David Abookasis and Joseph Rosen",
TITLE="Computer-generated three types of holograms of three-dimensional objects
synthesized by multiple perspective projections",
BOOKTITLE="The 23rd IEEE convention of Electrical and Electronics Engineers in Israel",
ADDRESS="Herzlia, Israel",
DAYS=6,
MONTH=sep,
YEAR=2004,
ABSTRACT="A new method of synthesizing computer-generated holograms of
three-dimensional (3-D) objects is proposed. Several projections of the 3-D
object are numerically processed to yield a two dimensional complex
function, which is then encoded as a computer-generated hologram. When this
hologram is illuminated by a plane wave, a 3-D real image of the object is
reconstructed. Although the hologram initially belongs to the type of
Fourier holograms, Fresnel and image holograms are also generated by
computing the propagation of the wave front from the Fourier plane to any
other desired plane. Computer and optical constructions of 3-D objects,
both of which show the feasibility of the proposed approach, are presented
herein."
}

@INPROCEEDINGS{Aboo0409:Computer,
AUTHOR="David Abookasis and Joseph Rosen",
TITLE="Computer generated correlation holograms",
BOOKTITLE="The 23rd IEEE convention of Electrical and Electronics Engineers in Israel",
ADDRESS="Herzlia, Israel",
DAYS=6,
MONTH=sep,
YEAR=2004,
ABSTRACT="A new method of synthesizing computer generated holograms has been
developed and experimentally tested. The method has been implemented by an
iterative optimization algorithm on a joint transform correlator. The
proposed hologram is a combination of two separated sub-holograms, and its
reconstructed image is obtained as a result of a spatial correlation
between the hologram's two parts. The double-holograms are displayed on the
correlator input plane illuminated by a plane wave. Consequently, a desired
image is constructed on part of the correlator output plane. The above
method has been extended for deciphering watermarks, and other hidden
information, from printed images. A spatial correlation between two
holograms; one containing the watermark and the other containing the
deciphering key, reveals the concealed watermark from the printed picture,
only when the two specific holograms are matched. Both simulation and
experimental results are presented."
}

@INPROCEEDINGS{Aboo0409:Imaging,
AUTHOR="David Abookasis and Joseph Rosen",
TITLE="Imaging through scattering medium from multiple speckle images using
microlens array",
BOOKTITLE="The 23rd IEEE convention of Electrical and Electronics Engineers in Israel",
ADDRESS="Herzlia, Israel",
DAYS=6,
MONTH=sep,
YEAR=2004,
ABSTRACT="We propose and experimentally demonstrate a new method of seeing objects
hidden in scattering medium from multiple speckle images. The objects
hidden between two biological tissues (chicken breast) are reconstructed
from many speckled images formed by a microlens array. Each microlens from
the array projects a small different speckle image of the hidden object
onto a CCD camera. The entire noisy images from the array are digitally
processed to obtain the desired image of the hidden objects. Following the
first proposed method, a different algorithm implemented on the same
optical system has been developed. This modified algorithm, based on the
point-source reference method improves the resolution of the previous
method. Laboratory experiments with two kinds of objects are presented."
}

@ARTICLE{Abou0404:Impact,
AUTHOR="Nianjun Zhou and Huaming Wu and Alhussein Abouzeid",
TITLE="The Impact of Traffic Patterns on the Overhead of Reactive Routing
Protocols",
JOURNAL="IEEE Journal on Selected Areas in Communications: Special Issue on Wireless
Ad Hoc Networks",
DAYS=7,
MONTH=aug,
YEAR=2004,
ABSTRACT="This paper presents a new mathematical and simulative framework for
quantifying the overhead of reactive routing protocols, such as DSR and
AODV, in wireless variable topology (ad-hoc) networks. A model of the
routing-layer traffic, in terms of the statistical description of the
distance between a source and a destination, is presented. The model is
used to study the effect of the traffic on the routing overhead. Two
network models are analyzed; a Manhattan grid model for the case of regular
node placement, and a Poisson model for the case of random node placement.
We focus on situations where the nodes are stationary but unreliable. For
each network model, expressions of various components of the routing
overhead are derived as a function of the traffic pattern. Results are
compared against ns-2 simulations, which corroborate the essential
characteristics of the analytical results. One of the key insights that can
be drawn from the mathematical results of this paper is that it is possible
to design infinitely scalable reactive routing protocols for variable
topology networks by judicious engineering of the traffic patterns to
satisfy the conditions presented in this paper."
}

@INPROCEEDINGS{Abou0405:Application,
AUTHOR="Mohammad Abou-Khsaiwan",
TITLE="Application of {OFDM} and Spread Spectrum to Power Line Communicatins
Technology",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="In recent years there has been a growing interest in using AC power lines
for high-speed data communications- an area conventionally referred to as
power line communications (PLC). In this paper, we present a class of
advanced communication technologies based on the hybrid of Spread Spectrum
(SS) and Orthogonal Frequency Division Multiplexing (OFDM) transmission
techniques for binary data transmission over low-voltage power lines.
Applications for such communication systems would include voice, data,
image and Internet traffic to domestic networks. The technology proposed
has the potential of achieving higher transmission speeds suitable for
first generation Internet traffic over power lines. The power line is an
extremely difficult and noisy communication medium characterized by several
unpredictable and strong forms of impairments including interference, noise
and attenuation, making it very hostile and challenging environment for
robust high-frequency communications. The important channel parameters,
namely the noise, impedance and attenuation are highly varying with time,
frequency and location in a dynamic manner. In this study we present the
power line channel characteristics and the parameters that influence its
behavior and use these parameters to optimize error rate performance over
power line channels, for broadband data communications. The hybrid
technologies proposed include Multi-Carrier (MC)-CDMA (Code Division
Multiple Access) and OFDM-CDMA systems. The performances of these systems
are simulated over power line channels to bring to light the potential of
these systems in terms of their bit error rate performance. While OFDM for
data transmission is a promising modulation technique that eliminates the
need for a complex equalizer, Spread Spectrum CDMA systems offer a multiple
access environment and are used to combat the unpredictable interference
with the potential processing gain in a multi-user environment due to the
wide bandwidth of the transmitted signal. Keywords: PLC, OFDM, spread
spectrum, channel characterization, noise modeling."
}

@INPROCEEDINGS{Abou0405:Signal,
AUTHOR="Mohamed Abou-Khousa and Ali Ghrayeb and Mohamed El-Tarhuni",
TITLE="{Signal-to-Interference} Ratio Estimation in {CDMA} Systems",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Code Division Multiple Access (CDMA) is a leading candidate for the
proposed third generation (3G) wireless communication systems. In such
systems, the signals transmitted are wideband in nature, which gives rise
to multipath fading. A key issue to dealing with multipath fading is to
first identify the potential paths at the front end of the receiver. Then,
a RAKE receiver is used to coherently combine the energy from these
multipath components. A RAKE receiver consists of several correlators
called fingers that are time-aligned with the different paths. Each finger
is intended to de-spread the corresponding path and then the outputs of
these fingers are properly combined to maximize the signal-to-interference
ratio (SIR) at the output of the RAKE receiver. The criterion by which a
finger is assigned to a multipath component is very crucial as it
significantly impacts the overall performance of the receiver. There are
two strategies available in the literature for assigning RAKE fingers to
multipath components. The first strategy assigns the paths with the largest
instantaneous amplitudes to the available fingers. The second strategy
assigns the paths with the largest average powers to the available fingers.
In both strategies, the finger assignment is based upon the assumption that
the multipath interferences at all fingers are mutually uncorrelated and
have equal energy. However, this is not always the case. For instance, if
we consider the forward link in CDMA systems, the multipath interferences
may differ in energy magnitude from one finger to another. Therefore,
finger assignment based on signal strength alone does not achieve
maximal-ratio combining. In this paper, we consider a new finger assignment
strategy that is based on estimates of the SIR per path as opposed to
signal strength in the conventional strategies. In particular, we estimate
the SIR values for the resolvable paths and select those paths that
correspond to the largest SIR values. The selected paths are then assigned
to the available RAKE fingers. In estimating the SIR values, we use a
simple estimator that utilizes already existing results obtained from the
acquisition circuit used to find the multipath components over a given
window of delay offsets, i.e., delay spread. We provide a performance
comparison between the proposed scheme and that of the conventional one,
and show that the performance of the former is superior to that of the
latter. Furthermore, we derive the Cramer-Rao bound (CRB) for the proposed
estimator, and we show that this estimator attains the CRB bound."
}

@INPROCEEDINGS{Abou0406:Novel,
AUTHOR="Mohamed Abou-Khousa and Mohamed El-Tarhuni and Ali Ghrayeb",
TITLE="A Novel Finger Assignment Algorithm for {RAKE} Receivers in {CDMA} Systems",
BOOKTITLE="Signal Processing in Communications Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="In CDMA systems, a RAKE receiver is commonly used to coherently combine the
energy of the received signal replicas arriving from different propagation
paths. To accomplish this, the RAKE receiver is equipped with a number of
fingers (correlators) where each finger is assigned to a multipath
component. Assignment of the RAKE fingers to the correct multipath
components is crucial for the receiver to combat fading and to take
advantage of the multipath diversity. This is particularly important since
the number of fingers available is normally limited in order to maintain
low receiver complexity. In this paper, we introduce a new RAKE receiver
finger assignment algorithm (FAA) based on estimates of the
signal-to-interference ratio (SIR) per path, as opposed to signal strength
in the conventional schemes. We also introduce a simple algorithm to
produce these SIR estimates. A performance comparison between the proposed
scheme and already existing schemes is presented. We show that the proposed
scheme provides a significant performance improvement relative to that of
the conventional schemes."
}

@INPROCEEDINGS{Abou0406:Optimal,
AUTHOR="Ibrahim Abou-Faycal and Muriel Medard",
TITLE="Optimal Uncoded Regeneration for Binary Antipodal Signaling.",
BOOKTITLE="Communication Theory Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="We derive, for a binary antipodal input signal, the optimal uncoded
regenerator function when the channels at the ingress and at the egress of
the regenerator are degraded by AWGN. We show that the optimal function is
a Lambert function parametrized on the energies of the noises and the
input. For comparison, we derive the performance of systems in which the
regenerator uses a hard limiter, amplifier or MSE estimator."
}

@INPROCEEDINGS{Abra0404:Set,
AUTHOR="Zoe Abrams and Ashish Goel and Serge Plotkin",
TITLE="Set {K-Cover} Algorithms for Energy Efficient Monitoring in Wireless Sensor
Networks",
BOOKTITLE="Information Processing in Sensor Networks",
ADDRESS="Berkeley, California",
DAYS=26,
MONTH=apr,
YEAR=2004,
ABSTRACT="Wireless sensor networks (WSNs) are emerging as an effective means for
environment monitoring. This paper investigates a strategy for energy
efficient monitoring in WSNs that partitions the sensors into covers, and
then activates the covers iteratively in a round-robin fashion. This
approach takes advantage of the overlap created when many sensors monitor a
single area. Our work builds upon previous work in \cite{Potkonjak}, where
the model is first formulated. We have designed three approximation
algorithms for a variation of the SET K-COVER problem, where the objective
is to partition the sensors into covers such that the number of covers that
include an area, summed over all areas, is maximized. The first algorithm
is randomized and partitions the sensors, in expectation, within a fraction
$1 - \frac{1}{e}$ ($\sim$.63) of the optimum. We present two other
deterministic approximation algorithms. One is a distributed greedy
algorithm with a $\frac{1}{2}$ approximation ratio and the other is a
centralized greedy algorithm with a $1 -\frac{1}{e}$ approximation ratio.
We show that it is NP-Complete to guarantee better than $\frac{15}{16}$ of
the optimal coverage, indicating that all three algorithms perform well
with respect to the best approximation algorithm possible. Simulations
indicate that in practice, the deterministic algorithms perform far above
their worst case bounds, consistently covering more than 72\\% of what is
covered by an optimum solution. Simulations also indicate that the increase
in longevity is proportional to the amount of overlap amongst the sensors.
The algorithms are fast, easy to use, and according to simulations,
significantly increase the longevity of sensor networks. The randomized
algorithm in particular seems quite practical."
}

@INPROCEEDINGS{Abra0409:HV,
AUTHOR="Eli Abramzon and Michael Wolf and Alex Pokryvailo and Shmuel Ben-Yaakov and
Yefim Yankelevich",
TITLE="A {HV} Pulse Generator for Driving Pulsed Corona Discharge",
BOOKTITLE="The 23rd IEEE convention of Electrical and Electronics Engineers in Israel",
ADDRESS="Herzlia, Israel",
DAYS=6,
MONTH=sep,
YEAR=2004,
ABSTRACT="As part of a pulsed corona system for pollution control applications, a
high-voltage pulse generator was developed, constructed and tested . A 1kW
generator delivers a 45kV, 100ns pulse across a 120Ohm load with a risetime
of 15ns and a repetition rate of up to 1kHz. It comprises of a single
magnetic compression stage which incorporates both amorphous metal and
ferrite cores for fast magnetic switching. The compressor does not contain
external remagnetization circuits that are commonly used in magnetic
compressors. A fast semiconductor ABB A-Z switch specified for 2.5kA, 3kV
is used as the main switch. A thorough theoretical analysis of the circuit
topology is presented. Experiments with a dummy load showed a fair
agreement with simulations. Typical voltage and current waveforms,
volt-ampere characteristics and the corona discharge appearance are
presented. The results of this study are used for developing a 6kW pulse
generator for an advanced industrial-grade system."
}

@INPROCEEDINGS{Abra0411:Traffic,
AUTHOR="Henrik Abrahamsson and Anders Gunnar",
TITLE="Traffic Engineering in Ambient Networks: Challenges and Approaches",
BOOKTITLE="The Second Swedish National Computer Networking Workshop 2004",
ADDRESS="Karlstad University",
DAYS=23,
MONTH=nov,
YEAR=2004,
ABSTRACT="The focus of this paper is on traffic engineering in ambient networks. We
describe and categorize different alternatives for making the routing more
adaptive to the current traffic situation and discuss the challenges that
ambient networks pose on traffic engineering methods. One of the main
objectives of traffic engineering is to avoid congestion by controlling and
optimising the routing function, or in short, to put the traffic where the
capacity is. The main challenge for traffic engineering in ambient networks
is to cope with the dynamics of both topology and traffic demands.
Mechanisms are needed that can handle traffic load dynamics in scenarios
with sudden changes in traffic demand and dynamically distribute traffic to
benefit from available resources. Trade-offs between optimality, stability
and signalling overhead that are important for traffic engineering methods
in the fixed Internet becomes even more critical in a dynamic ambient
environment."
}

@INPROCEEDINGS{Abu0409:New,
AUTHOR="Avi Abu",
TITLE="New Adaptive Blind Equalizer for {FIR} channels with non-zero delay
dominant tap",
BOOKTITLE="The 23rd IEEE convention of Electrical and Electronics Engineers in Israel",
ADDRESS="Herzlia, Israel",
DAYS=6,
MONTH=sep,
YEAR=2004,
ABSTRACT="This letter presents a new blind estimation and equalization algorithm of
digital communication Finite Impulse Response (FIR) Linear Time-Invariant
(LTI) channels with non-zero delay dominant tap. The algorithm is based on
a novel demonstration of a System and Observation state space equations,
and estimates the transmitted data without any a-priori knowledge on the
channel response. Traditional solutions for the problem of equalization,
that make use of state space model solutions, do not include the discrete
Low Pass Filter (LPF) that exists, in many communication system, in order
to limit the bandwidth of the transmitted symbols. These solutions cannot
perform well when the channel has a dominant tap (or more than one) with
non-zero delay. Our method shows robustness to different channels and
especially to channels with non-zero delay dominant tap."
}

@INPROCEEDINGS{Abu0409:Time,
AUTHOR="Avi Abu",
TITLE="Time Jitter Analysis of 1-bit {Sigma-Delta} Synthesizer",
BOOKTITLE="The 23rd IEEE convention of Electrical and Electronics Engineers in Israel",
ADDRESS="Herzlia, Israel",
DAYS=6,
MONTH=sep,
YEAR=2004,
ABSTRACT="This letter presents a general analysis of time jitter in Sigma-Delta
synthesizer. One of the practical applications of 1-bit Sigma-Delta systems
is a generation of high-resolution local oscillator (LO). LO signals in
transmit / receive circuits are typically generated using synthesizers,
direct-digital synthesis (DDS), etc. In order to generate LO signals, one
may use a single-bit Sigma-Delta technique to encode sine waves. Due to
hardware constraints, the Sigma-Delta output is generally injected into a
frequency multiplier system in order to generate a high frequency LO
signals. Today, direct generation of high frequency sinewave using a clock
with higher frequency, is possible. In this letter we will analyze these
different techniques and develop a practical way of computation to decide
how to choose the best configuration under minimum degradation of Signal to
Noise Ratio (SNR) at the output."
}

@INPROCEEDINGS{Acha0406:Design,
AUTHOR="Phani Gopal Achanta and Narasimha Reddy",
TITLE="Design and Evaluation of a partial state router",
BOOKTITLE="QoS and Performance Modeling Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="In this paper, we present the design and evaluation of a partial state
router. A partial state router maintains a fixed amount of state
irrespective of the number of flows served at the router. We show the
practical feasibility of partial state routers by implementing a novel
partial state scheme, LRU-FQ, on the Linux platform. The LRU-FQ scheme
makes use of an LRU cache to classify flows into non-responsive/high
bandwidth and low bandwidth/responsive classes. A class-based fair queuing
algorithm is used to obtain a policy-driven control of the proportion of
link bandwidth allocated to high bandwidth flows being served at the
router. We report on our experience in employing the developed LRU-FQ
router in several realistic experiments. Our results show that LRU-FQ can
provide effective control of high-bandwidth traffic and provide better
response times for web mice traffic. We report on the scalability of the
developed router. We present a worst-case analysis to determine the cache
size required to maintain state for a target non-responsive high-bandwidth
flow. We also present a discussion of possible applications of such a
router in alleviating Denial of Service (DoS) attacks."
}

@INPROCEEDINGS{Acha0406:Design,
AUTHOR="Arup Acharya and Archan Misra and Sorav Bansal",
TITLE="Design and Analysis of a Cooperative Medium Access scheme for
{High-Performance} Wireless Mesh Networks",
BOOKTITLE="Broadband Networks 2004 - Broadband Wireless Networking Symposium",
DAYS=3,
MONTH=jun,
YEAR=2004,
ABSTRACT="This paper presents the detailed design and performance analysis of MACA-P,
a RTS/CTS based MAC protocol, that enables simultaneous transmissions in
wireless mesh networks. The IEEE 802.11 DCF MAC enforces that no parallel
transmission is possible in either neighborhood of a sender or a receiver
(of an ongoing transmission). MACA-P is a set of enhancements to the 802.11
MAC that allows parallel transmissions in many situations when two
neighboring nodes are either both receivers or transmitters, but a receiver
and a transmitter are not neighbors. The performance of MACA-P in terms of
system throughput is obtained through a simulation of the protocol using ns
and is compared with the performance of 802.11 RTS/CTS MAC. Experiments
with the base MACA-P protocol reveal the need for certain enhancements,
especially to avoid the drawbacks associated with attempts at parallel
transmissions in scenarios where such parallelism is not feasible. Studies
with the enhanced MACA-P protocol also demonstrate how significant
performance gains in wireless mesh network performance may be realized if
the radio transceiver behavior is modified in tandem with the MAC protocol."
}

@INPROCEEDINGS{Acha0411:Optimal,
AUTHOR="Joydeep Acharya and Ritabrata Roy and Jasvinder Singh and Christopher Rose",
TITLE="Optimal Signature Sets for Transmission of Correlated Data over a Multiple
Access Channel",
BOOKTITLE="IEEE Globecom 2004",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="For multiple transmitters sending independent data to a single receiver,
the problem of optimizing transmitter codewords to maximize capacity has
already been addressed. This paper considers an analogous scenario when the
information sent by the transmitters is correlated. The optimal codeword
set and power allocation which minimizes TMSE (total mean square error) at
the receiver under a total power constraint have been derived. The
equivalence between TMSE and sum capacity is also shown, in the sense that
minimizing the former corresponds to maximizing the latter."
}

@INPROCEEDINGS{Acos0411:Measured,
AUTHOR="Guillermo Acosta and Mary Ingram and Kathleen Tokuda",
TITLE="Measured Joint Doppler-delay Power Profiles for Vehicle-to-vehicle
Communications at {2.4} {GHz}",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="Measured per-tap Doppler spectra are presented for a frequency selective
vehicle-to-vehicle or mobile-to-mobile wireless communications link in
various multipath environments in Atlanta, Georgia. The measurements were
taken using the direct sequence spread spectrum (DSSS) technique at 2.45
GHz. The environments, chosen for their exceptionally long delay spreads,
include an expressway, an urban T-intersection, and an exit ramp. The
different environments produced quite different spectra. Also, for a given
channel, the spectra corresponding to different delays were different,
implying a non-separable channel model."
}

@INPROCEEDINGS{Acqu0410:Design,
AUTHOR="Andrea Acquaviva and Emanuele Lattanzi and Alessandro Bogliolo",
TITLE="Design and Simulation of {Power-Aware} Scheduling Strategies of Streaming
Data in Wireless {LANs}",
BOOKTITLE="Seventh ACM/IEEE(*) International Symposium on Modeling, Analysis and
Simulation of Wireless and Mobile Systems",
ADDRESS="Venice, Italy",
DAYS=4,
MONTH=oct,
YEAR=2004,
ABSTRACT="One of the major concerns for 802.11b wireless local area networks is
energy efficiency. In fact, mobile devices spend a large amount of power on
their radio interface for accessing multimedia services such as audio and
video streaming. In this work we address the problem of energy-aware
scheduling of streaming data provided by a single server to multiple
clients. We propose both open-loop and closed-loop strategies that exploit
application level information to perform energy-efficient traffic
reshaping. We evaluate the effectiveness of the proposed strategies by
means of accurate power/performance simulations performed on top of
Mathworks' Simulink. System components are modeled as generalized
semi-markov processes (GSMPs) and characterized by means of real-world
measurements. In particular, the timing and power behavior of wireless
network interface cards is accurately captured in order to evaluate the
impact of power management strategies on a wireless 802.11b link.
Experimental results show that up to 75\% of the communication energy can
be saved by means of power-aware traffic scheduling with negligible
user-perceived performance degradation."
}

@INPROCEEDINGS{Adam0404:Patterns,
AUTHOR="Constantin Adam and Rolf Stadler",
TITLE="Patterns for Routing and {Self-Stabilization}",
BOOKTITLE="IEEE/IFIP Network Operations and Management Symposium",
ADDRESS="Seoul, Korea",
DAYS=19,
MONTH=apr,
YEAR=2004,
ABSTRACT="This paper contributes towards engineering self-stabilizing networks and
services. We propose the use of navigation patterns, which define how
information for state updates is disseminated in the system, as fundamental
building blocks for self-stabilizing schemes. We present two navigation
patterns for self-stabilization: the progressive wave pattern and the
stationary wave pattern. The progressive wave pattern defines the update
dissemination in Internet routing systems running the DUAL and OSPF
protocols. Similarly, the stationary wave pattern defines the interactions
of peer nodes in structured peer-to-peer systems, including Chord, Pastry,
Tapestry, and CAN. It turns out that both patterns are closely related. For
instance, they both disseminate information in form of waves. A wave is a
set of messages that originate from a single event. Further, we show how to
instrument patterns to obtain wave statistics, which allow us to monitor
the process of self-stabilization in a system. We are interested in
Internet routing and peer-topeer systems, because we believe that studying
these (existing) systems is the first step in developing engineering
principles for self-stabilizing system in various application areas."
}

@INPROCEEDINGS{Adam0406:Enabling,
AUTHOR="Dionisis Adamopoulos and Constantine Papandreou",
TITLE="Enabling Web Services: Towards Service Grids",
BOOKTITLE="The Ninth IEEE Symposium on Computers and Communications",
ADDRESS="Alexandria, Egypt",
DAYS=29,
MONTH=jun,
YEAR=2004,
ABSTRACT="Web services are emerging technologies that can be considered as the result
of the continuous improvement of Internet services due to the tremendous
increase in demand that is being placed on them. They are rapidly evolving
and are expected to change the paradigms of both software development and
use, by promoting software reusability over the Internet, by facilitating
the wrapping of underlying computing models with XML, and by providing
diverse and sophisticated functionality fast and flexibly in the form of
composite service offerings. In this paper, the different facets of Web
services are identified and a flexible approach to engineering complex Web
services is adopted in the form of a proposed framework for the development
of Web services that encompasses in an integrated manner a Web service
creation methodology and a Web services support environment. After the
examination of the main constituent parts of the proposed framework, it is
argued that its full potential and that of Web service engineering in
general, is realized through the gradual formation of a rich service grid
offering value-added supporting functionality and therefore the main
desirable properties of such a service grid are highlighted. Finally, the
paper outlines a validation approach for the proposed framework and
assembles important pointers for future work and concluding remarks."
}

@INPROCEEDINGS{Adam0406:Experimental,
AUTHOR="Davide Adami and Stefano Giordano and Matteo Repeti and Federico Orlandini
and Remo Maccaglia",
TITLE="An experimental study on the {EF-PHB} service in a {DiffServ} High Speed
Network",
BOOKTITLE="High-Speed Networks Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="This paper presents the results of an experimental activity concerning the
implementation and validation of an EF-PHB service in a high speed
metropolitan optical network with a Differentiated Services architecture.
As EF-PHB can be used to create a low latency, low loss, assured bandwdith
service, real-time traffic flows have been aggregated and classified as EF.
Measurements have been performed in different operating conditions to
evaluate how the setting of the EF class of service parameters affects the
time metrics of each flow belonging to the aggregate. The transfer delay
and the delay variation values specified by the ITU-T recommendation Y.1541
for real-time, time sensitive applications, have been taken as QoS
performance objectives to satisfy"
}

@INPROCEEDINGS{Adam0410:Director,
AUTHOR="Brett Adams and Svetha Venkatesh",
TITLE="Director in your pocket: Holistic help for the hapless home videographer",
BOOKTITLE="ACM Multimedia 2004 Short Papers",
ADDRESS="New York, NY",
DAYS=10,
MONTH=oct,
YEAR=2004,
ABSTRACT="We present a new aspect of our ongoing research aimed at providing
technology for the amateur home videographer. We aim to enable the
production of quality video presentations that are well structured and use
the expressive properties of the medium to full effect, regardless of the
technical or artistic abilities of the user. This task requires that help
be given to the user at or before capture time. We use a PDA platform to
deliver 3d visualizations of shot directives, instructions to the user
about the type of footage to capture, and discuss issues connected with
realizing high-level representations in concrete first person animations.
Additionally, we discuss the mechanism for mating that metadata with
captured footage and implementation issues."
}

@INPROCEEDINGS{Adam0410:Seeing,
AUTHOR="Piotr Adamczyk",
TITLE="Seeing Sounds: Exploring Musical Social Networks",
BOOKTITLE="ACM Multimedia 2004 Short Papers",
ADDRESS="New York, NY",
DAYS=10,
MONTH=oct,
YEAR=2004,
ABSTRACT="Information gathering from multimedia retrieval systems is aided by
effective visualization, but the degree to which visualization is effective
depends in part on the way the context of the results is presented. When
relationships represent media rich connections, static visualization alone
may not be enough. This work explores how to represent context and utilize
multimedia to convey a more accurate sense of search results. As a
representative case, we explore various presentations of social networks
formed by expert opinions of musical artist similarity. Our work extends
research in information visualization and music retrieval to create a
multimedia search experience. Three interactive presentation styles are
used; graph-based 2D, Desktop 3D (VRML), and CAVE (immersive Virtual
Reality). Visual models are augmented with spatial audio in 3D, and
hyperlinks to sound files in 2D. Results of a preliminary user study of
these styles are discussed along with implications for recommender system
design."
}

@INPROCEEDINGS{Adea0409:Improved,
AUTHOR="Jaime Adeane and Miguel Rodrigues and Inaki Berenguer and Ian Wassell",
TITLE="Improved Detection Methods for {MIMO-OFDM-CDM} in Fading Channels",
BOOKTITLE="VTC'F04 Transmission Technology",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="The major challenges in future wireless communications system design are
increased spectral efficiency and improved link reliability. The radio
channel constitutes a hostile propagation medium, which suffers from fading
and interference from other users. The use of multiple antennas at both
ends of a wireless link promises significant improvements in terms of
spectral efficiency and/or link reliability. Multiple-input multiple-output
(MIMO) technology has recently become very popular since it can improve
link reliability without sacrificing bandwidth efficiency. The focus of
this paper is the application of a code division multiplexing (CDM)
technique to a very high data rate MIMO communication systems. In this
context, the radio channel is frequency selective and therefore introduces
intersymbol interference(ISI). As a result, single-carrier based MIMO
systems require highly complex equalization techniques, e.g., a vector-MLSE
or a multi-channel equalization. Multicarrier based techniques such as OFDM
permit simple equalization by turning the frequency-selective channel into
a set of parallel narrowband flat fading channels. Only a constant matrix
has to be inverted for each OFDM tone. Furthermore, in a MIMO-OFDM-CDM
system, multipath diversity gain can be obtained by spreading the data
symbols over several OFDM sub-carriers, by the use of orthogonal spreading
codes. Hence, MIMO-OFDM-CDM has the potential to outperform MIMO-OFDM
systems in terms of bit error rate performance, owing to the additional
frequency diversity. The problem with MIMO-OFDM-CDM is the fact that the
radio channel normally destroys the orthogonality of the spreading codes,
which complicates the detection process. In this paper, we propose new and
improved detection methods for MIMO-OFDM-CDM systems, based on lattice
reduction and noise prediction techniques."
}

@INPROCEEDINGS{Adeg0411:Enhanced,
AUTHOR="Abiola Adegboyega and Rupinder Makkar and Ioannis Lambadaris and Kayvan
Mosharaf",
TITLE="An Enhanced Algorithm for Fair Traffic Conditioning in Differentiated
Services Networks",
BOOKTITLE="IEEE Globecom 2004 - Global Internet and Next Generation Networks",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="Fair bandwidth sharing among traffic flows with different characteristics
in Differentiated Services (Diffserv) networks is the focus of the current
research. This paper examines and enhances an algorithm developed to
enforce fairness among disparate TCP flows in the Assured Forwarding (AF)
service in Diffserv. Equation Based Marking (EBM) was introduced by K. Shin
et al to enforce fairness in AF by monitoring network conditions used in
marking decisions. The estimation of packet losses by the algorithm is
integral to marking. The loss rates of different connections were
demonstrated to converge hence enforcing fair marking regardless of
individual flow metrics. EBM is analyzed for fairness and enhanced by
implementing a more efficient technique for loss rate estimation.
Comparison is made between EBM and the enhanced technique. Results show
appreciable improvements in maintaining fairness. Furthermore, a service
definition required by QoS standards is met by implementing the additional
algorithm to EBM."
}

@INPROCEEDINGS{Adel0405:Impact,
AUTHOR="Ferran Adelantado and Oriol Sallent and Jordi Perez-Romero and Ramon Agusti",
TITLE="Impact of Traffic Hotspots in {3G} {W-CDMA} Networks",
BOOKTITLE="Mobile Networks",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="This paper is focused on the analysis of third generation (3G) mobile
communications systems in scenarios with non-uniformly distributed traffic,
and special attention is paid to the impact these situations have on RRM
strategies such as admission probability. Degradation suffered by users in
terms of BLER is observed by varying hotspot density, distance from hotspot
to surrounding base stations, etc. Results presented reveal that the
performance of the system depends a great deal on users distribution and
that some parameters of RRM strategies should be adapted to these varying
situations."
}

@INPROCEEDINGS{Adi0403:Secured,
AUTHOR="Wael Adi and Ali Al-Qayedi and Ali Mabrouk",
TITLE="Secured {Multi-Identity} Mobile Infrastructure and Offline
{Mobile-Assisted} {Micro-Payment} Application",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="Wireless networks are increasingly deployed in many everyday services. The
mobile device is becoming a part of the personal identity of its holder. As
the new mobile standards, as 3GPP are offering the user own application
area, it seems very useful to participate the mobile device itself to
support its owners security and his applications. As mobile devices have no
secured identity in current standards, we propose first a secured device
multi-identity infrastructure. This infrastructure would enable users to
accommodate provable identities without involving the network operator.
These physical provable identities stick physically to the device hardware
and can be securely authenticated over the whole network. We proposed in
[1] a global provable mobile identity mechanism. This concept is extended
to multi-identity profile to establish a powerful infrastructure. Based on
that infrastructure, a new mobile assisted offline micro-payment system is
presented. The system is equivalent to a certified payment, which can be
offline verified. The proposal deploys the mobile device multi-identity
capability to prove the validity and eligibility of an issued electronic
payment to a merchant. The merchant can verify offline that the customers
bank entitled the mobile device holder to issue an electronic payment
within given limits. The system exhibits public key facilities without
traditional high complexity public key processing and does not involve
online operations. That makes the proposal especially more efficient for
wireless environment. The proposed multi-identity mechanisms open also new
horizons for the use of such infrastructure to secure other new similar
applications."
}

@INPROCEEDINGS{Adin0406:Hybrid,
AUTHOR="Abdulkareem Adinoyi and Halim Yanikomeroglu and Sergey Loyka",
TITLE="Hybrid macro- and generalized selection combining microdiversity in
Lognormal shadowed Rayleigh fading channels",
BOOKTITLE="Communication Theory Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="The performance of hybrid micro-diversity, in the form of generalized
selection combining (GSC), and macro-diversity is presented for lognormal
shadowed Rayleigh fading channels. The GSC-augmented macrodiversity
consists of K ports in a cell site, each port carrying N microscopic
diversity antennas. The macroscopic diversity involves selecting the port
with the highest long-term local mean SNR among the K ports, and the GSC
uses n strongest signals of the N branch received signals from that port
for processing. We derive analytical expressions for error rate and outage
for systems employing this hybrid scheme. The expressions are valid for any
configurations of K, N, n. In microcell systems substantial correlation
could exist among the ports in contrast to the zero correlation assumption
of macrocell; results are also shown for correlated lognormal shadowed
Rayleigh channels. Extensive simulation is carried out to validate the
analytical expressions derived."
}

@INPROCEEDINGS{Adji0406:OLSR,
AUTHOR="Cedric Adjih and Anis Laouiti and Saadi Boudjit and Pascale Minet",
TITLE="{OLSR} for {IPv6} Networks",
BOOKTITLE="The Third Annual Mediterranean Ad Hoc Networking Workshop",
ADDRESS="Bodrum, Turkey",
DAYS=27,
MONTH=jun,
YEAR=2004,
ABSTRACT="Mobile ad-hoc networks are infrastructure-free, highly dynamics wireless
networks, which enjoy sustained interest, especially, inside IETF within
the MANET working-group. One of the MANET protocols which have been
recently promoted to experimental RFC is the OLSR routing protocol, on
which this article focuses. Like many MANET routing protocols, the
adaptation to IPv6 networks is entirely not straightforward, and the issues
addressed include IPv6 addressing issues (interface address selection,
multiple addresses per interface), multicast diffusion and, prominently,
the stateless address autoconfiguration of IPv6. This article aims at
complementing the OLSR routing protocol specification to run on IPv6
networks ; it analyzes the all those major issues relative to OLSR on IPv6
networks, and proposes comprehensive changes to OLSR, with an associated
set of algorithms, using existing and novel ideas. Its main contributions
are the set of algorithms used in the autoconfiguration and the handling of
addressing issues."
}

@INPROCEEDINGS{Adle0405:Images,
AUTHOR="Andy Adler",
TITLE="Images can be regenerated from quantized biometric match score data",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT={Biometric technologies, such as automatic face recognition, are currently
being implemented as part of many security applications, such as in
national border control, which require storage and management of millions
of biometric records. This paper addresses some of the security and privacy
implications of biometric data storage. Biometric algorithms function by
comparing a newly acquired a test image from a person to a recorded
{"}template{"}, composed of one or more enrolled images of a person. This
comparison yields a similarity score, which is related to likelihood that
the test image represents the same person as the enrolled image. Although
many vendors of biometric algorithms still claim that an image of the
person cannot be regenerated from the template, it has been shown that, in
general, this can be reliably accomplished using a {"}hill climbing
attack{"}. For example, for a face recognition system, an arbitrary face
image is presented to the system, and the similarity score acquired.
Subsequently, small modifications are made to the face, and those that
increase the score are retained. In order to defend against this attack,
the BioAPI consortium (2001), recommended that biometric algorithms emit
only quantized similarity scores. In this paper, we show that it is still
possible to regenerate biometric images even if the BioAPI recommendation
is implemented. An algorithm is described which can successfully calculate
regenerated images for all tested face recognition algorithms. In this
approach, the test image is split into four quadrants, and one iteration of
the hill climbing attack is applied to each quadrant at a time. Before each
calculation, the image in the opposite quadrant is {"}made worse{"}, such
that the similarity score is just below the threshold, and after the
calculation, the opposite quadrant is returned to its previous condition.
This step means that the area of interest, at each iteration, is brought
into a range where the quantized similarity score provides useful
information. This algorithm was tested for three different face recognition
algorithms, and shown to be able to successfully regenerate a template in
each case. In conclusion, we conclude that the quantization of similarity
score results does not protect stored biometric data from being
regenerated.}
}

@INPROCEEDINGS{Adle0407:Calculation,
AUTHOR="Andy Adler and Michael Schuckers",
TITLE="Calculation of a Composite {DET} Curve",
BOOKTITLE="Audio- and Video-based Biometric Person Authentication",
ADDRESS="Rye, New York, USA",
DAYS=20,
MONTH=jul,
YEAR=2004,
ABSTRACT="We propose two new ideas for evaluation of biometric systems. The first is
a new way to normalize match score distributions based on their ROC or DET
curve. Building on this normalization we can then develop an average DET
curve. Our methodology for this is to convert FMR and FNMR coordinates to
polar coordinates from some center. The normalized match scores are then
then based upon the angle from this center. It is then possible to average
the DET curves at each angle. We illustrate these procedures with an
application to data from a study of human matchers of facial images."
}

@INPROCEEDINGS{Adle0407:Vulnerabilities,
AUTHOR="Andy Adler",
TITLE="Vulnerabilities in biometric encryption systems",
BOOKTITLE="Audio- and Video-based Biometric Person Authentication",
ADDRESS="Rye, New York, USA",
DAYS=20,
MONTH=jul,
YEAR=2004,
ABSTRACT={The goal of a biometric encryption system is to embed a secret into a
biometric template in a way that it can only be decrypted with a biometric
image from the enroled person. This paper describes a potential
vulnerability in such systems that allows a less-than-brute force
regeneration of the secret and an estimate of the enrolled image. This
vulnerability requires the biometric comparison to ``leak'' some
information from which an analogue for a match score may be calculated.
Using this match score value, a {"}hill-climbing{"} attack is performed
against the algorithm to calculate an estimate of the enrolled image, which
is then used to decrypt the code. Results are shown against a simplified
implementation of the algorithm of Soutar et al. (1998).}
}

@INPROCEEDINGS{Adra0406:Iterative,
AUTHOR="Marc Adrat and P. Vary",
TITLE="Iterative {Source-Channel} Decoding with Code Rates near r=1",
BOOKTITLE="Communication Theory Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="We propose a specific channel encoder to support error concealment of
mutually independent source codec parameters. To introduce artificial
dependencies a recursive non-systematic convolutional (RNSC) code is
applied which exhibits a code rate near r=1. The channel encoder may be
considered as a smearing filter. A TURBO-like exploitation of artificial
dependencies and of residual source redundancy according to the iterative
source-channel decoding (ISCD) algorithm permits step-wise quality
improvements. Previously known error concealment techniques are
outperformed in the most interesting range of channel conditions."
}

@INPROCEEDINGS{Adus0403:Location,
AUTHOR="Isaac Adusei and Kyandoghere Kyamakya and Fazli Erbas",
TITLE="{Location-Based} Services: Advances and Challenges",
BOOKTITLE="IEEE International Conference on e-Technology, e-Commerce, and e-Service",
ADDRESS="Taipei, Taiwan",
DAYS=29,
MONTH=mar,
YEAR=2004,
ABSTRACT="Since the United States Federal Communications Commission (FCC) issued an
order in July 1996, requiring mobile operators to provide Wireless
Emergency Services (WES ) to it customers, we have continuously witnessed
evolving breed of mobile positioning technologies. The mobile network
operators, eager in seeking new and innovative ways to create
differentiation and increase profits envisaged potential new services with
the mobile position information. One of the best ways to accomplish this is
through the delivery of highly personalized services based on location.
This has proved to be very illusive to researchers at large and up to date
we are still waiting to see when the first commercial and large scale
Location Based Services (LBS) can be readily and economically available to
customers. In this paper, we discuss the research issues involved in the
development of LBS; describe recent work done in this area in our
department at Hanover University. We will finally outline some of the unmet
research challenges, including highly accuracy mobile positioning
techniques, roaming and billing issues, interoperability between operators
(both national and international) and privacy or security problems
associated with LBS."
}

@INPROCEEDINGS{Adus0405:Location,
AUTHOR="Isaac Adusei and Kyandoghere Kyamakya and Fazli Erbas",
TITLE="{Location-Based} Services: Advances and Challenges",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Since the United States Federal Communications Commission (FCC) issued an
order in July 1996, requiring mobile operators to provide Wireless
Emergency Services (WES ) to it customers, we have continuously witnessed
evolving breed of mobile positioning technologies. The mobile network
operators, eager in seeking new and innovative ways to create
differentiation and increase profits envisaged potential new services with
the mobile position information. One of the best ways to accomplish this is
through the delivery of highly personalized services based on location.
This has proved to be very illusive to researchers at large and up to date
we are still waiting to see when the first commercial and large scale
Location Based Services (LBS) can be readily and economically available to
customers. In this paper, we discuss the research issues involved in the
development of LBS; describe recent work done in this area in our
department at Hanover University. We will finally outline some of the unmet
research challenges, including highly accuracy mobile positioning
techniques, roaming and billing issues, interoperability between operators
(both national and international) and privacy or security problems
associated with LBS."
}

@INPROCEEDINGS{Aduw0409:Channel,
AUTHOR="Akinyemi Aduwo and Annamalai Annamalai",
TITLE="Channel Aware {Inter-Cluster} Routing Protocol for Wireless {Ad-Hoc}
Networks Exploiting Network Diversity",
BOOKTITLE="VTC'F04 Multimedia, Networks and Systems",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="Routing issues in ad hoc networks have been greatly impacted by fading
mechanisms present in wireless media such as path loss, lognormal shadowing
and multipath fading. Existing or newly proposed routing protocols identify
these issues but do not necessarily provide any mechanisms to combat such
issues. In this paper, we extend work done for a Selection based Route Path
Network Macro Diversity scheme (SRP) that exploits the random nature of
these fading mechanisms. We introduce the Maximal Ratio Route Path Network
Macro Diversity scheme (MRRP) that provides optimal solutions to combat
these fading mechanisms inherent in wireless media via network layer
implementation. This network diversity scheme is analyzed in the presence
of different channel models such as the Rice and Nakagami-m model for a
communication system using BPSK modulation. It is shown that the MRRP
scheme provides better performance than the SRP scheme in terms of
end-to-end outage probability and end-to-end average symbol error rate
(ASER). It is also shown that for a given performance threshold, the MRRP
scheme provides better relative power consumption than the SRP scheme.
These network diversity schemes will bring about untold benefits in ad hoc
networks in terms of power reduction, increased capacity, exploitation of
adaptive modulation and coding techniques and data reliability in the
presence of certain complexity trade-offs."
}

@INPROCEEDINGS{Adya0406:Multi,
AUTHOR="Atul Adya and Victor Bahl and Jitendra Padhye and Alec Wolman and Lidong
Zhou",
TITLE="A {Multi-Radio} Unification Protocol for {IEEE} {802.11} Wireless Networks",
BOOKTITLE="Broadband Networks 2004 - Broadband Wireless Networking Symposium",
DAYS=3,
MONTH=jun,
YEAR=2004,
ABSTRACT="We present a link layer protocol called the Multi-radio Unification
Protocol or MUP. On a single node, MUP coordinates the operation of
multiple wireless network cards tuned to non-overlapping frequency
channels. The goal of MUP is to optimize local spectrum usage via
intelligent channel selection in a multihop wireless network. MUP works
with standard-compliant IEEE 802.11 hardware, does not require changes to
applications or higher-level protocols, and can be deployed incrementally.
The primary usage scenario for MUP is a multihop community wireless mesh
network, where cost of the radios and battery consumption are not limiting
factors. We describe the design and implementation of MUP, and analyze its
performance using both simulations and measurements based on our
implementation. Our results show that under dynamic traffic patterns with
realistic topologies, MUP significantly improves both TCP throughput and
user perceived latency for realistic workloads."
}

@INPROCEEDINGS{Adya0409:Architecture,
AUTHOR="Atul Adya and Victor Bahl and Ranveer Chandra and Lili Qiu",
TITLE="Architecture and Techniques for Diagnosing Faults in {IEEE} {802.11}
Infrastructure Networks",
BOOKTITLE="10th ACM MobiCom Conference 2004",
ADDRESS="Philadelphia, Pennsylvania",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="The growing popularity and wide-scale adoption of IEEE 802.11 wireless
networks have generated significant challenges for Information Technology
(IT) departments in corporations. Users frequently complain about
connectivity and performance problems, and network administrators are
expected to diagnose these problems while managing corporate security and
coverage. Their task is particularly difficult due to a lack of intelligent
diagnostic tools for determining the cause of these problems. We present a
client-centric architecture for detecting, localizing, and diagnosing
faults in an IEEE 802.11 infrastructure wireless network. To the best of
our knowledge, ours is the first paper to address this issue. As part of
our architecture, we propose and evaluate a novel technique called Client
Conduit, which enables bootstrapping and fault diagnosis of disconnected
clients. We describe algorithms for carrying out root-cause analysis of
connectivity and performance problems, such as RF holes, RF interference
and traffic congestion; and we describe an approach for detecting illegal
or rogue access points. We have built a prototype of our fault diagnostic
architecture on the Windows operating system using IEEE 802.11 cards; our
initial results show that our techniques are effective and have low
overhead."
}

@INPROCEEDINGS{Aedu0403:Rapid,
AUTHOR="Sandeep Aedudodla and Saravanan Vijayakumaran and Tan Wong",
TITLE="Rapid Ultra-wideband Signal Acquisition.",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="Low transmission power and a highly spread bandwidth makes the acquisition
of ultra-wideband (UWB) signals a difficult problem. In a packet-based
network employing UWB in the physical layer, long preambles need to be
prepended to each packet because the low signal power requires the receiver
to process the signal for long periods of time in order to estimate the
timing information. The long spreading or hopping sequences used in UWB
result in a large search space for the acqusition system at the receiver.
This paper presents a signal acquisition system for UWB which employs a
hybrid signaling format involving direct sequence (DS) spreading and time
hopping (TH), which significantly reduces the search space in the UWB
acquisition system. The acquisition system employs equal gain combining
(EGC) which enables the utilization of the energy of the dense multipath,
typical of a UWB channel. The performance of the acquisition system has
been evaluated."
}

@INPROCEEDINGS{Affe0404:Packet,
AUTHOR="Thomas Afferton and Robert Doverspike and Charles Kalmanek and K. K.
Ramakrishnan",
TITLE="Packet Aware Transport for Metro Networks",
BOOKTITLE="13th IEEE Workshop on Local and Metropolitan Area Networks",
DAYS=25,
MONTH=apr,
YEAR=2004,
ABSTRACT="Todays metro networks have evolved from the need to support traditional
voice and private line services. However, the tremendous growth in access
to Frame Relay, ATM, IP and Ethernet services, coupled with the desire of
enterprise customers to interconnect via Ethernet interfaces, suggests the
need for a new approach. This paper proposes a new architecture for
Packet-Aware Transport Networks (PATN) which supports both packet and
traditional TDM services and which leverages an assemblage of emerging
technologies to provide efficient aggregation and switching of packet
traffic in metro networks. The PATN has the potential to provide
significant cost savings to carriers by reducing the number of network
elements, reducing transport costs through statistical multiplexing, and
eliminating the need for redundant multiplexing operations."
}

@INPROCEEDINGS{Agah0409:Non,
AUTHOR="Afrand Agah",
TITLE="A Non-cooperative Game Approach for Intrusion Detection in Sensor Networks",
BOOKTITLE="VTC'F04 Multimedia, Networks and Systems",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="Insufficiency of memory and battery power of sensors makes the security of
sensor networks a hard task to do. This insufficiency also makes applying
the existing methods of securing other type of networks on the sensor
networks unsuitable. We propose a game theoretic framework for defensing
nodes in a sensor network from attacks. We simulate four type of attacks to
a sensor network and our main concern is finding the most vulnerable node
and protecting it. We formulate attack-defense problem as a two-player,
nonzero-sum, non-cooperative game between an attacker and a sensor network.
We show that this game achieves Nash equilibrium and thus leading to a
defense strategy for the network. We show that the proposed game framework
significantly increases the chance of success in defense strategy for
sensor network."
}

@INPROCEEDINGS{Agam0405:Adaptive,
AUTHOR="Mohammed Agamy and Hasan Yousef and Omar Sebakhy",
TITLE="Adaptive Fuzzy Variable Structure Control Of Induction Motors",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Field oriented control has proven to be one of the most effective methods
to control the induction motor. This technique has the merit of decoupling
the torque the flux dynamics and thus, the induction motor can be treated
in the same manner as a dc machine. However, this method is very sensitive
to external load disturbances and motor parameter variations. Variable
structure control is a well known robust control technique. Therefore, a
sliding mode controller was introduced to the field oriented control system
in order to avoid the aforementioned drawbacks of the field oriented
control system. But in sliding mode control the upper bound of
uncertainties must be known in order to properly adjust the controller
parameters. Since these uncertainties are practically difficult to obtain,
they must be estimated during the system operation. Fuzzy inference systems
have also proven to be an effective method to model non-linear, ill-defined
systems and systems with uncertainties by means of expert knowledge.
Therefore, the merits of combining the sliding mode controller with a fuzzy
controller were studied, and a fuzzy inference mechanism was proposed in
order to compensate for the system uncertainties seen by the sliding mode
controller by automatically readjusting the controller gains. Another
problem facing the sliding mode controller is the high chattering
phenomenon and the high control effort required in order to satisfy the
sliding mode condition for all values of uncertainties. Therefore, an
adaptive fuzzy sliding mode controller is proposed. In this controller an
adaptation algorithm for the centers of the fuzzy membership functions is
applied, in order to obtain an optimal compensation for the uncertainties,
so that the control effort is minimized and the chattering phenomenon is
reduced. In this paper, a sliding mode controller is designed, and then a
fuzzy inference mechanism is used to compensate for the uncertainties
experienced by the system by adjusting the reaching rates of the sliding
mode controller. Finally an adaptation algorithm is used to adjust the
centers of the fuzzy sets in order to reduce the control effort and
chattering. Using the adaptive fuzzy sliding mode controller on a 5HP,
3-phase, 220 V I.M. showed a reduction in the amplitude and frequency of
the chattering around the sliding surfaces, tracking errors of less than
1\% for both speed and flux and also a 21.7\% reduction in the control
effort when using the adaptive fuzzy sliding mode controller. Key Words:
Variable structure control, Fuzzy logic control, Induction motor drives."
}

@ARTICLE{Agar0401:Energy,
AUTHOR="Manish Agarwal and Joon Ho Cho and Lixin Gao and Jie Wu",
TITLE="Energy Efficient Broadcast in Wireless Ad hoc Networks with Hitch-hiking",
JOURNAL={ACM/Kluwer MONET Special Issue on {"}Energy Constraints and Lifetime
Performance in Wireless Sensor Networks{"}},
DAYS=16,
MONTH=jan,
YEAR=2004,
ABSTRACT="In this paper, we have proposed a novel concept called Hitch-hiking in
order to reduce the energy consumption of broadcast application for
wireless networks. Hitch-hiking takes advantage of the physical layer
design that facilitates the combining of partial signals to obtain the
complete information. The concept of combining partial signals using
maximal ratio combiner [17] has been used to improve the reliability of the
communication channel but has never been exploited to reduce energy
consumption. We study the advantage of Hitch-hiking for the scenario when
the transmission power level of nodes is fixed as well as the scenario when
the nodes can adjust their power level. For both the scenarios, we have
shown that the Hitch-hiking is advantageous and proposed algorithms to
construct broadcast trees with Hitch-hiking taken into consideration. For
fixed transmission power case, we have proposed and analyzed a centralized
heuristic algorithm called SPWMH (Single Power Wireless Multicast with
Hitch-hiking) to construct a broadcast tree with minimum forwarding nodes.
For the latter case, we propose a centralized heuristic algorithm called
Wireless Multicast with Hitch-hiking (WMH) to construct an energy efficient
tree using Hitchhiking and also present a distributed version of the
heuristic. We also evaluate the proposed heuristics through simulation.
Simulation results show that Hitch-hiking can reduce the transmission cost
of broadcast by as much as 50\%. Further, we propose and evaluate a
protocol called Power Saving with Broadcast Tree (PSBT) that reduces energy
consumption of broadcast by eliminating redundancy in receive operation.
Finally, we propose an algorithm that takes advantage of both Hitch-hiking
and PSBT in conserving energy."
}

@INPROCEEDINGS{Agar0403:Energy,
AUTHOR="Manish Agarwal and Joon Ho Cho and Lixin Gao and Jie Wu",
TITLE="Energy Efficient Broadcast in Wireless Ad hoc Networks with Hitch-hiking",
BOOKTITLE="IEEE Infocom 2004",
ADDRESS="Hong Kong",
DAYS=7,
MONTH=mar,
YEAR=2004,
ABSTRACT="In this paper, we have proposed a novel concept called Hitch-hiking in
order to reduce the energy consumption of broadcast application for
wireless networks. Hitch-hiking takes advantage of the physical layer
design that facilitates the combining of partial signals containing the
same information to obtain the complete information. The concept of
combining partial signals using maximal ratio combiner has been used to
improve the reliability of the communication channel but has never been
exploited to reduce energy consumption. We propose a centralized heuristic
algorithm called Wireless Multicast with Hitch-hiking (WMH) to construct an
energy efficient tree using Hitch-hiking and also present a distributed
version of the heuristic. We have also analyzed the proposed heuristics
through simulation. Simulation results show that Hitch-hiking can reduce
the transmission cost of broadcast by as much as 50\%. Further, we propose
and analyze a protocol called PSBT which conserves energy for broadcast by
allowing nodes to discard the already received packets. Finally, we propose
an algorithm that takes advantage of both Hitch-hiking and PSBT in
conserving energy."
}

@INPROCEEDINGS{Agar0409:Experimental,
AUTHOR="Avesh Agarwal",
TITLE="An Experimental Study on Wireless Security Protocols over Mobile {IP}
Network",
BOOKTITLE="VTC'F04 Wireless Technology Applications to Global Security: Space,
Air/Land, and Sea",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="Security protocols have emerged as a vital issue to support secure and
reliable communications over wireless networks. Many papers discuss
security services offered by these protocols from a functional perspective;
however, there is lack of quantitative results demonstrating the impact of
security protocols on the system performance which can be affected
dramatically by applying the security policies in combination with mobile
environment. Therefore, we conduct an experimental study on wireless IP
testbed by analyzing the interaction of protocols at different layers and
the impact of protocols at different types of data streams with regard to
delay and throughput. In this paper, we present a comprehensive analysis of
performance impact and the overhead associated with the most widely used
protocols such as WEP, IPSEC, 802.1x and SSL."
}

@INPROCEEDINGS{Agar0411:Qos,
AUTHOR="Ajay Agarwal",
TITLE="{QoS-based} {On-Demand} Segmented Backup Routing in Mobile Ad Hoc Networks",
BOOKTITLE="IEEE International Conference on Networks 2004",
ADDRESS="Singapore",
DAYS=17,
MONTH=nov,
YEAR=2004,
ABSTRACT="Several real-time applications (e.g., video conferencing, remote control
systems) demand guarantees on the message delivery latency. Supporting
these QoS connections requires the existence of a routing mechanism, which
computes paths that satisfy QoS delay constraints (e.g., end-to-end delays
or failure recovery delays). In mobile ad hoc network, wireless links tend
to frequently fail as nodes move in and out of transmission range of one
another. To provide fault tolerance with QoS guarantees in such a network
is a challenging issue. The proposed new algorithm, also called a Segmented
Backup Routing (SBR), constructs a set of segmented backup paths. Each
segmented backup path, protects a segment of the primary path rather than
the entire path. The most important points that are made in this algorithm
are two. First, one is able to identify backup paths for any selected
primary path, as long as there exists (any) pair of node disjoint paths
from source to destination. In other words, if there are two node disjoint
paths, one is not forced to use either of them to be the primary path. This
has the advantage that the primary path may be selected based on QoS
considerations rather than a consideration of fault tolerance. The second
and major advantage is that there are multiple backup paths, each of which
protects breakdown of one or more nodes on the primary path. These may
again be selected based on QoS considerations. In this work, we have
primarily focused on end-to-end delay as the QoS parameter.We apply our
scheme to the AODV protocol and evaluate the performance improvements by
simulation."
}

@INPROCEEDINGS{Agaz0406:Maximum,
AUTHOR="Oscar Agazzi and Diego Crivelli and Hugo Carrer",
TITLE="Maximum likelihood sequence estimation in the presence of chromatic and
polarization mode dispersion in intensity modulation/direct detection
optical channels",
BOOKTITLE="Signal Processing in Communications Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="In this paper we investigate maximum likelihood sequence estimation (MLSE)
receivers operating on intensity modulated direct detection optical
channels. Our study focuses on long haul or metro links spanning several
hundred kilometers of single mode fiber with optical amplifiers. We
describe the structure of MLSE-based optical receivers operating in the
presence of amplified spontaneous emission (ASE) noise, and we develop a
theory of the error rate of these receivers. Computer simulations show a
close agreement between the predictions of the theory and simulation
results. We also address some important implementation issues. Optical
channels suffer from impairments that set them apart from other channels
and therefore they need a special investigation. Among these impairments
are the facts that the optical channel is nonlinear, and the dominant
source of noise is often ASE noise, which is distributed according to a
non-central chi-square probability density function. Additionally, optical
fibers suffer from chromatic and polarization mode dispersion. Although the
use of MLSE in optical channels has been discussed in earlier literature,
no detailed analysis of optical receivers using this technique has been
reported so far. This motivates the study reported in this paper."
}

@INPROCEEDINGS{Agel0411:Optoelectronic,
AUTHOR="Atanasios Sacki Agelis and Magnus Jonsson",
TITLE="Optoelectronic Router with {MOEMSBased} Reconfigurable Shuffle Network",
BOOKTITLE="The Second Swedish National Computer Networking Workshop 2004",
ADDRESS="Karlstad University",
DAYS=23,
MONTH=nov,
YEAR=2004,
ABSTRACT="An optoelectronic router with a shuffle exchange network is presented and
enhanced by adding micro-optical-electrical mechanical systems (MOEMS) in
the network to add the ability to reconfigure the shuffle network. The
MOEMS described here are fully connected any-to-any crossbar switches. The
added reconfigurability gives the opportunity to adapt for different common
application characteristics. Two representative application models are
described, where the first has symmetric properties and the second has
asymmetric properties. The router system is simulated with the specified
applications and an analysis of the results is carried out. By using MOEMS
in the optical network, and thus reconfigurability, over 50\% increased
throughput performance and decreased average packet delay is obtained for
the given application. Network congestions are shown to be avoided
throughout the system if reconfigurability is used."
}

@INPROCEEDINGS{Agga0409:Dynamic,
AUTHOR="Rohit Aggarwal and Kunal Verma and John Miller and William Milnor",
TITLE="Dynamic Web Service Composition in {METEOR-S}",
BOOKTITLE="IEEE SCC 2004 Web Services Track",
ADDRESS="Shanghai, China",
DAYS=15,
MONTH=sep,
YEAR=2004,
ABSTRACT="Creating Web processes using Web services technology gives us the
opportunity for selecting new services which best suit our need at the
moment. Doing this automatically would require us to quantify our criteria
for selection. In addition, there are challenging issues of correctness and
optimality. We present a Dynamic Web Service Composition tool in METEOR-S,
a system for dynamic composition of Web services, which allows the process
designers to design processes, based on business and process constraints.
Our approach is to reduce dynamic composition of Web services to a
constraint satisfaction problem. It uses a multi-phase approach for
constraint analysis. This work was done as part of the METEOR-S framework,
which aims to support the complete lifecycle of semantic Web processes."
}

@INPROCEEDINGS{Agga0410:Constrained,
AUTHOR="Sudhir Aggarwal and Madhura Limaye and Arun Netravali and Krishan Sabnani",
TITLE="Constrained Diameter Steiner Trees for Multicast Conferences in Overlay
Networks",
BOOKTITLE="The First International Conference on Quality of Service in Heterogeneous
Wired/Wireless Networks",
ADDRESS="Dallas, Texas, USA",
DAYS=18,
MONTH=oct,
YEAR=2004,
ABSTRACT="We consider a variation of a constrained Steiner minimal tree problem that
is applicable for multicast conferencing. Assume a network having cost and
delay values associated with each edge. Consider the following problem for
the above network: find an optimal shared tree with minimal cost subject to
the constraint that the delay between any two nodes of the tree must be
bounded by some maximal value. Such a constraint on the delay is
appropriate for an application such as a multicast conference that uses a
shared tree where any node can be both a sender and a receiver. We develop
and analyze a new heuristic algorithm for solving this problem. Our
approach is inspired by Lagrangian relaxation techniques. We first develop
a novel distance metric on trees that we term delta diameter. Using this
metric, our algorithm then uses a standard Prim-like labeling algorithm
coupled with the Takahashi Matsuyama Steiner tree algorithm. Simulation
results show how cost and delay can be traded off smoothly. Using
simulation, we also compare our heuristic with the optimal achievable. We
believe that our approach is practical for dynamically building multicast
shared trees to support applications such as real-time video conferencing
with delay constraints."
}

@INPROCEEDINGS{Agha0405:Link,
AUTHOR="Farshid Agharebparast and Victor Leung",
TITLE="{Link-Layer} Modeling of a Wireless Channel Using Stochastic Network
Calculus",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Network calculus (NC) is an elegant theory for performance evaluation of
QoS-based queueing Networks. Originally developed for deterministic
queueing systems, the theory has evolved as well to consider statistical
(soft) service guarantees. These probabilistic bounds are more applicable
for the applications in which the deployment of the worst-case bounds
causes inefficient usage of the resources, such as transmission of
multiplexed delay semi-sensitive data flows over a wireless link. We make
use of the stochastic NC to derive a dynamic service curve which
effectively models the behaviour of a wireless channel, observed from the
link level. The model incorporates the characteristics of a wireless link
such as delay, time-varying bandwidth, packet loss and fading effect. This
will allow a network operator to derive the end-to-end QoS metrics (e.g.
delay, backlog, and throughput) of a data network, containing wireless
links. The model consists of a number of pipeline stages; each stage models
a characteristic of the link employing NC components. An effective service
curve is then derived from these stages that collectively models the
wireless link within probabilistic constraints. We compare the effective
service curves derived from the two methods of dynamic F-servers and
effective envelopes. The stochastic filtering theory based on the (min, +)
algebra is then used to calculate probabilistic bounds for delay, backlog,
packet loss and output flow of the wireless link and by applying the
concatenation property, the end-to-end performance is evaluated. These
bounds are expressed by equations that provide the likelihood of attaining
these bounds within a desired probability. The effectiveness of the
proposed approach is more demonstrated with a practical example including
the wireless link model."
}

@INPROCEEDINGS{Aghv0405:Distributed,
AUTHOR="Hamid Aghvami and Mischa Dohler",
TITLE="{Distributed-MIMO} {Multi-Stage} Communication Networks",
BOOKTITLE="Vehicular Technology Conference Spring 2004",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="A communication network where an information source communicates with an
information sink via topologically imposed distributed relaying nodes,
factually creating distributed multiple-input-multiple-output (MIMO)
channels at each relaying stage, is referred to as a Distributed-MIMO
Multi-Stage Communication Network. The aim of this tutorial is to expose an
industrial and academic audience to the challenges related to the analysis,
design and deployment of such recently emerged networks at PHY, MAC and
network layers. The logical thread of the tutorial, ranging from the
underlying Shannon theory to resource allocation and scheduling within
distributed networks, proves vital in conveying the most essential issues
relating to the design of these networks. The tutorial will commence with a
brief overview of distributed-MIMO multi-stage communication networks,
including their potential applications as well as engineers' objectives
when designing such networks. This will be followed by a review of MIMO
Shannon theory and relaying technologies, both of which constitute inherent
ingredients to the understanding of the gains offered by distributed
relaying networks. A thorough Shannon theory of these networks will then be
presented with novel twists on closed form capacity formulas over ergodic
and non-ergodic, traditional and orthogonalised MIMO channels obeying
various channel fading statistics. The output from this will be shown to be
useful in deriving explicit optimum fractional resource allocation rules
such as to achieve optimum end-to-end throughput. The analysis, design and
performance of distributed space-time block and trellis codes, concatenated
with outer channel codes, will be dealt with in sufficient depth. The
derived deployment guidelines will then be utilised to design properly
functioning MAC protocols, which reflect the characteristics of the
underlying distributed PHY layer as well as the served IP traffic.
Performance examples will be given, and important cross-layer design
guidelines elaborated upon. Finally, open research topics for academia and
industry will be suggested."
}

@INPROCEEDINGS{Agra0406:Effect,
AUTHOR="Dharma Agrawal and Yunli Chen",
TITLE="Effect of Contention Window on the Performance of {IEEE} {802.11} {WLANs}",
BOOKTITLE="The Third Annual Mediterranean Ad Hoc Networking Workshop",
ADDRESS="Bodrum, Turkey",
DAYS=27,
MONTH=jun,
YEAR=2004,
ABSTRACT="In the IEEE 802.11, an exponential backoff has been adopted, which means
whenever a collision occurs, the contention window (CW) of the station is
doubled until it reaches the maximum value. The purpose of increasing CW is
to reduce the collision probability by distributing the traffic into a
larger time space. In this paper, we use a fixed fixed contention window
(FCW) and evaluate the performance of this scheme. Based on our analysis,
we determine an optimal contention window (OCW). Furthermore, we apply the
OCW scheme to 802.11e EDCF. The results show that the OCW scheme not only
can effectively enhance the performance for high priority packets, but can
also improve the overall system performance."
}

@INPROCEEDINGS{Agra0411:Medians,
AUTHOR="Divyakant Agrawal and Chiranjeeb Buragohain and Nisheeth Shrivastava and
Subhash Suri",
TITLE="Medians and Beyond: New Aggregation Techniques for Sensor Networks",
BOOKTITLE="The Second ACM Conference on Embedded Networked Sensor Systems",
ADDRESS="Baltimore, Maryland",
DAYS=3,
MONTH=nov,
YEAR=2004,
ABSTRACT="Wireless sensor networks offer the potential to inexpensively span and
monitor large geographical areas. Sensors, however, have significant power
constraint (battery life), making communication very expensive. Another
issue that arises in the context of sensor based information systems is
that individual sensor readings are inherently unreliable. In order to
address these two aspects, sensor database systems like TinyDB and Cougar
enable in-network data aggregation to reduce the communication cost and
improve reliability. The existing data aggregation techniques, however, are
limited to relatively simple types of queries such as SUM, COUNT, AVG, and
MIN/MAX. In this paper we propose a data aggregation scheme that
significantly extends the class of queries that can be answered using
sensor networks. These queries include (approximate) quantiles, such as the
median, the most frequent data values, a histogram of the data
distribution, as well as range queries. In our aggregation scheme, each
sensor aggregates the data it has received from other sensors into a fixed
(user specified) size message. We provide strict theoretical guarantees on
the approximation quality of the queries in terms of the message size. We
evaluate the performance of our aggregation scheme by simulation and
demonstrate its accuracy, scalability and low resource utilization for
highly variable input data sets."
}

@INPROCEEDINGS{Agra0411:Redesigning,
AUTHOR="Deepak Agrawal and Fabrizio Granelli",
TITLE="Redesigning an Active Queue Management System",
BOOKTITLE="IEEE Globecom 2004",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="PI and/or PD controllers are not effective in maintaining steady state
condition i.e. constant queue length to avoid or minimize jitter, because
each has its own advantages and limitations. In this paper we propose a new
AQM scheme. According to it, a PID controller is used for maintaining queue
length of desired level at bottleneck routers under varying load and
network conditions. The design criteria used is Linear Quadratic
Regulators. It is a robust PID controller design method compared to
classical methods like Gain Margin \& Phase Margin and Pole placement. The
logic behind maintaining the constant queue length is predictable delay to
support QoS provisioning. Presented simulation results support our
analysis."
}

@INPROCEEDINGS{Agui0405:Bi,
AUTHOR="Ana Aguiar and Jirka Klaue",
TITLE="Bi-directional {WLAN} Channel Measurements in Different Mobility Scenarios",
BOOKTITLE="Antennas and Propagation",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="The interest in the behaviour of the wireless channel increases as WLAN
access points become more widespread. In order to enhance the performance
of existing applications in wireless environments, especially when mobility
is present, knowledge about channel behaviour is of great importance.
Nevertheless, very few experimental results have been documented and
evaluated. We designed and realised a measurement campaign to investigate
channel characteristics in different mobility conditions and different
environments. Special attention is paid to the correlation between both
channel directions. This is particularly interesting for channel-adaptive
mechanisms; the strength of this correlation is important for the use of
such techniques without the need for additional signalling or feedback of
channel state information. In this paper we present the results of this
measurement campaign. We evaluate the channel behaviour in various
scenarios typical for WLAN. The linear time dependence within the same
direction and between the opposite directions are calculated and compared.
Furthermore, we show the distribution of the measured signal power. The
results are useful, e.g., for trace-based simulations or for the derivation
of specific channel models."
}

@INPROCEEDINGS{Agus0410:Fuzzy,
AUTHOR="Ramon Agusti and Oriol Sallent and Jordi Perez-Romero and Lorenza Giupponi",
TITLE="A {Fuzzy-Neural} based approach for Joint Radio Resource Management in a
Beyond {3G} Framework",
BOOKTITLE="The First International Conference on Quality of Service in Heterogeneous
Wired/Wireless Networks",
ADDRESS="Dallas, Texas, USA",
DAYS=18,
MONTH=oct,
YEAR=2004,
ABSTRACT="This paper presents a comprehensive scenario where to develop Joint RRM
(Radio Resource Management) strategies taking full advantage of the
reconfigurable equipment capabilities and the diversity offered by
available RATs (Radio Access Technologies) in a multi-radio environment. A
comprehensive JRRM treatment calls for establishing links with all the
entities involved, first at functional level, identifying realistic
scenarios in terms of deployment, technologies and services and managing
the emerging complexity with proper algorithms. Then, a Fuzzy-neural
methodology framework able to cope with the complexities and uncertainties
these new scenarios rise is presented. In particular both technical and
economical aspects are considered when selecting a particular RAT. Finally
some significant examples of the algorithm behaviour are shown."
}

@INPROCEEDINGS{Ah0404:Linear,
AUTHOR="Choi {Se Ah} and Kyeong Cheol Yang",
TITLE="Linear complexity and k-error linear complexity of sequences over {GF(p^m)}",
BOOKTITLE="The 14th JOINT CONFERENCE ON COMMUNICATIONS \& INFORMATION",
ADDRESS="Chungmu Marina Resort, Tongyoung city, Gyeongsangnam-do, KOREA",
DAYS=28,
MONTH=apr,
YEAR=2004,
ABSTRACT="The linear complexity and the k-error linear complexity play an important
role for stream ciphers in cryptology. Meidl and Niederreiter construct
sequences which have maximal linear complexity and large linear complexity.
However, it is important to analyze k-error linear complexity of sequences
which don't have maximal linear complexity. We construct sequences over
GF(p^m) which have certain linear complexity and k-error linear complexity.
Furthermore, we prove that theses sequences are the only ones which have
given linear complexity and k-error linear complexity."
}

@INPROCEEDINGS{Ahar0409:MEMS,
AUTHOR="Oren Aharon and Shai Feldman and Yael Nemirovsky",
TITLE="Silicon Single Crystalline {MEMS} Shunt Contact Switch for {RF} Application",
BOOKTITLE="The 23rd IEEE convention of Electrical and Electronics Engineers in Israel",
ADDRESS="Herzlia, Israel",
DAYS=6,
MONTH=sep,
YEAR=2004,
ABSTRACT="Micro-Electro-Mechanical (MEMS) DC to RF shunt switch was fabricated using
bulk micromachining process of single crystalline silicon. The switch was
vertically integrated to a microwave circuit using flip-chip bonding
technology. The pull-in voltage and switching time were measured. Also, RF
characterization of switch states was preformed. This new design offers the
potential for a high power applications switch. The concept of a packaged
switch described in this paper enables to offer a stand alone,
non-substrate material or technology dependent switch."
}

@INPROCEEDINGS{Ahle0405:Modeling,
AUTHOR="Elmar Ahle and Dirk {Söffker}",
TITLE="Modeling the Decision Process of the {Lane-Change} Maneuver Using a
{Situation-Operator} Model",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="The contribution demonstrates the application of a situation-operator
modeling (SOM) technique to the decision process of the lane-change
maneuver. The core of the approach is the assumption that changes of the
world are understood as a sequence of scenes and actions. These parts are
modeled using a special situation and operator calculus. The situation,
i.e. the scene the driver is encountered to during the decision process of
the lane-change maneuver, is described using a set of characteristics and
relations. Characteristics include the possibility of time dependent
parameters and relations of the characteristics fix the structure of the
considered scene of the real world modeled as situation. All possible
actions are formulated as operators, i.e. an information-theo\-retic
construct which is defined by its function as well as explicit and implicit
assumptions. For the internal structure of the operator, other descriptions
like textual, logical, mathematical or other problem-related descriptions
are allowed. The presented example describes the decision process driving
on a multilane road with different goals, e.g. change lanes as few as
possible, but get ahead at a suitable rate. With the description of the
real world as situation-operator model, planning of actions according to
the goals is realized. In particular, which action has to be applied in
which situation depending on the given goal. The decision is not
rule-based, it follows from the description as situation-operator model.
This formulation is independent of the given goals. The given example is
used to outline that this modeling methodology is suitable to model the
process of planning, acting and learning. The modeling technique is not
limited to describe the presented example, it can also be applied to
describe the 'human as controller' or autonomous systems. Furthermore, it
is able to describe human error and to design an advanced autonomous system
due to the ability to model learning."
}

@INPROCEEDINGS{Ahma0406:Restoration,
AUTHOR="Mohammad Ahmadi",
TITLE="Restoration Techniques and Delay Analysis for Fault Recovery in {WDM}
Networks",
BOOKTITLE="The Ninth IEEE Symposium on Computers and Communications",
ADDRESS="Alexandria, Egypt",
DAYS=29,
MONTH=jun,
YEAR=2004,
ABSTRACT="Extensive interest in using public networks has increased the traffic
volume and encouraged network providers to employ new technologies for
better quality of service and traffic protection. Wavelength Division
Multiplexing (WDM) is a new technology satisfying the growing demand for
network capacity. MultiProtocol Label Switching (MPLS) provides a mechanism
for traffic protection in IP networks. In this research, we have focused on
recovery techniques and restoration methods that operate at Label Switch
Paths (LSPs) in MPLS Networks. Mathematical analysis as well as simulation
programs for evaluation of different restoration techniques are given."
}

@INPROCEEDINGS{Ahma0409:Dynamic,
AUTHOR="Iftekhar Ahmad",
TITLE="Dynamic {Look-Ahead} Time with Conditional Call Admission based on
Predicted Lifetime",
BOOKTITLE="Ninth International Conference on Communication Systems",
ADDRESS="Singapore",
DAYS=6,
MONTH=sep,
YEAR=2004,
ABSTRACT="Book-Ahead (BA) reservation which allows reserving network bandwidth long
before its actual starting time is an effective technique to provide
enhanced functionality for multimedia and distributed applications in a
QoS-enabled network. Introduction of BA reservation disrupts service
continuity of on-going Instantaneous Request (IR) calls when resource
scarcity arises. A number of Call Admission Control (CAC) models have been
proposed in literature to address the problem of interrupted service
continuity. This work presents a comparative study of recently proposed
models. Simulation results show that among the proposed models Dynamic
Look-Ahead Time (DLAT) based CAC model [14] yields the best performance in
terms of low preemption probability and high resource utilization for low
to moderate BA limit. We also present a modified DLAT model with
conditional admission of IR calls that achieves better performance even at
high BA limit."
}

@INPROCEEDINGS{Ahma0411:Dynamic,
AUTHOR="Iftekhar Ahmad",
TITLE="Dynamic {Look-Ahead} Time in {Book-Ahead} Reservation in {QoS-Enabled}
Networks",
BOOKTITLE="IEEE International Conference on Networks 2004",
ADDRESS="Singapore",
DAYS=17,
MONTH=nov,
YEAR=2004,
ABSTRACT="In recent time Book-ahead (BA) reservation has drawn increasing attention
as multimedia and distributed applications become functionally richer.
Book-ahead reservation has proved itself as an effective technique for time
sensitive applications that require high amount of bandwidth with
guaranteed QoS. One of the major concerns in the implementation of BA
reservation in a QoS-enabled network is the preemption of on-going
Instantaneous Requests (IR) calls. Preemption is a threat to service
continuity which is seen as an important issue from users perceived QoS
definition found in recent studies. Earlier models proposed to reduce IR
preemption use constant look-ahead time. This paper proposes a novel model
to calculate look-ahead time dynamically taking traffic parameters and
network state into consideration. Simulation results show that the proposed
model achieves lower preemption probability, higher throughput, lower
wasted throughput and higher effective revenue."
}

@INPROCEEDINGS{Ahme0405:Down,
AUTHOR="Bazil Ahmed and Miguel {Ramón.} and Leandro {Haro y Ariet.}",
TITLE="{Down-Link} Analysis of a {FDSS-GSM} Overlay System",
BOOKTITLE="Mobile Networks",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="The overlay of a frequency diversity spread spectrum system (FDSS) on the
(GSM) system is studied. The worst-case condition is considered for the
downlink. The downlink capacity of both systems is studied using a model of
36 cells. The performance of the (GSM) and (FDSS) users is investigated for
different power ratios. An original GSM system with 48 channel/cell can be
substituted by a mixed system, which has a GSM system capacity of 48
users/cell and FDSS system capacity of 116 users/cell when the number of
the sectors of the cell is increased form 3 to 6 sectors."
}

@INPROCEEDINGS{Ahme0405:Embedded,
AUTHOR="Usman Ahmed and Gul Khan",
TITLE="Embedded System Partitioning with Flexible Granularity by using a Variant
of Tabu Search",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Almost all the embedded systems have a digital component executing software
application programs. Traditionally these systems are developed as a
two-stream process, hardware engineers delivering embedded computer
systems, which are programmed by software engineers. The typical design
cycle required the system to be partitioned early in the design phase
leaving very little room for modifications later in the design stage. This
early system partitioning along with the separate design flows for hardware
and software modules do not fully explore design space and is prone to high
cost, inefficient hardware and software. The solution is to combine
hardware and software design efforts by considering the efficiency of both
options and to find a design implementation that fulfills all the
specification requirements with a minimal cost. System partitioning
algorithms usually work with a high level of system description, which is
transformed into some form of Control Flow Graph (CFG). The nodes of CFG
are then partitioned into software and hardware modules by using some
optimization technique. Typical partitioning methods work with a fixed
granularity. Henkel and Ernst [1] have presented a partitioning algorithm
that works with a flexible granularity. The method optimizes a CFG using
Simulated Annealing. It has been shown that Tabu search technique performs
better than Simulated Annealing in terms of time as well as quality of
system partitioning results [2]. We present a method to partition a CFG
using a variant of Tabu Search, which uses a dynamic Tabu List [3] in place
of a fixed Tabu list as used by most of the conventional algorithms. Our
algorithm works with a flexible level of granularity as described by Henkel
and Ernst [1] and it merges CFG nodes into partitioning objects under a
defined set of rules. The set of all the partitioning objects define the
design space. An initial partitioning object is selected and improved on
subsequent iterations to find the best solution that satisfies the given
constraints. The performance of this technique is also compared against
Simulated Annealing and Conventional Tabu Search based approaches that
shows promising results. References [1] J Henkel, R Ernst, A
Hardware/Software Partitioner using a dynamically determined Granularity,
IEEE/ACM Proc. 34th Design Automation Conf., 1997, pp. 691696. [2] T
Wiangtong, P Cheung, W Luk, Comparing Three Heuristic Search Methods for
Functional Partitioning in Hardware-Software Codesign, Journal of Design
Automation for Embedded Systems, 2002 Vol. 6, pp. 425 - 449. [3] R
Montemanni, J Moon, D Smith, An Improved Tabu Search Algorithm for the
Fixed-Spectrum Frequency-Assignment Problem, IEEE Transactions on Vehicular
Technology, Vol. 52 Issue: 4, July 2003, pp. 891 -901."
}

@INPROCEEDINGS{Ahme0405:Fairness,
AUTHOR="Mohamed Hossam Ahmed and Halim Yanikomeroglu and Samy Mahmoud",
TITLE="Fairness of Link Adaptation Techniques in Broadband Wireless Access
Networks",
BOOKTITLE="Wireless Access",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="Link adaptation techniques, such as power control and adaptive coding and
modulation, aim at maximizing the resource utilization in wireless
networks. However, fair resource allocation must be taken into
consideration, particularly in fixed wireless access networks. The low/no
mobility of users in such networks leads to location-dependent resource
allocation, which can cause a significant variation in the amount of
resources from a user to another. For instance, adaptive coding and
modulation schemes increase the average throughput in the network; however,
they also increase the variation of the throughput. This is because users
with good link quality will always have high throughput, while users with
bad link quality will always have low throughput. In this paper, the
fairness and efficiency of various link adaptation techniques are analyzed."
}

@INPROCEEDINGS{Ahme0405:Maintenance,
AUTHOR="Rana Ahmed",
TITLE="Maintenance Issues in Outsourced Software Components",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="This paper proposes some recommendations for the maintenance of software
products developed heavily from outsourced software components.
Specifically, the paper addresses the roles of subcontractors (outsourcing
organizations) during the maintenance phase of the software product.
Outsourcing is becoming an alternative in software industry, and the
evidence for the importance of assuring the quality of subcontractors
contributions is found in ISO 9000-3 Std and ISO/IEC 2001, and other
literature on the subject [1-3]. Sometimes, more than one subcontractors
contributes in the project. There are some risks and benefits of
introducing subcontractors in the framework of the project. One of the
major risks is the future maintenance difficulties. Usually, one
organization, most probably the major contractor (or the parent company) is
responsible for the maintenance of the whole project. The contractor may be
faced with defective software product and documentations supplied by the
subcontractors. This may results in higher maintenance costs to the
contractor. Another complication in maintenance arises due to the fact that
the maintenance services could be supplied by more than one subcontractors,
suppliers of COTS software, and sometimes, the parent company. Each of
these bodies take limited responsibilities in case of a software failure.
Reliable maintenance is only possible if adequate measures are taken in
advance during projects development and maintenance planning phase, and
documented in the maintenance contract [3]. In this paper, we present and
make a justification for a set of recommendations to make such maintenance
reliable and cost-effective. Some of the major recommendations are outlined
as follows: Choice criteria regarding the subcontractors and defining the
scope of their level of participation Limit on the number of subcontractors
Involvement of subcontractors in the document reviews (such as requirements
specification, design document, test plan, maintenance plan, etc.)
Participation in software verification and validation activities, and
acceptance tests Participation in maintenance activities for a stipulated
period of time Sharing problem reporting and bug tracking tools
Participation in collecting software and product metrics We analyze the
associated risks and develop a model to estimate the overall product
quality metrics during the maintenance phase. Keywords: Software
Maintenance; Software Outsourcing; Risk management; Software Project
Management References 1. V. Basili and B. Boehm, COTS-based system Top 10
list, IEEE Computer, Vol. 34, No. 5, May 2001, pp. 91-93. 2. ISO 9000-3:
1997 (E), Quality Management and Quality Assurance Standards Part 3:
Guidelines for the Application of ISO 9001:1994 to the Development, Supply,
Installation and Maintenance of Computer Software, ISO, Geneva,
Switzerland. 3. D. Galin, Software Quality Assurance: From Theory to
Implementation, 2004, Pearson Education Ltd."
}

@INPROCEEDINGS{Ahme0405:Physics,
AUTHOR="Kousseil {Ben Ahmed} and Ammar Kouki",
TITLE="{Physics-Based} Analysis of Variable {RF} {MEMs} Capacitors",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Micro-Electro-Mechanical-Systems (MEMS) is an emerging technology that has
found a very wide range of application areas. In particular, this
technology offers several benefits in the RF area such as the ability to
produce compact, low-loss, very high Q components using moving structures
fabricated onto silicon chips. These components are the building blocks of
many RF devices such as filters, resonators, actuators switches and so on.
In order to reduce the production cycle of these devices, the building
structures have to be designed with a high degree of precision. This in
turn requires accurate electrical and mechanical modeling and simulation of
these structures. The electrical analysis consists of DC analysis, for
actuation purposes, and high frequency analysis, to determine the RF
frequency response. In DC, Laplaces differential equation is solved
subjected to the appropriate boundary conditions while at high frequency
the vector wave equation must be solved. The mechanical analysis requires
the solution of stress problems subject to applied load forces and
constraints to compute the movement and/or deformation of the structure.
For simple structures, these boundary value problems may have analytical
solutions. However, for complex and moving structures, such as the one
proposed here, only numerical solutions are possible. The most popular, and
best suited, numerical method for solving these proposed boundary value
problems is the finite element method. The aim of this paper is to design
MEMS variable capacitor using a physics-based simulation approach where DC,
stress and high frequency analyses are performed on the same geometric
model using a commercial software tool. The design targets a very large
capacitor tuning range of 0.8pF to 8pF, a range not currently available in
the literature. This is achieved by using a multi-finger parallel-plate
structure that has two electrodes: one stationary and one suspended by a
mechanical spring so that it moves by the affect of an applied force.
Capacitance, actuation voltage and electrostatic forces as well as tuning
range and RF frequency response are determined using a single software
interface and coupled multi-physics analyses. As this is a large structure,
the effect of deformation with motion could be only captured with the
numerical analysis technique used which allows full 3-dimensional
simulations without compromising the geometrical details. The resulting
final design is submitted for fabrication through CMC and will be tested
electrically."
}

@INPROCEEDINGS{Ahme0405:Role,
AUTHOR="Rana Ahmed and Abdul Khaliq",
TITLE="On the Role of Base Station in {Fault-Tolerant} Mobile Networks",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="The provision of fault-tolerance in cellular wireless mobile networks
presents unique challenges because of the scarce wireless resources,
limited storage, and limited battery power available to the mobile host
(MH). Checkpointing and rollback techniques can be used to provide
fault-tolerance in a distributed application consisting of a set of
cooperating processes. These techniques require that a system stores its
state (called a checkpoint) during normal fault-free operation on the
stable storage, and upon a failure, restores (rollbacks to) a previous
consistent state. The execution is then restarted from the restored state.
However, most of the checkpointing protocols proposed [1-2] for general
distributed systems are not efficient for wireless mobile networks with
respect to the efficient use of scarce network resources. This paper
introduces a new technique in which the base station is given certain roles
to assist in the provision of fault-tolerance process. The technique
requires the base stations to keep a record of interactions among various
MHs, and to use a filtering process to reduce the number of unnecessary
checkpoints and other control messages exchanges. The communication record
among interacting MHs will later help in asking only the related
interacting processes to take the checkpoint or rollback, without
disturbing other processes that never communicated with those interacting
processes. In the case of two-phase checkpointing protocols, the BS,
instead of initiating MH, can directly send the messages to affected MHs,
thus conserving wireless bandwidth and the number of control messages.
Moreover, the BS can group control messages destined for a process running
on a MH to take a checkpoint or recover from other processes, provided
global consistent state is maintained. The technique can be applied to any
existing checkpointing algorithm with the incorporation of above-mentioned
roles for the base stations. It is shown that the technique reduces the
checkpointing overhead in terms of message exchanges and the checkpoint
storage requirements for some representative algorithms (e.g., [2]).
References 1. Acharya, and Badrinath, Checkpointing Distributed
Applications on Mobile Computers, 3rd Intl. Conference on Parallel and
Distributed Information Systems, Sept. 1994, pp. 73-80. 2. R. Koo and S.
Toueg, Checkpointing and Rollback Recovery for Distributed Systems, IEEE
Transactions on Software Engg., Jan. 1987, vol. 13, no. 1, pp. 23-31."
}

@INPROCEEDINGS{Ahme0406:Hierarchical,
AUTHOR="Khaled {Sayed Ahmed} and Yuji Horikoshi and Hisayuki Kuriyama and K. Mori",
TITLE="Multi-layer Autonomous Community Overlay Network for Enhancing
Communication Delay",
BOOKTITLE="The Ninth IEEE Symposium on Computers and Communications",
ADDRESS="Alexandria, Egypt",
DAYS=29,
MONTH=jun,
YEAR=2004,
ABSTRACT="Autonomous Decentralized Community Communication System (ADCCS) is a
decentralized architecture that forms a community of individual and
autonomous end-users (community members) having the same interests and
demands in somewhere, at specified time. It enables them to mutually
cooperate and share information without loading up any single node
excessively. ADCCS does not seize the advantage of heterogeneity of the
community nodes-nodes latencies. Thus, this paper proposes
ADCCS-Multilayer. It is an autonomous decentralized multi-layer community
overlay network that enhances the communication delay among the community
members. This paper presents an efficient step-step construction technique
to reduce both the communication delays among members and the required time
to join/leave. Experimental results show that ADCCS-Multilayer enhances the
community communication delay."
}

@INPROCEEDINGS{Ahme0409:FDSS,
AUTHOR="Bazil Ahmed",
TITLE="{FDSS} Downlink Capacity in Urban Zone Near {ATSC} {8-VSB} Digital Video
Broadcasting Installations",
BOOKTITLE="VTC'F04 Wireless Personal Communication Systems",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="The FDSS macrocell downlink capacity is evaluated for macrocells that
operate at the same frequency of the ATSC 8-VSB Digital TV station and that
is nearby the DTV installations. It has been found that the cell capacity
vanishes for a very little distance from the 8-VSB transmitter and that the
critical distance is of 22 km from the 8-VSB transmitter. It has been shown
that the critical distance increases with the increment of the effective
transmitted power of the TV transmitter and with the increment of the TV
transmitting antenna. Moreover, it has been noticed that the effect of the
8-VSB system is null at a distance of 60 km and that the downlink vanishes
at the zone very near to the 8-VSB installations."
}

@INPROCEEDINGS{Ahme0409:Path,
AUTHOR="Bazil Ahmed",
TITLE="On the Path Loss Effect on {W-CDMA} Uplink Capacity in Urban Dense
Environment",
BOOKTITLE="VTC'F04 Poster Papers",
ADDRESS="Los Angeles, CA",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="Simple formulas to study the uplink capacity dependence on the path loss
are given. The case of voice users only and data users only (144
Kbits/sec.) are studied. For a macrocell it is noted that the capacity
depends on the maximum path. Up to 140 dB of path loss the capacity is
almost constant, but higher path loss values produce a decay of capacity up
to null capacity. From the results we can deduce that, a macrocell radius
of 0.6 km can be used with very little capacity degradation."
}

@INPROCEEDINGS{Ahme0409:UMTS,
AUTHOR="Bazil Ahmed",
TITLE="On the {UMTS} Macrocells Downlink Capacity in Open Rural Zone Near Shaded
Deep Space Network {(DSN)} Installations",
BOOKTITLE="VTC'F04 Wireless Technology Applications to Global Security: Space,
Air/Land, and Sea",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="The UMTS macro-cell downlink capacity is evaluated for macro-cells that
operate at the same frequency of the Deep Space Network (DSN) and that are
nearby shaded DSN installations. It has been found that the downlink
capacity is not affected when the distance between the DSN installations
and the macro-cell is more than 35 km. For a distance greater than the
obstacle distance, the effect of the DSN is less compared with the
un-shaded case."
}

@INPROCEEDINGS{Ahme0409:Uplink,
AUTHOR="Bazil Ahmed",
TITLE="Uplink Capacity and Interference Statistics of {W-CDMA} Highways
Cigar-shaped Microcells with Non-uniform Spatial Traffic Distribution",
BOOKTITLE="VTC'F04 Wireless Personal Communication Systems",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="Uplink Capacity and Interference Statistics of W-CDMA Highways Cigar-shaped
Microcells with Non-uniform Spatial Traffic Distribution Bazil Taha Ahmed,
Miguel Calvo Ramón and Leandro de Haro y Ariet Departamento Sistemas,
Señales y Radiocomunicaciones, ETSI Telecomunicación, Universidad
Politécnica de Madrid Ciudad Universitaria, Madrid, 28040
bazil(at)gr.ssr.upm.es Technical subject area: 5 Abstract The capacity and
the interference statistics of the sectors of the shaped W-CDMA cell are
studied. A model of 5 microcells is used to analyse the uplink. The cells
are assumed to exist in rural zones. The capacity and the interference
statistics of the cell are studied for different non-uniform spatial
traffic distributions. The conditions that describe the rural highway
cigar-shaped microcells under this study are the number of directional
sectors of the cigar-shaped microcell is two and a directional antenna is
used in each sector. a line-of-sight shaped cell has typically a range (R)
of one kilometer. the user speed in rural areas can reach 120 km/h. Five
different distributions are studied: Case 1: Case 2: Case 3: Case 4: Case
5: It has been noticed that, when the users density decreases when we move
away from the base station, the capacity of the sector increases due to the
less total power transmitted by the interfering users."
}

@INPROCEEDINGS{Ahme0409:W,
AUTHOR="Bazil Ahmed",
TITLE="{W-CDMA} Uplink Capacity and Interference Statistics of a",
BOOKTITLE="VTC'F04 Wireless Access",
DAYS=27,
MONTH=sep,
YEAR=2004,
ABSTRACT="Technical subject area: 5 Abstract The uplink capacity and the interference
statistics of the sectors of a long groove-shaped road W-CDMA microcell are
studied. A model of 9 microcells in a groove-shaped road is used to analyze
the uplink capacity and interference. A hybrid model for the propagation is
used in the analysis. The capacity and the interference statistics of the
cell are studied for different sector ranges, different specific
attenuation factors, different antenna azimuth sidelobe levels, different
bend loss and different power control standard deviation error. The
conditions that describe the long groove road cigar-shaped microcells under
this study are: the number of sectors of the cigar-shaped microcell is two
and a directional antenna with side lobe level Sll is used in each sector.
the sector has typically a range (R) of 1 kilometer. the groove length is
of the order of 10 km. the user speed in the groove road can reach 120
km/h. It has been noticed that Increasing the sector range R, increases the
sector capacity. With an antenna sidelobe level of 15 dB, the capacity is
quasi the maximum possible. The lower is the bend loss; lower is the sector
capacity. Increasing the shadowing standard deviation \1 and
\2 will reduce the sector capacity. The higher is the specific
attenuation factor of the walls n, the higher is the sector capacity. The
microcells that most strongly contribute to the interference are the three
microcells that exist in the center of the nine microcells model."
}

@INPROCEEDINGS{Ahme0411:Delay,
AUTHOR="Nadeem Ahmed and Mohammad Khojastepour and Richard Baraniuk",
TITLE="Delay-limited Throughput Maximization for Fading Channels using Rate and
Power Control",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="The fading channels seen in many wireless systems provide a particularly
hostile environment for reliable communication. Current metrics for
evaluating the performance limits of fading channels have shortcomings.
Ergodic capacity, representing the ultimate error-free communications
limit, only applies to systems with infinite coding delay. Practical
systems are delay-limited and must use finite-length codes. For
delay-limited systems outage-capacity and delay-limited capacity are
typically used to quantify the communications performance. However,
outage-capacity is not an estimate of error-free performance while
delay-limited capacity tends to be an overly conservative measure. We model
practical systems as a single server queue and quantify the communications
performance as the average throughput through the queue. Throughput is
maximized by optimally selecting the transmission rate and power control
strategy. Using this approach we arrive at striking conclusions. First, we
show that a throughput very close to ergodic capacity can be achieved with
a small coding delay. Second, the optimal transmission rate for some
systems can be higher than the ergodic capacity of the channel. Third, we
demonstrate the notion that power adaptation does not improve communication
performance does not hold for delay-limited systems."
}

@INPROCEEDINGS{Ahme0411:Lower,
AUTHOR="Mohamed Hossam Ahmed and Halim Yanikomeroglu",
TITLE="A Lower bound on {SIR} Threshold for Call Admission Control in
{Multiple-Class} {CDMA} Systems with Imperfect {Power-Control}",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="Signal to interference ratio (SIR)-based call admission control schemes
admit calls as long as SIR is higher than a threshold value (SIRth).
Lowering this threshold level is desirable to reduce the blocking rate.
However, a lower bound of SIRth is vital to keep the outage probability
(Pout) below a maximum value. In this paper, we derive this lower bound of
SIRth (SIRth-lb) for multi-class CDMA systems with imperfect power control.
SIRth-lb of class i (SIRth-lb(i), i=1, 2,., L) is determined by finding the
relationship between the outage probabilities of all classes (Pout(i), i=1,
2,., L) and SIRth of all classes (SIRth(i), i=1, 2,., L) where L is the
number of classes. Then, SIRth-lb(i) is determined as the lowest value of
SIRth(i) that keeps the outage probability of all classes below the
corresponding maximum values."
}

@INPROCEEDINGS{Ahn0403:MIMO,
AUTHOR="Kyung Seung Ahn",
TITLE="{MIMO} channel estimation and data detection algorithm for space-time block
coded transmission over multipath channels",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="In this paper, channel estimation for space-time block coded transmission
system is considered. By assuming that the channel frequency response is
quasi-static, we develop channel estimation based on the use of space-time
block coded (STBC) training block. And the optimality criterion for
training sequence design is derived and the design tradeoffs associated
with the choice of training length is discussed. A novel data detection
algorithm for the Alamouti scheme is developed, which is derived from the
max-log maximum a posteriori (MAP) algorithm for conventional
single-antenna systems. Numerical results are provided to demonstrate the
performance of the proposed channel estimation and data detection algorithm
for space-time block coded transmission systems."
}

@INPROCEEDINGS{Ahn0404:Analysis,
AUTHOR="Chi Hun Ahn and Young Min Ki and Jun Yeop Jung and Dong Ku Kim",
TITLE="Analysis of call blocking probability and Queuing modeling in portable
internet network interworking with {WLAN}",
BOOKTITLE="The 14th JOINT CONFERENCE ON COMMUNICATIONS \& INFORMATION",
ADDRESS="Chungmu Marina Resort, Tongyoung city, Gyeongsangnam-do, KOREA",
DAYS=28,
MONTH=apr,
YEAR=2004,
ABSTRACT="Call blocking probabilities of streaming data service in CDMA system with
access point(AP) of WLAN are analyzed for different cell geometry of base
station and AP and queuing is modeled. The considered system leads to
successful handoffs between the APs of WLAN. Blocking probabilities are
enumerated as a function for ratio of base station and AP sizes, their
locations and the number of buffer in the queue. Results show that blocking
probability is not influenced by base station and AP locations but mainly
by ratio of their sizes. For CDMA system of radius 100m, 5 buffers in the
queue and 7dB noise rise(NR), in order to obtain 1\% call blocking
probability, a cell with hot spot of radius 20m has more 0.6Erlang than
that of radius 60m."
}

@INPROCEEDINGS{Ahn0404:Intelligent,
AUTHOR="Chang Wook Ahn and R. s. Ramakrishna",
TITLE="An Intelligent Dynamic Connection Admission Control for Adaptive Multimedia
Services",
BOOKTITLE="The 14th JOINT CONFERENCE ON COMMUNICATIONS \& INFORMATION",
ADDRESS="Chungmu Marina Resort, Tongyoung city, Gyeongsangnam-do, KOREA",
DAYS=28,
MONTH=apr,
YEAR=2004,
ABSTRACT="This paper presents a dynamic connection admission control (CAC) algorithm
for adaptive multimedia services. The proposed algorithm is mainly devoted
to finding the best possible QoS levels for all the connections (i.e., QoS
vector) that maximize resource utilization by fairly distributing wireless
resources among the connections while maximizing the statistical
multiplexing gain (i.e., minimizing the blocking and dropping
probabilities). The problem itself is formulated as a multi-objective
optimization problem. The algorithm employs a Hopfield neural network (HNN)
for finding the QoS vector. Hardware-based HNN exhibits high
(computational) speed that permits real-time running of the CAC algorithm.
Simulation results show that the algorithm can maximize resource
utilization and maintain fairness in resource sharing, while maximizing the
statistical multiplexing gain in providing acceptable service grades.
Furthermore, the results are relatively insensitive to handoff rates."
}

@INPROCEEDINGS{Ahn0404:Mechanism,
AUTHOR="Gaeil Ahn",
TITLE="Mechanism for Determining Rate-limit of Abnormal Traffic",
BOOKTITLE="The 14th JOINT CONFERENCE ON COMMUNICATIONS \& INFORMATION",
ADDRESS="Chungmu Marina Resort, Tongyoung city, Gyeongsangnam-do, KOREA",
DAYS=28,
MONTH=apr,
YEAR=2004,
ABSTRACT="This paper proposes a mechanism for determining rate-limit of attacking
traffic that degrades the quality of network service by generating abnormal
traffic while executing Denial of Service attacks or worm scan attacks. The
proposed mechanism determines how much bandwidth to rate-limit and which
aggregate flows to rate-limit by analyzing current network state, bandwidth
of aggregate flows, and abnormal grade of aggregate flows synthetically.
The proposed mechanism is able to defeat abnormal aggregate flows while
protecting normal aggregate flows."
}

@INPROCEEDINGS{Ahn0404:Method,
AUTHOR="Jinyong Ahn",
TITLE="The method of {PLC-to-UPnP} Bridge Design and Implementation",
BOOKTITLE="The 14th JOINT CONFERENCE ON COMMUNICATIONS \& INFORMATION",
ADDRESS="Chungmu Marina Resort, Tongyoung city, Gyeongsangnam-do, KOREA",
DAYS=28,
MONTH=apr,
YEAR=2004,
ABSTRACT="In PLC network, PLC device is connected at PLC gateway through power line.
PLC gateway is connected at PLC server through ethernet. And control
device(ex. homepad, PDA...) is connected at PLC server through various
media to control PLC devices. Device-to-device control is not possible in
the existing PLC technology. It is hard to implement PLC control
application that has various functions in the existing PLC technology.
Also, each control device has to set the PLC server IP address. This paper
applies UPnP technology to the existing PLC tehcnology for overcoming the
above mentioned limits. We designed and implemented a method of PLC-to-UPnP
bridge to have the interoperability between PLC and UPnP network."
}

@INPROCEEDINGS{Ahn0404:Performance,
AUTHOR="Jang-Hwan Ahn and Sung-Hoon Moon and Chae-Hyun Lim and Jung-Tae Kim and
Dong-Seog Han and Seung-Won Kim",
TITLE="Performance Improvement of Mobile Reception of {ATSC} System Using Hybrid
Adaptive Beamforming",
BOOKTITLE="The 14th JOINT CONFERENCE ON COMMUNICATIONS \& INFORMATION",
ADDRESS="Chungmu Marina Resort, Tongyoung city, Gyeongsangnam-do, KOREA",
DAYS=28,
MONTH=apr,
YEAR=2004,
ABSTRACT="This paper proposes a hybrid Capon-LMS adaptive beamforming algorithm to
improve the performance of mobile reception of ATSC DTV receivers. The
proposed beamforming algorithm has good multipath interference rejection
capability. The performances of mobile reception are analyzed with a
developed channel model. In addition, the proposed algorithm can
efficiently compensate the phase distortion caused by Doppler shift."
}

@INPROCEEDINGS{Ahn0404:Symbol,
AUTHOR="Chi Jun Ahn and Jae Min Ahn",
TITLE="The symbol timing estimation algorithm for the {IEEE} 802.11a based
{MIMO-OFDM} systems",
BOOKTITLE="The 14th JOINT CONFERENCE ON COMMUNICATIONS \& INFORMATION",
ADDRESS="Chungmu Marina Resort, Tongyoung city, Gyeongsangnam-do, KOREA",
DAYS=28,
MONTH=apr,
YEAR=2004,
ABSTRACT="we proposed The symbol timing estimation algorithm for the IEEE 802.11a
based MIMO-OFDM systems. The long preamble symbols of the MIMO-OFDM system
is used to estimate the symbol timing. The simulations are performed over
the multipath fading channel and the result is evaluated by the estimation
error variance."
}

@INPROCEEDINGS{Ahn0406:Reverse,
AUTHOR="Chang-Jun Ahn and Yukiyoshi Kamio and Hiroshi Harada",
TITLE="Reverse Link Performance Improvement for Dynamic Parameter Controlled
{OFDM} Using Alamouti Coded Heterogeneous Polarization Antennas",
BOOKTITLE="The Ninth IEEE Symposium on Computers and Communications",
ADDRESS="Alexandria, Egypt",
DAYS=29,
MONTH=jun,
YEAR=2004,
ABSTRACT="The combination of OFDM and multiple antennas in either the transmitter or
receiver is attractive to increasing the diversity gain. However, multiple
antennas system requires an antenna separation of 5~10 lambda to keep the
correlation coefficient below 0.7 for the full space diversity, so this may
be difficult to implement in mobile station with high mobility. Recently,
the polarization transmit diversity is considered in mobile station.
However, polarization transmit diversity requires twice transmit powers to
compare with the conventional transmit diversity, since only vertical type
polar antenna cannot receive the horizontal signal components. Moreover,
the cross polarization discriminator (XPD) is shown about 5~15 dB.
Therefore, it is difficult to obtain full diversity, since a large
imbalance in the received power would render the whole diversity system
worthless. To reduce these problems, we propose a dynamic parameter
controlled OFDM using Alamouti coded heterogeneous polarization antennas
for obtaining the equal power. From the simulated results, the proposed
system shows better BER performance than that of the conventional
STBC/OFDM."
}

@INPROCEEDINGS{Ahn0409:Training,
AUTHOR="Kyung Seung Ahn",
TITLE="{Training-Based} Channel Estimation and Equalization for {Space-Time}
{Block-Coded} Systems over {Frequency-Selective} Fading Channels",
BOOKTITLE="VTC'F04 Transmission Technology",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="In this paper, channel estimation for space-time block coded transmission
system is considered. By assuming that the channel frequency response is
quasi-static, we develop channel estimation based on the use of space-time
block coded (STBC) training block. And the optimality criterion for
training sequence design is derived and the design tradeoffs associated
with the choice of training length is discussed. A novel equalization and
detection algorithm for the Alamouti scheme is developed, which is derived
from the max-log maximum a posteriori (MAP) algorithm for conventional
single-antenna systems. Zero-forcing (ZF) and minimum mean square error
(MMSE) equalization are derived for suboptimal detection algorithm.
Numerical results are provided to demonstrate the performance of the
proposed channel estimation and equalization algorithm for space-time block
coded transmission systems."
}

@INPROCEEDINGS{Ahn0410:Implementation,
AUTHOR="Baik-song Ahn and Sung-Hoon Sohn and Chei-Yol Kim and Gyu-Il Cha and
Sung-In Jung and Myung-Joon Kim and Yun-Cheol Baek",
TITLE="Implementation and Evaluation of {EXT3NS} Multimedia File System",
BOOKTITLE="ACM Multimedia 2004 Long Papers",
ADDRESS="New York, NY",
DAYS=10,
MONTH=oct,
YEAR=2004,
ABSTRACT="The EXT3NS is a scalable file system designed to handle video streaming
workload in large-scale on-demand streaming services. The EXT3NS is based
on a special H/W device, called Network-Storage card (NS card), which is
designed to accelerate streaming operation by shortening the data path from
storage device to network interface. The design objective of EXT3NS is to
minimize the delay and the delay variance of I/O request in the sequential
workload on NS card. File organization, metadata structure, unit of
storage, or etc. are elaborately tailored to achieve this objective.
Further, EXT3NS provides the standard API¯s to read and write files in
storage unit of NS card. The streaming server utilizes EXT3NS on NS card to
gain high disk I/O bandwidth, to avoid unnecessary memory copies on the
data path from disk to network, and to alleviates CPU¯s burden by
offloading parts of network protocol processing, The EXT3NS file system is
a full functional file system based on the popular EXT3 which has been
implemented on Linux operating system. The performance measurements on our
prototype video server show obvious performance improvements. Specifically,
we obtained better result from file system benchmark program, and obtained
performance improvements in disk read and network transmission, which leads
to overall streaming performance increase. Especially, the streaming server
shows much less CPU utilization, and the fluctuation of client bit rate is
much smaller, hence more reliable streaming service is possible."
}

@INPROCEEDINGS{Ai0406:Adaptive,
AUTHOR="Jing Ai and Jingfei Kong and Damla Turgut",
TITLE="An Adaptive Coordinated Medium Access Control for Wireless Sensor Networks",
BOOKTITLE="The Ninth IEEE Symposium on Computers and Communications",
ADDRESS="Alexandria, Egypt",
DAYS=29,
MONTH=jun,
YEAR=2004,
ABSTRACT="In this paper, we have developed Adaptive Coordinated Medium Access Control
(AC-MAC), a contention-based Medium Access Control protocol for wireless
sensor networks. To handle the load variations in some real-time sensor
applications, AC-MAC introduces the adaptive duty cycle scheme within the
framework of sensor-MAC (S-MAC). The novelty of our protocol is that it
improves latency and throughput under a wide range of traffic loads while
remaining as energy-efficient as S-MAC. We illustrate such optimized
trade-offs of AC-MAC via extensive simulations performed over wireless
sensor networks. Our simulation results show that AC-MAC is as
energy-efficient as S-MAC while its latency and throughput are always
trying to follow the classic IEEE 802.11 MAC (no duty cycle), which
outperform the S-MAC (fixed duty cycle), specially under the heavy load."
}

@INPROCEEDINGS{Aiof0410:Dynamic,
AUTHOR="Wagner Aioffi and Geraldo Robson Mateus and Jussara Almeida and Daniel
Mendes",
TITLE="Mobile Dynamic Content Distribution Networks",
BOOKTITLE="Seventh ACM/IEEE(*) International Symposium on Modeling, Analysis and
Simulation of Wireless and Mobile Systems",
ADDRESS="Venice, Italy",
DAYS=4,
MONTH=oct,
YEAR=2004,
ABSTRACT="Mobile networks are becoming increasingly popular as a means for
distributing information to a large number of users. In comparison to
traditional wired networks, mobile networks are distinguished by a
potentially much higher variability in client demand due to user mobility.
Most previous content distribution techniques assume a static client demand
distribution and, thus, may not perform well in mobile networks. This paper
proposes and analyzes a Mobile Dynamic Content Distribution Network model,
which takes demand variations into account to decide whether to replicate a
content and whether to remove previously created replicas in order to
minimize total traffic over the network. We develop two solutions to our
model: an offline optimal, which provides an ideal lower-bound on the total
traffic for content distribution in a mobile network, and a practical
approximate online algorithm, which uses demand forecasting to make
replication decisions. Using a previously developed mobility simulator, we
provide a thorough evaluation of our content placement algorithms,
comparing them against the previous ACDN algorithm for dynamic content
placement. Our results show that the new approximate online algorithm
significantly outperforms the ACDN algorithm the only previous dynamic
content placment agorithm that we aware of, reducing total network traffic
in up to 85\\%, in a number of experiments covering a large system design
space. Furthermore, it provides solutions that are at most 2.7 times the
ideal offline optimum, in our experiments."
}

@INPROCEEDINGS{Airy0411:Practical,
AUTHOR="Manish Airy and Antonio Forenza and Robert Heath and Sanjay Shakkottai",
TITLE="Practical Costa Precoding for the Multiple Antenna Broadcast Channel",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="For a multiple antenna broadcast channel, the sum-rate capacity achieving
transmit strategy requires the centralized transmitter to simultaneously
communicate with multiple receivers. The objective of this paper is to
design an implementable sum-rate capacity achieving transmit strategy that
uses a combination of beamforming and coding for known interference. For a
two-user vector broadcast channel, results indicate that in the context of
typical QAM constellations, with two transmit antennas and one receive
antenna per receiver, there is significant gain in sum-rate capacity over
an approach that uses only beamforming."
}

@INPROCEEDINGS{Ajem0405:Fuzzy,
AUTHOR="Peter Ajemba and Lino Ramirez and Nelson Durdle and Doug Hill and James
Raso",
TITLE="A Fuzzy Classifier Approach to Assessing the Progression of Adolescent
Idiopathic Scoliosis from Radiographic Indicators",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="A fuzzy classifier approach was used to predict the progression of
adolescent idiopathic scoliosis (AIS), a condition that causes the spine to
shift laterally and to twist, resulting in visible asymmetries of the
trunk. As the aetiology of AIS is unknown, its progression (condition
getting more severe) can only be predicted from measured features. Previous
studies have shown that individual features of AIS do not reliably predict
progression. Complex indicators with improved predictive values have been
developed but are unsuitable for clinical use as obtaining their values is
often onerous, involving much skill and repeated measurements taken over
time. Our hypothesis was that combining common features of AIS using a
fuzzy classifier approach would produce better prediction results more
quickly. We conducted a study using a dataset comprising 44 moderate AIS
patients (30 observed, 14 treated with brace; 13 progressed less than 5
degrees, 31 progressed more than 5 degrees). Twenty-one radiographic and
clinical indicators were obtained for each patient. The analysis of
variance technique was used to select the 10 most significant indicators.
The data obtained was clustered using a fuzzy c-means classifier. Once the
number of clusters was found, fuzzy rules were designed to represent each
cluster. The resulting rules were used to classify the records in the
dataset. Results showed that the system achieved 100\% accuracy in training
and up to 70\% accuracy in testing. It outperformed a stepwise linear
regression model and a statistically equivalent logistic regression model
on the dataset. Less than 20 minutes per patient is required to measure the
features, input the data into the system and generate the needed results
enabling it to be used in a clinical environment to aid in management of
AIS."
}

@INPROCEEDINGS{Ajem0405:Re,
AUTHOR="Peter Ajemba and Nelson Durdle and Doug Hill and James Raso",
TITLE="Re-positioning Effects on a Full Torso Imaging System for the Assessment of
Scoliosis",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Scoliosis is a condition characterized by lateral deviation and rotation of
the spine resulting in visible trunk deformities. Back surface imaging is
used in the assessment of scoliosis. Full torso imaging systems that
utilize multiple cameras or scanners to capture views simultaneously are
being proposed. To reduce the cost of full torso imaging systems, a system
utilizing a rotating positioning frame and a single Minolta VIVID 700 laser
scanner was developed. The system requires four images taken at 90 degree
intervals over 10 seconds to generate a torso image. The volunteers were
required to hold their breath as each shot was taken. The effect of motion
artifacts on the reconstruction of the torso was assessed. Two volunteers
having no scoliosis were imaged 10 times at 30-minute intervals. Ten
evenly-spaced cross-sections were computed for each torso image. The
distance between a line joining the centroids of successive cross-sections
and the reference vertical axis was computed at each cross-section. The
standard deviation of this distance at each cross-section was indicative of
the variability due to sway for each volunteer. The variability due to
breathing was assessed by computing the standard deviation of the widths
and lengths of each cross-section for each volunteer. Results obtained
showed that the variability due to re-positioning was less than 5 mm at
each cross-section level for both volunteers. The variability due to sway
ranged from 0 4.5 mm while that due to breathing ranged from 0 4 mm. These
results indicate that our new torso imaging system is adequate for the
assessment of AIS as re-postitioning effects were within tolerable limits."
}

@INPROCEEDINGS{Akar0410:Exact,
AUTHOR="Nail Akar and Ezhan Karasan",
TITLE="Exact Calculation of Blocking Probabilities for Bufferless Optical Burst
Switched Links with Partial Wavelength Conversion",
BOOKTITLE="Broadband Networks 2004 - Broadband Optical Networking Symposium",
ADDRESS="San Jose, CA, USA",
DAYS=25,
MONTH=oct,
YEAR=2004,
ABSTRACT="In this paper, we study the blocking probabilities in a wavelength division
multiplexing-based asynchronous bufferless optical burst switch equipped
with a bank of tuneable wavelength converters that is shared per output
link. The size of this bank is generally chosen to be less than the number
of wavelengths on the link because of the relatively high cost of
wavelength converters using current technologies; this case is referred to
as partial wavelength conversion in the literature. We present a
probabilistic framework to exactly calculate the blocking probabilities.
Burst durations are assumed to be exponentially distributed and burst
arrivals are first assumed to be Poisson and later generalized to the more
general phase-type distribution. Unlike existing literature based on
approximations and/or simulations, we formulate the problem as one of
finding the steady-state solution of a continuous-time Markov chain with a
block tridiagonal infinitesimal generator. We propose a numerically
efficient and stable solution technique based on block tridiagonal LU
factorizations. We show that blocking probabilities can exactly and
efficiently be found even for very large systems and rare blocking
probabilities. Based on the results of this solution technique, we also
show how this analysis can be used for provisioning wavelength channels and
converters."
}

@INPROCEEDINGS{Akas0409:Mathematical,
AUTHOR="Takeshi Akasaki and Iwata Motonori and Yoshihiko Akaiwa",
TITLE="A Mathematical Expression of Nonlinear Distortion in a Power Amplifier",
BOOKTITLE="VTC'F04 Modeling and Simulation",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="For radio communications, signal bandwidth is much less than the carrier
frequency. In this case, only the odd order distortion appears in the
signal band. Other components appears in baseband and higher harmonic band.
The base band components are due to even order distortion. Therefore, only
odd order distortion becomes a problem. However, for wide band systems such
as W-CDMA, the baseband components of the even order distortion contain
higher frequency components, which perturbs bias conditions, and generate
new odd order distortion. In this paper, first, we give a mathematical
model of odd order distortion of a power amplifier for narrow band system.
An approximated series expansion of a power amplifier characteristic is
obtained by finding out the optimum parameters by using an iterative
algorithm. Next, we show an approximated series expansion of a power
amplifier characteristic which is affected by base band components of the
even order distortion. The hysteresis effects and umballanced
intermodulation are successfully described."
}

@INPROCEEDINGS{Akay0405:Bit,
AUTHOR="Enis Akay and Ender Ayanoglu",
TITLE="{Bit-Interleaved} Coded Modulation: Low Complexity Decoding",
BOOKTITLE="Transmission Technology",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="It has been shown by Zehavi that the performance of coded modulation can be
improved over a Rayleigh fading channel by bit-wise interleaving at the
encoder output, and by using an appropriate soft-decision metric for a
Viterbi decoder at the receiver. Caire \textit{et al} presented the details
of the theory behind bit-interleaved coded modulation (BICM). In this paper
we show that for Gray encoded $M$-ary quadrature amplitude modulation (QAM)
systems, the bit metrics of BICM can be further simplified. In QAM systems,
the maximum likelihood (ML) detector for BICM uses the minimum distance
between the received symbol and M/2 constellation points on the complex
plane as soft-decision metrics. We show that soft-decision bit metrics for
the ML decoder can be further simplified to the minimum distance between
the received symbol and square root of M/2 constellation points on the real
line. This reduces the complexity of the decoder in the order of square
root of M without compromising the performance. Simulation results for
single carrier modulation (SCM), and multi-carrier modulation (MCM) systems
over additive white Gaussian noise (AWGN) and Rayleigh fading channels
agree with our findings. In addition, we tie this result to the decoding
methods for bit interleaved convolutional code standards used in industry."
}

@INPROCEEDINGS{Akay0405:High,
AUTHOR="Enis Akay and Ender Ayanoglu",
TITLE="High Performance Viterbi Decoder for {OFDM} Systems",
BOOKTITLE="Transmission Technology",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="It is well-known that, for systems that deploy conventional convolutional
codes, a Viterbi decoder is the best solution in maximum likelihood sense
to decode an information sequence. Typically, a Viterbi decoder uses
Euclidean or Hamming distance as a metric. The use of a conventional metric
leads to a high performance for systems that are employed for non-frequency
selective channels (e.g. additive white Gaussian noise (AWGN), or Rayleigh
fading). However, if the system is based on orthogonal frequency division
multiplexing (OFDM) and the channel has frequency selective multipath
fading, then the performance can be further improved. In this paper we
propose a simple modification to the conventional Viterbi metric (Euclidean
distance) that improves the performance substantially if the channel is
frequency selective. Simulation results on wireless local area network
(WLAN) standard IEEE 802.11a shows that the performance is improved about
10 dB when the proposed metric is used. Furthermore, the proposed metric
gives the same high performance as the conventional Viterbi metric if the
channel is AWGN or flat fading."
}

@INPROCEEDINGS{Akay0406:Low,
AUTHOR="Enis Akay and Ender Ayanoglu",
TITLE="Low Complexity Decoding of {Bit-Interleaved} Coded Modulation for M-ary
{QAM}",
BOOKTITLE="Communication Theory Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="It has been shown by Zehavi that the performance of coded modulation can be
improved over a Rayleigh fading channel by bit-wise interleaving at the
encoder output, and by using an appropriate soft-decision metric for a
Viterbi decoder at the receiver. Caire et al presented the details of the
theory behind bit-interleaved coded modulation (BICM). In this paper we
show that for Gray encoded M-ary quadrature amplitude modulation (QAM)
systems, the bit metrics of BICM can be further simplified. In QAM systems,
the maximum likelihood (ML) detector for BICM uses the minimum distance
between the received symbol and M/2 constellation points on the complex
plane as soft-decision metrics. We show that soft-decision bit metrics for
the ML decoder can be further simplified to the minimum distance between
the received symbol and square root of M over 2 constellation points on the
real line. This reduces the complexity of the decoder in the order of
square root of M without compromising the performance. Simulation results
for single carrier modulation (SCM), and multi-carrier modulation (MCM)
systems over additive white Gaussian noise (AWGN) and Rayleigh fading
channels agree with our findings. In addition, we tie this result to the
decoding methods for bit interleaved convolutional code standards used in
industry."
}

@INPROCEEDINGS{Akay0409:Bit,
AUTHOR="Enis Akay and Ender Ayanoglu",
TITLE="Bit Interleaved Coded Modulation with Space Time Block Codes for {OFDM}
Systems",
BOOKTITLE="VTC'F04 Transmission Technology",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="Wireless systems often implement one or more types of diversity in order to
achieve reliable communication. Different types of diversity techniques
such as temporal, frequency, code, and spatial have been developed in the
literature. In addition to the destructive multipath nature of wireless
channels, frequency selective channels pose intersymbol interference (ISI)
while offering frequency diversity for successfully designed systems.
Orthogonal frequency division multiplexing (OFDM) has been shown to fight
ISI extremely well by converting the frequency selective channel into
parallel flat fading channels. On the other hand, bit interleaved coded
modulation (BICM) was shown to have high performance for flat fading
Rayleigh channels. Combination of BICM and OFDM was shown to exploit the
diversity that is inherited within the frequency selective fading channels.
In other words, BICM-OFDM is a very effective technique to provide
diversity gain, employing frequency diversity. On the other hand,
orthogonal space-time block codes (STBC) make use of diversity in the space
domain by coding in space and time. Thus, by combining BICM-OFDM and STBC,
diversity in frequency and space can be taken advantage of. In this paper
we show and quantify both analytically and via simulations that for
frequency selective fading channels, BICM-STBC-OFDM systems can fully and
successfully exploit the frequency and space diversity to the maximum
available extent."
}

@INPROCEEDINGS{Akay0409:Full,
AUTHOR="Enis Akay and Ender Ayanoglu",
TITLE="Full Frequency Diversity Codes for Single Input Single Output Systems",
BOOKTITLE="VTC'F04 Transmission Technology",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="Due to the severe conditions of wireless channels, it is crucial for
wireless systems to accommodate some sort of diversity to achieve reliable
communication. Different types of diversity techniques such as temporal,
frequency, code, and spatial have been developed in the literature. In
addition to the destructive multipath nature of wireless channels,
frequency selective channels pose intersymbol interference (ISI) while
offering frequency diversity for successfully designed systems. Orthogonal
frequency division multiplexing (OFDM) has been shown to fight ISI very
well by converting the frequency selective channel into parallel flat
fading channels. On the other hand, bit interleaved coded modulation (BICM)
was shown by Zehavi and later by Caire et al to have high performance for
flat fading Rayleigh channels. It is natural to combine BICM and OFDM to
exploit the common ground of both techniques to improve overall system
performance. In this paper we show both analytically and via simulations
that for L tap frequency selective fading channels, BICM-OFDM can achieve a
diversity order of min(d(free),L), where d(free) is the minimum Hamming
distance of the convolutional code used for BICM."
}

@INPROCEEDINGS{Akba0405:Formal,
AUTHOR="Behzad Akbarpour and Sofiene Tahar",
TITLE="Formal Verification of {FFT} Algorithms Designed in {SPW}",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="The fast Fourier transform (FFT) is an algorithm to compute the discrete
Fourier transform with a substantial time saving over conventional methods.
FFT algorithms are based on the fundamental principle of decomposing the
computation of the discrete Fourier transform of a sequence of length N
into successively smaller discrete Fourier transforms. The manner in which
this principle is implemented leads to a variety of different algorithms,
all with comparable improvements in computational speed. Two basic classes
of FFT algorithms are the decimation-in-time and decimation-in-frequency.
In this paper we describe the formal verification of the
decimation-in-frequency FFT algorithm based on a framework incorporating
formal methods in the design flow of SPW (Signal Processing WorkSystem) in
a rigorous way. The SPW of Cadence is an integrated framework for
developing DSP (digital signal processing) and communication products.
Formal verification is a complementary technique to simulation based on
mathematical logic. In the proposed approach we model and verify SPW
descriptions at different abstraction levels using higher-order logic based
on the HOL theorem prover. The framework encompasses the whole SPW design
path, starting from top level floating and fixed-point algorithmic
descriptions down to RTL (Register Transfer Level), and gate level
implementations. We make use of existing theories in HOL on the
formalization of IEEE standard based floating-point arithmetic and SPW
fixed-point arithmetic to model the FFT algorithm in HOL. We use the
valuation functions to find the real values of the floating-point and
fixed-point FFT outputs and define the error as the difference between
these values. Then we introduce the fundamental theorems on the error
analysis of floating-point and fixed-point roundings and arithmetic
operations against their abstract mathematical counterparts. Finally, we
use these theorems to derive expressions for the accumulation of roundoff
error in floating-point and fixed-point FFT algorithms by recursive
definitions and initial conditions, considering the effects of input
quantization and inaccuracy in the coefficients. Based on the extensively
studied theoretical work on computing the errors due to finite precision
effects in the realization of FFT algorithms with floating-point and
fixed-point arithmetics, we performed a similar analysis using the HOL
theorem proving environment. The formal results are found to be in good
agreement with the theoretical ones."
}

@INPROCEEDINGS{Akel0405:Optimum,
AUTHOR="A. Akella",
TITLE="Optimum Utilization of Renewable Energy Sources in a Remote Area",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="OPTIMUM UTILIZATION OF RENEWABLE ENERGY SOURCES IN A REMOTE AREA A.K.
Akella Dr. R.P. Saini Dr. M.P. Sharma Alternate Hydro Energy Centre, Indian
Institute of Technology, Roorkee-247 667 E-mail: akakella(at)indiatimes.com
ABSTRACT Energy plays a vital role in the development of a remote area.
There is a need to develop and operate an integrated renewable energy
system. The energy planning is proposed for a remote area to meet out the
energy demand by considering the optimal applications of renewable energy
sources. Separate models are to be proposed for lighting, cooking, shaft
motive power for local industry and other productivity using different
combination of renewable energy sources. Most of the developing nations are
poor in conventional fossil fuel resources. Energy demand, its consumption
and tapping sources has been changing with time. Usable energy is either
purchased from energy Supply Company or obtained as free commodity from
nature (e.g. small hydro, solar, biomass, wind etc.). The annual per capita
electrical energy consumption is increasing. The twentieth century has been
the peak fossil fuel period. The search for renewables like solar, small
hydro, biomass and wind began since1973 in wake of energy crisis. The share
of renewable is increasing due to depleting fossil fuels and also
increasing cost of fossil fuels. Many researches have been carried out for
the integration of renewable energy but optimization has been briefly
reviewed. The present work has been carried out to optimize the utilization
of renewable energy sources with emphasis on micro hydropower. MODEL
CONSIDERATIONS FOR ENERGY SYSTEMS USING LINEAR PROGRAMMING Some renewable
energy generation sectors such as Small hydropower, Solar, Biomass and Wind
energies and consumption sectors like Domestic, Industries, Agriculture,
and Transportation will be discussed. Supply Constraints: The energy
available using each resource with associated needs to be assessed for
inclusion in the models. This energy is actually the potential energy that
is available in the particular resource and needs combination and serves as
a supply constraint. Demand Constraints: The energy demand in the study
area needs to be evaluated for each of the energy sectors of interest. The
total demand can be assessed by means of energy surveys and the same will
serve as a constraint in deciding the optimal mix of various
resources/needs that are considered in the model. The total energy of the
optimal mix must be equal to the energy demand that has been computed. Cost
Functions: The effective cost per unit of energy for each of the proposed
resource-need combinations is an important factor in the optimization
model. The cost function governs the optimal mix in such a manner that
resources with lesser-cost function share the greater proportion of the
total energy demand to optimize (minimize) the objective function. Energy
Model: Based on the various considerations, the energy model may be
formulated in the general format given as; Minimize z = c1 x1 + c2 x2 + c3
x3 + c4 x4 Subject to x1 + x2 + x3 + x4 = D a11 x1 \≤ s1 a22 x2
\≤ s2 a33 x3 \≤ s3 a44 x4 \≤ s4 And x1, x2, x3, x4
\≥ 0 Where x1, x2, x3 and x4 are resources used a11, a22, a33 and a44
are efficiencies \& s1, s2, s3 and s4 are total energy supply potential
from various resources. D is the total energy demand for a given energy
sector. SHP= Small hydropower, SE= Solar Energy, BE= Biomass energy, and
WE= Wind energy Actual (Final) Energy Model as: Minimizes Cost z = SHP c1 +
SE c2 + BE c3 + WE c4 Subject to SHP + SE + BE + WE = D SHP SHP \η
\≤ s1 SE SE \η \≤ s2 BE BE \η \≤ s3 WE WE
\η \≤ s4 And SHP, SE, BE, WE \≥ 0 Where a11 = SHP \η
1 efficiency of SHP, a22 = SE \η 1 efficiency of SE, a33 = BE \η
1 efficiency of BE, a44 = WE \η 1 efficiency of WE"
}

@INPROCEEDINGS{Akhb0408:Efficient,
AUTHOR="Mohammad Akhbarizadeh and Mehrdad Nourani",
TITLE="Efficient Prefix Cache for Network Processors",
BOOKTITLE="Hot Interconnects 12",
ADDRESS="Stanford University",
DAYS=25,
MONTH=aug,
YEAR=2004,
ABSTRACT="Conventional routing cache systems store destination IP addresses in their
cache directory. Instead, we present a routing cache technique that stores
the most recently used route prefixes to achieve significantly smaller
cache size. A nesting prefix is partially represented in this cache by its
minimal expansions. Such expanded prefixes are obtained using an
incremental technique without any modifications to the routing table.
Consequently, our cache works with most of the common route lookup
algorithms and is efficient in maintaining coherency with the routing
table. Experiments show that for a hit ratio over 0.96 our design can
achieve more than 33 times reduction in cache size, compared to a
conventional routing cache."
}

@INPROCEEDINGS{Akhb0411:TCAM,
AUTHOR="Mohammad Akhbarizadeh",
TITLE="{TCAM-Based} Packet Forwarding Engine Using Prefix Segregation Scheme",
BOOKTITLE="IEEE Globecom 2004 - Global Internet and Next Generation Networks",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="We propose a novel approach for IP packet forwarding based on a new Ternary
Content Addressable Memory configuration. Our design is an efficient
hardware solution for the Longest Matching Prefix problem in the Internet
routers. Our scheme segregates the enclosure prefixes into a separate,
practically small TCAM module. Consequently, the remaining prefixes that
often conform more than 92\% of the lookup table, form a disjoint set. The
big TCAM module that accommodates this set will have a simplified
architecture, with no priority encoder. Our architecture has lower update
complexity, lower cost and shorter search time, compared to the
conventional TCAM structure."
}

@INPROCEEDINGS{Akht0405:Improved,
AUTHOR="Jabran Akhtar",
TITLE="Improved detection for zero-forced {V-BLAST}",
BOOKTITLE="Transmission Technology",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="Multiple antenna systems offer a large increase in capacity compared to
traditional single antenna setups. V-BLAST is one popular algorithm for use
with MIMO systems with a simple coding and decoding structure. In this
article we look at the decoding aspect of zero-forced V-BLAST and show how
the performance of the algorithm can be improved through a new symbol
ordering criteria."
}

@INPROCEEDINGS{Akht0405:Low,
AUTHOR="Jos Akhtman and Lajos Hanzo",
TITLE="{Low-Complexity} Channel Estimation for {OFDM} and {MC-CDMA}",
BOOKTITLE="Wireless Access",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="A low complexity decision-directed channel estimation method is proposed,
which is system invariant and hence is suitable for a wide range of
multi-carrier modulation schemes such as OFDM and MC-CDMA. The method
exploits the a priori knowledge available concerning the nature of the
wireless channel and utilises both time- and frequency-domain correlation
of the channel parameters, yet it is shown to be robust to the channel
model mismatch routinely encountered in practical propagation environments.
The performance of the OFDM system using the channel estimation scheme
proposed under worst-case scenario multipath Rayleigh-fading channel
conditions is shown to be close to that of the system assuming perfect
channel knowledge. The method is also shown to be prone to decision-error
propagation."
}

@INPROCEEDINGS{Akht0405:Variable,
AUTHOR="Jabran Akhtar",
TITLE="Variable Number of Independent Streams for Spatial Multiplexing {MIMO}
Systems",
BOOKTITLE="Transmission Technology",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="In this paper we investigate a MIMO spatial-multiplexing (SM) system with
linear decoding at the receiver. The majority of existing MIMO transmission
schemes, such as V-BLAST, \%based upon channel matrix inversion, focus
preliminary upon spatial multiplexing and can only offer diversity
advantages if the number of receiver antenna exceeds the number of
transmitters. In this article we propose a rate-preserving linear coding
and linear decoding algorithm that through power weighting allows for a
tradeoff between spatial multiplexing and receiver diversity while
preserving the data-rate under the same modulation. The optimal tradeoff
between SM and receiver diversity for a given MIMO system is also
investigated."
}

@INPROCEEDINGS{Akht0411:Linear,
AUTHOR="Jabran Akhtar and David Gesbert and Are {Hjørungnes}",
TITLE="Linear {Closed-Form} Precoding of {MIMO} Multiplexing Systems in the
presence of Transmit Correlation and Ricean channel",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="This paper presents a closed-form linear precoder for a MIMO spatial
multiplexing (SM) system in the presence of transmit correlation and a
Ricean component. Existing SM (V-BLAST and similar schemes), based upon
channel matrix inversion, rely on the linear independence of antenna
channel responses for stream separation and suffer considerably from high
levels of fading correlation and/or dominating ill-conditioned
line-of-sight channel components. We propose a simple algorithm that
adjusts the transmitted constellation through power weighting and phase
shifts that can be interpreted in some extreme case as a higher order
constellation design scheme. We obtain a rate-preserving MIMO multiplexing
scheme that can operate smoothly at any degree of correlation and any type
of LOS channel component."
}

@INPROCEEDINGS{Akim0411:Study,
AUTHOR="Mamoru Akimoto and Kazuji Watanabe",
TITLE="Study on Rain Attenuation Considering {Rainfall-Intensity} Dependent
Spatial Correlation Characteristics",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="For the link budget of a wireless access system that uses a frequency
higher than the quasi-millimeter-wave band, we calculate the required rain
attenuation margin that satisfies the required quality level based on the
cumulative distribution of the amount of rain attenuation. To reflect the
non-uniformity of the rainfall in a wireless transmission line when
designing a wireless access system, the spatial correlation characteristics
of the rainfall intensity should be considered because the cumulative
distribution of the rain attenuation is derived from the rain rate
distribution. On the other hand, the spatial correlation has a tendency to
be dependent on the rainfall intensity. However, there is no method for
predicting the rain attenuation distribution which considers this tendency.
The distance characteristics of the rainfall spatial correlation are
analyzed based on high-resolution evaluation of radar observation rainfall
data in addition to the rainfall data obtained through the Automated
Meteorological Data Acquisition System (AMeDAS) administered by the
Meteorological Agency, which is often used to analyze the rain rate
distribution in Japan. The dependency on the rainfall intensity is
confirmed by this research. As a result of reflecting this characteristic
in a typical link budget, and the rain attenuation margin is approximately
4.6 dB less than the one of the existing method."
}

@INPROCEEDINGS{Akin0404:Resource,
AUTHOR="Cahit Akin",
TITLE="Resource Allocation and Scheduling in Uplink for Multimedia {CDMA} Wireless
Systems",
BOOKTITLE="2004 IEEE Sarnoff Symposium",
ADDRESS="Princeton, New Jersey",
DAYS=26,
MONTH=apr,
YEAR=2004,
ABSTRACT="We introduce a novel power allocation and scheduling scheme in a DS-CDMA
(Direct Sequence - Code Division Multiple Access) wireless communication
system with real-time connections. Generally in a CDMA system all users
share the same bandwidth which makes the system, interference limited.
Because of this nature of such a system, power control is crucial
especially in uplink. Traditionally power control is aimed to have equal
received powers at the base station to overcome the near-far effect. We
will relax this design objective and explore a different power allocation
and scheduling scheme to achieve maximum total throughput in the system. We
formulate the optimization problem which achieves the optimum power
allocation and scheduling scheme, and then we reduce the optimization
problem to a linear programming problem and solve it. We analytically study
the intercell interference performance of our scheme . We use our results
to discuss and compare our novel scheme with the traditional perfect power
controlled CDMA systems, to show that the introduced scheme outperforms
tradition perfect power controlled CDMA. We introduce a roadmap of an
overlay of the suggested algorithms over existing 3G standards (parts of
the work is not included in this extended summary, because of space
limitations)."
}

@INPROCEEDINGS{Akit0409:Phase,
AUTHOR="Koji Akita and Ren Sakata and Kazumi Sato",
TITLE="A phase compensation scheme using feedback control for {IEEE} 802.11a
receiver",
BOOKTITLE="VTC'F04 Poster Papers",
ADDRESS="Los Angeles, CA",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="In Orthogonal Frequency Division Multiplexing (OFDM) receivers, a phase
compensator plays an important role to provide good Packet Error Rate (PER)
performance in channels with carrier frequency offset. A feedback type
phase compensator realizes a less complex OFDM receiver. However, the
conventional feedback type phase compensator has two disadvantages. First,
a residual phase distortion proportional to a residual carrier frequency
offset remains. Second, the estimated phase distortion may vibrate. Both of
them degrade phase compensation accuracy, then PER performance becomes
worse. In this paper, we propose a new feedback type compensator which
calculates a phase compensation value for pilot subcarriers in order to
avoid the vibration of the estimated phase distortion and another phase
compensation value for data subcarriers in order to avoid the residual
phase distortion. The proposed method removes conventional method
disadvantages and improves the PER performance."
}

@INPROCEEDINGS{Akiy0404:Distributed,
AUTHOR="Kazuyoshi Akiyama",
TITLE="A Distributed Data Driven Architecture for Operations Support Systems",
BOOKTITLE="IEEE/IFIP Network Operations and Management Symposium",
ADDRESS="Seoul, Korea",
DAYS=19,
MONTH=apr,
YEAR=2004,
ABSTRACT="Operations Support Systems (OSSs) are required to process a large number of
messages per second, so conventional OSSs are comprised of large-scale UNIX
servers. Consequently, communications carriers have been forced not only to
make large capital investments in OSSs. This paper describes the basic
concept of a Distributed Data Driven Architecture (D3A), an architecture
devised for application to OSSs. By applying this architecture to OSSs,
communications carriers can introduce and expand OSS hardware at low. This
paper also describes the mounting of the prototype systems that apply this
architecture, and presents fundamental performance evaluation results for
the systems."
}

@INPROCEEDINGS{Akka0411:Energy,
AUTHOR="Kemal Akkaya and Mohamed Younis",
TITLE="Energy-aware Routing to a Mobile Gateway in Wireless Sensor Networks",
BOOKTITLE="IEEE GLOBECOM Wireless Ad hoc and Sensor Networks",
ADDRESS="Dallas, Texas, USA",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="Almost all of the energy-aware routing protocols that have been proposed
for wireless sensor networks aim at optimizing network performance while
relaying data to a stationary gateway (sink). However, mobility of the
gateway can make routes established through such contemporary protocols,
unstable and non-optimal. The use of mobile gateways introduces a
non-traditional trade-off between the need for frequent re-routing to
ensure optimal network operation and the desire for minimizing the overhead
of topology management. In this paper, we propose an energy aware mechanism
for efficient and continual data delivery to a moving gateway. Our approach
tracks the distance of the gateway from the last hops to the gateway, and
dynamically adjust the routes either via increasing the last hop nodes'
radio ranges or introducing new forwarder nodes as part of the routes.
Rerouting is triggered when the current routes become unacceptably
inefficient. The presented approach is validated in a simulation
environment."
}

@INPROCEEDINGS{Akon0401:Routing,
AUTHOR="Mohammad Akon and Dhrubajyoti Goswami and Shaila Jyoti",
TITLE="Routing in Telecommunication Network with Controlled Ant Population",
BOOKTITLE="IEEE Consumer Communications \& Networking 2004",
ADDRESS="Las Vegas, Caesar's Palace",
DAYS=5,
MONTH=jan,
YEAR=2004,
ABSTRACT="Swarm intelligence based algorithms for routing in telecommunication
networks have gained considerable amount of attention in recent years.
Swarm intelligence, demonstrated by natural biological swarms, exhibits
numerous powerful features that are desirable in communication systems.
Mobile agents having swarm intelligence similar to the real life ants have
been employed to achieve a general, flexible and modular solution for
routing in communication networks. In this paper, we propose a novel scheme
to control population of ant-like mobile agents that can ultimately result
in better load balancing and better performance within the network."
}

@INPROCEEDINGS{Akon0405:Controlling,
AUTHOR="Mohammad Akon and Dhrubajyoti Goswami and Shaila Jyoti",
TITLE="Controlling Ant Population in Ant Based Routing Using Neural Network",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Swarm intelligence based algorithms for routing in telecommunication
networks have gained considerable amount of attention in recent years.
Swarm intelligence, demonstrated by natural biological swarms, exhibits
numerous powerful features that are desirable in communication systems.
Mobile agents having swarm intelligence similar to the real life ants have
been employed to achieve a general, flexible and modular solution for
routing in communication networks. It has been reported in the literature
that mobile agent based routing systems perform significantly better than
systems with traditional routing. It has also been reported that the
performance of a telecommunication system using mobile agents depends on
the agent population. A bigger agent population results in faster
convergence. On the contrary, a bigger population also consumes higher
bandwidth and larger amount of other resources. In this contradictory
situation, it is very difficult to come up with an optimal size for the
agent population. Moreover, in a network environment, it is not possible to
obtain a global view of the entire network at a particular instant.
Consequently, finding a near optimal solution is rather complicated. Some
of the recent publications tried to address the issue of population control
of agents, but these approaches are ad-hoc in nature. In most of these
approaches, it is required to tune some system parameters according to the
underlying network. In most cases tuning is impossible to achieve. In this
paper, we propose an adaptive approach to control the agent population.
Each router in our system consists of a manager component. The manager
component controls birth and death of the agents. The manager also
perceives different parameters of the network environment that are locally
available and acts accordingly to optimize its performance. Through this
process, the manager learns and tries to enhance its activities to achieve
better performance in the future. We employ a neural network based learning
system as the internal architecture of the manager component. Our paper
will elaborate on the neural network model to be employed by each manager
and the simulation results."
}

@INPROCEEDINGS{Akso0409:Cost,
AUTHOR="Demet Aksoy",
TITLE="Cost and Accuracy Issues in Mobile Positioning for Security",
BOOKTITLE="VTC'F04 Wireless Technology Applications to Global Security: Space,
Air/Land, and Sea",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="Recent advances in sensor technology have given rise to mobile positioning
applications to track, and/or to navigate vehicles. Based-on the estimated
location, traffic, emergency routes, or personalized information can be
exploited for travelers. However, sophisticated positioning techniques can
be quite costly for the average user. In this paper we consider mobile
positioning techniques such as A-GPS and E-OTD and investigate their
scalability, energy consumption, and accuracy issues. Our results suggest
that E-OTD can be a feasible alternative provided that network support is
available."
}

@INPROCEEDINGS{Akso0409:Satellite,
AUTHOR="Demet Aksoy and Aysegul Aksoy",
TITLE="{Satellite-Linked} Sensor Networks for Planetary Scale Monitoring",
BOOKTITLE="VTC'F04 Mobile Satellite",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="In this paper we introduce our interdisciplinary project PLASMA (PLAnetary
Scale Monitoring Architecture) with the primary theme of disaster and
emergency response systems. Our design is based on satellite-linked sensor
networks for reliable and high performance communication for capturing the
interactions between different sensor systems. We discuss the research
challenges for such planetary scale monitoring."
}

@INPROCEEDINGS{Akso0411:Pull,
AUTHOR="Demet Aksoy and Mason Sin-Fai Leung",
TITLE="Pull vs Push: A Quantitative Comparison for Data Broadcast",
BOOKTITLE="IEEE Globecom 2004 - Global Internet and Next Generation Networks",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="Advances in wireless technology have resulted in an emerging
broadcast-capable Internet infrastructure for content delivery. A major
debate for such infrastructures is whether we should use push or pull to
support large client populations. To date, push was suggested to provide a
scalability that is not otherwise possible with pull. In this paper we
conclude otherwise based on simulation and experimental prototype results.
A major contribution of this paper is to show that pull-based algorithms
outperform push-based ones. Contrary to the conventional wisdom, this is
true even for environments where request processing and scheduling
overheads are a significant factor."
}

@INPROCEEDINGS{Al-F0406:Routing,
AUTHOR="Ala Al-Fuqaha and Ghulam Chaudhry and Cory Beard and Mohsen Guizani and
Miguel Labrador and Ibrahim Habib",
TITLE="Routing Framework for {All-Optical} {DWDM} {Metro-Core} and {Long-Haul}
Networks with Sparse Wavelength Conversion Capabilities",
BOOKTITLE="Optical Networking Symposium",
ADDRESS="Paris",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="Next generation IP over optical networks are gaining a lot of attention due
to their savings potential and support of foreseen applications and
bandwidth demands. However, many new protocols and mechanisms have been
introduced at a very fast pace and they still need to be evaluated, refined
and sometimes re-invented. In this paper, we propose an entire routing
solution that supports optical switches with limited wavelength conversion
capabilities suitable for wide area as well as metropolitan area networks.
First, we propose two new LSAs to the standard OSPF protocol that will
advertise the availability of wavelengths and converters per switch. A
fuzzy logic algorithm is proposed to reduce the amount of advertisements
due to the rapidly changing nature of these variables without increasing
the blocking probability. Then, a fuzzy logic-based new Routing and
Wavelength Assignment computation engine is introduced that outperforms
current schemes in terms of blocking probability and average path cost."
}

@INPROCEEDINGS{Al-G0403:Iterative,
AUTHOR="Samir Al-Ghadhban and Brian Woerner",
TITLE="Iterative Joint and Interference Nulling/ Cancellation Decoding Algorithms
for {Multi-Group} Space Time Trellis Coded Systems",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="In this paper, we will propose and evaluate the performance of several
decoding algorithms for multi-group space time trellis coded (MGSTTC)
systems. By considering a single user who transmits simultaneously through
K parallel space time trellis encoders, the system can provide high
spectral efficiencies, transmit diversity advantages and coding gains. The
system is analogous to synchronous multi-users each is transmitting a space
time trellis code. The transmitter will divide the information stream and
transmits from each encoder (called a group) simultaneously resulting in an
increase in the transmitted data rates. The receiver will apply some
multi-user detection (MUD) algorithms to detect and decode each group. The
paper will focus on joint detection and interference nulling/ cancellation
algorithms"
}

@INPROCEEDINGS{Al-G0406:Analysis,
AUTHOR="Abdullah Al-Ghamdi",
TITLE="Analysis of optical wireless links employing a beam clustering method and
diversity receivers",
BOOKTITLE="Wireless Communications Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="High-speed non-directed optical wireless (OW) transmission is greatly
desired for freedom of user mobility. In a mobile infrared wireless
environment, it is difficult to maintain a signal-to-noise ratio (SNR)
sufficient to support low error probability using the conventional diffuse
optical wireless systems. We propose a novel beam clustering method (BCM)
based on a line strip multibeam transmitter system (LSMS) combined with a
diversity receiver and examine its performance under adverse conditions
such as multipath dispersion and background noise. The BCM consists of
three sets of spots aimed at different directions. BCM design, multipath
dispersion, ambient light interference, and diversity receiver design are
discussed. We investigate and compare the impact of user mobility on the
performance of OW links for both BCM and conventional diffuse system (CDS).
Simulation results for the BCM link characteristics are presented and
comparison is made with CDS. Our results indicate that at the worst
conventional communication link, BCM can substantially reduce the signal
delay spread by nearly a factor of six and increase the SNR by more than 30
dB over the CDS."
}

@INPROCEEDINGS{Al-G0406:Characterization,
AUTHOR="Abdullah Al-Ghamdi",
TITLE="Characterization of mobile spot diffusing optical wireless systems with
diversity receiver",
BOOKTITLE="Access and Home Networks Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="Channel characteristics of mobile non-directed diffuse optical wireless
communication under the constraints of multipath dispersion and ambient
light noise have received little attention to date. This paper presents an
original study of transmitter motion and diversity receivers and their
effects on the system performance for both conventional diffuse systems
(CDS) and line strip multi-spot diffusing systems (LSMS). Under these
conditions, simulation results show that high-received signal power can be
obtained by using a LSMS in conjunction with a composite receiver
consisting of seven branches. Furthermore, under ambient noise corruption,
LSMS provides signal-to-noise ratio (SNR) improvements of more than 30 dB
over the conventional non-directed diffuse system at the worst
communication link. Moreover, we evaluate the effect of path loss on the
proposed system and it is confirmed that the path loss is reduced by more
than 6 dB over the CDS."
}

@INPROCEEDINGS{Al-G0409:Iterative,
AUTHOR="Samir Al-Ghadhban and Maruf Mohammad",
TITLE="Iterative Spatial Sequence Estimator for {Multi-Group} Space Time Trellis
Coded Systems",
BOOKTITLE="VTC'F04 Transmission Technology",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="In this paper, we will present and evaluate a new detection algorithm for
decoding multi-group space time trellis coded (MGSTTC) systems. These
systems consider a single user who transmits simultaneously through K
parallel space time trellis encoders. Therefore, they can provide high
spectral efficiencies similar to the BLAST architecture plus transmit
diversity advantages and coding gains. The developed detector is called
maximum a posteriori spatial sequence estimator (MAP-SSE) and it has the
flexibility of trading complexity with diversity advantage. The algorithm
could provide higher receive diversity with higher complexity. The
algorithm description, performance and complexity will be presented."
}

@INPROCEEDINGS{Al-G0411:Line,
AUTHOR="Abdullah Al-Ghamdi",
TITLE="Line Strip Multibeam Transmitter to Combat the Multipath Dispersion and
Background Noise of the Indoor Optical Wireless Links",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="This paper presents and evaluate a novel optical wireless configuration
that employs multibeam transmitters in conjunction with direction diversity
receivers. Such a configuration overcomes the drawbacks and combines the
advantages of both types of optical wireless links including line-of-sight
and diffuse links. Investigate the effect of this configuration on the
optical channel over the entire communication floor considering two
important channel parameters received power and delay spread is presented.
Multibeam transmitter placed on the communication floor was adopted to
produce multiple diffusing spots on the middle of the ceiling in the form
of a line strip. The results show that a high-received signal power, when
the system operates under the constraints of background noise and multipath
dispersion, can be obtained by using the proposed line strip multibeam
transmitter (LSMT). Furthermore, with only three branches diversity, the
proposed system gives about 23 dB SNR improvement over the conventional
diffuse system."
}

@INPROCEEDINGS{Al-G0411:Performance,
AUTHOR="Abdullah Al-Ghamdi",
TITLE="Performance analysis of Line Strip Multispot Diffusing System, Fully
Diffuse, and Hybrid Optical Wireless Techniques in a Real Environment",
BOOKTITLE="IEEE Globecom 2004",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="Performance comparison and evaluations for indoor optical wireless systems
in three different environments are carried out. Channel characteristics of
infrared links have been evaluated under various conditions including an
empty room, a room with glass windows and a door, and a room that has very
strong shadowing effects caused by mini cubical offices. The corresponding
results have been analyzed and compared for conventional hybrid/diffuse
systems (CDS/CHS) and line strip multibeam transmitter systems (LSMS) that
use spot diffusing techniques. Eight directive lamps represented the
ambient light noise and allowed further signal impairments to be taken into
account. Under these conditions, our results indicate that LSMS can reduce
pulse spread by a factor of 11 and 30 lower than the delay spread
associated with CDS and CHS respectively. Furthermore, LSMS links can
increase the SNR by more than 50 dB and about 55 dB compared to the CDS and
CHS respectively."
}

@INPROCEEDINGS{Al-H0409:Blind,
AUTHOR="Yahya Al-Harthi and Mohamed-Slim Alouini",
TITLE="Blind Adaptive Modulation Systems for Wireless Channels with Binary
Feedback",
BOOKTITLE="VTC'F04 Transmission Technology",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="In our paper, we propose to investigate the performance of a blind adaptive
modulation scheme that does not require any channel knowledge and uses
binary feedback, thereby decreasing feedback load. Retransmission of
erroneous packet is not considered. In particular, we present an analytical
framework for the performance evaluation of a simple wireless system in
terms of receiver and transmitter structure. The system requires no
knowledge of the channel and relies on a binary feedback, which makes it
less complex, compared to adaptive modulation systems based on channel
estimation. Therefore this system can be quite suitable for applications
where there is not any channel information available at the transmitter.
The results show the packet error rate (PER) and spectral efficiency for
both coded and uncoded modulation systems."
}

@INPROCEEDINGS{Al-J0403:ESPRIT,
AUTHOR="Saleh Al-Jazzar and James Caffery",
TITLE="{ESPRIT-based} Joint {AOA/Delay} Estimation for {CDMA} Systems",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="In this paper, we present a joint delay/AOA estimator for CDMA systems in a
multiuser environment. The algorithm is applicable to space-time channel
estimation for space-time processing systems and to location systems that
employ hybrid AOA/TOA technology. The estimator is based on a novel
formulation of ESPRIT in which the delays and AOAs of each user can be
estimated and automatically paired. The estimator avoids the computational
burden of a matching, or pairing, procedure and does not require the use of
a Fourier transform to aid the estimation of the delays. Further, the
algorithm has lower computational complexity than other joint angle/delay
estimators. An asymptotic first order error analysis as well as the
Cramer-Rao lower bound (CRLB) are derived. Simulations are presented to
show the performance of the estimator."
}

@INPROCEEDINGS{Al-J0409:New,
AUTHOR="Saleh Al-Jazzar and James Caffery and P. Ramamoorthy",
TITLE="A New Delay Estimation and Tracking Filter for {CDMA} Systems",
BOOKTITLE="VTC'F04  Digital Signal Processing",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="In this paper, we present a new delay estimation and tracking filter for
asynchronous CDMA systems in a multiuser environment. The algorithm is
based on utilizing the filter output error in the gain update equation. The
filter is less complex and converges more quickly compared to the unscented
filter (UF) and does not require linearization in the measurement equations
as in the extended Kalman filter (EKF). Computer simulations are presented
to illustrate the new filter's performance."
}

@INPROCEEDINGS{Al-J0409:NLOS,
AUTHOR="Saleh Al-Jazzar and James Caffery",
TITLE="{NLOS} Mitigation for Urban Environments",
BOOKTITLE="VTC'F04 Urban Radio Communications",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="A major source of error for cellular and PCS-based wireless location
systems arises due to the effect of non-line-of-sight (NLOS) propagation.
In order to mitigate the NLOS effect and improve location accuracy under
such conditions, we propose a new location technique for urban microcells,
where the signal is predominately channeled along the streets. The method
utilizes the fact that in urban areas, the buildings are usually organized
into a regular pattern in blocks \%This fact helps in giving ideas about
\%how the channel would affect the time of arrival (TOA) measurements.
which provides useful constraints on the location problem. The algorithm is
based on an optimization of a set of nonlinear equations with inequality
constraints. Simulation results show that the algorithm provides
considerable improvement over traditional location algorithms in urban
areas."
}

@INPROCEEDINGS{Al-K0401:Optimal,
AUTHOR="Jamal Al-Karaki and Ahmed Kamal and Raza Ul-Mustafa",
TITLE="On the Optimal Clustering in Mobile Ad hoc Networks",
BOOKTITLE="IEEE Consumer Communications \& Networking 2004",
ADDRESS="Las Vegas, Caesar's Palace",
DAYS=5,
MONTH=jan,
YEAR=2004,
ABSTRACT="A Mobile Ad hoc Network (MANET) can be represented by a set of
logical clusters with clusterheads acting like virtual
base-stations, hence forming a wireless virtual backbone. The role
of clusterhead is a temporary role, which changes dynamically as
the topology or other factors affecting it change. Finding the
minimal set of clusterheads is an NP-Complete problem. In this
paper, we study the performance tradeoffs between two clustering
approaches. The first one is a simple clustering strategy based on
a fixed rectilinear virtual topology, while the second one is an
optimal clustering strategy. We consider networks with large and
small number of users. For large networks, we derive expressions
for the number of clusterheads, worst case path length, average
case path length, and the communication overhead. For small
networks, we develop an Integer Linear Program (ILP) that finds
the optimal number of connected clusterheads. Analytical and
simulation results show that our proposed algorithm, although
being simple, is close to optimal."
}

@INPROCEEDINGS{Al-K0403:Simple,
AUTHOR="Jamal Al-Karaki and J. Morris Chang",
TITLE="A Simple Distributed Access Control Scheme for Supporting {QoS} in {IEEE}
{802.11} Wireless {LANs}",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="Supporting Quality of Service (QoS) in wireless networks is a challenging
problem. The IEEE 802.11 LAN standard was developed primarily for elastic
data allications. In order to support the transmission of real-time data, a
polling-based scheme called the Point Coordination Function (PCF) was
introduced in IEEE 802.11. However, PCF was not able to meet the desired
and practical service differentiation requirements needed to fulfill the
need of real-time data. Therefore, several IEEE 802.11e drafts, whose main
task is to support QoS, were released after IEEE 802.11 The polling scheme
of PCF is extended in IEEE 802.11e into the more complex Hybrid
Coordination Function (HCF). We found that HCF has several performance
issues that may affect its anticipated performance. In this paper, we
address these issues and propose a QoS enhancement over PCF, called
Enhanced PCF (EPCF) that enables Wireless LAN to send a combination of
vocie, data and isochronous data packets using the current IEEE 802.11 PCF.
First, we compare the performance of the proposed model (EPCF) with the HCF
function of the IEEE 802.11e through simulation. Second, we extend the
proposed model (EPCF) to work in a multi-hop wireless ad hoc mode. The
obtained simulation results demonstrate an enhanced performance of our
scheme over the legacy PCF and a comparable performance to the IEEE 802.11e
HCF in terms of the average delay and system throughput. However, EPCF is
much simpler, provides service differentiation on flow level, and is easy
to implement in the current IEEE 802.11 standard."
}

@INPROCEEDINGS{Al-K0404:Data,
AUTHOR="Jamal Al-Karaki and Ahmed Kamal and Raza Ul-Mustafa",
TITLE="Data Aggregation in Wireless Sensor Networks - Exact and Approximate
Algorithms",
BOOKTITLE="Workshop on High Performance Switching and Routing 2004",
ADDRESS="Phoenix, Arizona",
DAYS=18,
MONTH=apr,
YEAR=2004,
ABSTRACT="A fundamental challenge in the design of Wireless Sensor Networks (WSNs) is
to maximize their lifetimes. Data aggregation has emerged as a basic tenet
in WSNs in order to reduce the number of transmissions of sensor nodes,
hence minimizing the overall power consumption in the network. In this
paper, we study optimal data aggregation in WSNs. Data aggregation is
affected by several factors such as the placement of aggregation points,
the aggregation function, and the density of the sensors in the network.
The determination of an optimal selection of aggregation point is thus
extremely important. We present an exact as well as approximate algorithms
to find the minimum number of aggregation points in order to satisfy the
aforementioned objective. Our algorithms use a fixed virtual wireless
backbone that is built on top of the physical topology. We also study the
tradeoffs between energy savings and the potential delay involved in the
data aggregation process. Numerical results show that our approach provides
substantial energy savings."
}

@INPROCEEDINGS{Al-K0406:Correlated,
AUTHOR="Jamal Al-Karaki and Ahmed Kamal",
TITLE="On the Correlated Data Gathering Problem in Wireless Sensor Networks",
BOOKTITLE="The Ninth IEEE Symposium on Computers and Communications",
ADDRESS="Alexandria, Egypt",
DAYS=29,
MONTH=jun,
YEAR=2004,
ABSTRACT="A fundamental challenge in the design of Wireless Sensor Networks (WSNs) is
to maximize their lifetimes. Data aggregation has emerged as an efficient
approach in WSNs in order to reduce the overall power consumption in the
network. The success of data aggregation in reducing power consumption, and
hence extending the WSN lifetime is affected by several factors such as the
placement of aggregation points and the type of the aggregation function.
The determination of an optimal selection of aggregation points is thus
extremely important. In this paper, we consider the problem of correlated
data gathering in WSNs, where the objective is to minimize the total
transmission cost (or maximize network lifetime) of transporting the data
collected by the sensor nodes, to an external node called the base-station.
We particulary focus on the problem of finding the set of aggregation
points that satisfy our objective. Two solution strategies are presented:
an exact solution using an Integer Linear Program (ILP) formulation and a
near optimal, but simple and efficient approximate algorithm, called
Clustering-Based Aggregation Heuristic (CBAH). Our solutions use a {\it
fixed} virtual wireless backbone that is built on top of the physical
topology. Numerical results show that our proposed scheme provides
substantial energy savings."
}

@INPROCEEDINGS{Al-K0409:Wireless,
AUTHOR="Amin Al-Ka'bi",
TITLE="Wireless Communication System Performance Enhancement Using Adaptive Array
Antennas",
BOOKTITLE="VTC'F04 Antenna and Propagation",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="The performance of the steered beam adaptive array can be affected by many
factors like the signal to noise ratio of the desired and undesired
signals, the number and spacing between the sensor elements, feedback loop
gain of the array and the accuracy of our knowledge of the direction of the
desired signal. This paper discusses the effect of these factors on the
performance of the array."
}

@INPROCEEDINGS{Al-M0405:Low,
AUTHOR="Ibrahim Al-Mohandes",
TITLE="A low power 5 Mb/s turbo decoder for third generation wireless terminals",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Please see the attached pdf file for A low power 5 Mb/s turbo decoder for
third generation wireless terminals Please see the attached pdf file for A
low power 5 Mb/s turbo decoder for third generation wireless terminals
Please see the attached pdf file for A low power 5 Mb/s turbo decoder for
third generation wireless terminals"
}

@INPROCEEDINGS{Al-N0411:Receiver,
AUTHOR="Tareq Al-Naffouri and Olufunmilola Awoniyi and Oghenekome Oteri and
Arogyaswami Paulraj",
TITLE="Receiver Design for {MIMO} {OFDM} Transmission over Time Variant Channels",
BOOKTITLE="IEEE Globecom 2004 - Signal Processing for Communications",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="AbstractXThis paper considers receiver design for Space Time Block Coded
MIMO OFDM transmission over frequency selective time-variant channels. The
receiver employs the expectation-maximization (EM) algorithm for joint
channel and data recovery. It makes collective use of the data and channel
constraints that characterize the communication problem. The data
constraints include pilots, the cyclic prefix, the finite alphabet
constraint, and space-time block coding. The channel constraints include
the finite delay spread and frequency and time correlation. The receiver
employs an EM-based Kalman filter for channel estimation. The receiver is
able to recover the channel (which varies from one space-time block to the
next) and the data with no latency and to reduce the number of pilots
needed. Simulations show that the receiver outperforms other least-squares
based iterative receivers."
}

@INPROCEEDINGS{Al-Q0412:Effect,
AUTHOR="Malik Al-Qdah",
TITLE="Effect of Optical Beat Interference in {MOC-SCM} Optical Networks in
Presence of {FWM}",
BOOKTITLE="Australian Telecommunication Networks  and Applications Conference",
ADDRESS="Sydney, Australia",
DAYS=8,
MONTH=dec,
YEAR=2004,
ABSTRACT="Subcarrier multiplexing (SCM) with Wavelength Division multiplexing (WDM)
can be used to increase the capacity of any optical network. For
simultaneously accessible subcarrier channels the capacity should ideally
increase linearly with the number of subcarrier channels. However, when two
lasers carrying subcarrier channel multiplexed data operate with very
closed spaced wavelength, beating between the lasers and between the lasers
and Four-Wave mixing terms can occur. This will increase the noise at the
photodetector. This paper presents a general model of optical beat
interference in presence of Four-Wave Mixing (FWM). Computer simulations
for externally modulated single-mode laser transmitted through a Dispersion
Shifted Fiber (DSF) are presented. For degenerate case, the results show
degradation in Carrier to Interference Ratio (CIR) when the laser frequency
separation is equal to and half the subcarrier channel frequency."
}

@INPROCEEDINGS{Al-R0406:Reversible,
AUTHOR="Anas Al-Rabadi",
TITLE="Reversible Conservative Elementary Cellular Automata {(ECA)} Circuits and
their Quantum Computation",
BOOKTITLE="International Workshop on Logic and Synthesis",
ADDRESS="Temecula, California, USA",
DAYS=2,
MONTH=jun,
YEAR=2004,
ABSTRACT="Modeling noisy discrete systems utilizing conservative reversible
elementary cellular automata (CRECA) is presented. The new method results
in adding variable redundancy to incorporate noise. Since noise is an
inte-gral part of any real process and since the reduction of power
consumption is a main requirement for circuit de-sign of future
technologies such as in quantum computing (QC), the main features of
several future technologies will include reversibility, and thus the method
for designing noise-incorporating conservative and reversible circuits can
play an important role in the design of circuits that consume minimal power
for purposes such as low-power efficient simulation of noisy discrete
system dynamics."
}

@INPROCEEDINGS{Al-S0403:Discovery,
AUTHOR="Ehab Al-Shaer and Hazem Hamed",
TITLE="Discovery of Policy Anomalies in Distributed Firewalls",
BOOKTITLE="IEEE Infocom 2004",
ADDRESS="Hong Kong",
DAYS=7,
MONTH=mar,
YEAR=2004,
ABSTRACT="Firewalls are core elements in network security. However, managing
firewall rules, particularly in multi-firewall enterprize
networks, has become a complex and error-prone task. Firewall
filtering rules have to be written, ordered and distributed
carefully in order to avoid firewall policy anomalies and network
vulnerability. Therefore, inserting or modifying filtering rules
in any firewall requires a thorough intra- and inter-firewall
analysis to determine the proper rule placement and ordering in
firewalls. In this paper, we identify all anomalies that could
exist in a single- or multi-firewall environments. We also present
a set of techniques and algorithms to discover and rectify
firewall policy anomalies automatically in centralized and
distributed legacy firewalls. These techniques are implemented in
a user-friendly tool called ``Firewall Policy Advisor'' which
simplifies the management of filtering rules and maintains the
integrity of next-generation firewall security."
}

@INPROCEEDINGS{Al-S0403:Modified,
AUTHOR="Ali Al-Shaikhi and Maan Kousa",
TITLE="Modified Algorithm for Hard Decision Decoding of Product Codes",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="Product coding produces powerful long codes from short constituent codes.
The conventional row-column decoding algorithm of the product code does not
exploit its full power of correcting random errors. We propose a
modification to the conventional decoding algorithm, which makes it capable
of reaching the theoretical error correction capability of the code. In
addition to its theoretical significance, the modified algorithm is shown
to provide a gain of 0.5 dB over the conventional algorithm for AWGN
channels."
}

@INPROCEEDINGS{Al-S0404:MRMON,
AUTHOR="Ehab Al-Shaer",
TITLE="{MRMON:} Remote Multicast Monitoring",
BOOKTITLE="IEEE/IFIP Network Operations and Management Symposium",
ADDRESS="Seoul, Korea",
DAYS=19,
MONTH=apr,
YEAR=2004,
ABSTRACT="Although IP multicasting has been deployed for more than a decade,
management of multicast networks and service is still challenging. The fact
that IP multicast is a receiver-oriented and stateless protocol makes
end-to-end multicast monitoring intractable task. Important multicast
information such as join/leave status, group membership, tree information,
path/traffic characteri stics, and session conditions is either unexpressed
or distributed in various locations on the network. In this paper, we
present a new remote passive multicast monitoring infrastructure, called
MRMON, to capture, analyze and present multicast session, traffic and
membership information at real-time. The MRMON probes inhabit a
well-organized multicast information structure (MIB) that provides a
comprehensive and unique view of multicast network activities in remote
subnets. We show how inform ation can be collected from different MRMON
probes and correlated to diagnose multicast session problems. The paper
also describes our well-engineered architecture to implement high -
performance MRMON agent/probe. MRMON is a crucial step toward effective
multicast management, and our goal is to promote MRMON as a standard MIB in
multicast management."
}

@INPROCEEDINGS{Al-S0409:Analytical,
AUTHOR="Mazin Al-Shalash and Jaber Khoja and Muhieddin Najib",
TITLE="An Analytical Model for Forward Link Blocking in {CDMA} Systems",
BOOKTITLE="VTC'F04 Poster Papers",
ADDRESS="Los Angeles, CA",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="A fundamental requirement in the design of communications systems it to be
able predict resource utilization. This allows the network planner to
correctly dimension the network in order to achieve a certain performance
at a given traffic load. Analytical formulas such as Erlang B, Erlang C,
have traditionally been used to predict probability of blocking in wireless
as well as wireline systems. Unfortunately, these analytical models do not
apply well to the soft blocking mechanisms employed in CDMA systems.
Whereas there has been significant study of call admission control
mechanisms for the reverse link, the forward link has not received similar
attention. This is a significant limitation, because it is typically the
forward link power and code space, rather than the reverse link noise that
limits the capacity of a CDMA system. Thus, a simple model for forward link
blocking would fulfill a real need. This paper presents a simple model for
forward link power-based blocking in CDMA systems. This model augments an
earlier model we have proposed, and allows it be extended to include
multi-service types, as well as load balancing, and other traffic
management schemes."
}

@INPROCEEDINGS{Al-S0410:Real,
AUTHOR="Ehab Al-Shaer and Lopamudra Roychoudhuri",
TITLE="Real Time Analysis of Delay Variation for Packet Loss Prediction",
BOOKTITLE="7th IFIP/IEEE International Conference on Management of Multimedia Networks
\& Services",
ADDRESS="San Diego, California, USA",
DAYS=3,
MONTH=oct,
YEAR=2004,
ABSTRACT="The effect of packet loss on the quality of real-time audio is significant.
Nevertheless, Internet measurement experiments continue to show a
considerable variation of packet loss, which makes audio error recovery and
concealment challenging. Our objective in this work is to predict packet
loss in real-time audio streams based on the available bandwidth and delay
variation and trend, enabling proactive error recovery for real-time audio
over the Internet. Our preliminary simulation and experimentation results
with various sites on the Internet show the effectiveness and the accuracy
of our loss predictor technique."
}

@INPROCEEDINGS{Al0406:Bandwidth,
AUTHOR="Ahmed {Abd El Al} and Tarek Saadawi and Myung Lee",
TITLE="Bandwidth Aggregation in Stream Control Transmission Protocol",
BOOKTITLE="The Ninth IEEE Symposium on Computers and Communications",
ADDRESS="Alexandria, Egypt",
DAYS=29,
MONTH=jun,
YEAR=2004,
ABSTRACT="Stream Control Transmission Protocol (SCTP) specifications utilize the
multiple paths capabilities between the sender and receiver for
retransmission of lost data chunks and as a backup in case of primary path
failure. Under normal conditions, all data chunks are sent on the primary
path chosen by the SCTP user during the transport connection initiation. In
this paper, we address in detail various aspects related to extending and
engineering SCTP in order to utilize the available paths for simultaneous
transmission of data chunks, while maintaining the SCTP congestion control
on each path so as to ensure fair integration with other traffic in the
network. The extended SCTP, referred to as Load-Sharing SCTP (LS-SCTP), is
able to aggregate the bandwidth of all the active transmission paths
between the communicating endpoints. LS-SCTP monitors the paths, and
accordingly it chooses the paths that are suitable for load sharing.
LS-SCTP retransmission mechanism accelerates the delivery of missing data
to the receiver in order to prevent stalling the transport connection while
waiting for missing data chunks. Simulation results show that LS-SCTP is
extremely beneficial for networks with limited bandwidth and failure prone
links."
}

@ARTICLE{Al0406:LS,
AUTHOR="Ahmed Al and Tarek Saadawi and Myung Lee",
TITLE="{LS-SCTP:} a bandwidth aggregation technique for stream control
transmission protocol",
JOURNAL="Computer Communications",
VOLUME=27,
NUMBER=10,
PAGES="1012-1024",
MONTH=jun,
YEAR=2004,
REFERENCES=25,
KEYWORDS="Stream control transmission protocol; Bandwidth aggregation; Multi-homing",
ABSTRACT="Stream Control Transmission Protocol (SCTP) specifications utilize the
multiple paths capabilities between the sender and receiver for
retransmission of lost data chunks and as a backup in case of primary path
failure. Under normal conditions, all data chunks are sent on the primary
path chosen by the SCTP user during the transport connection initiation. In
this paper, we address in detail various aspects related to extending and
engineering SCTP in order to utilize the available paths for simultaneous
transmission of data chunks, while maintaining the SCTP congestion control
on each path so as to ensure fair integration with other traffic in the
network. The extended SCTP, referred to as Load-Sharing SCTP (LS-SCTP), is
able to aggregate the bandwidth of all the active transmission paths
between the communicating endpoints. LS-SCTP monitors the paths, and
accordingly it chooses the paths that are suitable for load sharing.
LS-SCTP retransmission mechanism accelerates the delivery of missing data
to the receiver in order to prevent stalling the transport connection while
waiting for missing data chunks. Simulation results show that LS-SCTP is
extremely beneficial for networks with limited bandwidth, high loss rate
and failure prone links.",
URL="http://www.sciencedirect.com/science?\_ob=MImg\&\_imagekey=B6TYP-4BRP0MP-1-2P\&\_cdi=5624\&\_orig=browse\&\_coverDate=06\%2F20\%2F2004\&\_sk=999729989\&view=c\&wchp=dGLbVzz-zSkWb\&\_acct=C000002018\&\_version=1\&\_userid=18704\&md5=c9ab7048a87a000aa156a159b71ad5b3\&ie=f.pdf"
}

@INPROCEEDINGS{Al0410:Improving,
AUTHOR="Ahmed {Abd El Al}",
TITLE="Improving Interactive Video in {Ad-Hoc} Networks Using Path Diversity",
BOOKTITLE="The 1st IEEE International Conference on Mobile Ad-hoc and Sensor Systems",
ADDRESS="Fort Lauderdale, Florida",
DAYS=25,
MONTH=oct,
YEAR=2004,
ABSTRACT="The increase in the bandwidth of wireless channels and the computing power
of mobile devices increase the interest in video communications over
wireless Ad-Hoc networks. However, the high error rate and the rapidly
changing quality of the radio channels can be devastating for the transport
of compressed video. In motion compensated coding, errors due packet losses
are propagated from reference frames to dependant frames causing lasting
and annoying visual effects. In addition, the bounded playout delay for
interactive video limits the effectiveness of the retransmission-based
error control. In this paper, we propose extending retransmission-based
error control to provide different levels of protection to packets
according to their importance to the reconstructed video quality. This type
of prioritization is achieved through redundant retransmission on diverse
paths. We evaluated the effectiveness of the mechanism under different
network conditions. Simulation results show that the mechanism is able to
maintain the video quality under different loss rates, and with less
overhead compared to other error control techniques, such as reference
frame updates."
}

@INPROCEEDINGS{Al0410:Improving,
AUTHOR="Ahmed {Abd El Al}",
TITLE="Improving Interactive Video in Wireless Networks Using Path Diversity",
BOOKTITLE="7th IFIP/IEEE International Conference on Management of Multimedia Networks
\& Services",
ADDRESS="San Diego, California, USA",
DAYS=3,
MONTH=oct,
YEAR=2004,
ABSTRACT="The increase in the bandwidth of wireless channels and the computing power
of mobile devices increase the interest in video communications over
wireless networks. However, the high error rate and the rapidly changing
quality of the radio channels can be devastating for the transport of
compressed video. In motion compensated coding, errors due packet losses
are propagated from reference frames to dependant frames causing lasting
visual effects. In addition, the bounded playout delay for interactive
video limits the effectiveness of current retransmission-based error
control. In this paper, we propose a mechanism that combines
retransmission-based error control with path diversity in wireless
networks, to provide different levels of protection to packets according to
their importance to the reconstructed video quality. We evaluated the
effectiveness of the mechanism under different network conditions.
Simulation results show that the mechanism is able to maintain the video
quality under different loss rates, with less overhead compared to other
error control techniques, such as reference frame updates."
}

@INPROCEEDINGS{Alam0409:Sub,
AUTHOR="Fakhrul Alam",
TITLE="Sub-band Beamforming for {OFDM} System in Practical Channel Condition",
BOOKTITLE="VTC'F04 Antenna and Propagation",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="Orthogonal Frequency Division Multiplexing (OFDM) is a multi-carrier
technique that has recently received considerable attention for high speed
wireless communication and ad hoc networks. Interference rejection from
beamforming can enable more than one pair of nodes of an ad hoc network to
share the same channel and can potentially increase the system throughput.
In this paper we develop a simple pilot symbol assisted frequency domain
beamforming technique for the OFDM receiver. The weight vector estimated
with the proposed scheme cancels strong interference and minimizes channel
impairments. We investigate different aspects of the beamforming technique
in a simple AWGN environment. The performance of the proposed beamforming
scheme is demonstrated for vector channel based on actual measurement data.
The applicability of computationally simple LMS algorithm instead of the
RLS algorithm is also investigated in this paper."
}

@INPROCEEDINGS{Alam0409:Turbo,
AUTHOR="Osamah Alamri and Bee Leong Yeap and Lajos Hanzo",
TITLE="Turbo Detection of {Channel-Coded} {Space-Time} Signals Using Sphere
Packing Modulation",
BOOKTITLE="VTC'F04 Transmission Technology",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="A recently proposed space-time signal construction method that combines
orthogonal design with sphere packing, referred to here as
(\textbf{STBC-SP}), has shown useful performance improvements over
Alamouti's conventional orthogonal design. In recent years, iterative
decoding algorithms have attained substantial performance improvements in
the context of wireless communication systems. In this paper, we
demonstrate that the performance of STBC-SP systems can be further improved
by concatenating sphere packing aided modulation with channel coding and
employing iterative demapping as well as turbo detection. The sphere
packing demapper is modified for the sake of accepting \textit{a priori}
information that is obtained from the channel decoder. At a $BER$ of
$10^{-5}$, the proposed system is capable of achieving a coding gain of
about $17.5dB$ over uncoded STBC-SP schemes for transmission over
correlated Rayleigh fading channels. It also achi\-eved a coding gain of
approximately $1.5dB$ over channel-coded STBC-SP schemes that employ no
turbo detection."
}

@INPROCEEDINGS{Alam0411:Predictive,
AUTHOR="Sathishkumar Alampalayam and Anup Kumar",
TITLE="Predictive Security Model using Data Mining",
BOOKTITLE="IEEE Globecom 2004 - Security and Network Management",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="Abstract: In this paper, we propose a practical predictive security model
for intrusion detection in a computer networking environment using data
mining. This model uses classification and regression technique for data
mining. The goal of the proposed model is to identify significant variables
that measure the network intrusion from wealth of raw network data and
perform an efficient vulnerability evaluation based on those variables. We
also present a methodology of classification and regression analysis for
intrusion detection in a system. Analysis of experimental results using the
DARPA benchmark dataset shows that the CART approach performs better
compared to related models like random projection and principal component
analysis. The results also indicate that the model performs better as
dimension of the input data decreases, without compromising the prediction
success rate. Keywords: Intrusion Detection, Predictive Security, Computer
Network, Classification and Regression Trees (CART), Data Mining."
}

@INPROCEEDINGS{Alan0406:Joint,
AUTHOR="Murat Alanyali and Bulent Yener",
TITLE="Joint Route and Power Assignment in Asynchronous Multi-hop Wireless
Networks",
BOOKTITLE="The Third Annual Mediterranean Ad Hoc Networking Workshop",
ADDRESS="Bodrum, Turkey",
DAYS=27,
MONTH=jun,
YEAR=2004,
ABSTRACT="We consider constructive techniques for joint route and transmit power
assignment in asynchronous multi-hop wireless networks. A constrained
optimization problem is formulated to maximize power efficiency of the
network while enforcing a minimum signal to interference ratio at each link
to ensure desired end-to-end QoS. Numerical comparisons suggest that
allowing a controlled level of interference may lead to better utilization
of available spectrum than prohibiting interference via CSMA/CA."
}

@INPROCEEDINGS{Alan0411:Multicast,
AUTHOR="Olli Alanen and Mikko Paakkonen and Timo {Hämäläinen} and Jyrki
Joutsensalo",
TITLE="Multicast Admission Control in {DiffServ} Networks",
BOOKTITLE="IEEE International Conference on Networks 2004",
ADDRESS="Singapore",
DAYS=17,
MONTH=nov,
YEAR=2004,
ABSTRACT="Multicast admission control in Differentiated Services network is an
important but shortly researched subject. Our admission control method
rejects new multicast join requests that would otherwise decrease the
quality experienced by the existing receivers. Edge nodes filter join
requests and generate new requests. The method was developed as an
extension to the DSMCast protocol but it could also be adapted to other
protocols. It decreases delays, jitter and losses and maintains them within
the desired constraints."
}

@INPROCEEDINGS{Alas0405:Application,
AUTHOR="Clémence Alasseur and Lionel Husson and Fernando {Pérez-Fontán}",
TITLE="Application of {MCMC} to Determination of {HMM} for Mobile Satellite
Channels",
BOOKTITLE="Antennas and Propagation",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="The fluctuations of mobile satellite channels are usually modelled by
Markov chains. Existing models postulate the number of states, and their
associated distributions based on physical considerations. This produces
good models but that are not convenient in different contexts. In this
paper, we focus on the methodology of extraction of Hidden Markov Model
(HMM) from experimental data to describe the time fluctuations of received
power in a mobile satellite service (MSS) context. It is based on a MCMC
(Monte Carlo Markov Chain) method associated with a k-means classification.
Its complexity is reduced when compared to traditional MCMC method.
Contrary to existing detection methods, the only assumption is the HMM
states number and it enables an accurate estimation of the HMM parameters
and of the transitions location."
}

@INPROCEEDINGS{Alas0406:Modelling,
AUTHOR="Clémence Alasseur and Lionel Husson and Fernando {Pérez-Fontán}",
TITLE="Modelling of the Markovian Behaviour of Mobile Satellite Channels with
{MCMC} methods",
BOOKTITLE="Wireless Communications Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="Classical models for mobile satellite channels are based on Markov chains
where each state is linked to special propagation conditions. In this
paper, we focus on the methodology of extraction of Hidden Markov Model
(HMM) from experimental data to describe the time fluctuations of received
power in a mobile satellite service (MSS) context. The method developed in
this paper is based on a MCMC (Monte Carlo Markov Chain) training phase
associated with a k-means classification. Its complexity is reduced when
compared to traditional MCMC method. Contrary to existing detection
methods, nearly no prior are necessary and it enables an accurate
estimation of the HMM parameters and the possibility to detect the
evolution of the channel sequentially. Furthermore, a sequential method,
based on estimated HMM parameters, is presented and enables to follow the
on-line variation of the state sequence."
}

@INPROCEEDINGS{Alas0406:Service,
AUTHOR="Mehdi Alasti and Farrokh {R. Farrokhi} and Masoud Olfat and 0,1,2 Liu",
TITLE="Service Level Agreement {(SLA)} Based Scheduling Algorithms for Wireless
Networks",
BOOKTITLE="High-Speed Networks Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="The objective of scheduling algorithms in wireless networks is to provide
Quality of Service (QoS) for mobile users in a shared environment and at
the same time utilizethe system resources e±ciently. We have introduced
an income maximization notion to increase throughput for multimedia
wireless systems and to maintain the QoS for each user above an agreed
level. We have proposed greedy and dynamic programming approaches to solve
the optimization problem. The simulation results reveal that our scheduling
algorithms provide high network throughput, support QoS even under heavy
network loads, and generate high income for service provider."
}

@INPROCEEDINGS{Alba0407:Combining,
AUTHOR="Jose Alba-Castro and Daniel Gonzalez-Jimenez",
TITLE="On Combining Textural and Geometrical Scores for Discriminative Face
Authentication",
BOOKTITLE="Audio- and Video-based Biometric Person Authentication",
ADDRESS="Rye, New York, USA",
DAYS=20,
MONTH=jul,
YEAR=2004,
ABSTRACT={In this paper, a combined shape-texture approach to discriminative face
authentication is studied. Facial texture information is captured through
Gabor responses (jets), similarly to the Elastic Bunch Graph Matching
approach, but the points where filters are applied are located over lines
that sketch the face. In this way, textural information is
{"}shape-driven{"} and unlike other Gabor-based approaches, it shows a
person-dependent behaviour. For every pair of face images, the score
obtained through jets is combined with 3 measurements of pair-wise shape
distortion. Discriminative Fisher methods are applied at the shape
algorithm level and at the score combination level, in order to get a
unified score ready for classification. Face verification results are
reported on configuration I of the XM2VTS database.}
}

@INPROCEEDINGS{Albr0406:Performance,
AUTHOR="Christoph Albrecht and Pascal Witte and Andreas Kuehlmann",
TITLE="Performance and Area Optimization using Sequential Flexibility",
BOOKTITLE="International Workshop on Logic and Synthesis",
ADDRESS="Temecula, California, USA",
DAYS=2,
MONTH=jun,
YEAR=2004,
ABSTRACT="Due to the ad-hoc specification methodology, typical ASIC designs are
highly unbalanced with respect to the timing criticality of their logic
paths. Traditional combinational synthesis does not support ``borrowing''
of timing slack across registers and therefore may result in a drastic
overdesign of many paths and an overall loss of performance. This can be
particularly harmful when paths are sped up through resizing which incurs
an exponential cost in area. In this paper we present how clock latency
scheduling interleaved with combinational optimization can be applied to
optimize the performance and area of designs. In contrast to a retiming
based approach, we show that clock latency scheduling is computationally
more efficient for inclusion in an inner synthesis loop and can also
perform slack balancing which provides a good starting point for heuristic
area minimization. Our preliminary experiments applying the presented flow
based on an industrial synthesis tool to standard benchmark circuits and
customer ASIC designs show an average improvement in performance of 7\\%
and in area of 18\\%."
}

@ARTICLE{Albu0402:Network,
AUTHOR="Celio Albuquerque and Brett Vickers and Tatsuya Suda",
TITLE="Network Border Patrol: Preventing Congestion Collapse and Promoting
Fairness in the Internet",
JOURNAL="IEEE/ACM Transactions on Networking",
VOLUME=12,
NUMBER=1,
PAGES="173-186",
MONTH=feb,
YEAR=2004,
REFERENCES=34,
KEYWORDS="border control; congestion control; congestion collapse; core-stateless
mechanisms; end-to-end argument; Internet; max-min fairness",
ABSTRACT="The Internet's excellent scalability and robustness result in part from the
end-to-end nature of Internet congestion control. End-to-end congestion
control algorithms alone, however, are unable to prevent the congestion
collapse and unfairness created by applications that are unresponsive to
network congestion. To address these maladies, we propose and investigate a
novel congestion-avoidance mechanism called network border patrol (NBP).
NBP entails the exchange of feedback between routers at the borders of a
network in order to detect and restrict unresponsive traffic flows before
they enter the network, thereby preventing congestion within the network.
Moreover, NBP is complemented with the proposed enhanced core-stateless
fair queueing (ECSFQ) mechanism, which provides fair bandwidth allocations
to competing flows. Both NBP and ECSFQ are compliant with the Internet
philosophy of pushing complexity toward the edges of the network whenever
possible. Simulation results show that NBP effectively eliminates
congestion collapse and that, when combined with ECSFQ, approximately
max-min fair bandwidth allocations can be achieved for competing flows.",
URL="http://ieeexplore.ieee.org/iel5/90/28372/01268087.pdf?isNumber=28372\&prod=JNL\&arnumber=1268087\&arSt=+173\&ared=+186\&arAuthor=Albuquerque\%2C+C.\%3B+Vickers\%2C+B.J.\%3B+Suda\%2C+T."
}

@INPROCEEDINGS{Aldo0404:Fusion,
AUTHOR="Saeed Aldosari and Jose Moura",
TITLE="Fusion in Sensor Networks with Communication Constraints",
BOOKTITLE="Information Processing in Sensor Networks",
ADDRESS="Berkeley, California",
DAYS=26,
MONTH=apr,
YEAR=2004,
ABSTRACT="In this paper, we address the problem of optimizing the detection
performance of sensor networks under communication constraints. Our work
helps understanding tradeoffs between sensor network parameters like number
of sensors, degree of quantization at each local sensor, and SNR.
Traditionally, this problem is tackled using asymptotic assumptions on the
number of sensors, an approach that leads to the abstraction of important
details such as the structure of the fusion center. We adopt a
non-asymptotic approach and optimize both, the sensing and the fusion sides
with respect to the probability of detection error. We show that the
optimal fusion rule has an interesting structure similar to the
majority-voting rule. In addition, we study the convergence with respect to
the number of sensors of the performance of the fusion rule. We show that
convergence is SNR dependent and that, in low-SNR environments, asymptotics
may require a large number of sensors."
}

@INPROCEEDINGS{Alek0405:Efficient,
AUTHOR="Milivoje Aleksic",
TITLE="Efficient {DCT} Based Video Coding Framework",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="The rapidly expanding field of multimedia wireless communications has
prompted strong research and development work in the area of real-time
video encoding. Several manufacturers offer dedicated hardware solutions
based on cost-efficient hardware encoders. The main advantage of the
hardware solution over software solutions based on a general purpose or a
programmable digital signal processor (DSP), is smaller area and power
consumption. The key merit of the software solution is that it can easily
adopt different algorithm schemes in the variable section of the codec.
Considering this we have developed a partition for video encoding in
wireless devices that yields very good power-performance tradeoffs. The
proposed solution is a set of optimized core components: motion estimation
(ME), the discrete cosine transform (DCT), quantization engine, and Run
Length encode, combined with the standard 2D engine. General-purpose
processor is used for implementing coding flow and control, VLC -variable
length codec and bit rate control . This framework proposes the use of a
new rate/distortion algorithm for motion estimation. We employ optimization
techniques that use bits of the variable length coded motion vector
difference and the numbers of bits contributed by the resulting quantized
DCT coefficients in the bit stream. Up until now, gaining the exact number
of bits after DCT coding and quantization was not feasible. Our VLSI
implementation allows the execution of an orthogonal search algorithm in
real time and leaves the decision making to the general purpose processor.
The presented solution reuses the 2D engine for calculating the difference
between the incoming block and the reference based on the motion vector.
Performance of our method is evaluated by comparing to the conventional
method that exhaustively searches for the best vector. PSNR distortion was
calculated averaging 100 frames where only luminance component was taken
into account."
}

@INPROCEEDINGS{Alek0405:Improving,
AUTHOR="Milan {Ton\čev} and Milo Tomasevic and Jovan Djordjevic and Milivoje
Aleksic",
TITLE="Improving performance of a {DSM} system by the communication controller
optimization",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="A DSM system is typically made up of nodes which communicate by sending and
receiving messages over the interconnection network. The handling of
messages in a node is carried out in the communication controller which
includes the protocol processor as its most occupied part. The performance
of a DSM system depends greatly on the efficiency of handling of messages.
In order to improve this efficiency, some optimizations of the
communication controller, such as: the decentralized control of the message
flow and the message priority queues are proposed. The first optimization
is based on finding that some messages dont require special handling (e.g.
messages that should be only routed and forwarded), so they can bypass the
protocol processor. Also delegating some straightforward processing (e.g.
reformatting the message) to a particular piece of logic can additionally
off-load the protocol processor. The second optimization is based on the
observation that some messages are critical for the processor utilization
while some others are non-critical (e.g., blocking vs. non-blocking read).
If the critical messages are processed more promptly the stalling time of
the processor can be reduced. Therefore, those messages are considered as
of higher priority and the waiting queues in the communication controller
should be organized as priority queues, where critical messages can bypass
the non-critical ones. The efficiency of the proposed optimizations is
evaluated by simulation means. The simulation environment is based on Tango
Lite package using the representative real parallel applications from
SPLASH-2 workload suite. The results of the analysis are presented and
discussed for different system parameter values (number of processor in a
node, realization of the protocol processor, etc). Based on these results,
it can be generally concluded that the proposed optimizations can decrease
the stalling time of the processor for 15\% in average. Keywords:
distributed shared memory systems; cache coherence protocols; simulation
analysis"
}

@INPROCEEDINGS{Alek0405:Local,
AUTHOR="Marko Aleksic and Rastislav Lukac",
TITLE="Local Correlation Based {CFA} Interpolation",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Single-sensor digital color cameras use a mosaic filter, so-called color
filter array (CFA), to separate incoming light into a specific spatial
arrangement of the color components. Most solutions utilize a 3-color
Red-Green-Blue (RGB) Bayer CFA pattern. This pattern alternates a row of
alternated G and R filters with a row of alternated B and G filters. A
twice frequent occurrence of the G filters compared to the R and B filters
reflects the sensitivity of the human visual system (HVS). The raw output
from a sensor, mostly a charge coupled device (CCD) or a complementary
metal oxide semiconductor (CMOS) sensor, with a Bayer filter is a mosaic of
red, green and blue pixels of different intensity. Since the two color
components are missing in each spatial location, they must be interpolated
from its neighbors. This procedure refers to CFA interpolation,
demosaicking or color reconstruction. The paper introduces a new CFA
interpolation method for digital still cameras. The proposed method
interpolates the missing color components using edge-sensing interpolation
and correction (postprocessing) steps. Moreover, the procedure utilizes
color-difference model of to increase precision in estimates. Since the
correction step is usually counter productive in regions with weak spectral
correlation and natural images typically vary in regions of high and low
correlation between the color channels, the correction step should be
performed only in highly-correlated image areas. Therefore, based on the
spectral correlation of the initially restored, full color output, the
correction step is applied to interpolated color outputs only in the
spatial locations, where the corresponding correlation coefficient is
larger than the determined parameter. It will be shown that the proposed
method yields excellent performance, in terms of subjective and objective
image quality measures, and outperforms previously developed CFA
interpolation methods."
}

@INPROCEEDINGS{Alek0405:Subsampling,
AUTHOR="Milivoje Aleksic and Ioannis Kouramanis",
TITLE="{Subsampling-Based} Image Compression Prediction",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="The current trend in wireless connectivity shows very strong deployment of
the digital camera functionality in new cellular phones. This year the
typical camera has a VGA resolution approaching 2 Mega pixels, and market
analysts expect next years sales of CMOS sensors in cellular phones will
surpass the sales of digital still cameras. The dominant image compression
standard in wireless camera is ITU-T.81 JPEG encoding. A limitation of the
baseline JPEG standard is that it cannot guarantee the final encoded image
size; this conflicts with the typical constraints in wireless devices, like
limited CPU capability, memory size and available bandwidth. In this paper
we present our solution for overcoming resource limitations in the cellular
phone environment. Our approach is implemented and deployed in the Imageon
series of multimedia chips. In our design we use line buffers and fast
compression on-the-fly to eliminate the immediate memory requirements for
full images. To overcome the unpredictable compressed file size issue we
run a prediction algorithm during preview mode. The main idea is based on
the camera usage model. The user typically first pans the scene in preview
mode on the small screen (176x220) before he is ready take the picture and
compress it. During the previewing of the image, the CMOS sensor is
configured to subsample the image before sending it to the image processing
chip. The image processing chip collects statistics and preforms video
encoding for the preview image. Based on the encoding of the subsampled
image we can predict the size of the final compressed image and compute an
optimal quantize table to maximize compression and image quality within the
constraints of available memory resources."
}

@INPROCEEDINGS{Alem0411:Dynamic,
AUTHOR="Tigist Alemu and Alain Jean-Marie",
TITLE="Dynamic Configuration of {RED} Parameters",
BOOKTITLE="IEEE Globecom 2004 - Global Internet and Next Generation Networks",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="Our work focuses on an adaptive approach of RED namely ARED (Adaptive RED)
that performs a constant tuning of RED parameters according to the traffic
load. ARED requires no hypothesis on the type of traffic, which diminishes
its dependency on the scenario parameters such as the bandwidth, the
round-trip time and the number of active connections. Our goal is to find a
simple extension to ARED in order to improve the predictability of
performance measures like queueing delay and delay jitter without
sacrificing the loss rate. To achieve this goal, we propose a new algorithm
that sets the RED parameters and evaluate it by extensive simulations. Our
results show that compared to the original ARED, our algorithm can
stabilize the queue size, keep it away from buffer overflow and underflow,
and achieves a more predictable average queue size without substantially
increasing the loss rate."
}

@INPROCEEDINGS{Alex0405:Channel,
AUTHOR="Dimiter Alexandrov and Christina Gallagher",
TITLE="Channel Conductivity of High Frequency Field Effect Transistor Designed on
Nitride Semiconductors",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Investigation of the conductivity of the n-channel of new type field effect
transistor designed on nitride semiconductors is given in this paper. The
transistor contains two parts vertical and horizontal structures. The
vertical structure contains three layers n-In(0.5)Ga(0.5)N -
p-In(0.1)Ga(0.9)N - GaN (non-doped). The conductivity of the top layer GaN
(non-doped) is ruled by tunnel injection of electrons coming from the
border of p-In(0.1)Ga(0.9)N - GaN (non-doped). The top layer GaN
(non-doped) belonging to the vertical structure acts as FET channel of
horizontal field effect transistor n-GaN (FET-source) - GaN (non-doped)
(FET-channel) - n-GaN (FET-drain). The vertical structure is modeled by
high frequency equivalent circuit-model of n-p-n bipolar transistor having
floating base. The horizontal structure is modeled by high frequency
equivalent circuit-model of n-channel FET where the influence of the
vertical structure (giving the channel conductivity) is accounted by
virtual generator having the characteristics following from the equivalent
circuit-model of the vertical n-p-n transistor structure. The simulation of
this FET model is performed for threshold FET voltage Vt= 2.8V, voltage
gate-source Vgs=3.4V, length of the channel 1um, and thickness of the
channel (GaN (non-doped)) 50nm. The results show increasing of the
conductivity of the channel from 0 up to ~E14 cm-3 for time ~163 fs, and
the cutoff frequency is ~1200 GHz. Also experimental investigation of the
static conductivity of layer GaN (non-doped) as function of the voltage
applied on the vertical structure is performed. The thickness of the top
layer GaN (non-doped) varies in range ~30 - ~50 nm for the different
samples. The threshold voltage varies in the range 1.6 - 3.1 V for the
different samples, and the conductivity increases respectively from 0 up to
1.3*E15 - 1.0*E16 cm-3 for an increase of the voltage with 0.5 V above the
threshold value."
}

@INPROCEEDINGS{Alex0405:Re,
AUTHOR="Angeliki Alexiou and Mohammed Qaddi",
TITLE="Re-configurable linear precoders to compensate for antenna correlation in
orthogonal and quasi-orthogonal space-time block coded systems",
BOOKTITLE="Transmission Technology",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="The impact of critical parameters, such as antenna correlation on the
performance of MIMO transceivers has been investigated and some approaches
have been proposed aimed at accounting for the performance degradation due
to the critical parameters impact and allow for a robust performance. In
this paper linear precoding, which combats the effects of antenna
correlation, is applied to orthogonal and quasi-orthogonal space-time block
coded systems of any number of transmit antennas. The precoding technique
assumes the knowledge of the long-term characteristics of the channel,
namely the channel correlation matrix at the transmitter. For low antenna
correlation values the proposed technique is equivalent to space-time block
coding, whereas for high correlation values it is proved to be equivalent
to beamforming. For intermediate antenna correlation values the proposed
techniques outperform both conventional approaches. The achieved
performance enhancement is higher in the orthogonal space-time block coding
case."
}

@ARTICLE{Alfa0402:Performance,
AUTHOR="Attahiru Alfa and Bin Liu",
TITLE="Performance analysis of a mobile communication network: the tandem case",
JOURNAL="Computer Communications",
VOLUME=27,
NUMBER=3,
PAGES="208-221",
MONTH=feb,
YEAR=2004,
REFERENCES=14,
KEYWORDS="Tandem network; Mobile communication networks; Performance; Corridor
movements; Fixed channel allocations; Call loss probabilities",
ABSTRACT="This paper investigates mobile communication networks consisting of N-cells
in tandem. Two models with fixed channel assignment are considered, which
correspond to (A) a uni-directional traffic flow and (B) bi-directional
traffic flows, respectively. We develop an approximate method to obtain
main performance measures of systems such as the loss probabilities of
handover calls and fresh calls, and the expected number of occupied
channels in each cell. Our approximation is based on decomposing the
N-cells in tandem network into N\−1 pairs of cells with overlaps. The
stochastic correlation among neighboring pairs are captured by
appropriately selecting the state-dependent Poisson processes as the
approximation of handover processes. Some numerical examples are given to
demonstrate the accuracy and the convergence of the proposed approach.",
URL="http://www.sciencedirect.com/science?\_ob=MImg\&\_imagekey=B6TYP-494GKJF-1-C6\&\_cdi=5624\&\_orig=browse\&\_coverDate=02\%2F29\%2F2004\&\_sk=999729996\&view=c\&wchp=dGLbVlb-zSkWA\&\_acct=C000002018\&\_version=1\&\_userid=18704\&md5=6e59a14b739bf15e001777685cb836e0\&ie=f.pdf"
}

@INPROCEEDINGS{Alfi0411:Maximizing,
AUTHOR="Arianna Alfieri and Paolo Brandimarte and Andrea Bianco and Carla-Fabiana
Chiasserini",
TITLE="Exploiting Sensor Spatial Redundancy to Improve Network Lifetime",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="One of the most critical issues in wireless sensor networks is represented
by the limited availability of energy within network nodes; thus, making
good use of energy is a must to increase network lifetime. In this paper,
we define as network lifetime the period from the time instant when the
network starts functioning till the network runs satisfying its quality
requirements, i.e., a given level of coverage in the area of interest is
guaranteed. To maximize system lifetime, we propose to exploit sensor
spatial redundancy by defining sub-sets of sensors active in different time
period, to allow sensors to save energy when inactive. Two approaches are
presented: the first one, based on mathematical programming techniques,
must run in a centralized way, whereas the second one is based on a greedy
algorithm aiming at a distributed implementation. To asses their
performance and provide guidance to network design, the two approaches are
compared by varying several network parameters."
}

@INPROCEEDINGS{Alfr0411:4G,
AUTHOR="Stefan Alfredsson and Anna Brunstrom and Mikael Sternad",
TITLE="A {4G} Link Level Emulator for Transport Protocol Evaluation",
BOOKTITLE="The Second Swedish National Computer Networking Workshop 2004",
ADDRESS="Karlstad University",
DAYS=23,
MONTH=nov,
YEAR=2004,
ABSTRACT="This paper presents a wireless link and network emulator, based upon the
``Wireless IP'' 4G system proposal from Uppsala University and partners. In
wireless fading downlinks (base to terminals) link-level frames are
scheduled and the transmission is adapted on a fast time scale. With fast
link adaptation and fast link level retransmission, the fading properties
of wireless links can to a large extent be counteracted at the physical and
link layers. A purpose of the emulator is to investivate the resulting
interaction with transport layer protocols. The emulator is built on
Internet technologies, and is installed as a gateway between communicating
hosts. The paper gives an overview of the emulator design, and presents
preliminary experiments with three different transport protocols. The
results clearly show the effect of changing link layer parameters on the
different transport protocols."
}

@ARTICLE{Alfu0309:Routing,
AUTHOR="Ala Al-Fuqaha and Miguel Labrador",
TITLE="Routing Framework for {All-Optical} {DWDM} {Metro-Core} and {Long-Haul}",
JOURNAL="IEEE JSAC Special Issue on Metro Optical Networks",
DAYS=6,
MONTH=sep,
YEAR=2004,
ABSTRACT="Next generation IP over optical networks are gaining a lot of attention due
to their savings potential and support of foreseen applications and
bandwidth demands. However, many new protocols and mechanisms have been
introduced at a very fast pace and they still need to be evaluated, refined
and sometimes re-invented. In this paper, we propose an entire routing
solution that supports optical switches with limited wavelength conversion
capabilities suitable for wide area as well as metropolitan area networks.
First, we propose two new LSAs to the standard OSPF protocol that will
advertise the availability of wavelengths and converters per switch. A
fuzzy logic algorithm is proposed to reduce the amount of advertisements
due to the rapidly changing nature of these variables without increasing
the blocking probability. Then, a fuzzy logic-based new Routing and
Wavelength Assignment computation engine is introduced that outperforms
current schemes in terms of blocking probability and average path cost."
}

@INPROCEEDINGS{Alha0404:Low,
AUTHOR="Fahd Alharbi and Nirwan Ansari",
TITLE="Low Complexity Distributed Bandwidth Allocation for Resilient Packet Ring
Networks",
BOOKTITLE="Workshop on High Performance Switching and Routing 2004",
ADDRESS="Phoenix, Arizona",
DAYS=18,
MONTH=apr,
YEAR=2004,
ABSTRACT="The Resilient Packet Ring (RPR), defined under IEEE 802.17 [1], has been
proposed as a high-speed backbone technology for metropolitan area
networks. RPR is introduced to mitigate the underutilization and unfairness
problems associated with the current technologies SONET and Ethernet,
respectively. The key performance objectives of RPR are to achieve high
bandwidth utilization, optimum spatial reuse on the dual rings, and
fairness. The challenge is to design an algorithm that can react
dynamically to the traffics in achieving these objectives. The RPR fairness
algorithm [2] is comparatively simple, but it poses some critical
limitations that require further investigation and remedy. One of the major
problems is that the amount of bandwidth allocated by the algorithm
oscillates severely under unbalanced traffic scenarios. These oscillations
are barrier to achieving spatial reuse and high bandwidth utilization. DVSR
[3] was another algorithm proposed to solve the fairness issue with no
oscillation at the steady state, but at the expense of a high computational
complexity O(NlogN), where N is the number of nodes in the ring. In this
paper, we propose the Low Complexity Distributed Bandwidth Allocation
(LCDBA) algorithm to allocate bandwidth fairly to RPR nodes with a very low
computational complexity O(1) that will converge to the exact max-min
fairness in a few round trip times with no oscillation at the steady state."
}

@INPROCEEDINGS{Alha0404:Novel,
AUTHOR="Fahd Alharbi and Nirwan Ansari",
TITLE="A Novel Fairness Algorithm for Resilient Packet Ring Networks with Low
Computational and Hardware Complexity",
BOOKTITLE="13th IEEE Workshop on Local and Metropolitan Area Networks",
DAYS=25,
MONTH=apr,
YEAR=2004,
ABSTRACT="The Resilient Packet Ring (RPR), defined under IEEE 802.17 [1], has been
proposed as a high-speed backbone technology for metropolitan area
networks. RPR is introduced to mitigate the underutilization and unfairness
problems associated with the current technologies SONET and Ethernet,
respectively. The key performance objectives of RPR are to achieve high
bandwidth utilization, optimum spatial reuse on the dual rings, and
fairness. The challenge is to design an algorithm that can react
dynamically to the traffics in achieving these objectives. The RPR fairness
algorithm [2] is comparatively simple, but it poses some critical
limitations that require further investigation and remedy. One of the major
problems is that the amount of bandwidth allocated by the algorithm
oscillates severely under unbalanced traffic scenarios. These oscillations
are barrier to achieving spatial reuse and high bandwidth utilization. In
this paper, we propose a Low Complexity Fairness Algorithm (LCFA) to
allocate bandwidth fairly to RPR nodes with a very low computational
complexity O(1) that requires a simple hardware requirement similar to that
of the RPR fairness algorithm."
}

@INPROCEEDINGS{Alha0406:Genetic,
AUTHOR="Reda Alhajj",
TITLE="Genetic Algorithms Based Optimization of Membership Functions for Fuzzy
Weighted Association Rules Mining",
BOOKTITLE="The Ninth IEEE Symposium on Computers and Communications",
ADDRESS="Alexandria, Egypt",
DAYS=29,
MONTH=jun,
YEAR=2004,
ABSTRACT="It is not an easy task to know a priori the most appropriate fuzzy sets
that cover the domains of quantitative attributes for fuzzy association
rules mining. Besides, it is unrealistic that experts can always provide
such sets. Further, finding the most appropriate fuzzy sets becomes a more
complex problem when items are not considered to have equal importance and
the support and confidence parameters needed in the mining process are
specified as linguistic terms. Existing clustering based automated methods
are not satisfactory because they do not consider the optimization of the
discovered membership functions. In order to tackle this problem, we
propose Genetic Algorithms (GAs) based clustering method, which dynamically
adjusts the fuzzy sets to provide maximum profit based on user specified
linguistic minimum support and confidence terms. This is achieved by tuning
the base values of the membership functions for each quantitative attribute
in a way that maximizes the number of large itemsets. To the best of our
knowledge, this is the first effort in this direction. Experiments
conducted on 100K transactions from the adult database of United States
census in year 2000 showed that the proposed clustering method exhibits a
good performance in terms of the number of produced large itemsets and
interesting association rules."
}

@ARTICLE{Alhe0401:AR,
AUTHOR="A. Alheraish and S. Alshebeili",
TITLE="{AR-based} quadratic modeling for {GOP} {MPEG-encoded} video traffic in
{ATM} networks",
JOURNAL="Computer Communications",
VOLUME=27,
NUMBER=1,
PAGES="81-92",
MONTH=jan,
YEAR=2004,
REFERENCES=21,
KEYWORDS="Non-linear model; AR; Video traffic modeling; ATM",
ABSTRACT="Statistical analysis and performance modeling of compressed video traffic
streams are efficient tools to estimate network resources and to predict
network behavior under various conditions. Among current video traffic
models, Autoregressive (AR) processes have been extensively used as good
representation of variable bit rate video services, due basically to their
simplicity and ease of computation. Recently, an elegant approach to the
modeling of teleconferencing video has been proposed by Zhang in IEEE
Trans. Circuits Syst. Video Technol. 9 (1999) p. 1130. This approach
decomposes the traffic data into a linear combination of a number of
chi-square sequences, each of which is obtained by passing a Gaussian AR
process through a simple non-linearity. In this article, we first show that
the model presented by Zhang is a special case of the general form of
models represented by quadratic filters that are widely used in modern
digital signal processing. Second, we extend Zhang's approach to model MPEG
video traffic; an important full motion video source that exhibits dynamic
and complex pattern. Specifically, we propose modeling MPEG video at GOP
layer in ATM packet switching networks. This layer has an important feature
in that it reflects the behavior of video scene activities. Finally, by
using a wide variety of real MPEG video sequences, we experimentally
demonstrate that the proposed GOP-based model approximates the real video
traffic extremely well in terms of first and second order statistics as
well as queuing performance.",
URL="http://www.sciencedirect.com/science?\_ob=MImg\&\_imagekey=B6TYP-49FPHMM-1-50\&\_cdi=5624\&\_orig=browse\&\_coverDate=01\%2F01\%2F2004\&\_sk=999729998\&view=c\&wchp=dGLbVzb-zSkWA\&\_acct=C000002018\&\_version=1\&\_userid=18704\&md5=243f05ec16b5a0e201b97950ba98bc53\&ie=f.pdf"
}

@INPROCEEDINGS{Ali0403:Joint,
AUTHOR="Mohammed Ali and Murat Torlak",
TITLE="Joint Processing of Packet Combining and Adaptive Retransmission Control in
{DS-CDMA} Random Access Networks",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="A joint processing protocol of packet combining and adaptive retransmission
control (ARC) in DS-CDMA random access networks has been investigated. The
proposed system uses diversity packet combining while adaptively adjusting
the retransmission probability of backlog users to optimize packet
retransmissions. A soft decision DS-CDMA analysis is used to derive the
optimum channel input for ARC. Simulation results show that a joint control
of packet combining and adaptive retransmission can significantly increase
the channel throughput and maintain the performance very close to its
optimum in the high traffic region."
}

@INPROCEEDINGS{Ali0405:CSN,
AUTHOR="Muneeb Ali and Zartash Uzmi",
TITLE="{CSN:} A Network Protocol for Serving Dynamic Queries in {Large-Scale}
Wireless Sensor Networks",
BOOKTITLE="Conference on Communication Networks and Services Research (CNSR)",
PUBLISHER="IEEE Computer Society Press",
ADDRESS="Fredericton, N.B, Canada",
PAGES="165-174",
MONTH=may,
YEAR=2004,
KEYWORDS="Chord, DHT, distributed hash tables, sensor networks, network protocol,
mapping, serving queries",
ABSTRACT="A fundamental problem that confronts future applications
of sensor networks is how to efficiently locate the sensor
node that stores a particular data item. It is known
that distributed hash table (DHT) based Internet peer-topeer
(P2P) protocols provide near-optimum data lookup
times for queries made on networks of distributed nodes
[2, 23-25]. A generic mapping of these protocols to sensor
networks is, however, perceived as difficult [1]. We
present a novel DHT based network protocol for sensor
networks---Chord for Sensor Networks (CSN)---for which
bounded times for data lookup, in the order of O(logN)
messages, can be achieved in an energy efficient manner.
CSN makes system lifetime of the sensor network proportional
to its effective use. Furthermore, CSN scales well
to large-scale sensor networks when the information about
other nodes logarithmically increases with an increase in
the number of sensor nodes.",
URL="http://suraj.lums.edu.pk/~muneeb/alim\_csn.pdf"
}

@INPROCEEDINGS{Ali0405:Diffserv,
AUTHOR="Racha {Ben Ali} and Yves Lemieux and Samuel Pierre",
TITLE="{DiffServ} {QoS} Performance Evaluation of Multimedia Telephony",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="The differentiated services architecture (DiffServ) is a scalable and
economic solution which provides relative QoS to different kind of
services. Due to the critical QoS constraints of conversational multimedia
services (including voice and video-telephony), a QoS mapping between those
services and DiffServ classes must be well defined. Voice and
video-telephony services are always mapped within the same EF Premium
DiffServ class to provide them with the best service. However, voice and
video have divergent stochastic characteristics. Consequently, this
standard mapping leads to heterogeneous traffic multiplexing within the
same queues in the aggregating routers, which may deteriorate the best
service always provided to voice traffic. Thus, we have proposed a refined
mapping that differentiates between voice and video-telephony using
different scheduling schemes. In order to carry out a performance study of
voice/video packet scheduling, we have considered two different traffic
models for voice and video-telephony which reconstitute their specific and
respective characteristics. Simulation results show that WFQ scheduling
with a well chosen weights performs better than FIFO and PQ. In our case, a
weight of 0.25 for the voice DiffServ class gives the optimal overall delay
performance for multimedia telephony traffic. Keywords: DiffServ, Voice,
Video-telephony"
}

@INPROCEEDINGS{Ali0405:Impact,
AUTHOR="Abdul Ali",
TITLE="The Impact of {Two-Path} Radio Environment on Bit Error Rate in {UMTS}
Networks",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="In radio communication systems, the receiver receives signal from a single
source or multiple sources. The latter is known as quasi-synchronous system
or when repeaters are in used in the network. The same signal from multiple
sources with differential propagation delays causes dispersion of
transmission pulses, as a results the intersymbol interference increases
which degrade the systems performance. This paper studies the link level
performance of the Wideband Code Division Multiple Access Frequency
Division Duplex focus on downlink system by employing a Maximum Ratio
Combing (MRC) Rake receiver."
}

@INPROCEEDINGS{Ali0405:Performance,
AUTHOR="Mustafa {Mehmet Ali}",
TITLE="Performance Study of {High-Speed} {TCP}",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Recently, the performance of TCP congestion control algorithm over
high-speed transmission links has been receiving a growing attention. As
the speed of the Internet increases, the users are demanding higher
throughput from the network. We propose that the low and high throughput
traffic queue up separately and then use weighted fair queueing or weighted
round robin scheduling algorithm to protect the low throughput users. The
simulation study of our proposal shows satisfactory results for both types
of traffic."
}

@INPROCEEDINGS{Ali0405:WMPLS,
AUTHOR="Najah {Abu Ali} and Hamidreza {Saligheh Rad} and Saeed Gazor and Hussein
Mouftah",
TITLE="{WMPLS} Throughput Efficiency in Multipath Rayleigh Fading Environments",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="This paper studies the throughput efficiency of Wireless Multiprotocol
Label Switching (WMPLS) applying data link Automatic Repeat reQuest (ARQ),
Go Back N and Selective REJect (SERJ) protocols, for reliable packet
transmission. The paper investigates the impact of the packet size on the
throughput efficiency of the ARQ protocol for a reliable service under
different conditions of a multipath fading channel. Reliable data link
protocols insure that all data transmitted is received correctly at the
destination; any lost or erroneous packet is retransmitted. The probability
of retransmission increases with the increase of the channel bit errors.
Therefore, finding a compromised packet size between losses due to the
percentage of the overhead and losses due to retransmission will improve
the throughput performance of the ARQ protocols. Dynamics of a fading
channel is characterized by its power spectrum density or Doppler factor at
the packet-level. The channel attributes are related to the optimized
packet size, and are used to evaluate the throughput efficiency of WMPLS
network. The integration between channel modeling, as well as packet size
and throughput efficiency analysis provides us with valuable information
about the impact of channel statistics on the wireless-network factors.
Specifically, the throughput efficiency and the optimum packet size depend
on the bit error rate (BER) of the channel at a given time. A study is
elaborated to allow for optimizing the WMPLS packet size based on the BER
in a multipath fading channel. This is accomplished by allowing the ARQ
protocols to optimize the packet size based on second order statistics of a
wireless fading channel. Keywords: WMPLS, Packet Size, Rayleigh Fading
Channel, and Multipath Channel Modeling."
}

@INPROCEEDINGS{Ali0406:Energy,
AUTHOR="Muneeb Ali and Zartash Uzmi",
TITLE="An {Energy-Efficient} Node Address Naming Scheme for Wireless Sensor
Networks",
BOOKTITLE="IEEE International Networking and Communications Conference (INCC'04)",
ADDRESS="IEEE Communications Society Press",
MONTH=jun,
YEAR=2004,
KEYWORDS="address, addressing, naming, sensor networks",
ABSTRACT="In wireless sensor networks the small data rate,
generally 16 bytes per packet, makes the overhead of globally
unique network and MAC addresses, which is typically as much
as the payload itself, undesirable [12]. We present a node address
naming scheme that assigns locally unique addresses, which could
be spatially reused, to nodes in an energy efficient manner and
reduces the address size by a factor of 3.6. The focus of our
work is solely on clustering routing approaches [8]. Further, we
question the need of separate MAC and network addresses and
show how our spatially reused locally unique node address could
be used in both contexts, leading to greater energy efficiency.",
URL="http://suraj.lums.edu.pk/~muneeb/naming\_INCC.pdf"
}

@INPROCEEDINGS{Ali0411:Adaptive,
AUTHOR="Mohammed Ali",
TITLE="Adaptive Retransmission and Error Control in {DS-CDMA} Random Access
Networks",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="An adaptive retransmission with packet error control scheme in DS-CDMA
random access networks is presented. The system provides error correction
coding (ECC) by using code redundancy into CDMA data packets and Adaptive
Retransmission Control (ARC) by using steady state Markov process.
Simulation results show that packet error control can be effectively linked
to ARC. A joint adaptation processing on ECC and retransmission probability
improves the system capacity significantly. The performance optimization is
more feasible in high traffic wireless systems. The results are useful in
designing such systems for deployment."
}

@INPROCEEDINGS{Alia0409:Genetic,
AUTHOR="Mohamad Yusoff Alias and Sheng Chen and Lajos Hanzo",
TITLE="Genetic Algorithm Assisted Minimum Bit Error Rate Multiuser Detection in
Multiple Antenna Aided {OFDM}",
BOOKTITLE="VTC'F04 Wireless Access",
DAYS=27,
MONTH=sep,
YEAR=2004,
ABSTRACT="The family of minimum bit error rate (MBER) multiuser detectors (MUD) is
capable of outperforming the classic minimum mean-squared-error (MMSE) MUD
in term of the achievable bit-error rate (BER) owing to directly minimising
the BER cost function. In this paper, we will invoke genetic algorithms
(GA) for finding the optimum weight vectors of the MBER MUD in the context
of multiple-antenna aided multi-user OFDM."
}

@INPROCEEDINGS{Alic0403:Pre,
AUTHOR="Mansoor Alicherry and Randeep Bhatia",
TITLE="{Pre-Provisioning} Networks to Support Fast Restoration with Minimum
{Over-Build}",
BOOKTITLE="IEEE Infocom 2004",
ADDRESS="Hong Kong",
DAYS=7,
MONTH=mar,
YEAR=2004,
ABSTRACT="Supporting fast restoration for general mesh topologies
with minimal network over build is a technically challenging
problem. Traditionally, ring based
SONET networks have offered 50ms restoration at the cost of
requiring 100\% over-build.
Recently, fast (local) reroute has gained momentum in the
context of MPLS networks.  Fast reroute, when combined with
pre-provisioning of protection capacities and bypass tunnels,
comes close to providing fast restoration for mesh networks.
Pre-provisioning has the additional advantage of
greatly simplifying network routing and signaling. Thus even
for protected connections, online routing can now be oblivious to
the offered protection, and may only involve single shortest path
computations.
In this paper we are interested in the problem of reserving the
least amount of the network capacity for protection, while
guaranteeing fast
restoration to all the supported connections.
We show that the problem is NP-complete, and we present efficient
approximation algorithms for the problem. The solution output
by our algorithms is guaranteed to use at most twice the protection
capacity, compared to any optimal solution. These guarantees
are provided even when the protection is for multiple link failures.
In addition, the total amount of protection capacity reserved
by these algorithms is just a small fraction of the amount reserved by
existing ring based schemes (e.g. SONET), especially on
dense networks.
The presented algorithms are computationally efficient, and can even
be implemented on the network elements.
Our simulation, on some standard core networks,
show that our algorithms work well in practice as well."
}

@INPROCEEDINGS{Alic0411:Balancing,
AUTHOR="Mansoor Alicherry and Harsha Nagesh and Chitra Phadke and Sumesh Philip and
Viswanath Poosala",
TITLE="Balancing the Accuracy and Practicality of Location Tracking in
Heterogeneous Mobile Networks",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="Location tracking has several applications in mobile (cellular or ad hoc)
networks, such as location-based routing algorithms and consumer services.
It is often difficult to precisely obtain the location of a node because of
the infrastructure costs and the errors inherent in most tracking
techniques. Furthermore, this accuracy differs amongst the nodes based on
the scattered availability of equipment such as GPS. In this paper, we
focus on heterogeneous mobile networks, wherein some nodes know their
locations more precisely than others and there is a short-range
peer-to-peer communication channel such as Bluetooth, 802.11. We consider a
generalized notion of location called vicinity which is the set of
potential locations for a node. We formulate a hierarchy of distance
constraints that can be applied in a network and devise efficient
distributed techniques for computing the most optimal (smallest) vicinities
under various constraint classes. In particular, our algorithms use both
proximity and non-proximity relationships between the nodes. We present
simulation results establishing the effectiveness of using these different
types of constraints."
}

@INPROCEEDINGS{Alip0411:Radio,
AUTHOR="Cesare Alippi and Giovanni Vanini",
TITLE="Radio Localization with {MICA2} Wireless Sensor {Network:A} Metrological
Analysis",
BOOKTITLE="First IEEE Workshop on Embedded Networked Sensors",
ADDRESS="Tampa, FL, USA",
DAYS=16,
MONTH=nov,
YEAR=2004,
ABSTRACT="Based on a Crossbow MICA2 wireless sensor network we investigate and
quantify the effectiveness of using the received power sensor (RSSI) for
the indoor localization of a probe node device. An accurate metrological
characterization of the sensor in terms of precision, repeatability of the
measurements, influence of the device factory parameter production,
influence of the battery level is provided. These results can be used to
identify the limits, in terms of spatial accuracy, introduced by the
envisaged sensor errors when used to solve the localization problem."
}

@INPROCEEDINGS{Aliz0406:Analytical,
AUTHOR="Farshid Alizadeh-Shabdiz and Suresh Subramaniam",
TITLE="Analytical Models for {Singe-Hop} and {Multi-Hop} Ad Hoc Networks",
BOOKTITLE="Broadband Networks 2004 - Broadband Wireless Networking Symposium",
DAYS=3,
MONTH=jun,
YEAR=2004,
ABSTRACT="There is considerable interest in modeling the performance of ad hoc
networks analytically. This paper presents approximate analytical models
for the throughput performance of single-hop and multi-hop ad hoc networks.
The inherent complexity of analysis of a multi-hop ad hoc network together
with the fact that the behavior of a node is dependent not only on its
neighbors' behavior, but also on the behavior of other unseen nodes makes
multi-hop network analysis extremely difficult. However, our approach in
this paper to analyze multi-hop networks offers an accurate approximation
with moderate complexity. Our approach is based on characterizing the
behavior of a node by its state and the state of the channel it sees. This
approach is used to carry out an analysis of single-hop and multi-hop ad
hoc networks in which different nodes may have different traffic loads. In
order to validate the model, it is applied to IEEE 802.11-based networks,
and it is shown through extensive simulations that the model is very
accurate."
}

@INPROCEEDINGS{Aliz0411:MAC,
AUTHOR="Farshid Alizadeh-Shabdiz and Suresh Subramaniam",
TITLE="{MAC} layer Performance Analysis of {Multi-Hop} Ad Hoc Networks",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="This paper presents an analytical model for a MAC layer of multi-hop ad hoc
networks. The inherent complexity of analysis of a multi-hop ad hoc network
together with the fact that the behavior of a node is dependent not only on
its neighbors' behavior, but also on the behavior of other unseen nodes
makes the MAC layer analysis of multi-hop networks extremely difficult.
However, the approach used in this paper in analyzing multi-hop ad hoc
networks' MAC layer offers a very accurate performance approximation for
these complex networks. This approach can be used to capture different
aspects of multi-hop networks. The accuracy of the model is shown by
applying the model to 802.11 ad hoc networks, as the most studied ad hoc
networks' MAC protocol."
}

@INPROCEEDINGS{Alla0405:Provably,
AUTHOR="Ali Allam",
TITLE="Provably Secure Entity {Authentication-The} Three Party Case",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="In an open network-computing environment, a workstation cannot be trusted
to identify its users correctly to network services. Authentication
protocols provide an approach for the receiver of a message to ascertain
its origin and to verify the identity of the sender in a distributed
environment. Since they exchange cryptographic messages at the beginning of
communication, their security is an essential requirement. However, most of
the protocols have suffered from several kinds of attacks. A replay attacks
is one kind of those attacks. Attackers could launch it easily by replaying
an eavesdropped message. Therefore, it is necessary to verify
authentication protocols deliberately with such attacks as a basis. This
paper presents a new cryptographic protocol for an open network-computing
environment. It describes the weaknesses and limitations in previous
protocols and shows how the new protocol overcomes these weaknesses and
limitations. We also demonstrate how the new protocol provides an
additional service, privacy, beside the authentication service in less
number of messages than the previous authentication protocols."
}

@INPROCEEDINGS{Alla0406:Provably,
AUTHOR="Ali Allam",
TITLE="Provably Secure Entity {Authentication-The} Three Party Case",
BOOKTITLE="The Ninth IEEE Symposium on Computers and Communications",
ADDRESS="Alexandria, Egypt",
DAYS=29,
MONTH=jun,
YEAR=2004,
ABSTRACT="In an open network-computing environment, a workstation cannot be trusted
to identify its users correctly to network services. Authentication
protocols provide an approach for the receiver of a message to ascertain
its origin and to verify the identity of the sender in a distributed
environment. Since they exchange cryptographic messages at the beginning of
communication, their security is an essential requirement. However, most of
the protocols have suffered from several kinds of attacks. A replay attacks
is one kind of those attacks. Attackers could launch it easily by replaying
an eavesdropped message. Therefore, it is necessary to verify
authentication protocols deliberately with such attacks as a basis. This
paper presents a new cryptographic protocol for an open network-computing
environment. It describes the weaknesses and limitations in previous
protocols and shows how the new protocol overcomes these weaknesses and
limitations. We also demonstrate how the new protocol provides an
additional service, privacy, beside the authentication service in less
number of messages than the previous authentication protocols."
}

@INPROCEEDINGS{Alla0410:Maximum,
AUTHOR="Miriam Allalouf and Yuval Shavitt",
TITLE="Maximum Flow Routing with Weighted {Max-Min} Fairness",
BOOKTITLE="First International Workshop on QoS Routing",
ADDRESS="Barcelona, Catalunya, Spain",
DAYS=1,
MONTH=oct,
YEAR=2004,
ABSTRACT="Max-min is an established fairness criteria for allocating bandwidth for
flows. In this work we look at the combined problem of routing and
bandwidth allocation such that the flow allocation for each connection will
be maximized and fairness will be maintained. We extend the max-min
criteria to allow weights for flow, and then, for the first time, solve the
combined routing and bandwidth allocation problem for the case where flows
are allowed to be splitted along several paths. We use multi commodity flow
(MCF) formulation which is solved using linear programming (LP) techniques.
These building blocks are used by our algorithm to derive the required
optimal routing and allocation."
}

@INPROCEEDINGS{Alle0409:Automated,
AUTHOR="Stuart Allen and Steve Hurley and Richard Taplin and Roger Whitaker",
TITLE="Automated cell planning to improve network rollout",
BOOKTITLE="VTC'F04 Wireless Personal Communication Systems",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="The use of automated cell planning techniques has become more widespread in
recent years, due to the improvements in both network quality and cost that
have been demonstrated. This paper describes an optimisation algorithm for
cell planning based on Simulated Annealing, which is used to investigate
the effect of several strategies for planning the staged roll out of
cellular networks. Techniques to balance the various objectives of
different stages of rollout are described, and the improvements possible
are demonstrated using practical problems."
}

@INPROCEEDINGS{Alle0411:MAGNA,
AUTHOR="William Allen and Gerald Marin",
TITLE="{MAGNA:} Modeling And Generating Network Attacks",
BOOKTITLE="The 29th Annual IEEE Conference on Local Computer Networks",
ADDRESS="Tampa, Florida",
DAYS=16,
MONTH=nov,
YEAR=2004,
ABSTRACT="We present a system that generates synthetic attack traffic from
state-based models of the behavior of real network attacks. The execution
of these attacks can be carefully controlled to produce realistic training
data that could prove useful in the evaluation and development of intrusion
detection systems. This tool can also be used to test host systems and
networks for known vulnerabilities by launching controlled attacks and
observing their impact on the target."
}

@INPROCEEDINGS{Alm0405:Adaptive,
AUTHOR="Martin Alm and Stephen Craig",
TITLE="Adaptive Antenna Systems and {EGPRS} - Data Protocol Aspects",
BOOKTITLE="Antennas and Propagation",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="The deployment of adaptive antennas can ideally boost the capacity of an
EGPRS network by as much as 200\%. However, the combination of adaptive
antennas and GPRS/EGPRS involves some challenges for system design.
Especially the signaling for uplink transmission permission by means of the
Uplink State Flag (USF) could potentially reduce performance. The reason
for this is that the USF is integrated in the header of the downlink radio
block whose data payload could be intended for another user. If the mobiles
are located in different beams, one of them will receive a very weak signal
and might have trouble decoding the information. The goal with the present
study has been to solve the USF dilemma through intelligent system design
and realistically quantify the performance gains obtainable from adaptive
antennas in EGPRS data networks. It has been found that more than 90\% of
the ideal performance gain can be retained with an intelligent scheduling
and transmission strategy. Installing adaptive antennas can therefore still
be a very attractive method for increasing the packet data capacity of a
GSM/EDGE network, even when the USF dilemma is considered. Not explicitly
considering the USF issue in system design is shown to lead to a
substantial degradation in performance."
}

@INPROCEEDINGS{Alme0411:Coupons,
AUTHOR="Kevin Almeroth and Anargyros Garyfalos",
TITLE="Coupons: Wide Scale Information Distribution for Wireless Ad Hoc Networks",
BOOKTITLE="IEEE Globecom 2004 - Global Internet and Next Generation Networks",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT={Integrating ad hoc networks into the Internet requires overcoming a number
of difficult technical challenges. In particular, ad hoc networks must not
only overcome intermittent connectivity, but they also need a strong
incentive mechanism to encourage users to participate in the cooperative
relay of data traffic. We believe that inherent in solving these problems
is the development of new applications that might, in fact, be more easily
deployed in an ad hoc environment than in a traditional fixed network
infrastructure. To this end, we develop and evaluate the idea of
``coupons{"} for wide-scale information distribution in ad hoc networks.
``Coupons{"} provides a simple incentive to nodes for relaying a piece of
information. By using mechanisms on top of basic flooding to efficiently
control distribution, it provides an elegant solution for scalable data
dissemination with reduced network costs.}
}

@INPROCEEDINGS{Almo0409:Novel,
AUTHOR="Ronen Almog",
TITLE="Novel nanomechanical displacement sensing using a suspended Superconducting",
BOOKTITLE="The 23rd IEEE convention of Electrical and Electronics Engineers in Israel",
ADDRESS="Herzlia, Israel",
DAYS=6,
MONTH=sep,
YEAR=2004,
ABSTRACT="Developoment of highly sensitive displacement detector integrated with a
mechanical resonator that can approach the quantum mechanical limit could
have important applications in the detection of very weak forces, such as
single molecule NMR, gravitational wave detection and more. Intensive
efforts are being made to reach the so-called standard quantum limit of
displacement detection [1]. A displacement sensitivity of 2 1015m/ Hz , for
nanomechanical resonator coupled to a single electron transistor was
recently demonstrated- this was only 100 times larger than the standard
quantum limit for this oscillator [2]. Our proposed scheme is based on a
suspended Superconducting QUantum Interference Device (SQUID), combining
nanomechanical fabrication with Niobium (Nb) superconducting technology.
This may allow near quantum limited sensitivity. A dc SQUID is composed of
two Josephson junctions enclosed by a superconducting loop and serves as a
sensitive magnetic flux-to-voltage transducer, based on two phenomena
typical for superconductivity: flux quantization and the Josephson effect.
A dc SQUID is usually biased with a constant current and the resulting
voltage developed across the SQUID is a periodic function of the flux with
a period of the flux quantum 0 h/2e 2 1015 Wb (Fig. 1). The proposed device
is a suspended dc SQUID, clamped at both ends, with a mechanical torsional
degree of freedom, where the SQUIDs current leads serve as the rotational
axes (Fig. 2). An applied in-plane external magnetic field couples the
electrical degree of freedom with the mechanical degree of freedom. When
the SQUID rotates around the devices rotation axes, the magenetic flux
threading the SQUID changes, causing a measurable change in the voltage
across the device. For an optimal design, the SQUIDs internal magnetic flux
noise is given by S 16kbTL2/R [3]. For temperature T100mk, Josephson shunt
resistanse of 10 and ring inductance of 0.1 nH, we expect flux sensitivity
of S 1070/ Hz. For external in-plane magnetic field B 0. 1T and Square ring
of 10m 10m, we expect displacement sensitivity of Sx 1016m/ Hz for the
edges of the SQUID supporting the Josephson junctions. The device
fabrication is based on a bulk nanomachining process. We begin with a Si
wafer covered by 100nm of Si3N4. The first step consists of fabrication of
Si3N4 membranes using KOH wet Si etch. The Si3N4 membrane is used as the
sacrificial layer for the suspended structures. In the second step, the
sample is covered with PMMA and the device is directly written by electron
beam lithography. The SQUID is made of sputtered Nb with Josephsonn
junctions made by shadow sputtering of Nb-Al-AlOx-Al-Nb [4]. The
measurments will be made in a cryogenic enviroment of 4.2K and in a
dilution refrigerator. In order to use the device as a transducer, we are
going add an adjacent Lorentz force actuator for driving the torsional
vibrations while the SQUID serves as the displacement detector (Fig. 3)."
}

@INPROCEEDINGS{Alnu0406:Complexity,
AUTHOR="Hussein Alnuweiri and Haitham Tayyar",
TITLE="The Complexity of Computing {Virtual-Time} in Weighted Fair Queuing
Schedulers",
BOOKTITLE="QoS and Performance Modeling Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="This paper presents two fundamental theorems that show that the O(N)
complexity for updating the virtual time in a weighted fair queuing (WFQ)
scheduler with N sessions is caused mainly by simultaneous departures of
packets, and not by iterated deletion as was previously claimed. Iterated
deletion is caused by an avalanche of consecutive, but not necessarily
simultaneous, departures that incur more departures due to increments in
available bandwidth from idling sessions. Iterated deletion potentially
leads to large numbers of consecutive departures within a given time
period. The number of departures is, however, a function of such
implementation details as the resolution of the time-stamp and the
scheduler clock. On the other hand, the problem of simultaneous time-stamps
can not be solved by any increase in the time resolution of virtual-time
update. Essentially, all equal time-stamps must be processed during a
single virtual-time update operation. We present a proof to show that O(N)
simultaneous departures can occur during a single virtual-time update. We
also show that this is a fundamental property of WFQ that holds even under
the most restrictive conditions, viz. all packets arrive serially to the
scheduler (no simultaneous arrivals), and the input bit-rate does not
exceed the output bit-rate."
}

@INPROCEEDINGS{Alon0409:Dynamic,
AUTHOR="Jesús Alonso and Luis Alonso",
TITLE="Dynamic {Self-Constructing} {Master-Slave} Architecture for {AD} {HOC}
Wireless Networks with a Distributed {MAC} Scheme",
BOOKTITLE="VTC'F04 Multimedia, Networks and Systems",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="This paper proposes and analyses a novel MAC protocol for mobile wireless
ad hoc networks (MANETS) that makes use of distributed queues to achieve an
efficient use of the radio channel. The protocol behaves as a random access
protocol when the total offered payload is low, and switches automatically
to a reservation protocol as the total offered payload increases. The
protocol includes a dynamic self-configurable master-slave architecture
that allows the synchronism between the nodes of the network and that
adapts itself to the dynamism of the network topology. Computer simulations
demonstrate that the proposed scheme outperforms throughput bounds achieved
when using a legacy 802.11 MAC protocol for mobile wireless ad hoc networks
in lots of different communication scenarios."
}

@INPROCEEDINGS{Alon0411:Equalization,
AUTHOR="Elad Alon and Vladimir Stojanovic and Joseph Kahn and Stephen Boyd and Mark
Horowitz",
TITLE="Equalization of Modal Dispersion in Multimode Fiber using Spatial Light
Modulators",
BOOKTITLE="IEEE Globecom 2004",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="Intersymbol interference (ISI) due to modal dispersion is the dominant
limitation to the bit rate-distance product in multimode fiber-optic
communication systems. If the light launched into the fiber excites only
the desired principal modes, modal dispersion can be eliminated. We can
achieve this by using spatial light modulators (SLMs) to perform adaptive
spatial filtering on the electric fields of the light. In this paper, we
develop an optimization framework for setting the SLMs to obtain an upper
bound on the achievable performance and develop heuristics that nearly
reach this upper bound. Using this framework, we show that both a
sophisticated semidefinite programming-based algorithm and a simple
adaptive algorithm achieve performance close to the upper bound.
Performance and system complexity tradeoff curves are constructed, showing
that a 20x20 array of SLM pixels with binary phase control performs within
15\% of more complex implementations. Finally, we extend the framework and
present preliminary results showing the promise of further increases in the
capabilities of multimode fiber by using the fiber as a multiple-input,
multiple-output (MIMO) transmission medium."
}

@INPROCEEDINGS{Alpa0409:Combined,
AUTHOR="Onur Alparslan and Nail Akar and Ezhan Karasan",
TITLE="Combined Use of Prioritized {AIMD} and {Flow-Based} Traffic Splitting for
Robust {TCP} Load Balancing",
BOOKTITLE="Fifth International Workshop on Quality of future Internet Services",
ADDRESS="Barcelona, Catalunya, Spain",
DAYS=29,
MONTH=sep,
YEAR=2004,
ABSTRACT="In this paper, we propose an AIMD-based TCP load balancing architecture in
a backbone network where TCP flows are split between two explicitly routed
paths, namely the primary and the secondary paths. We propose that primary
paths have strict priority over the secondary paths with respect to packet
forwarding and both paths are rate-controlled using ECN marking in the core
and AIMD rate adjustment at the ingress nodes. We call this technique
``prioritized AIMD''. The buffers maintained at the ingress nodes for the
two alternative paths help us predict the delay difference between the two
paths which forms the basis for deciding on which path to forward a
new-coming flow. We provide a simulation study for a large mesh network to
demonstrate the efficiency of the proposed approach in terms of the average
blocking rate and the average per-flow goodput."
}

@INPROCEEDINGS{Alro0409:Discrete,
AUTHOR="Idan Alrod and Simon Litsyn",
TITLE="Discrete and Continuous Maxima in {OFDM} signals",
BOOKTITLE="The 23rd IEEE convention of Electrical and Electronics Engineers in Israel",
ADDRESS="Herzlia, Israel",
DAYS=6,
MONTH=sep,
YEAR=2004,
ABSTRACT="We discuss a method for estimation of the ratio between the discrete and
continuous maxima of OFDM signals. We improve on the earlier known bounds
when the oversampling rate is between 1 and 2."
}

@INPROCEEDINGS{Alsh0405:Optimized,
AUTHOR="Hamada Alshaer and Eric Horlait",
TITLE="An optimized adaptive broadcast scheme for Inter-vehicle communication",
BOOKTITLE="Vehicular Technology Conference Spring 2005 Mobile Applications and
Services",
ADDRESS="Stockholm, Sweden",
DAYS=29,
MONTH=may,
YEAR=2004,
ABSTRACT="A Vehicular network topology changes rapidly due to the high mobility of
network nodes. This network is formed spontaneously to support high speed
and guaranteed communications, which in turn makes the delivery of
emergency warning packets (EWPs) through dynamic routing protocols not
guaranteed and unreliable. Hence, we propose a broadcast scheme through
which the EWPs in the ad hoc part in Client-Server
Ad-Hoc(CSAH)communication platform~\cite{E:client} are transmitted from an
abnormal vehicle to others in its zone. This broadcast scheme is efficient
since it delivers rapidly the EWPs, and it is adaptive since the
rebroadcast probability of a vehicle node changes dynamically in term of
the number of vehicle nodes in its zone. Consequently, this broadcast
scheme alleviates the problem of the simple flooding broadcast which is
referred to broadcast storm and represented by packets redundancy,
contention, and collision in the network."
}

@INPROCEEDINGS{Alsh0409:Emerging,
AUTHOR="Hamada Alshaer",
TITLE="Emerging {Client-Server} and Ad-hoc approach In Inter-vehicle communication
Platform",
BOOKTITLE="VTC'F04  EMC Issues for Wireless and Mobile Network",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="Integrating different communication approaches in an Inter-vehicle
communication platform to guarantee a continuous and reliable communication
between the communicating vehicles is an inherently challenging task. It
requires very good functionality of each communication approach, transition
mechanisms between these approaches and adaptation between their
communicating functions. We present Inter-vehicle communication platform in
which the Client-Server and Ad-hoc communication approaches have been
integrated. This platform, called Client-Server Ad-Hoc(CSAH)platform,
requires a host to allocate dynamically IP addresses to the communicating
vehicles which are equipped by a computer controlled radio modem IEEE
802.11b, GPS, and GSM modem. Our platform maintains a high quality of
communication and a reliable guarantee transition from client-server to
ad-hoc communication. We present the results of two simulation experiments
showing that the two communication approaches have been very well emerged
to work together in one communication unit."
}

@INPROCEEDINGS{Alsi0403:Performance,
AUTHOR="Nayef Alsindi and Xinrong Li and Kaveh Pahlavan",
TITLE="Performance of {TOA} Estimation Algorithms in Different Indoor Multipath
Conditions",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="Using TOA to determine the distance between the transmitter and the
receiver is the most popular technique for accurate indoor positioning.
Accuracy of measuring the distance using TOA is sensitive to the bandwidth
of the system and the multipath condition between the wireless terminal and
the access point. The behavior of the distance measurement error using TOA
techniques in LOS and OLOS indoor environments are substantially different.
In general, as the bandwidth increases the distance measurement error
decreases. However, for the so called undetected direct path (UDP)
conditions the system exhibits substantially high distance measurement
errors that can not be eliminated with the increase in the bandwidth of the
system. In this paper we provide an analysis of the behavior of
super-resolution and traditional TOA estimation algorithms in LOS, OLOS and
UDP conditions in indoor areas. The analysis is based on the frequency
domain measurements of the indoor radio channel propagations in several
indoor areas with special attention to the UDP conditions."
}

@INPROCEEDINGS{Alsu0409:Low,
AUTHOR="Emad Alsusa",
TITLE="A Low Complexity {MIMO} Assisted Iterative Multiuser Detector for {DS-CDMA}
Systems",
BOOKTITLE="VTC'F04 Wireless Access",
DAYS=27,
MONTH=sep,
YEAR=2004,
ABSTRACT="The aim of this paper is to propose an efficient MIMO tree-search based
iterative multiuser detector (MUD) that can achieve near optimal
performance while operating at manageable complexity levels. To control the
complexity of the proposed receiver, we apply adaptive selective soft
cancellation combined with iterative detection to help minimise complexity
while at the same time still provide a systems performance very close to
that achieved when using the optimal maximum likelihood receiver. The
adaptive selective cancellation feature of the proposed receiver appeals
very well to a multi-antenna system and it is the aim of this paper to show
how this can be fully exploited to achieve high system performance at
practical complexity levels."
}

@INPROCEEDINGS{Alta0401:Virtual,
AUTHOR="Abdulrahman Altalhi",
TITLE="Virtual Paths Routing: A Highly Dynamic Routing Protocol for Ad Hoc
Wireless Networks",
BOOKTITLE="IEEE Consumer Communications \& Networking 2004",
ADDRESS="Las Vegas, Caesar's Palace",
DAYS=5,
MONTH=jan,
YEAR=2004,
ABSTRACT="In this paper, we introduce the Virtual Paths Routing (VPR) Protocol for ad
hoc wireless networks. VPR provides highly dynamic, correct, and efficient
paths creation and maintenance between nodes. Innovatively, the protocol
utilizes a technique to monitor the mobility of the nodes, and factorizes
it in its operations. VPR is a distributed, on-demand, and adaptive
protocol that comprises two phases. The first phase is path discovery, in
which VPR discovers and creates a virtual path between source and
destination nodes. The second phase is path maintenance, in which the
protocol monitors the usability of all active paths."
}

@INPROCEEDINGS{Altm0403:Analysis,
AUTHOR="Eitan Altman and Chadi Barakat and Victor Ramos",
TITLE="Analysis of {AIMD} protocols over paths with variable delay",
BOOKTITLE="IEEE Infocom 2004",
ADDRESS="Hong Kong",
DAYS=7,
MONTH=mar,
YEAR=2004,
ABSTRACT="The throughput of AIMD protocols in general and of TCP
in particular, has been computed by taking the round-trip time to
be constant and setting it to its average. There are many
scenarios in which the delays of packets vary, causing a variation
of the round-trip time. A typical scenario is the case of wireless
and mobile networks. We propose in this paper an analytical model
that accounts for the variability of delay, while computing the
throughput of an AIMD protocol. We derive a closed-form expression
for the throughput, that illustrates the impact of the variability
of delay. We show by analysis and simulation, that an increase in
the variability of delay improves the performance of an AIMD
protocol. Differently speaking, an analytical model that only
considers the average delay underestimates the performance of an
AIMD protocol in scenarios where delay is variable."
}

@INPROCEEDINGS{Altm0403:Dps,
AUTHOR="Eitan Altman and Tania Jimenez and Daniel Kofman",
TITLE="{DPS} queues with stationary ergodic service times and the performance of
{TCP} in overload",
BOOKTITLE="IEEE Infocom 2004",
ADDRESS="Hong Kong",
DAYS=7,
MONTH=mar,
YEAR=2004,
ABSTRACT="In a recent paper, Bonald and Roberts \cite{thomas} studied
non-persistent TCP connections in
transient overload conditions,
under the assumption that all connections
have the same round-trip times.
In this paper our goal is to develop theoretical tools
that will enable us to relax this assumption and obtain
explicit expressions for the rate of growth
of the number of connections at the system, the rate at which
TCP connections leave the system, as well as the time needed
for the completion of a connection.
To that end, we model the system as a DPS (Discriminatory
Processor Sharing) system which we analyze under
very mild assumptions on the probability distributions related to
different
classes of arrivals: we only assume that the arrival
rates of connections exist, and that the amount of information
transmitted during a connection
of a given type forms a stationary ergodic sequence.
We then proceed to obtain explicit expressions for
the growth rate of the number of connections at the
DPS system for several specific probability distributions. We check
through simulations the applicability of our queueing
results for modeling TCP connections sharing a bottleneck."
}

@INPROCEEDINGS{Altm0404:Transaction,
AUTHOR="Jörn Altmann and Junseok Hwang and Ibrahim Okumus and Praveen Aravamudham",
TITLE="Transaction Management for {Sender/Receiver-Payment} Schemes in Charging
and Accounting Systems for Interconnected Networks",
BOOKTITLE="IEEE/IFIP Network Operations and Management Symposium",
ADDRESS="Seoul, Korea",
DAYS=19,
MONTH=apr,
YEAR=2004,
ABSTRACT="In this paper, we present an Internet transaction management system for
sender/receiver payment schemes. This system allows an arbitrary split of
transaction charges between two communication partners. Using this kind of
system, new business models can be implemented on the Internet, which could
not be implemented before because of the lack of flexibility in existing
charging schemes. Under these new business models, service providers can
pick up a share of the cost for the transaction with any of their
customers; offer collect-call type of services; or provide services as the
900 services on the telephone network. With the proliferation of P2P
services, this kind of transaction management system will be even more
important. It will help to solve the free-rider problem, by enabling
P2P-users to get rewarded for providing resources to the P2P community.
This paper describes in detail the transaction management protocol (TMP),
its implementation, and the transaction management service platform (TMS).
The TMP specifies the protocol state diagram as well as the process of how
the costs for resource usage can be allocated to communicating end-users.
The TMS platform defines the architecture and the modules, simplifying the
implementation of the TMP on the Internet. The TMS provides a module-based
transaction management environment, carrying transaction signals such as
message schema, accounting policy information, communication reference
information, and end-user agreement information. In addition to this, an
application of the TMS in the framework of bandwidth broker interconnection
networks and a short evaluation of the proposed transaction management
system are given."
}

@INPROCEEDINGS{Altm0406:Game,
AUTHOR="Eitan Altman and Dhiman Barman and Rachid ElAzouzi and Jimenez Tania",
TITLE="A game theoretic approach for delay minimization in slotted aloha",
BOOKTITLE="Wireless Networking Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="This paper studies distributed choice of retransmission probabilities in
slotted ALOHA. Both the cooperative team problem as well as the
noncooperative game problem are considered. In previous work that has
focused on the maximization of throughput, it was shown that in heavy load,
this maximization is obtained at the cost of a huge delay of backlogged
packets. This motivates us to investigate the delay minimization problem as
well as the multicriterion problem of minimizing the average expected delay
(or maximizing the throughput) subject to constraints on the expected delay
of backlogged packets. A Markov chain analysis is used to obtain optimal
and equilibrium retransmission probabilities and expected delays."
}

@INPROCEEDINGS{Altu0411:Addressing,
AUTHOR="Hayriye Altunbasak and Sven Krasser and Henry Owen and Joachim Sokol and
Jochen Grimminger and Hans-Peter Huth",
TITLE="Addressing the Weak Link Between Layer 2 and Layer 3 in the Internet
Architecture",
BOOKTITLE="The 29th Annual IEEE Conference on Local Computer Networks",
ADDRESS="Tampa, Florida",
DAYS=16,
MONTH=nov,
YEAR=2004,
ABSTRACT="In the data link control layer, a Medium Access Control (MAC) address is
utilized to uniquely identify each node of a network. With the rapid
expansion and evolution of the Internet, the methodology of addressing in
the data link layer and mapping between network and data link layers has
become inadequate to provide secure services in networks. Since the current
protocols used in networks do not provide a secure binding between the
Internet Protocol (IP) and MAC addresses, they create a weak link between
network and data link layers in Local Area Networks (LANs). In this paper,
we examine the security concerns in the data link layer as well as the IP
and MAC address binding problem in LANs."
}

@INPROCEEDINGS{Alut0411:Diagonal,
AUTHOR="Mikko Alutoin and Pertti Raatikainen",
TITLE="Diagonal Tuple Space Search - A Multidimensional Packet Classification
Scheme",
BOOKTITLE="IEEE Globecom 2004",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="The introduction of the quality of service (QoS), policy based routing and
security to the Internet implies the need to classify IP packets based on
multiple protocol fields. Theory has proved that any general
multidimensional look-up algorithm is either time or storage hungry.
However, it has been anticipated that more feasible algorithms could be
obtained for conflict-free classifiers. This paper studies the implications
of the conflict-free constraint for a well-known field in packet
classification - the algorithms which derive from the tuple space paradigm.
Also a heuristic packet classification algorithm that makes use of the
conflict-free constraint in multidimensional tuple space is introduced."
}

@INPROCEEDINGS{Alwa0409:Comparison,
AUTHOR="Esam Alwagait",
TITLE="A Comparison of Alternative Web Service Allocation and Scheduling Policies",
BOOKTITLE="IEEE SCC 2004 Grid and Utility Computing Track",
ADDRESS="Shanghai, China",
DAYS=15,
MONTH=sep,
YEAR=2004,
ABSTRACT="Web Services (WSs) are emerging as the building block of Internet scale
database management systems (IDBMSs). These systems must intelligently
execute plans that reference autonomous WSs. This requires policies and
mechanisms for both scheduling and allocating WSs that constitute a plan.
In this study, we analyze two scheduling strategies and four allocation
policies. Obtained results show that dynamic scheduling with Least Response
Time (LRT) allocation policy is superior to other alternatives when the
service time of a WS can be estimated accurately. The traditional Least
Recently Used (LRU) allocation policy is inferior to all policies including
Random. These observations are important because they impact the
scalability of a system. Only with a smart allocation policy, one should
expect improved system performance by increasing the number of nodes that
constitute an IDBMS to support a larger number of WS replicas."
}

@INPROCEEDINGS{AlWe0405:Packet,
AUTHOR="Abdullah AlWehaibi and Kadoch Michel and Ahmed Elhakeem",
TITLE="Packet Loss Probability for {DiffServ} over Heterogeneous {MPLS} Multicast
Networks : A Simulation Study",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Multicasting has become increasingly important with the emergence of
Internet-based applications such as IP telephony, audio/video conferencing,
distributed databases and software upgrading. IP Multicasting is an
efficient way to distribute information from a single source to multiple
destinations at different locations. In practice IP is considered as a
layer 3 protocol. Multiprotocol label Switching (MPLS) replaces the IP
forwarding by a simple label lookup. MPLS combines the flexibility of layer
3 routing and layer 2 switching. In order to provide QoS in group
communications for real time applications such as video conferencing,
reliable multicasting is used. Miscellaneous efforts have been undertaken
to provide reliability on top of IP multicast. Two error control strategies
have been popular in practice. These are the FEC (Forward Error Correction)
strategy, which uses error correction alone, and the ARQ (Automatic Repeat
Request) strategy, which uses error detection, combined with retransmission
of data. In this paper, we present a Fair Share Policy (FSP) that utilizes
Differentiated Services to solve the problems of QoS and congestion control
when reliable FEC/ARQ multicast is adopted. Simulation programs are used to
evaluate the Fair Share Policy. The results should provide insights into
the comparisons between homogeneous IP multicast networks, homogeneous MPLS
multicast networks and heterogeneous MPLS multicast networks using the same
FSP when DiffServ are adopted and when reliable FEC/ARQ multicast is
considered. This comparison will be based on the residual packet loss
probability."
}

@INPROCEEDINGS{Alya0411:Dynamic,
AUTHOR="Anwar Alyatama",
TITLE="Dynamic Routing and Wavelength Assignment Using Learning Automata Technique",
BOOKTITLE="IEEE Globecom 2004 - Optical Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="Dynamic routing and wavelength assignment RWA is one of the most important
issues in wavelength routed all optical networks. We introduce the learning
automata technique for the dynamic RWA in WDM networks without conversion
under different load conditions. Learning automata will be used to choose a
shortest path from the source to the destination if more than one shortest
path exist. Furthermore, learning automata will be used to select which
wavelength to be used on the chosen path. We compare our wavelength
assignment technique with some greedy wavelength assignment algorithms that
scan all wavelengths on a predetermined shortest path. The use of learning
automata wavelength assignment technique reduces the call setup time by
pursing a small number of wavelengths. In addition, the technique is used
to achieve fairness among different source/destination pairs. Simulation
results are presented which indicate the benefits of using learning
automata technique for the dynamic routing and wavelength assignment in WDM
networks."
}

@INPROCEEDINGS{Amab0405:Performance,
AUTHOR="Giuseppe Amabili and Claudia Carciofi and Mario Frullone and Matteo Zanzi",
TITLE="Performance evaluation of a {Differential-GPS} ground station for high
accurate satellite navigation services",
BOOKTITLE="Satellite Networks and Services",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="This paper focuses on some performance assessment criteria related to the
Ground Based Augmentation System (GBAS) currently under development at the
Aerospace Laboratories of Forlì, University of Bologna, with the aim of
providing differential GPS corrections to be used for high reliable
terrestrial and air vehicle positioning. Accuracy characterization of the
computed corrections that are broadcast by the GBAS inside its coverage
volume is described here by means of an assessment of the correction total
error, as well as each multipath contribution, that affects the GPS signals
received by three GPS reference receivers located along Forlì aerodrome.
Low-error corrections are expected to be generated from the GBAS by
averaging the corrections, and so their uncorrelated errors, provided by
the three GPS reference receivers. The spread of each different GPS
receiver correction with respect to the total average provides a good
estimate of the system accuracy as well as correction reliability.
Nevertheless, the non-compensated residual multipath error after the
averaging process behaves as a polarization causing a non-null mean
correction error. The impact of this effect is described by the analysis of
GPS correction data collected during many experimental campaigns. The
analysis has been carried on based on measured data filtering and has been
supported by ray-tracing simulations."
}

@PROCEEDINGS{Amad04:Modeling,
AUTHOR="Roberto Amadio and Sanjiva Prasad",
TITLE="Modeling {IP} mobility",
ORGANIZATION="INRIA Technical Report",
YEAR=2004,
ABSTRACT="We study the modelling of mobile hosts on a network in a simple
name-passing
process calculus, with the intention of being able to prove properties
about a protocol for
supporting mobility. Our model may be considered a highly simplied version
of proposals
for mobility support in the version 6 of the Internet Protocols (IP).
Being fairly general,
the model may also apply to mobile software architectures. We believe that
such simplied
models help in prototyping mobility protocols and reasoning about them
while abstracting
away excessive details.
We concentrate on the issue of ensuring that messages to and from mobile
agents are
delivered without loss of connectivity. We provide three models of
increasingly complex
nature of a network of routers and computing agents that are
interconnected via the routers:
the rst is without mobile agents and is treated as a specication for the
next two; the second
supports mobile agents, and the third additionally allows correspondent
agents to cache the
current location of a mobile agent. Following a detailed analysis of the
three models to
extract invariant properties, we show that the three models are related by
a suitable notion
of equivalence based on barbed bisimulation."
}

@INPROCEEDINGS{Amal0405:WLAN,
AUTHOR="Edoardo Amaldi and Antonio Capone and Matteo Cesana and Federico Malucelli
and Fabrizio Palazzo",
TITLE="{WLAN} Coverage Planning: Optimization Models and Algorithms",
BOOKTITLE="Mobile Networks",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="Wireless Local Area Networks (WLANs) are spreading all over the planet with
impressive speed and market penetration. They are expected to replace
traditional wired local indoor networks and allow flexible access outdoor,
eventually competing with classical cellular systems ($GSM$, $GPRS$,
$UMTS$, etc.) in the provision of wireless services. Although the small
systems currently installed are planned using rules of thumb, their rapid
spread and size increase require quantitative methods to determine proper
Access Points (AP) positioning. Previously proposed approaches to the
coverage planning neglect the effect of the IEEE802.11 access mechanism,
which limits system capacity when Access Points coverage areas overlap.
Here we describe a new modelling approach that directly accounts system
capacity and we propose effective heuristics able to provide nearly optimal
solution in a reasonable amount of time."
}

@INPROCEEDINGS{Amal0406:Optimization,
AUTHOR="Edoardo Amaldi and Antonio Capone and Federico Malucelli and Gianluca Villa",
TITLE="Optimization of packet scheduling in wireless systems with smart antennas:
geometric models and algorithms",
BOOKTITLE="Wireless Networking Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="Beam forming techniques of adaptive antenna arrays (smart antennas) allow
to reduce the mutual interference of simultaneous transmission in wireless
access systems exploiting angular separation of user terminals. At the
radio resource management layer the information on the arrival direction of
signals can be taken into account by the scheduling algorithm so that
transmissions of too close user terminals can be scheduled in different
time-slots, while transmissions of users with an enough angular separation
can be simultaneous. In other words, time diversity is exploited by the
scheduling algorithm when spatial diversity is not sufficient to obtain
good quality transmissions. In this paper we propose a novel approach to
the problem of packet scheduling with smart antennas using mathematical
programming. Based on a simplified system model we formulate two
combinatorial optimization problems. In the first problem we have to select
a subset of users which can be simultaneously served in a given time slot
so as to maximize the number or the total priority of the users served. An
arc-circular model is proposed together with an exact polynomial-time
algorithm which searches for a path of maximum total weight in an
appropriate graph. In the second problem users must be partitioned into
non-interfering subsets so as to minimize the number of time slots needed
to transmit all the given packets. For both problems heuristics have been
devised in order to obtain approximate solutions in the short time
available for packet scheduling in real systems."
}

@INPROCEEDINGS{Amal0406:Optimizing,
AUTHOR="Edoardo Amaldi and Antonio Capone and Matteo Cesana and Federico Malucelli",
TITLE="Optimizing {WLAN} Radio Coverage",
BOOKTITLE="Access and Home Networks Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="Wireless Local Area Networks (WLANs) are spreading all over the planet with
impressive speed and market penetration. They will replace traditional
indoor wired local networks and allow flexible access outdoor, eventually
competing with classical cellular systems ($GSM$, $GPRS$, $UMTS$, etc.) in
the provision of wireless services. Although the small systems currently
installed are planned using rules of thumb, their rapid spread and size
increase requires quantitative methods to determine proper Access Points
(AP) positioning. Previously proposed approaches to the coverage planning
neglect the effect of the IEEE802.11 access mechanism, which limits system
capacity when Access Points coverage areas overlap. Here we propose a new
modelling approach that directly accounts system capacity and show that the
resulting optimization problems of WLAN coverage planning can be seen as
extensions of the classical set covering or maximum coverage problems. We
present and discuss different formulations based on quadratic and
hyperbolic objective functions and report some preliminary results on
synthetic instances we generated."
}

@INPROCEEDINGS{Aman0409:Performance,
AUTHOR="Yoshiaki Amano and Masayuki Nakano and Takashi Inoue and Yoshio Takeuchi
and Toshio Kawazawa",
TITLE="Performance of Forward link Beamforming with {SDMA} Packet Cellular System",
BOOKTITLE="VTC'F04 Wireless Access",
DAYS=27,
MONTH=sep,
YEAR=2004,
ABSTRACT="We developed a space division multiple access (SDMA) packet cellular
testbed system. One of the main features of the testbed is a forward link
beamforing technology that is available to transmit data packets to multi
access terminal (AT) in same time slot by allocation of the orthogonal beam
pattern to each user in forward link, and another is space-time scheduling
algorithm supporting to select the best set of multi-AT in consideration of
orthogonality of beam patterns in spatial domain as well as instantaneous
forward link channel condition of each AT. We are now conducting
experiments in an anechoic chamber for the evaluation of the forward link
beamforming performances."
}

@INPROCEEDINGS{Amat0409:Novel,
AUTHOR="Alexandre {Graell i Amat} and Boris Bellalta and Miquel Oliver",
TITLE="A Novel {ARQ} Protocol for {IEEE802.11a} Based on Rate-compatible Codes",
BOOKTITLE="VTC'F04 Multimedia, Networks and Systems",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="In this paper we present a new ARQ protocol for the IEEE802.11a Wireless
LAN, based on the concept of rate-compatible punctured codes. The proposed
protocol uses a progressive lower coding rate at each retransmission based
on different puncturing schemes of the 64-state convolutional code proposed
in the 802.11a standard. The key idea of the new ARQ protocol is the
transmission of the punctured bits at each retransmission to re-form a
lower coded packet at the receiver side. The proposed approach improves the
throughput of the 802.11a standard defined PHY/MAC modes."
}

@INPROCEEDINGS{Amat0409:Robust,
AUTHOR="Alexandre {Graell i Amat} and Monica Navarro and Alberto Tarable",
TITLE="Robust {Space-Time} Trellis Codes on Correlated Channels",
BOOKTITLE="VTC'F04 Transmission Technology",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="We give a performance analysis for space-time trellis codes under
correlated fading channels, and propose a new code design criterion that
takes into account channel correlation. A simple form for a distance metric
that characterizes the code performance in presence of transmit correlation
is also given. Acting on the proposed distance metric, we give simple
design rules for space-time trellis codes that perform well over a range of
correlated fading channels. For the particular case of two and three
transmit antennas we found new codes based on the proposed new criterion
and report several simulation results to prove the validity of the new
design rules."
}

@INPROCEEDINGS{Amay0409:Performance,
AUTHOR="Cesar Amaya",
TITLE="Performance Evaluation of a {LEO} System in {Urban/Suburban} Environments
in Ottawa, Canada",
BOOKTITLE="VTC'F04 Mobile Satellite",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="The performance of a Globalstar-like LEO system has been predicted based on
digital hemispherical photographs taken in downtown Ottawa and in a
suburban area west of Ottawa, Bells Corners. The simulated satellite look
angles were combined with the digital pictures to determine the path state
for each satellite, i.e., shadowed, blocked or clear line-of-sight.
Cumulative distributions of narrowband fading at L-band were developed for
the case when the receiver utilizes one (best or highest) satellite, and up
to three-fold diversity with either switching or coherent combining of the
received signals. By selecting the best satellite instead of the highest, a
significant reduction in fading was obtained. For downtown Ottawa, the
necessary fade margin to obtain 1\% outage was reduced by about 14 dB when
using three-fold coherent combining diversity instead of the single best
satellite. As expected, fade CDFs for Bells Corners showed lower
attenuation levels than those for downtown Ottawa."
}

@INPROCEEDINGS{Amei0409:Performance,
AUTHOR="Pablo Ameigeiras and Jeroen Wigard and Preben Mogensen",
TITLE="Performance of Scheduling Methods with Different Degree of Fairness for
{NRT} Traffic in {HSDPA}",
BOOKTITLE="VTC'F04 Wireless Access",
DAYS=27,
MONTH=sep,
YEAR=2004,
ABSTRACT="The present paper focuses on assessing the performance of the Packet
Scheduler in HSDPA. The investigation has concentrated on assessing
different scheduling methods with different degrees of fairness for non
delay-sensitive elastic traffic because the fairness ultimately determines
the QoS perceived by the users. The results have shown that very unfair
scheduling methods provide the highest HSDPA cell capacity for best effort
NRT traffic, although, under heavy load situations, the unfairness of these
policies cause the starvation of users under poor average radio propagation
conditions. Under minimum user throughput guarantees, the Proportional Fair
algorithm provides the highest cell capacity of all tested algorithms. The
provision of data rates guarantees of 64, 128 and 384 kbps (at 5\% outage)
incurs on a cell capacity reduction respectively of around 10, 30 and 80\%
relative to the maximum cell capacity."
}

@INPROCEEDINGS{Amei0409:System,
AUTHOR="Pablo Ameigeiras and Jeroen Wigard and Preben Mogensen",
TITLE="System Level Performance of the {M-LWDF} Scheduling Algorithm for Streaming
Services in {HSDPA}",
BOOKTITLE="VTC'F04 Wireless Access",
DAYS=27,
MONTH=sep,
YEAR=2004,
ABSTRACT="The present article analyses the system level performance of the M-LWDF
(Modified Largest Weighted Delay First) scheduling algorithm for CBR
(Constant Bit Rate) encoded video flows in HSDPA. The results have shown
that the M-LWDF algorithm, which aims at satisfying the packet delay while
utilizing the fast channel quality information, represents a well suited
algorithm for providing high efficiency CBR streaming services on HSDPA.
From a system level performance point of view, it has been shown that the
M-LWDF algorithm is a rather unfair scheduling principle where the users
with poor average radio propagation conditions. However, a fair version of
the M-LWDF has been shown to yield a cell capacity reduction (at 5\%
outage). Regarding the sensitivity to the application delay jitter
constraints, it has been shown that a discard timer increase from 1 to 4
seconds in a Pedestrian A and 3 km/h environment produces a cell capacity
gain of around 35\% gain, while the same discard timer increase in a
Vehicular A and 3 km/h environment yields a 20\% gain."
}

@INPROCEEDINGS{Amer0405:Hadamard,
AUTHOR="Ihab Amer and Wael Badawy and Graham Jullien",
TITLE="Hadamard Transform in {MPEG-4} Part {10:} A Hardware Prototype",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="In 2001, the Joint Video Team (JVT) was formed to represent the cooperation
between the ITU-T Video Coding Expert Group (VCEG) and the ISO/IEC Moving
Picture Expert Group (MPEG) aiming for the development of a new
Recommendation/International Standard. The JVT are currently finalizing a
new standard for the coding (compression) of natural video images. The name
H.264 (or MPEG4 Part 10, Advanced Video Coding (AVC)) is given to the new
standard. AVC shares common features with other existing standards, while
at the same time, it has a number of new features that distinguish it from
conventional standards. This paper presents a hardware prototype for the
4x4 Hadamard transform and quantization that is applied to the DC
coefficients of the luma components when the macroblock is encoded in 16x16
Intra prediction mode. In MPEG4 Part 10, the idea of using hierarchal
transform is adopted. The implemented transform represents the second level
in the transformation hierarchy. It comes after the forward 4x4 integer
approximation of the DCT transform. The proposed architecture uses only add
and shift operations to reduce the computational requirements for the
transform operation. The architecture can be integrated on the same chip
with the forward 4x4 transform that is adopted by the AVC standard.
Alternatively, It can be implemented on a separate chip. In both cases,
simulation results show that the developed architecture satisfies the
real-time constraints required by different digital video applications. Due
to its high performance, the introduced architecture targets
high-resolution applications such as High Definition Television (HDTV) and
Digital Cinema. The architecture is prototyped and simulated using ModelSim
5.4®. It is synthesized using Leonardo Spectrum®."
}

@INPROCEEDINGS{Amft0403:Towards,
AUTHOR="Oliver Amft and Julian Randall and Gerhard {Tröster}",
TITLE="Towards {LuxTrace:} Using solar cells to support human position tracking",
BOOKTITLE="Second Interanational Forum on Applied Wearable Computing",
DAYS=17,
MONTH=mar,
YEAR=2004,
ABSTRACT="Tracking the position of humans within a building usually implies
significant infrastructure investment; also devices are usually too high in
weight and volume to be integrated into garments. We propose a system that
relies on existing infrastructure (and therefore requires little
infrastructure investment) and is based on a sensor that is low cost, low
weight, low volume and can be manufactured to have similar characteristics
to everyday clothing (flexible, range of colours). The proposed
contribution to this area is based on solar modules. This paper
investigates their theoretical and practical characteristics in a
simplified scenario. Forward motions on the large scale up to 10m long as
well as small scale motions related to the human body on the spot of less
than 10cm are investigated. Models with accuracy in the centimetre range
have been achieved. The case that energy harvesting technology could be
used for both sensing and providing power is thus strengthened."
}

@INPROCEEDINGS{Amin0403:Effective,
AUTHOR="Lisa Amini and Anees Shaikh and Henning Schulzrinne",
TITLE="Effective Peering for Multi-provider Content Delivery Services",
BOOKTITLE="IEEE Infocom 2004",
ADDRESS="Hong Kong",
DAYS=7,
MONTH=mar,
YEAR=2004,
ABSTRACT="Peering allows service providers to handle traffic surges without
over-provisioning, reduce the cost of dedicated infrastructure, and
leverage the specialization and prices of partner providers.  In this
paper, we develop a peering system for multi-provider content delivery
based on a cost-optimized peer selection algorithm.  We formulate a cost
model for evaluating competing peering strategies, and use measurement data
collected from globally distributed network probe stations, large-scale Web
sites, and existing service provider infrastructures to empirically
evaluate proposed peering strategies.  Our analysis shows that our peer
selection algorithm is significantly more efficient than greedy
alternatives, in terms of minimizing service cost and respecting network
delay and server capacity thresholds, over a broad range of real-world
scenarios."
}

@ARTICLE{Amin0404:Issues,
AUTHOR="Lisa Amini and Anees Shaikh and Henning Schulzrinne",
TITLE="Issues with inferring Internet topological attributes",
JOURNAL="Computer Communications",
VOLUME=27,
NUMBER=6,
PAGES="557-567",
MONTH=apr,
YEAR=2004,
REFERENCES=19,
KEYWORDS="Internet mapping; Topology; Traceroute; Border Gateway Protocol; BGP",
ABSTRACT="A number of recent studies of Internet network structure are based on data
collected from inter-domain BGP routing tables and tools, such as
traceroute, to probe end-to-end paths. The goal of these studies is often
to infer Internet topological properties. There is growing evidence,
however, that the amount and diversity of the data has a significant impact
on the conclusions drawn about some of the structural properties. While
systematic data collection from a number of network vantage points can
reduce certain ambiguities, thus far, no methods have been reported for
fully resolving these issues. The goal of our study was to quantify the
effects of these anomalies on key Internet structural attributes. We report
on our analysis of over 290,000 measurements from globally distributed
sites. We contrast results obtained from router-level measurements with
those obtained from BGP routing tables, and offer insights as to why
certain inferred properties differ. We use multiple views of the same data
to demonstrate that some topological attributes, such as the average path
length, are relatively consistent across a variety of data sources. We also
illustrate how using the same methodology to model other attributes, such
as those based on the actual forwarding path between a pair of nodes, or
the level of AS path asymmetry, can produce substantially misleading
results.",
URL="http://www.sciencedirect.com/science?\_ob=MImg\&\_imagekey=B6TYP-4B473DY-1-10\&\_cdi=5624\&\_orig=browse\&\_coverDate=04\%2F30\%2F2004\&\_sk=999729993\&view=c\&wchp=dGLbVtz-zSkWb\&\_acct=C000002018\&\_version=1\&\_userid=18704\&md5=0089e7448eeab2adbf45db709af94fa3\&ie=f.pdf"
}

@INPROCEEDINGS{Amin0406:Scheduling,
AUTHOR="Alaa Amin and Reda Ammar and Ayman Ibrahim",
TITLE="Scheduling Real Time Parallel Structure on Cluster Computing with Possible
Processor failures",
BOOKTITLE="The Ninth IEEE Symposium on Computers and Communications",
ADDRESS="Alexandria, Egypt",
DAYS=29,
MONTH=jun,
YEAR=2004,
ABSTRACT="Efficient task scheduling is essential for achieving high performance
computing applications for distributed systems. Most of existing real-time
systems consider schedulability as a main goal and ignores other effects
such as machines failures. In this paper we develop an algorithm to
efficiently schedule parallel task graphs (fork-join structures). Our
scheduling algorithm considers more than one factor at the same time. These
factors are scheduability, reliability of the participating processors and
achieved degree of parallelism. To achieve most of these goals, we composed
an objective function that combines these different factors simultaneously.
The proposed objective function is adjustable to provide the user with a
way to prefer one factor to the others. The simulation results indicate
that our algorithm produces schedules where the applications deadlines are
met, reliability is maximized and the application parallelism is exploited."
}

@INPROCEEDINGS{Amir0405:10,
AUTHOR="Amir Amirabadi and Mohammad {Moghaddam Tabrizi} and M. Sharifkhani and Omid
Shoaei",
TITLE="A 10 b, 40 Msample/s, 25 mW Pipeline Analog to Digital Converter",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="This paper describes a 10 b pipelined ADC designed in 0.35um CMOS
technology which achieves a power dissipation of 25 mW at full speed
operation from a single 3 V supply. The proposed high speed gain-boosted
opamp make it possible to achieve requirements of 10-bit resolution and
settling time of 8 ns within 0.01\% accuracy. A dynamic comparator is used
for power efficiency. This design achieves INL and DNL of 0.68 LSB and 0.45
LSB respectively, while SNDR is 58.2 dB and SFDR is 73.4."
}

@INPROCEEDINGS{Amir0411:Multi,
AUTHOR="Amir Amirkhany and Vladimir Stojanovic and Mark Horowitz",
TITLE="Multi-tone Signaling for High-speed Backplane Electrical Links",
BOOKTITLE="IEEE Globecom 2004",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="A Multi-tone architecture is proposed for high-speed backplane serial
links. To limit complexity the links use analog multi-tone rather than the
more modern DMT. The tradeoffs involved in the design of such a system are
examined and the performance of a serial link based on this approach is
compared to a baseband architecture in terms of data rate and complexity
using a convex optimization framework. Slightly less than 2x improvement in
data rate at reasonable complexity is shown to be achievable with the
proposed architecture"
}

@INPROCEEDINGS{Amma0403:Frequency,
AUTHOR="Nejib Ammar",
TITLE="Frequency Selective Channel Estimation in {Time-Reversed} {Space-Time}
Coding",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="Time reversed space-time block code (TR-STBC) was originally proposed to
handle frequency selective fading channels. Its detection requires accurate
channel knowledge at the receiver side. In this work, we present a channel
estimation approach that does not require training data under TR-STBC
encoding. We provide identification conditions that are based on the known
code parameters as well as channel matrix rank. We present a simple
subspace algorithm for channel estimtion. Additionally, simulations results
are presented to highlight the performance of the estimation scheme."
}

@INPROCEEDINGS{Amma0405:Increasing,
AUTHOR="Mohamed Lassaad Ammari and Francois Gagnon and Jean Belzile and Naïm
Batani",
TITLE="Increasing the rate of wireless link when multiple {QoS} traffics are
considered",
BOOKTITLE="Transmission Technology",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="This document provides a system analysis for hitless flexible dada rate
adapted to received power with fixed spectrum. In our investigation we are
interested in digital Line-Of-Sight (LOS) microwave link. The channel
fading state, the grade of service and the adaptive modulation scheme are
examined. Essentially, the flexible communication scheme consists in
modifying, from one frame to the next, the modulation level used to
communicate on a wireless link. The radio thus provides for a significant
capacity gains if tra±c streams requiring di®erent Quality of Service
are being communicated. Most significant scenarios are considered and
quantified to obtain a realistic analysis of the grades of services
allocated to each tra±c stream. In this paper, we show for example, that
a 34 Mbit/s carrier grade link (99.9995\% availability) may be modified
into the sum of a 34 Mbit/s carrier grade link with a 100 Mbit/s data link
of 99.9\% availability."
}

@INPROCEEDINGS{Amma0406:Flat,
AUTHOR="Nejib Ammar",
TITLE="Flat Fading Channel Estimation Under Generic Linear {Space-Time} Block
Coded Transmissions",
BOOKTITLE="Signal Processing in Communications Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="Linear space-time block codes (STBC) are well established as efficient
means to improve performance of wireless MIMO communication systems. Their
success is contingent upon accurate knowledge of the channel parameters. In
this paper we present a blind channel estimation scheme for general linear
STBC. We furnish a set of identification conditions that are largely
verifiable in terms of the code parameters and the antennae array
configuration. We also present a simple algorithm to estimate the unknown
channel matrix. Finally we supply some simulation results to illustrate the
performance of the proposed scheme."
}

@INPROCEEDINGS{Amma0406:Modeling,
AUTHOR="Doaa ElZanfaly and Reda Ammar and Ahmed {Sharaf Eldin}",
TITLE="Modeling and Analysisof a Multi-level Caching in Distributed Database
Systems",
BOOKTITLE="The Ninth IEEE Symposium on Computers and Communications",
ADDRESS="Alexandria, Egypt",
DAYS=29,
MONTH=jun,
YEAR=2004,
ABSTRACT="Caching frequently asked queries is an effective way to improve the
performance of both centralized and distributed database systems. Intensive
works have been done in this area to propose different query caching
techniques and to evaluate their performance. However, most of these works
were confined to caching previous query results in a single-level caching
architecture. Evaluations of these works were based on simulations. In [1],
we proposed a new query caching technique for caching both query results
and execution plans in a multi-level caching architecture. The centralized
version of this technique was evaluated and the results were reported in
[2]. In this paper, we present an analytical model to evaluate the
performance of the proposed technique in distributed database systems."
}

@INPROCEEDINGS{Amma0406:Performance,
AUTHOR="Habib M. Ammari and Hesham El-Rewini",
TITLE="Performance Evaluation of Hybrid Environments with Mobile Gateways",
BOOKTITLE="The Ninth IEEE Symposium on Computers and Communications",
ADDRESS="Alexandria, Egypt",
DAYS=29,
MONTH=jun,
YEAR=2004,
ABSTRACT="To combine the advantages of Mobile ad hoc networks (MANETs) and the
Internet, we propose an approach that will integrate them into a hybrid,
unified network enabling MANET nodes to have Internet connectivity
regardless of their location in MANET. In order to best benefit MANET from
Internet resources access, we introduce mobile gateways, which are moving
around the boundary of fixed Internet gateways coverage range, to act as an
interface between MANET and the Internet. Mobile gateways are designed in a
way to overcome the network architectural mismatches that exist between
MANET and the Internet and widen the coverage range of fixed Internet
gateways. More specifically, mobile gateways are equipped with two
interfaces allowing them to communicate simultaneously with MANET and the
Internet using an ad hoc routing protocol and Mobile IP, respectively. Our
experiments, which were conducted using the network simulator ns2, adopted
Mobile IP protocol and Dynamic Source Distance Vector (DSDV) ad hoc routing
protocol, and showed that density and mobility of gateways as well as
time-to-live of agent advertisement have an impact on the hybrid network
performance based on some quantitative metrics."
}

@INPROCEEDINGS{Amma0406:TCOFDM,
AUTHOR="Mohamed Lassaad Ammari and François Gagnon",
TITLE="{TCOFDM} symbols detection : joint channel estimation and decoding",
BOOKTITLE="Communication Theory Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="In this paper, we consider the detection of turbo coded symbols in
orthogonal frequency division multiplexed (OFDM) systems and propose a
turbo detector composed of a turbo decoder and a channel estimator. These
modules perform jointly and exchange a soft information through an
iterative process. The decoder consists of the maximum a posteriori
MAP-BCJR algorithm and the channel estimator is based on the minimum mean
square error (MMSE) criterion. The proposed approach allows for the use of
all available information, increases the quality of channel estimation and
improves the system performance. Simulation results for rate 1/3 turbo code
show the efficiency of the proposed detector."
}

@INPROCEEDINGS{Amma0409:Multi,
AUTHOR="Mohamed Lassaad Ammari and Francois Gagnon and Philippe Dumais and Claude
Thibeault",
TITLE="Multi-equalization a powerful adaptive filtering for time varying wireless
channels",
BOOKTITLE="VTC'F04 Transmission Technology",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT={Nowadays, high quality equalizers are needed for wireless communication
systems. In fact, theses systems have to provide wireless data services
that require low bit error rates. In this paper, we propose a new
equalization architecture which uses multiple equalizers having different
structure that perform in parallel. Thus, for this technique, the received
signal is filtered by all used equalizers. Then, a selective module chooses
the {"}best{"} equalized signal based on an appropriate criterion. Hence,
one of the equalized signals is passed to the demodulator. This scheme
allows us to take advantage of several equalization architectures. For time
varying channel and long communications, multi-equalization becomes very
profitable. In fact, during such communications, channel characteristics
vary and so the best equalizer structure can change. Simulations results
show the efficiency of the proposed multi-equalization technique. In fact,
BER performances of the multi-equalizer composed by the three suggested
equalizers are better than those of each equalizer taken separately.}
}

@INPROCEEDINGS{Amma0410:Using,
AUTHOR="Habib M. Ammari",
TITLE="Using Hybrid Selection Schemes to Support {QoS} When Providing Multihop
Wireless Internet Access to Mobile Ad Hoc Networks",
BOOKTITLE="The First International Conference on Quality of Service in Heterogeneous
Wired/Wireless Networks",
ADDRESS="Dallas, Texas, USA",
DAYS=18,
MONTH=oct,
YEAR=2004,
ABSTRACT="The Quality of Service (QoS) of wireless Internet access that could be
provided to multihop wireless networks, so-called mobile ad hoc networks
(MANETs), is highly dependent on the quality of the design of the
intermediate facility that will integrate MANET and the Internet. This
facility is equipped with a hybrid mechanism being able to fulfill the
working requirements of MANET and the Internet so that it can act
appropriately when it connects to one of these orthogonal network
architectures. The architecture that we propose in order to provide MANET
nodes with wireless Internet access utilizes fixed gateways (or access
points) and exploits the mobility capability of additional mobile ones.
Because wireless Internet access to MANET nodes is guaranteed through
mobile gateways, the quality of such service depends on the selection
procedure used by MANET nodes to choose the most convenient mobile gateways
and register with. In this paper, we suggest to use a hybrid criterion
based on the weighted sum of the Euclidean distance between MANET nodes and
mobile gateways, and the load of mobile gateways, defined as the number of
MANET nodes currently registered with them. Moreover, the sum of the
weights is normalized to one, where each weight measures the level of
interest (or the degree of participation) of the corresponding criterion in
the hybrid one. Experimental results show that the hybrid criterion has an
impact on the quality of wireless Internet access service, measured in
terms of well-known quantitative metrics, depending on the level of
interest assigned to each of the Euclidean distance and load criteria in
the weighted sum."
}

@INPROCEEDINGS{Amor0401:Paper,
AUTHOR="Alessandro Amoroso and Leonardo Quirini",
TITLE="A paper-digital agenda",
BOOKTITLE="IEEE Consumer Communications \& Networking 2004",
ADDRESS="Las Vegas, Caesar's Palace",
DAYS=5,
MONTH=jan,
YEAR=2004,
ABSTRACT="We describe an application of a novel technology that provides an
innovative way to use the traditional pen and paper; by means of this
technology it is possibly to capture, and digitally process, any hand made
drawings and notes. In this paper we describe the architecture of an
Application Service Handler to synchronize a digital agenda with its
classical paper counterpart. A user may create, modify, or delete
appointments in the paper agenda, and the system transports these
modifications into the digital agenda almost transparently to the user. The
same results applies to the address book of the agenda. By means of our
system, the classical paper agenda becomes a proactive tool instead of a
passive one."
}

@ARTICLE{Amor0402:Self,
AUTHOR="Marcelo {de Amorim} and Otto Duarte",
TITLE="A self-extracting accurate modeling for bounded-delay video services",
JOURNAL="Computer Communications",
VOLUME=27,
NUMBER=3,
PAGES="197-207",
MONTH=feb,
YEAR=2004,
REFERENCES=32,
KEYWORDS="Bounded-delay services; MPEG video; Deterministic characterization;
Modeling accuracy",
ABSTRACT="This article proposes the XGOP-B deterministic traffic model for MPEG video
services requiring strict bounds on the quality of service provided by the
network. The XGOP-B model takes advantage of two characteristics of MPEG
video traffic by performing a two-level analysis of such sources. In our
scheme, the traffic parameters are directly obtained by a single-input
single-output parameter extracting algorithm. The proposed algorithm is
autonomous and leads to a single set of parameters for each video stream
avoiding user interaction determine the most appropriate set of parameters.
We show through analysis of several video traces that these original
features of the XGOP-B model yield accurate parameterizations at a low
complexity cost. Our results show that the accuracy of the XGOP-B model
leads to significant improvements when compared with the accuracy of the
other traffic models. Furthermore, the complexity is evaluated through the
number of traffic parameters and we show that it can be substantially
decreased.",
URL="http://www.sciencedirect.com/science?\_ob=MImg\&\_imagekey=B6TYP-49SM25P-1-5N\&\_cdi=5624\&\_orig=browse\&\_coverDate=02\%2F29\%2F2004\&\_sk=999729996\&view=c\&wchp=dGLbVtz-zSkWb\&\_acct=C000002018\&\_version=1\&\_userid=18704\&md5=187d0d3efd22f42aa71e5375dc2f3e73\&ie=f.pdf"
}

@INPROCEEDINGS{Amor0411:Fast,
AUTHOR="Alessandro Amoroso",
TITLE="Fast Colored Surface Rendering for Entertainment Applications on Small
Devices - An Experimental Study",
BOOKTITLE="1st IEEE International Workshop on Networking Issues in Multimedia
Entertainment",
ADDRESS="Dallas Texas, USA",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="The actual small devices, such as smartphones, PDAs, and handheld devices,
represent a challenging scenario. The applications running on those devices
require a tradeoff between the responsiveness felt by the user, and the
onboard computational power. The latter resembles to the computational
power of the early eighties computers. Therefore, this kind of hardware is
inadequate to support the same solutions adopted by the actual personal
computers. This paper emphasizes the usage of colors and wire--frame
visualization as an effective solution to the above limitations. The focus
of this work is on the visualization of bivariate function surfaces. This
proposal allows both an high visual impact, still remaining fast and
accurate, both to the fast rendering of scenarios in several entertainment
applications. The proposed visualization technique provides color
visualization and is faster than any other presented in literature. The
experiments here shown refer to the implementation of this proposal by
means of the Java programming language, and to its execution into a
smartphone."
}

@INPROCEEDINGS{An0405:Empirical,
AUTHOR="John An",
TITLE="Empirical Analyses on Maritime Radio Propagation",
BOOKTITLE="Antennas and Propagation",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="Abstract: Empirical model, based on extensive measurement data, was
developed to characterize maritime radio propagation at 1.8 GHz frequency.
The experiments were conducted using seashore-to-ship radio with different
sea wave heights. Instead of cumulative time distribution of signal
intensity, multipath power was estimated and analyzed to determine its
cumulative distributions and level crossing rates for fade depth and fade
intensity, respectively. Overall signal statistics (direct path plus
reflections) were found to be non-conclusive in Rician factor attribution
versus sea wave height. However, two typical phenomena, based on our
empirical data, were presented to express the effects of physical change in
sea conditions. The cumulative distribution of overall signal power was
found to be a mixture of the Rician and log-normal distributions with the
occurrence of large scale unsteady currents in sea waves. From our
observations, a coherent reflection component may be voluntarily imposed
over non-coherent components, resulting in a large value of Rician factor,
especially under small sea wave height or calm sea condition."
}

@INPROCEEDINGS{An0406:Cluster,
AUTHOR="Huiyao An",
TITLE="A {Cluster-Based} Multipath Routing for {MANET}",
BOOKTITLE="The Third Annual Mediterranean Ad Hoc Networking Workshop",
ADDRESS="Bodrum, Turkey",
DAYS=27,
MONTH=jun,
YEAR=2004,
ABSTRACT="To support QoS routing in MANET (Mobile Ad hoc Networks) is a core issue in
the research of MANET. This article proposes a Cluster-Based Multipath
Routing in MANET (CBMRP). It distributes traffic among diverse multiple
paths to avoid congestion, which optimizes bandwidth using and improves the
sharing rate of channel. It uses clustering¯s hierar-chical structure
diverse to decrease routing control overhead and improve the networks
scalability. By implementing the algorithm on the OPNET environ-ment, the
result shows that this algorithm balances the load of the network and deal
with the change ef-fectively of the network topology, and also improves the
reliability, throughput and stability of the network efficiently."
}

@INPROCEEDINGS{An0411:Design,
AUTHOR="Liming An and Hung-Keng Pung and Lifeng Zhou",
TITLE="Design and Implementation of a Dynamic Protocol Framework",
BOOKTITLE="IEEE International Conference on Networks 2004",
ADDRESS="Singapore",
DAYS=17,
MONTH=nov,
YEAR=2004,
ABSTRACT="Future distributed applications are expected to be deployed in an
environment that is more dynamic and heterogeneous than ever before. The
environment features are difficult to predict beforehand due to their
variations. To cope with such variations, it is important that the protocol
stack is adaptable to changing requirements. This paper proposes a
component-based Dynamical Protocol Framework (DPF) for multimedia
applications. It dynamically builds an adaptive protocol stack by automatic
discovery of protocol components and runtime configuration/reconfiguration
of the protocol stack. Performance measurement shows that compared with
directly using interfaces provided by JMF, using DPF to set up a dynamic
protocol stack incurs slight overhead in unicast, and the similar condition
is observed in multicast. This is the trade-off for the abilities to
configure/reconfigure stack during the media stream set-up and run time."
}

@INPROCEEDINGS{Anan0404:Virtual,
AUTHOR="Bharath Ananthasubramaniam and Upamanyu Madhow",
TITLE="Virtual Radar Imaging for Sensor Networks",
BOOKTITLE="Information Processing in Sensor Networks",
ADDRESS="Berkeley, California",
DAYS=26,
MONTH=apr,
YEAR=2004,
ABSTRACT="Most approaches to sensor data collection in the literature are based on
multihop wireless relay between sensor nodes forming an ad hoc network to
reach a remote data-processing destination. In this paper, we propose an
alternative Virtual Radar paradigm, which, in its most rudimentary form, is
implementable with sensor nodes without networking capabilities. We
introduce this concept for a simple setting in which each sensor only has
one bit of information to send (e.g., indicating whether the level of a
certain chemical has crossed a threshold). ``Active'' sensors (those which
have one to send) respond to a beacon sent by a collector node, precisely
timed with a trigger sequence in the beacon. The collector node uses a
modified version of synthetic aperture radar processing to obtain an
``image'' of the activity in the sensor network."
}

@INPROCEEDINGS{Anas0406:Experimental,
AUTHOR="Giuseppe Anastasi and Marco Conti and Enrico Gregori and Andrea Passarella",
TITLE="Experimental Analysis of an Application-independent Energy Management
Policy for {Wi-Fi} Hotspots",
BOOKTITLE="The Ninth IEEE Symposium on Computers and Communications",
ADDRESS="Alexandria, Egypt",
DAYS=29,
MONTH=jun,
YEAR=2004,
ABSTRACT="In the near future more and more users will access Internet services by
means of portable devices through wireless links. However, mobile computing
is still strongly limited by the scarcity of energetic resources of
portable devices. In this paper we propose and evaluate an
application-independent energy management scheme for a Wi-Fi hotspot
scenario. Unlike energy management schemes operating at the MAC layer
(e.g., the IEEE 802.11 power management), the solution considered in this
paper is able to adapt to the application traffic profile saving a
considerable amount of energy. For the same reason it is flexible, i.e., it
exhibits good performance irrespective of the specific network application,
and even in the presence of multiple active applications. Experimental
measurements performed on a prototype implementation with different traffic
types have shown that our energy management scheme is able to save up to
80\% of the energy consumed in a legacy architecture even in a
multi-application environment. Furthermore, this energy saving does not
produce a significant degradation on the QoS perceived by the user."
}

@INPROCEEDINGS{Anas0410:Performance,
AUTHOR="Giuseppe Anastasi and Marco Conti and Alessio Falchi and Enrico Gregori and
Andrea Passarella",
TITLE="Performance Measurements of Mote Sensor Networks",
BOOKTITLE="Seventh ACM/IEEE(*) International Symposium on Modeling, Analysis and
Simulation of Wireless and Mobile Systems",
ADDRESS="Venice, Italy",
DAYS=4,
MONTH=oct,
YEAR=2004,
ABSTRACT="In this paper we investigate the performance of Mica2 and Mica2dot Berkeley
motes by means of an extensive experimental analysis. This study is aimed
at analyzing the main elements that characterize the performance of a
sensor network, e.g., power consumption in different operating conditions,
impact of weather conditions, interference between neighboring nodes, etc.
Even if the analysis is related to a specific technology it provides some
general useful information. Specifically, we found that the transmission
range of mote sensor nodes decreases significantly in the presence of fog
or rain. We also investigate the interference between neighboring nodes
and, based on the experimental results, we propose a channel model for mote
sensor nodes. This model is very similar to the channel model of IEEE
802.11 networks."
}

@INPROCEEDINGS{Anda0412:OFDM,
AUTHOR="Zohreh Andalibi and S. Hamidreza Jamali and Farokh Arazm",
TITLE="Orthogonal Frequency Division Multiplexing Synchronization in Software
Radio Implementation of {IEEE802.16a}",
BOOKTITLE="Australian Telecommunication Networks  and Applications Conference",
ADDRESS="Sydney, Australia",
DAYS=8,
MONTH=dec,
YEAR=2004,
ABSTRACT="In this paper we apply and compare different methods for timing and
frequency synchronization in Fixed-point Broadband Wireless Access 802.16a
standard from SWR viewpoint and then select the best one. The selected
method must have a good performance in order to keep acceptable total
complexity loading of system."
}

@INPROCEEDINGS{Ande0405:Use,
AUTHOR="Henrik Andersson and Per Larsson and Patrik {Wikström}",
TITLE="The Use of {HVAC} Ducts for {WCDMA} Indoor Solutions",
BOOKTITLE="Antennas and Propagation",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="In this paper the use of in-building solutions in WCDMA is studied. In
particular HVAC ducts for RF distribution is studied. Measurement results
from a real HVAC (Heating, Ventilation, and Air Conditioning) installation
is used as input to a simulation study where coverage, capacity and quality
for the whole radio network are evaluated. The basic idea is to use
existing HVAC systems for radio signal distribution. Typically one or more
antennas are installed into the HVAC ducts at a central place. In many
cases the HVAC solution can replace or complement a traditional DAS
(Distributed Antenna System). This is a method of spreading RF signals. It
does not matter which standard that is carried over the air as long as it
is RF signals. We have performed measurements and case studies showing the
feasibility for GSM900, GSM1800, WCDMA/FDD and IEEE802.11b. In this paper
we focus on WCDMA. Indoor solutions are needed for coverage, capacity and
quality reasons. In the paper these performance criterias are evaluated for
the HVAC solution."
}

@INPROCEEDINGS{Ande0410:Speech,
AUTHOR="Richard Anderson and Crystal Hoyer and Craig Prince and Fred Videon and
Steve Wolfman and Jonathan Su",
TITLE="Speech, Ink, and Slides: The Interaction of Content Channels",
BOOKTITLE="ACM Multimedia 2004 Long Papers",
ADDRESS="New York, NY",
DAYS=10,
MONTH=oct,
YEAR=2004,
ABSTRACT="In this paper, we report on an empirical study of digital ink and speech
usage in lecture presentation. We studied the video archives of five
masters level courses to understand how instructors use ink and speech
together while lecturing, and to evaluate techniques for analyzing digital
ink. The motivation for the study was to have an empirical basis for speech
and ink recognition work to support the analysis of recorded lectures. Our
results include an evaluation of handwritten word recognition in the
lecture domain, an approach for associating attentional marks with content,
an analysis of linkage between speech and ink, and an application of
recognition techniques to infer speaker actions."
}

@INPROCEEDINGS{Ando0401:Qos,
AUTHOR="Satoshi Ando and Masao Ohmoto and Yuji Shimizu",
TITLE="{QoS} Technology for Home Network",
BOOKTITLE="IEEE Consumer Communications \& Networking 2004",
ADDRESS="Las Vegas, Caesar's Palace",
DAYS=5,
MONTH=jan,
YEAR=2004,
ABSTRACT="It is entailed with the diffusion of the Internet and the increase of  the
number of  users and  devices in the home that the installation of the
network (LAN) into the home is proceeding.It shows a tendency to be
composed by several types of layer-2 which have different characteristic
,such as wired or wireless Ethernet.And even if the a type of layer-2 is
same,it have also several characteristics in communication speed and
communication mode.In the near future, the realtime communication of AV
appliances and IP telephone which needs QoS will increase.In such a case,
it is necessary for providing QoS to discover precise topology of the
network and resource (L2 type, communication speed , communication mode) in
the network. This paper presents the discovery mechanism to discover
topology which has the high possibility of  changing to another feature in
some condition ,and the reservation mechanism to reserve resource."
}

@INPROCEEDINGS{Andr0403:Scheduling,
AUTHOR="Matthew Andrews and Lisa Zhang",
TITLE="Scheduling over non-stationary wireless channels with finite rate sets",
BOOKTITLE="IEEE Infocom 2004",
ADDRESS="Hong Kong",
DAYS=7,
MONTH=mar,
YEAR=2004,
ABSTRACT="We consider a wireless basestation transmitting high-speed data to
multiple mobile users in a cell.  The channel conditions between the
basestation and the users are time-varying and user-dependent.  We
wish to define which user to schedule at each time step.  Previous
work on this problem has typically assumed that the channel conditions
are governed by a stationary stochastic process.  In this
setting a popular algorithm known as Max-Weight has been shown to have
good performance.

However, the stationarity assumption is not always reasonable.  In
this paper we study a more general worst-case model in which the
channel conditions are governed by an adversary and are not
necessarily stationary. In this model, we show that the
non-stationarities can cause Max-Weight to have extremely poor
performance. In particular, even if the set of possible transmission
rates is finite, as in the CDMA 1xEV-DO system, Max-Weight can
produce queues size that are exponential in the number of users.  On
the positive side, we describe a set of Tracking Algorithms that aim to
track the performance of a schedule maintained by the adversary.  For
one of these Tracking Algorithms the queue sizes are only quadratic. 

We discuss a number of practical issues associated with the
Tracking Algorithms. We also illustrate the performance of Max-Weight
and the Tracking Algorithms using simulation."
}

@INPROCEEDINGS{Ang0409:Novel,
AUTHOR="Wee-Peng Ang",
TITLE="A Novel Channel Estimator For Turbo Decoding In Stationary and
Non-stationary Flat Fading Channel",
BOOKTITLE="Ninth International Conference on Communication Systems",
ADDRESS="Singapore",
DAYS=6,
MONTH=sep,
YEAR=2004,
ABSTRACT="A new and efficient Fast Fourier Transform (FFT) channel estimation filter
with an integrated fading rate calculator is developed for turbo decoding
in a flat fading channel. It removes the need for a-priori knowledge of the
channel fading rate for good performance which is a key requirement in the
many filters in existing literatures. Under both time-invariant and
time-varying fading rate, it achieves BER performance close to the optimum
Wiener filter with a lower computational count."
}

@INPROCEEDINGS{Ang0411:Attacks,
AUTHOR="Mei-Chiun Ang and Raphael Phan",
TITLE="Attacks on the Secure {SSM} Architecture Proposed at {ICON} 2002",
BOOKTITLE="IEEE International Conference on Networks 2004",
ADDRESS="Singapore",
DAYS=17,
MONTH=nov,
YEAR=2004,
ABSTRACT="The Source Specific Multicast (SSM) model is a collection of approaches
standardized by the Internet Engineering Task Force (IETF) to optimize the
communication used by multimedia applications involving several
participants. At ICON2002, it was highlighted that the SSM does not cater
to security services such as access control and content provider
protection, and hence a variant called the Secure SSM (S-SSM) was proposed.
In this paper, we present attacks on the S-SSM and hence show that the
security that it provides is still insufficient. We also suggest some
countermeasures to increase its security."
}

@INPROCEEDINGS{Anib0405:Fast,
AUTHOR="Ghassane Aniba and Sonia Aissa",
TITLE="Fast Packet Scheduling Assuring Fairness and Quality of Service in {HSDPA}",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Channels in wireless networks are characterized by their fast and random
variations in time making it a challenge to ensure fairness among users
with different quality of service (QoS) requirements. Fast packet
scheduling is the main component of HSDPA (High Speed Downlink Packet
Access) that aims at tracking the variations of the channels. In each
transmission time interval (TTI) the schedulers objective is to choose the
user or users for which packets would be transmitted depending on their
modulation and channel coding schemes (MCS) for the purpose of increasing
the systems performance both in terms of throughput and fairness. One of
the known algorithms that attempt to achieve a reasonable
throughput-fairness tradeoff is the Proportional Fairness (PF) algorithm,
which is implemented in HDR (High Data Rate). The PF algorithm was
introduced to compromise between a fair throughput for each user and the
total throughput. However, recent studies based on this algorithm showed
unevenness in the throughput achieved by the different users when these
experience different channel conditions. In this paper, we introduce a new
Fast Packet Scheduling Algorithm which resolves this problem improving,
hence, fairness in satisfying the QoS of active users. Our algorithm is
executed in two steps. In the first, the algorithm attempts to obtain
convergence of the throughput of different users to target values, using
specified initial parameters. Then, these parameters are updated to achieve
fairness among the different users based on their required QoS. Simulation
results and comparisons show that the proposed algorithm significantly
improves fairness with a slight decrease in total throughput."
}

@INPROCEEDINGS{Anib0411:Adaptive,
AUTHOR="Ghassane Aniba and Sonia Aissa",
TITLE="Adaptive Proportional Fairness for Packet Scheduling in {HSDPA}",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="This paper considers packet scheduling in High Speed Downlink Packet Access
(HSDPA) networks. The main component of HSDPA is the capability of tracking
fast channel variations, which should be used to conduct fast scheduling of
packets while ensuring fairness between users. We consider the operating
environment where the scheduling is performed in heterogeneous channels. In
this case, Proportional Fairness (PF) scheduling and its enhanced version,
the Data Rate Control (DRC) Exponent rule, fail to achieve the goal of
providing fair throughput to the users. We propose in this paper an
approach that resolves this shortcoming. The proposed scheduling algorithm,
called Adaptive Proportional Fairness (APF) is shown to ensure proportional
fairness even under different QoS requirements for users experiencing
different channel conditions. The APF algorithm is subdivided in two
modules: a short-term module which consists of an enhanced version of the
selection criterion adopted in the DRC Exponential rule, and a long-term
one, in which we make updating of the parameters that we introduce to
ensure fairness among users. Simulation results and comparisons show the
high efficiency of our approach compared to PF scheduling."
}

@INPROCEEDINGS{Anja0403:Lsp,
AUTHOR="Tricha Anjali and Caterina Scoglio and Ian Akyildiz",
TITLE="{LSP} and {Lambda-SP} Setup in {GMPLS} Networks",
BOOKTITLE="IEEE Infocom 2004",
ADDRESS="Hong Kong",
DAYS=7,
MONTH=mar,
YEAR=2004,
ABSTRACT="In this paper, a new optimal policy is introduced to determine and 
adapt the Generalized MultiProtocol Label Switching (GMPLS) network 
topology based on the current traffic load. The objective of the new
policy is to minimize the costs involving bandwidth, switching and 
signaling. The policy is derived by utilizing the powerful theoretical 
tool of Markov Decision Process theory. The policy is split into two 
levels, the first deals with the MPLS network and the second with the 
optical level. The new Integrated Traffic Engineering paradigm 
provides mechanisms for dynamic addition of physical capacity to 
optical networks. In the absence of such mechanisms, the rejection of 
incoming requests will be higher. In addition to the optimal policy, a 
sub-optimal policy and a threshold-based policy are also proposed 
which are less computationally intensive but have comparable 
performance to the optimal policy. The proposed policies have been 
evaluated by simulation and compared to some heuristics. Numerical 
results, which show their effectiveness and the achieved performance 
improvement, are presented."
}

@INPROCEEDINGS{Anja0403:Threshold,
AUTHOR="Tricha Anjali and Caterina Scoglio and Ian Akyildiz",
TITLE="{Threshold-Based} Policy for {LSP} and Lightpath Setup in {GMPLS} Networks",
BOOKTITLE="IEEE Infocom 2003",
MONTH=mar,
YEAR=2004
}

@INPROCEEDINGS{Anja0406:Threshold,
AUTHOR="Tricha Anjali and Caterina Scoglio",
TITLE="{Threshold-Based} Policy for {LSP} and Lightpath Setup in {GMPLS} Networks",
BOOKTITLE="QoS and Performance Modeling Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="In this paper, a new policy is introduced to determine and adapt the
Generalized MultiProtocol Label Switching (GMPLS) network topology based on
the current traffic load. The objective of the new policy is to minimize
the costs involving bandwidth, switching and signaling. The new policy is
based on a threshold criterion. The policy is split into two levels, the
first deals with the MPLS network and the second with the lightpath level.
The two thresholds depend on the cost coefficients and the number of the
intermediate hops. Our policy also performs a filtering control to avoid
oscillations which occur due to highly variable traffic. The proposed
policy has been evaluated by simulation and numerical results, which show
its effectiveness and the achieved performance improvement."
}

@INPROCEEDINGS{Anja0411:Traffic,
AUTHOR="Tricha Anjali and Caterina Scoglio",
TITLE="Traffic Routing in {MPLS} Networks based on {QoS} Estimation and Forecast",
BOOKTITLE="IEEE Globecom 2004",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="Emerging applications demand strict Quality of Service from the network. To
meet these demands, a suitable path with enough resources needs to be
selected. This paper focuses on the path computation in an MPLS network for
a traffic flow, based on distance, bandwidth and delay constraints. The
goal of the paper is to find a feasible path that minimizes the cost
incurred. The cost is attributed to bandwidth carriage, and switching and
signaling efforts in the network for the requested connection."
}

@INPROCEEDINGS{Anju0409:Lightweight,
AUTHOR="Farooq Anjum and Rajesh Talpade",
TITLE="Lightweight Packet Drop Detection for Ad hoc Networks",
BOOKTITLE="VTC'F04 Wireless Access",
DAYS=27,
MONTH=sep,
YEAR=2004,
ABSTRACT={We present a scalable, effective and practical approach for detection of
packet-drop attacks in ad hoc networks. In this attack, a malicious network
node chooses to selectively drop packets that are supposed to be forwarded,
which results in adverse impact on application good-put and network
stability. Briefly, our approach requires network nodes to report
statistics on IP flow packets originated, received, or forwarded to
neighbors. These statistics are analyzed and correlated to determine nodes
suspected of dropping packets. Preliminary OPNet-based simulation results
with simplistic network topology suggest that our approach is quite
accurate in detecting a malicious packet-dropping node even in the presence
of non-malicious {"}natural{"} link-loss, and when the malicious node is
{"}lying{"} by reporting incorrect statistics. Initial estimates of
bandwidth overhead consumed by the approach are low, and can be modulated
by configuration parameters. We are in the process of augmenting the
simulation to better handle large networks and node mobility, so as to
determine the performance of the approach in more realistic scenarios.}
}

@INPROCEEDINGS{Anna0403:Analysis,
AUTHOR="Ramesh Annavajjala and Laurence Milstein",
TITLE="Analysis of Selection Combining Schemes on Rayleigh Fading Channels with
Noisy Channel Estimates",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="The optimum selection combining (SC) scheme, proposed recently by Kim and
Kim, requires estimation of complex channel fades on every diversity
channel for minimizing the average probability of error. In this paper, we
quantify the effect of imperfect channel estimation on the performance of
the optimum SC receiver. By modeling the estimation errors as independent
Gaussian random variables, we obtain a simple closed-form expression for
the average probability of error. We also analyze a simple sub-optimum SC
scheme, based on the output of the coherent matched filter alone, without
requiring the knowledge of the fade amplitudes, in the presence of channel
estimation errors. Finally, we provide some numerical results to illustrate
the comparative performances of various SC receivers with pilot-aided
minimum mean-square error (MMSE) channel estimation."
}

@INPROCEEDINGS{Anna0403:Capacity,
AUTHOR="Ramesh Annavajjala and Laurence Milstein",
TITLE="On the Capacity of Dual Diversity Combining Schemes on Correlated Rayleigh
Fading Channels with Unequal Branch Gains",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="In this paper, we investigate the effect of fade correlation and the level
of unbalance in the mean signal strength on the capacity of Rayleigh fading
channels with dual antenna receive diversity. We consider maximal ratio
combining (MRC), equal gain combining (EGC) and selection combining (SC)
diversity schemes and derive expressions for the average and the outage
capacity of the channel. For the case of MRC and SC schemes we obtain
closed-form expressions for the average and the outage capacities, whereas
efficient Gauss-Hermite quadrature rule based expressions are provided for
EGC diversity. Numerical results are provided to illustrate the capacity
degradation due to channel correlation and the unbalanced diversity
branches."
}

@INPROCEEDINGS{Anne0405:Providing,
AUTHOR="Antonio Annese and Gennaro Boggia and Pietro Camarda and Luigi Grieco and
Saverio Mascolo",
TITLE="Providing Delay Guarantees in {IEEE} 802.11e Networks",
BOOKTITLE="Mobile Networks",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="This paper proposes a novel bandwidth allocation algorithm for IEEE 802.11e
WLANs with HCF. The algorithm has been designed by following a control
theoretic approach. It distributes the limited WLAN capacity to meet the
desired queueing delay that audio/video applications would expect. The
effectiveness of the control algorithm has been compared with respect to
the standard HCF 802.11e scheduling algorithm and with respect to the DCF
mechanism, by using the ns-2 simulator. Simulation results have shown that
the proposed algorithm provides bounded delays and outperforms both the
standard scheduling algorithm and the DCF mechanism."
}

@INPROCEEDINGS{Anne0407:Space,
AUTHOR="Fred Annexstein and Ken Berman",
TITLE="A {Space-Efficient} Model for Sharing Personal Knowledge Objects in Peer
Communities",
BOOKTITLE="Peer-to-Peer Knowledge Management workshop",
ADDRESS="Boston, Massachusetts, USA",
DAYS=22,
MONTH=aug,
YEAR=2004,
ABSTRACT="In the future it is likely that peer communities will be routinely
established for the purpose of sharing electronic resources and targeted
information among groups of peers with common interests. This sharing will
be possible by building on existing Internet technologies, such as web
applications and services, and peer-to-peer networks. Today many
peer-to-peer networks do not work well for sharing large heterogeneous
collections among common home users. In this paper we present a model for
organizing personal knowledge and a two-fold framework for improving
methods of information sharing. Our framework is based on a) the creation
of compact, portable, organizational objects through the ad-hoc structuring
of knowledge on a personal computer, and b) the aggregation of these
organizational objects into a visual catalog that can provide a peer
community with a conceptual view of the information resources residing in
the community. We call our model the BookQuest framework, and we show how
it addresses several key information sharing issues, including
space-efficient summarization, naming and locating resources in a peer
com-munity, and user interface and visualization issues. Our model employs
a vari-ety of techniques for space-efficient representations, including use
of generalized Bloom filters to support ranked keyword searches, and
statistical sampling methods to support similarity comparisons between
collections. We describe applications of our model to peer-based, inquiry
orientated educational activi-ties."
}

@INPROCEEDINGS{Anne0409:GSM,
AUTHOR="KoteswaraRao Anne and Kyandoghere Kyamakya and Fazli Erbas and Claude
Takenga and Jean Chamberlain Chedjou",
TITLE="{GSM} {RSSI-based} positioning using Extended Kalman Filter for training
Artificial Neural Network",
BOOKTITLE="VTC'F04 GPS Technologies and User Equipments for Mobile and Handheld
Communications",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="**INVITED PAPER FOR SESSION 8 of track 9 (Applications of Non-linear
filters and Chaos Theory in Security, Positioning and Communication
Systems) chaired by Kyamakya ** abstract: The precise position of the
mobile station is critical for the ever increasing number of applications
based on location. In this paper, we introduce a novel positioning
technique for positioning a GSM mobile phone in real-time. This technique
is based on the GSM mobile phone feature, that it can measure the signal
strengths from a number of nearby base stations. In this approach we use
the GSM signal strengths measured in real environment to train a neural
network. The neural network is trained using the second order learning
algorithm (Extended Kalman Filter), because of its superiority in the
learning speed and mapping accuracy. The mobile position can be determined
accurately by providing the current signal strength data to a previously
trained neural network. The good accuracy of the calculated position with
the EKF training and the back propagation training is tabled."
}

@INPROCEEDINGS{Anti0409:Evaluating,
AUTHOR="Stavros Antifakos and Adrian Schwaninger and Bernt Schiele",
TITLE="Evaluating the Effects of Displaying Uncertainty in {Context-Aware}
Applications",
BOOKTITLE="Ubicomp 2004",
ADDRESS="Nottingham, England",
DAYS=7,
MONTH=sep,
YEAR=2004,
ABSTRACT="Many context aware systems assume that the context information they use is
highly accurate. In reality, however, perfect and reliable context
information is hard if not impossible to obtain. Several researchers have
therefore argued that proper feedback such as monitor and control
mechanisms have to be employed in order to make context aware systems
applicable and useable in scenarios of realistic complexity. As of today,
those feedback mechanisms are difficult to compare since they are too
rarely evaluated. In this paper we propose and evaluate a simple but
effective feedback mechanism for context aware systems. The idea is to
explicitly display the uncertainty inherent in the context information and
to leverage from the human ability to deal well with uncertain information.
In order to evaluate the effectiveness of this feedback mechanism the paper
describes two user studies which mimic a ubiquitous memory aid. By changing
the quality respectively the uncertainty of context recognition the
experiments show that human performance in a memory task is increased by
explicitly displaying uncertainty information. Finally, we discuss
implications of these experiments for today's context-aware systems."
}

@INPROCEEDINGS{Anto0405:Role,
AUTHOR="Mirko Antonini and Daniele Teotino",
TITLE="The role of High Altitude Platforms {(HAPs)} within the Galileo locally
assisted services.",
BOOKTITLE="Vehicular Technology Conference Spring 2004",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="The role of High Altitude Platforms (HAPs) within the Galileo locally
assisted services. Mirko Antonini, Marina Ruggieri, Daniele Teotino.
Galileo will provide the first satellite positioning and navigation system
specifically for civil purposes [1]. The mission requirements were
developed with a service-oriented approach. Business plan and market
researches studies have shown that commercial services should play an
important role on producing Galileo revenues [2]. Nevertheless,
communication capabilities are a must for advanced navigation related
services. In this frame, the Galileo local components, that aim at
enhancing Galileo navigation performance and capabilities, will play a key
role in the future navigation system. The paper aims at explaining this
role, considering, in particular, the High Altitude Platforms (HAPs) as
local components. Some integration scenarios with 3G and 4G terrestrial
communication networks are shown and detailed. Therefore, commercial
applications of the local component concept are foreseen. The scenarios
propose a frame of guaranteeing service agreements for advanced telematics
and info-mobility applications. Finally, this frame could drive the price
of selling policies regarding to public utilities services, best effort
commercial services and guaranteed commercial services. [1] GALILEO Mission
High Level Definition, Issue 3, 23 September 2002 [2] GALILEO Study Phase
II, PriceWaterHouseCoopers, 17 January 2003"
}

@INPROCEEDINGS{Anto0406:Managing,
AUTHOR="Daria Antonova and Arvind Krishnamurthy and Zheng Ma and Ravi Sundaram",
TITLE="Managing a portfolio of overlay paths",
BOOKTITLE="NOSSDAV 2004",
ADDRESS="Kinsale, County Cork, Ireland",
DAYS=16,
MONTH=jun,
YEAR=2004,
ABSTRACT="In recent years, several architectures have been proposed and developed for
supporting streaming applications that take advantage of multiple paths
through the network simultaneously. We consider the problem of computing a
set of paths and the relative amounts of data conveyed through them in
order to support these high-bandwidth data streams. Given the expectation
and variance of the throughput of each path in the system along with the
covariances of the throughputs of pairs paths, we attempt to solve the
underlying resource allocation problem by applying methods used in managing
a finance portfolio. We observe that the flow allocation problem requires
highly constrained application of these methods and discuss the
tractability of enforcing the constraints. We finally present simulation
and experimental results to evaluate the effectiveness of our proposed
techniques."
}

@INPROCEEDINGS{Anto0406:Reduced,
AUTHOR="Carles Anton-Haro and Christoph {Mecklenbräuker} and Jose Vicario",
TITLE="Reduced-complexity Methods for Throughput Maximization in {MIMO} Channels",
BOOKTITLE="Signal Processing in Communications Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="This paper is focused on how computational complexity associated to an
algorithm for the maximisation of throughput in a Multiple-Input
Multiple-Output system can be reduced. Throughput optimisation is achieved
by selecting the appropriate subset of antennas on the transmit side. Given
the highly non-linear nature of the throughput expression and the finite
set of combinations, a straightforward approach consists in checking every
single subset. However, this results in a prohibitive complexity. This
paper presents two methods, named top-down and bottom-up approaches, that
lower computational burden by recursively obtaining throughput expressions
and, thus, avoiding unnecessary re-computations. The resulting schemes are
compared in terms of number of floating operations required."
}

@INPROCEEDINGS{Anto0410:Restorability,
AUTHOR="Zoe Antoniou and Wee-Seng Soh",
TITLE="Restorability Enhancement and {Service-Oriented} Protection in Radio Access
Networks",
BOOKTITLE="The First International Conference on Quality of Service in Heterogeneous
Wired/Wireless Networks",
ADDRESS="Dallas, Texas, USA",
DAYS=18,
MONTH=oct,
YEAR=2004,
ABSTRACT="Previously proposed solutions for wireless network reliability have focused
on protection against base station failures, which may require
significantly more base stations than necessary. Actual data from wireless
carriers suggest that problems in the backhaul are the uttermost
reliability problems faced, and is therefore the main focus of this work.
Current radio access networks are based on tree and star-like topologies,
which have no inherent restorability properties. This paper proposes a
heuristic topology enhancement method that adds redundant spans and
upgrades existing infrastructure cost-effectively, in order to create
partially meshed architectures that could provide the desired level of
restorability against single span failure scenarios. The algorithm is
tested using several different variants of restoration mechanisms,
including span and path restoration. Results show that the proposed
heuristic algorithm is able to achieve reasonably good solutions in a time
scale that is several orders of magnitude faster than an optimization
approach based on binary integer programming formulation. Finally, this
paper presents a service-oriented model for both protection traffic classes
and service classes requirements with flexible recovery mechanisms and
granularity. Attributes are defined and used to create differentiated
protection classes."
}

@INPROCEEDINGS{AnXi0409:Receiver,
AUTHOR="AX Lee",
TITLE="Receiver Design of {MIMO} Systems in a Mixture of Gaussian Noise and
Impulsive Noise",
BOOKTITLE="VTC'F04 Transmission Technology",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="Most of the analyses of Multiple-Input Multiple-Output (MIMO) systems so
far have been based on the ideal Gaussian noise model. In this paper,
performance analysis and receiver design of MIMO systems are performed in a
mixture of Gaussian noise and impulsive noise modeled as a symmetric
alpha-stable process. Both spatial multiplexing systems (SM-systems) and
space-time coding systems (STC-systems) are considered. The optimal
receiver and several suboptimal receivers are developed and the related
problems, such as performance, computational complexity and robustness, are
discussed. Simulation shows that the proposed receivers can achieve much
better performance than the traditional MIMO receivers in the mixed noise."
}

@INPROCEEDINGS{Aoua0401:UTRAN,
AUTHOR="Hazar Aouad and Samir Tohme and Ibrahim Abbas",
TITLE="{UTRAN} traffic parameters estimation",
BOOKTITLE="IEEE Consumer Communications \& Networking 2004",
ADDRESS="Las Vegas, Caesar's Palace",
DAYS=5,
MONTH=jan,
YEAR=2004,
ABSTRACT="The aim of this paper is to characterize the statistical distribution of
the inter arrival packet time of the UTRAN traffic at the SAP level of the
MAC layer. Since the UMTS networks are not deployed at this time, we
analyse simulated traffic trace to characterize the nature of the
aggregated flows. We chose an MMPP-2 process to model the inter-arrival
time between the packets."
}

@INPROCEEDINGS{Aoul0411:FAFC,
AUTHOR="Yassine {Hadjadj Aoul} and Hamid Nafaa and Daniel Negru and Ahmed Mehaoua",
TITLE="{FAFC:} Fast Adaptive Fuzzy {AQM} Controller For {TCP/IP} Networks",
BOOKTITLE="IEEE Globecom 2004 - Global Internet and Next Generation Networks",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="Recently, many Active Queue Management (AQM) algorithms have been proposed
to address performance degradations of end-to-end congestion control.
However, these AQM algorithms present weaknesses for stabilizing delays in
heavy loaded networks. In this paper, we describe a novel adaptive fuzzy
control algorithm to improve best effort TCP/IP Networks performance.
Comparing to traditional AQM algorithms (RED, PID and others), our proposal
avoids buffer overflows/underflows, and minimizes packets dropping. We
propose an on-line adaptation mechanism that captures fluctuating network
conditions, while classical AQM algorithms require static tuning. The
algorithm stability is mathematically proven. Simulation results show that
for the same link utilization, FAFC provides better performance than RED
and PID."
}

@INPROCEEDINGS{Appi0410:Improved,
AUTHOR="Venkatakrishnan {Balasubramanian Appiah}",
TITLE="An enhanced {HCF} for {IEEE} 802.11e Wireless Networks",
BOOKTITLE="Seventh ACM/IEEE(*) International Symposium on Modeling, Analysis and
Simulation of Wireless and Mobile Systems",
ADDRESS="Venice, Italy",
DAYS=4,
MONTH=oct,
YEAR=2004,
ABSTRACT="In this paper the behavior of the upcoming MAC protocol for wireless LANs
IEEE 802.11e is investigated. Based on the results, we propose an
enhancement for Hybrid Coordination Function (HCF) to improve its Admission
Control Unit (ACU). The analysis of Enhanced Distributed Coordination
Function (EDCF) and HCF schemes are performed for different network sizes
using ns-2 simulator. Three types of traffic voice, video and busty data
are used in this investigation. Four metrics transfer delay, jitter,
throughput and packet loss are considered in studying these schemes. The
investigations show that EDCF does well for small to moderate size of
networks whereas HCF performs better for larger networks. However, bursty
traffic receives very poor service from both schemes and is likely to
starve in a heavily loaded system. The performance of the enhanced HCF
(eHCF) scheme is also evaluated through simulation and then compared
against the standard schemes in 802.11e. The eHCF scheme shows fairness in
allocating bandwidth to different priority classes by employing a
Class-Based Queuing mechanism in its ACU."
}

@INPROCEEDINGS{Apte0409:Electrooptical,
AUTHOR="Boris Apter and Eldad Bahat-Treidel and Uzi Efron",
TITLE="Electrooptical {Wide-Angle} Beam Deflector Based on
{Fringing-Field-Induced} Refractive Inhomogeneity In a Liquid Crystal Layer",
BOOKTITLE="The 23rd IEEE convention of Electrical and Electronics Engineers in Israel",
ADDRESS="Herzlia, Israel",
DAYS=6,
MONTH=sep,
YEAR=2004,
ABSTRACT="A controllable, refractive, electrooptical liquid crystal (LC) beam
deflector was studied both theoretically and experimentally. The principle
of operation of this deflector is based on the generation of a high
gradient of refractive index in a thick LC layer by the fringing field
between two lateral electrodes in a simple 3-electrode LC cell. A Gaussian
laser beam, focused into the narrow region at the electrode gap was
effectively deflected by the refractive index gradient. A large deflection
angle of ~15o as well as a high deflection efficiency of 98\% were
demonstrated experimentally backed by a theoretical analysis."
}

@INPROCEEDINGS{Araú0409:Differential,
AUTHOR="Teresa {Araújo} and Rui Dinis",
TITLE="A Differential Receiver for {Single-Carrier} Modulations with Iterative
{Frequency-Domain} Equalization",
BOOKTITLE="VTC'F04 Transmission Technology",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="n this paper we propose a differential receiver for SC modulations
employing IB-DFE techniques. For the first iteration, we employ a
conventional differential detection after the equalization procedure; for
the remaining iterations, a coherent detection with differential decoding
is used, taking advantage of the improved carrier and phase synchronization
from the previous iterations. Our results show that the proposed receiver
structure has an excellent performance, allowing BERs (Bit Error Rate) very
close to the MFB (Matched Filter Bound), even with moderate frequency
offsets and severe time-dispersive channels."
}

@INPROCEEDINGS{Araú0411:Analytical,
AUTHOR="Teresa {Araújo} and Rui Dinis",
TITLE="Analytical Evaluation and Optimization of the {ADC} {(Analog-to-Digital}
Converter) in Software Radio Architectures",
BOOKTITLE="IEEE Globecom 2004",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="The software radio concept is a topic of widespread interest in wireless
cellular systems. Due to the high sampling ratio and quantization
requirements, the ADC (Analog-to-Digital Converter) is as key component of
any software radio architecture. In this paper we present an analytical
tool for evaluating the quantization requirements within the ADC used in
software radio architectures. For this purpose, we take advantage of the
Gaussian behavior of the multi-band/multi-user signal at the input of the
wideband ADC and employ results on Gaussian signals and memoryless
nonlinearities. This characterization is then used for the performance
evaluation and optimization of different quantization characteristics."
}

@INPROCEEDINGS{Araú0411:Iterative,
AUTHOR="Teresa {Araújo} and Rui Dinis",
TITLE="Iterative Equalization and Carrier Synchronization for {Single-Carrier}
Transmission over Severe {Time-Dispersive} Channels",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="In this paper we consider a broadband wireless system employing SC
(Single-Carrier) modulations combined with FDE (Frequency-Domain
Equalization). We propose a receiver structure for joint carrier
synchronization and equalization which combines IB-DFE (Iterative Block
Decision Feedback Equalization) and post-equalization carrier
synchronization schemes. The proposed receiver can be regarded as a
modified IB-DFE where we perform a decision-directed frequency offset
estimation within each iteration of the equalizer. Our results show that
the proposed receiver structure has a good performance, allowing BERs (Bit
Error Rate) close to the MFB (Matched Filter Bound), even with moderate
frequency offsets and severe time-dispersive channels."
}

@TECHREPORT{Arab0403:Gloserv,
AUTHOR="Knarig Arabshian and Henning Schulzrinne",
TITLE="{GloServ:} Global Service Discovery Architecture",
INSTITUTION="Department of Computer Science, Columbia University",
ADDRESS="New York",
MONTH=mar,
YEAR=2004,
KEYWORDS="service location; directory services",
ABSTRACT="Due to the growth in ubiquitous computing technology in the past few
years, the need for context-aware service discovery across wide area
networks is becoming prevalent. We propose GloServ, which is a global
service discovery architecture that locates services throughout wide
and local area networks. It supports services encompassing different
domains such as events, people or places. Services can be described
semantically using the Resource Description Framework (RDF) and can be
queried using the RDF Query Language (RQL). GloServ hierarchically
defines services using RDF schemas and assigns each service a URI
according to its location within the hierarchy. The hierarchical
architecture for GloServ is similar to how domain names are
categorized in DNS. Service discovery can either be initiated by the
user or by the system. For automated service discovery, users are
detected with sensors and are presented with services available
according to their preferences. Graphical user interfaces for querying
data is dynamically generated through the processing of RDF data.",
URL="http://www1.cs.columbia.edu/~knarig/gloservTR.pdf"
}

@INPROCEEDINGS{Arab0408:Glo,
AUTHOR="Knarig Arabshian and Henning Schulzrinne",
TITLE="{Glo-Serv:} Global Service Discovery Architecture",
BOOKTITLE="MobiQuitous 2004 Services",
ADDRESS="Boston, Massachusetts, USA",
DAYS=22,
MONTH=aug,
YEAR=2004,
ABSTRACT="Due to the growth in ubiquitous computing technology in the past few years,
the need for context-aware service discovery across wide area networks is
becoming prevalent. We propose Glo-Serv, which is a global service
discovery architecture that locates services throughout wide and local area
networks. It supports services encompassing different domains such as
events, people or places. Services can be described semantically using the
Resource Description Framework (RDF) and can be queried using the RDF Query
Language (RQL). Glo-Serv hierarchically defines services using RDF schemas
and assigns each service a URI according to its location within the
hierarchy. The hierarchical architecture for Glo-Serv is similar to how
domain names are categorized in DNS. Service discovery can either be
initiated by the user or by the system. For automated service discovery,
users are detected with sensors and are presented with services available
according to their preferences. The user interfaces for querying data is
dynamically generated through the processing of RDF data."
}

@INPROCEEDINGS{Arab0408:Gloserv,
AUTHOR="Knarig Arabshian and Henning Schulzrinne",
TITLE="{GloServ:} Global Service Discovery Architecture",
BOOKTITLE="First Annual International Conference on Mobile and Ubiquitous Systems:
Networking and Services (Mobiquitous)",
MONTH=aug,
YEAR=2004,
KEYWORDS="service discovery, context-aware, ubiquitous computing",
ABSTRACT="Due to the growth in ubiquitous computing technology in the past few
years, the need for context-aware service discovery across wide area
networks is becoming prevalent. We propose GloServ, which is a global
service discovery architecture that locates services throughout wide
and local area networks. It supports services encompassing different
domains such as events, people or places. Services can be described
semantically using the Resource Description Framework (RDF) and can be
queried using the RDF Query Language (RQL). GloServ hierarchically
defines services using RDF schemas and assigns each service a URI
according to its location within the hierarchy. The hierarchical
architecture for GloServ is similar to how domain names are
categorized in DNS. Service discovery can either be initiated by the
user or by the system. For automated service discovery, users are
detected with sensors and are presented with services available
according to their preferences. Graphical user interfaces for querying
data is dynamically generated through the processing of RDF data.",
URL="http://www.cs.columbia.edu/~knarig/gloserv.pdf"
}

@INPROCEEDINGS{ARAD0407:Headprint,
AUTHOR="Hrishikesh Aradhye and Martin Fischler and Robert Bolles and Gregory Myers",
TITLE="Headprint {---} Person Authentication Using Visual Features of Hair in
Overhead Surveillance Video",
BOOKTITLE="Audio- and Video-based Biometric Person Authentication",
ADDRESS="Rye, New York, USA",
DAYS=20,
MONTH=jul,
YEAR=2004,
ABSTRACT="In this paper, we present the results of our investigation of the use of
the visual characteristics of human hair as a primary recognition attribute
for human ID in indoor video imagery. The emerging need for unobtrusive
biometrics has led to recent research interest in using the features of the
face, gait, voice, and clothes, among others, for human authentication.
However, the characteristics of hair have been almost completely excluded
as a recognition attribute from state-of-the-art authentication methods. We
contend that people often use hair as a principal visual biometric.
Furthermore, hair is the part of the human body most likely to be visible
to overhead surveillance cameras free of occlusion. Although hair can
hardly be trusted to be a reliable long-term indicator of human identity,
we show that the visual characteristics of hair can be effectively used to
unobtrusively re-establish human ID in the task of short-term recognition
and reacquisition in a video-based multiple-person continuous tracking
application. We propose new pixel-based and line-segment-based features
designed specifically to characterize hair, and recognition schemes that
use just a few training images per subject. Our results demonstrate the
feasibility of this approach, which we hope can form a basis for further
research in this area."
}

@INPROCEEDINGS{Aran0409:User,
AUTHOR="Giuseppe Araniti and Antonio Iera and Antonella Molinaro and Salvatore
Pulitanò",
TITLE="User Profiling Techniques for Adaptive {QoS} Management in Multibearer
Mobile Radio Networks",
BOOKTITLE="International Symposium on Wireless Communication Systems",
ADDRESS="MAURITIUS",
DAYS=20,
MONTH=sep,
YEAR=2004,
ABSTRACT={In the modern telecommunications scenario, Quality of Service (QoS)
management and maintenance represent one of the main research concerns.
According to our opinion, to improve the user-perceived QoS, not only the
constraints imposed by the network (like technologies, user mobility,
system heterogeneity), but also the {"}user preferences{"} must be kept
into account. In this paper, we propose a user profiling technique that
enables the user to decide, from time to time, which range of rate
combinations are to be used to the CN. This range is used during the
negotiation/re-negotiation procedure. Hence, we add to the dynamism and
flexibility of the UMTS system also the concept of service personalization.
We aim at defining a dynamic profiling technique that allows modifying the
user profile considering both users preferences and network constrictions.}
}

@INPROCEEDINGS{Arda0405:Design,
AUTHOR="Shahab Ardalan and Akbar Adibi",
TITLE="Design, Simulation and Synthesis of a 32-bit {Math-Processor}",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="This paper is presented the design and results of simulation and synthesis
of a 32-bit math-processor. The emphasis was placed on implementation of
floating-point arithmetic unit and it results in math-processor. This
processor is designed in fully behavioral level by using VHDL and is able
to do floating-point operation on double precision. Also as nature of
behavioral description, it is easy to convert the precision to 64-bit or
more. Its ALU includes four separate ALUs. Sign ALU, integer number ALU,
mantissa and exponent ALU (Real number ALU) are contributing to each other
to overcome from all the tasks (Fig.1). This processor uses the
micro-controlling method for control unit. Four different branches (CALL,
JMP, RETURN and MAP) are available in this control unit and two nesting
subroutines can be done. 61 micro-instructions are defined for this
mathprocessor and user is able to define own instructions based on these
micro-instructions. User defined instruction are limited to the 1024
instructions. This processor has six 32-bit registers. Fig. 2 shows
register diagram of this processor. This behavioral design is
synthesis-able and ready for layout and fabrication or FPGA based digital
circuits. Synthesis was done by Leonardo Exemplar tool and it shows this
design includes 27000 standard cells and can work on 40 MHz clock in 1µm
CMOS technology. Fig.1: Main ALU Fig.2: Register Architecture"
}

@INPROCEEDINGS{Arde0405:2,
AUTHOR="Yasaman Ardeshirpour and M. Jamal Deen and Shahram Shirani",
TITLE="{2-D} {CMOS} Based Image Sensor System for Fluorescent Detection",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="In this project, we have been investigating methods to enhance the quality
of CMOS-based image sensors for fluorescent detection of DNA Microarrays.
For this purpose, different types of photodiodes and phototransistors were
designed in two different technologies, standard CMOS 0.35um and 0.18um
technologies. Also complete blocks of image sensors with photodiodes and
phototransistors were designed to investigate the response of an entire
image system. Each block consist of a matrix of image sensors with an
amplifier in each pixel, column amplifiers and sample and hold circuits.
The paper will discuss in detail each component of the optical image
sensors."
}

@INPROCEEDINGS{Arek0408:Configuring,
AUTHOR="Srikanth Arekapudi and Shang-Tse Chuang and Isaac Keslassy and Nick McKeown",
TITLE="Configuring a {Load-Balanced} Switch in Hardware",
BOOKTITLE="Hot Interconnects 12",
ADDRESS="Stanford University",
DAYS=25,
MONTH=aug,
YEAR=2004,
ABSTRACT="The load-balanced switch architecture is a promising way to scale router
capacity. We explained in [1] how it can be used to build a 100Tb/s router
with no centralized scheduler, no memory operating faster than the
line-rate, no packet mis-sequencing, a 100\% throughput guarantee for all
traffic patterns, and an optical switch fabric that simply spreads traffic
evenly among linecards. This switch fabric uses optical MEMS switches that
are reconfigured only when linecards are added and deleted, allowing the
router to function when any subset of linecards is present and working. In
[2] we introduced a configuration algorithm that will find a correct
configuration of the MEMS switches in polynomial time. However, we found
that our algorithm takes over 50 seconds to run in software for a 100Tb/s
router. Our goal is to restore the router to operation within 50ms upon
failure. So we modified our algorithm for implementation in dedicated
hardware. In particular, we reduced memory accesses, and used bit
manipulation schemes, to simplify the Ford-Fulkerson algorithm in bipartite
matches. Then, we decompose permutations using the Slepian-Duguid algorithm
and reduce the configuration time with a simplified memory scheme. Our
experimental results show that it is possible to achieve the 50ms target."
}

@INPROCEEDINGS{Ares0406:Resource,
AUTHOR="Aristos Aresti and Bobby Ninan and Michael Devetsikiotis",
TITLE="Resource Allocation Games in {Connection-Oriented} Networks under Imperfect
Information",
BOOKTITLE="High-Speed Networks Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="Game-theoretic formulations of the resource allocation problem have existed
for a while. However, the issue of perfect knowledge continues to be a
significant hurdle on the path to realistic implementations. In this paper,
the notion of playing bandwidth allocation games is investigated under
imperfect information. Specifically we look at the case of connection
oriented networks regulated by resource pricing. We devise a distributed
adaptive control strategy based on dynamic estimation in order to cope up
with the uncertainty of noise and delay. Simulation results illustrate the
scalability and accuracy of the algorithms under multiple scenarios.
Potential applications include teletraffic and optical networks, as well as
ad hoc wireless networks, enabling users to partition bandwidth without the
need of a centralized synchronizing entity."
}

@ARTICLE{Argi0401:Channel,
AUTHOR="Nikos Argiriou and Leonidas Georgiadis",
TITLE="Channel sharing by rate-adaptive streaming applications",
JOURNAL="Performance Evaluation",
VOLUME=55,
NUMBER="3-4",
PAGES="211-229",
MONTH=jan,
YEAR=2004,
REFERENCES=18,
KEYWORDS="Rate adaptation; Streaming applications; Performance analysis; Internet
QoS; Channel sharing; HFC networks; Cellular networks",
ABSTRACT="There are various techniques for adapting the transmission rate of an
application while maintaining the perceived quality at the receiver at
acceptable levels. Shared-channel systems can use this rate adaptation
capability to increase the number of concurrent applications in the system.
This can be achieved by appropriately modifying the rate of the already
running applications when a new connection arrives in the system. In this
paper we present an analytical model for a class of algorithms for channel
sharing by rate-adaptive applications. We provide means for calculating
performance measures related to the quality of reception of an application.
We also present the design of algorithms that ensure fair channel sharing
while keeping the application performance within acceptable levels.",
URL="http://www.sciencedirect.com/science?\_ob=MImg\&\_imagekey=B6V13-49NRPDY-1-87\&\_cdi=5663\&\_orig=browse\&\_coverDate=02\%2F29\%2F2004\&\_sk=999449996\&view=c\&wchp=dGLbVlz-zSkWz\&\_acct=C000002018\&\_version=1\&\_userid=18704\&md5=b39c001e13378d6a45c28f907ab81026\&ie=f.pdf"
}

@INPROCEEDINGS{Argy0401:Streaming,
AUTHOR="Antonios Argyriou and Vijay Madisetti",
TITLE="Streaming {JVT/H.26L} Video over the Internet",
BOOKTITLE="IEEE Consumer Communications \& Networking 2004",
ADDRESS="Las Vegas, Caesar's Palace",
DAYS=5,
MONTH=jan,
YEAR=2004,
ABSTRACT="In this paper we propose a novel end-to-end architecture
for streaming H.26L unicast video over the Internet.
The proposed video streaming architecture is based primarily
on a new transport layer protocol, the Stream Control Transmission
Protocol (SCTP). We show that the networkfriendly specification of H.26L
and the novel technical characteristics of SCTP, when coupled together, are
able to provide a highly adaptive and flexible system for unicast video
streaming. With simulation results we prove (1) that our system is capable
of maintaining good perceptual quality under various loss conditions and
(2) that the proposed system maintains TCP-friendliness."
}

@INPROCEEDINGS{Argy0403:Novel,
AUTHOR="Antonios Argyriou",
TITLE="A Novel Mechanism for Transport Layer {Load-Balancing} in {Ad-Hoc} Networks",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="The advent of wireless ad-hoc networks has provided a cost effective way
for exploiting mobile hosts in the absence of infrastructure. However, the
full potential that these networks offer for performance enhancement, still
remains to be exploited. In this paper we exploit the existence of multiple
paths between the hosts in an ad-hoc network. More specifically, we
introduce a new scheme for load-balancing for mobile multi-homed hosts that
are part of an ad-hoc network. Our approach differs from previously
proposed schemes since it consists an entirely end-to-end approach built on
top of the Stream Control Transmission Protocol (SCTP), while the Dynamic
Source Routing (DSR) protocol is used for routing. We provide both
analytical and simulation results that prove the efficiency of our approach
over a wide range of mobility scenarios."
}

@TECHREPORT{Argy0403:Protecting,
AUTHOR="Katerina Argyraki and David Cheriton",
TITLE="Protecting {Public-Access} Sites Against Distributed {Denial-of-Service}
Attacks",
TYPE="arXiv report",
NUMBER="cs.NI/0403042",
MONTH=mar,
YEAR=2004,
KEYWORDS="Networking and Internet Architecture",
ABSTRACT={We present Active Internet Traffic Filtering (AITF), an automatic DDoS
defense mechanism that focuses on protecting public access sites like web
servers and ftp servers. AITF efficiently manages the {"}filtering
capacity{"} of
the Internet in order to block attack traffic fast and protect the
victims'
resources. At the same time, AITF prevents a malicious node from abusing
the
mechanism to interfere with another node's communications. We identify
filters
as a scarce resource and show that AITF protects a significant amount of
the
victim's bandwidth, while it requires a reasonable number of filters that
can
be accommodated by today's routers.},
URL="http://arxiv.org/abs/cs/0403042"
}

@INPROCEEDINGS{Arhi0411:Navigation,
AUTHOR="Leena Arhippainen and Tapani Rantakokko and Marika Tahti",
TITLE="Navigation with an Adaptive Mobile {Map-Application:} User Experiences of
Gesture- and {Context-Sensitiveness}",
BOOKTITLE="The 2nd International Symposium on Ubiquitous Computing Systems",
ADDRESS="Tokyo, Japan",
DAYS=8,
MONTH=nov,
YEAR=2004,
ABSTRACT="In this paper, we identify fundamental navigation sub-tasks related to a
mobile map-application, and apply adaptive and gesture-based control
methods having improved user experience as our goal. We investigate how
automated positioning and rotating of maps and intuitive gesture control
for zooming and scrolling relieves navigation. Several smart features are
implemented into a PDA-based prototype: Map is positioned and rotated
according to current location and orientation. Zooming is performed with
hand gestures in front of a proximity sensor. Scrolling is controlled by
accelerometers using tilting movements. Graphical icons and effects are
used in visualizing interesting objects, their directions and distances. We
estimate the prototype by analyzing the effort needed for performing
navigation tasks with and without smart control. Moreover, user experience
evaluation was conducted with the smart control prototype."
}

@INPROCEEDINGS{Aric0403:Adaptive,
AUTHOR="Tarik Arici and Yucel Altunbasak",
TITLE="Adaptive Sensing for Environment Monitoring using Wireless Sensor Networks",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="We present Adaptive Sensing, an energy-efficient monitoring method for
densely deployed sensor network applications for environment monitoring.
Adaptive Sensing puts \textit{redundant} nodes into passive mode as
auxiliary nodes to be used later on, thereby extending the system lifetime.
Sensor data is collected at powerful macro nodes periodically and a
low-order model is fitted to compute a prediction area for each sensor.
This prediction area is used to measure the redundancy level of the sensors
covered in it. The redundant nodes are put into passive mode by macro nodes
while keeping the distortion in the output low. We analyze the
energy-distortion tradeoff in monitoring applications, introduce the
Adaptive Sensing algorithm based on this analysis. We also include a
performance study demonstrating the advantages of our approach based on
simulation results."
}

@INPROCEEDINGS{Arif0406:Efficient,
AUTHOR="Sharifah {Syed Ariffin}",
TITLE="Efficient Accelerated Simulation Technique for Packet Switched Networks: A
Buffer with Two Priority Inputs",
BOOKTITLE="QoS and Performance Modeling Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="An Enhanced Traffic Aggregation (E\_TA) technique for acceleration
simulation of packet switched network is proposed. This technique
simplifies the simulation model and improves the efficiency by using
packet-train or packet rate source traffic with non FIFO scheduler in the
buffer. The model employs power law traffic which recently proved to be
able to capture both long-range dependence and the burstiness of aggregate
broadband network traffic. Our results show that using E\_TA with FIFO
scheduler simulation times can be reduced by 39\%, and using E\_TA with non
FIFO scheduler by 83 \%."
}

@INPROCEEDINGS{Arif0406:Inferring,
AUTHOR="Dogu Arifler and Gustavo {de Veciana} and Brian Evans",
TITLE="Inferring Path Sharing Based on Flow Level {TCP} Measurements",
BOOKTITLE="QoS and Performance Modeling Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="We develop methods to infer path, or bottleneck, sharing among TCP flows
based on flow level measurements available from current traffic monitoring
tools. Our premise is that flows that temporally overlap on congested
resources will have correlated throughputs. We propose to use factor
analysis to explore the correlation structure among such flows in order to
hypothesize which flow classes might share congested resources. The
effectiveness of this ``black box'' approach is studied using empirical
data. We show that making such inferences based on flow level statistics is
viable in practice, and can serve as an effective, novel tool for network
design and configuration decisions. Our work on inferring bottleneck
sharing differs significantly from previous work in that we consider flow
level instead of packet level statistics, and hence may potentially
influence research in that area. Possible applications of this technique
include network monitoring, root cause analysis for poor performance, and
postmortem tracing of intrusions or denial of service attacks."
}

@INPROCEEDINGS{Ariy0405:Improvement,
AUTHOR="Masayuki Ariyoshi and Iwao Sasase",
TITLE="Improvement on Turbo Code Decoder by Upddating Redundant Likelihood
Information",
BOOKTITLE="Transmission Technology",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="This paper presents a novel decoding algorithm for turbo codes, in which
the likelihood values for redundant parts are updated in order for those
values to become more reliable. A criterion for updating the redundant
likelihood values is proposed, which is based on the comparisons of the
channel values with the re-generated values by the soft-input and
soft-output encoders. It is shown that the proposed method can improve the
error correcting capabilities, i.e., the improvement of BER/ BLER
performance and the achievable BER limit."
}

@INPROCEEDINGS{Arke0409:ADC,
AUTHOR="Vincent Arkesteijn and Eric Klumperink and Bram Nauta",
TITLE="{ADC} Clock Jitter Requirements for Software Radio Receivers",
BOOKTITLE="VTC'F04 Transmission Technology",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="The effective number of bits of an analogue-to-digital converter (ADC) is
not only limited by the quantisation step inaccuracy but also by sampling
time uncertainty. According to a commonly used model, timing jitter errors
should not introduce a sampling error bigger than 1 quantisation level for
full swing input signals at a frequency equal to half the sample rate. This
results in unfeasible phase noise requirements for the sampling clock in
software radio receivers with direct RF sampling. This paper explores the
clock jitter requirements for a software radio application, using a more
realistic model found in the literature and taking into account the power
spectrum of both the input signal and the spectrum of the sampling clock
jitter. Using this model, we show that the clock jitter is not a limiting
factor in the feasibility of software radio receivers."
}

@INPROCEEDINGS{Armi0412:Dynamic,
AUTHOR="Grenville Armitage and Claudio Favi",
TITLE="Dynamic Performance limits of the {Benko-Veres} Passive {TCP} Packet Loss
Estimation Algorithm",
BOOKTITLE="Australian Telecommunication Networks  and Applications Conference",
ADDRESS="Sydney, Australia",
DAYS=8,
MONTH=dec,
YEAR=2004,
ABSTRACT="In this paper we evaluate and discuss the performance of a passive TCP
packet loss estimation algorithm described by Benko and Veres [1]. Our
analysis is motivated by recent work modeling web traffic patterns [2][3]
and the network conditions experienced by TCP sessions carrying web traffic
[4]. We experimentally determine the dynamic characteristics of the
Benko-Veres estimation algorithm, focusing on how quickly the algorithm
converges to a reasonable estimate of packet loss rate for a given TCP
session and path. The Benko-Veres algorithm is stimulated in a small IP
network testbed, using repeated TCP sessions over a path with variable and
controlled packet loss rates. Our results show that the Benko-Veres
algorithm requires many packets and loss events before it converges to
reasonably accurate loss rate estimates. Finally we identify and discuss
the limited real-world scenarios where this method of passive, external
estimation of packet loss rates can be applied."
}

@INPROCEEDINGS{Arms0411:Decision,
AUTHOR="Jean Armstrong and Himal Suraweera",
TITLE="Decision Directed Impulse Noise Mitigation for {OFDM} in Frequency
Selective Fading Channels",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="Impulse noise is a significant problem in some OFDM applications including
digital television broadcasting. In this paper we study a novel decision
directed impulse mitigation algorithm both analytically and with
simulations for the DVB-T parameters. In this algorithm the noise component
in each received input sample is estimated based on preliminary decisions
on the transmitted data. When the estimate is large enough to indicate that
impulse noise is present in the sample, the estimated noise component is
subtracted from the input sample before final demodulation. This technique
has been shown to be extremely effective in flat fading channels. In this
paper its application in frequency selective fading channels is analyzed.
The optimum weighting factors for combining noise estimates from
subcarriers subject to different fading are calculated. Simulation results
are presented for Rayleigh and Ricean channels which show that the
technique can reduce the error rates due to impulsive noise by an order of
magnitude"
}

@INPROCEEDINGS{Armu0406:Ad,
AUTHOR="Ivan Armuelles and Hakima Chaouchi and Tomas {Robles Valladares} and Ivan
Ganchev and Mairtin O'Droma and Matthias Siebert",
TITLE="On Ad Hoc Networks in the {4G} Integration Process",
BOOKTITLE="The Third Annual Mediterranean Ad Hoc Networking Workshop",
ADDRESS="Bodrum, Turkey",
DAYS=27,
MONTH=jun,
YEAR=2004,
ABSTRACT="The imminent combination of different wireless technologies will provide a
very flexible and powerful platform to support requirements for future
services and applications, which will be part of mobile communications
beyond 3G. The main goal of this paper is to present the preliminary
results of the ongoing research in the project ANWIRE (Academic Network on
Wireless Internet Research in Europe) with respect to the system
integration process for an envisioned environment of heterogeneous
integrated networks. Specially, this paper is focused on the ad hoc network
integration with fixed and wireless mobile networks in order to fulfill
requirements imposed by mobile users with the expected anytime, anywhere
with anybody type of communication. Besides the ad hoc networks
introduction, the implications of ad hoc networks in the 4G integration
process are also elaborated. The requirements for this integration are
identified. A special focus thereby was put on the evolution of business
models and their long sight to consider ad hoc related properties. Finally,
a proposed Generic ANWIRE system and service Integration framework
Architecture (GAIA) is described."
}

@INPROCEEDINGS{Arom0405:Time,
AUTHOR="Sami Aromaa and Pertti Henttu and Markku Juntti",
TITLE="Time-frequency Analysis based Interference Suppression Algorithms for
{CDMA} Communications",
BOOKTITLE="Wireless Access",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="Three methods for suppressing interference, whose frequency properties
change over time, are presented. The methods take advantage of both time
and frequency information of the received signal. Two algorithms are based
on modifications of the Fourier transform (short-time Fourier transform
(STFT) and fractional Fourier transform (FrFT)) and the third method is
based on in-stantaneous frequency estimation. The performance of the
algorithms in a direct sequence spread spectrum (DS-SS) communication
system is evaluated through simula-tions and the most promising method is
considered to be FrFT based exciser. A problem with FrFT is choosing the
order of the transform."
}

@INPROCEEDINGS{Aron0411:Handling,
AUTHOR="Michael Aron and Gilles Simon and Marie-Odile Berger",
TITLE="Handling uncertain sensor data in vision-based camera tracking",
BOOKTITLE="ISMAR'04",
ADDRESS="Arlington, VA,",
DAYS=2,
MONTH=nov,
YEAR=2004,
ABSTRACT="A hybrid approach for real-time markerless tracking is presented. Robust
and accurate tracking is obtained from the coupling of camera and inertial
sensor data. Unlike previous approaches, we use sensor information only
when the image-based system fails to track the camera. In addition, sensor
errors are measured and taken into account at each step of our algorithm.
Finally, we address the camera/sensor synchronization problem and propose a
method to resynchronize these two devices online. We demonstrate our method
in two example sequences that illustrate the behavior and benefits of the
new tracking method."
}

@INPROCEEDINGS{Aror0410:Toward,
AUTHOR="Harpreet Arora and Lloyd Greenwald",
TITLE="Toward the use of local monitoring and network-wide correction to achieve
{QoS} guarantees in mobile ad hoc networks",
BOOKTITLE="The First IEEE International Conference on Sensor and Ad hoc Communications
and Networks",
ADDRESS="Santa Clara, CA",
DAYS=4,
MONTH=oct,
YEAR=2004,
ABSTRACT="This paper presents the exploration of novel mechanisms to provide Quality
of Service (QoS) guarantees in mobile ad hoc networks. We study mechanisms
that provide differentiated services to packets of varying priority traffic
flows. These mechanisms do not require any central coordination and do not
depend on any specific protocols at the physical, MAC, or network layers.
Nodes independently monitor the rates of the highest priority flows and
signal corrective mechanisms when these rates fall outside of specified
local bounds. Triggering conditions for network-wide corrective mechanisms
are designed to trade-off rapid reactive response to local QoS violations
with control packet overhead. A range of corrective mechanisms are explored
that attempt to maintain reactive response while improving total network
utilization, including resources consumed by lower priority traffic. We
provide simulation results that demonstrate the effectiveness of
monitoring, reactive triggering, and basic and advanced corrective
mechanisms. We discuss the extension of these novel mechanisms to a
complete QoS solution for mobile ad hoc networks."
}

@INPROCEEDINGS{Aror0411:Directional,
AUTHOR="Aman Arora and Marwan Krunz and Alaa Muqattash",
TITLE="Directional Medium Access Protocol {(DMAP)} with Power Control for Wireless
Ad Hoc Networks",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="Protocols for mobile ad hoc networks (MANETs) are often designed with the
assumption that nodes are equipped with omnidirectional antennas. Spatial
reuse in such networks can be significantly improved by using directional
antennas, leading to higher system capacity. This gain is associated with a
substantial energy saving that results for beamforming the transmitter
and/or receiver antennas in the appropriate directions. However, several
medium access problems (e.g., hidden terminal, deafness) resurface when
directional antennas are integrated into existing MAC protocols. In this
paper, we propose a power-controlled MAC protocol for directional antennas
that ameliorates many these problems. Our protocol uses separate control
and data channels to reduce collisions. It allows for dynamic adjustment of
the datapacket transmission power, such that this power is just enough to
overcome interference at the receiver. Simulation results demonstrate that
the combined gain from using directional antennas and power control results
in significant energy saving and improved throughput performance."
}

@INPROCEEDINGS{Arpa0404:Scalability,
AUTHOR="Onur Arpacioglu and Zygmunt Haas",
TITLE="On the Scalability and Capacity of Wireless Networks with Omnidirectional
Antennas",
BOOKTITLE="Information Processing in Sensor Networks",
ADDRESS="Berkeley, California",
DAYS=26,
MONTH=apr,
YEAR=2004,
ABSTRACT="Abstract-In this paper, we extend the previously known results on the
capacity of wireless networks, and determine the implications of our
results on scalability. We find bounds on the maximum achievable per node
end-to-end throughput, Lambda\_e, and the maximum number of simultaneously
successful wireless transmissions, N\_t^max, under a more general network
scenario than the network scenarios of previous works. In particular, we
put no restrictions on the mobility pattern of the nodes or on the number
simultaneous transmissions and/or receptions that the nodes are capable of
maintaining. Moreover, we analyze the effect of parameters like the area of
the network domain, A, the path loss exponent, gamma, the processing gain,
G, and the SINR threshold, beta. Specifically, we prove the following
results for a wireless network of N nodes that are equipped with
omnidirectional antennas: (1) Lambda\_e is O(1/N) even when the mobility
pattern of the nodes, the spatial-temporal transmission scheduling policy,
the temporal variation of transmission powers, the source-destination
pairs, and the possibly multi-path routes between them are optimally
chosen. This result continues to hold even when the nodes are capable of
maintaining multiple simultaneous transmissions and/or receptions, or the
communication bandwidth is divided into sub-channels of smaller bandwidth.
(2) N\_t^max has an upper bound that does not depend on N. The upper bound
is the simultaneous transmission capacity of the network domain, N\_t^Q.
For a circular network domain, N\_t^Q is O(A^min{gamma/2,1}) if gamma is
not equal to 2 and O(A/log(A)) if gamma=2. In addition, N\_t^Q is
O(gamma^2) and O(G/beta). Moreover, lack of attenuation and lack of space
are equivalent, where N\_t^Q cannot exceed 1+G/beta. (3) Regarding
scalability of practical systems, a desired per node end-to-end throughput
is not achievable as N tends to infinity, unless the following conditions
apply: Average number of hops between a source and a destination does not
grow indefinitely with N, A also grows with N, and N is O(A^min{gamma/2,1})
if gamma is not equal to 2 and O(A/log(A)) if gamma=2."
}

@INPROCEEDINGS{Arpa0404:Scalability,
AUTHOR="Onur Arpacioglu and Zygmunt Haas",
TITLE="On the Scalability and Capacity of Wireless Networks with Omnidirectional
Antennas",
BOOKTITLE="IEEE/ACM Information Processing in Sensor Networks (IPSN'04)",
PAGES="169-177",
MONTH=apr,
YEAR=2004,
REFERENCES=15,
KEYWORDS="network capacity; network scalability; network throughput; omnidirectional
antennas; wireless networks",
ABSTRACT="We consider a wireless network of N nodes equipped with omnidirectional
antennas, and we extend the capacity results of some previous works by
finding bounds on the maximum achievable per-node end-to-end throughput,
Lambda\_e, while using a general network model and a bounded propagation
model. Specifically, we show that when the network domain has a fixed area,
Lambda\_e is Theta(1/N) even when the mobility pattern of the nodes, the
temporal variation of transmission powers, the source-destination pairs,
and the possibly multi-path routes between them are optimally chosen. This
result continues to hold even when the nodes are capable of maintaining
multiple transmissions and/or receptions simultaneously, or when the
communication bandwidth is partitioned into sub-channels of smaller
bandwidth. We also address how Lambda\_e depends on the other network
parameters such as the area of the network domain, the path loss exponent,
or the average number of hops between a source and a destination. Finally,
we determine some required conditions to achieve a non-vanishing per-node
end-to-end throughput as the number of nodes in the network grows large.",
URL="http://www.people.cornell.edu/pages/oa27/publications/IPSN04.pdf"
}

@INPROCEEDINGS{Arsa0405:Performance,
AUTHOR="Muhammad Arsalan and Maitham Shams",
TITLE="Review of Charge Sharing Logic Circuits",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Energy efficient circuit design is one of the crucial requirements for
future consumer devices, especially portable products and computers.
Conventional dynamic circuit techniques are mostly aimed at high-speed
operation rather than low power consumption. Recently, several techniques
are published utilizing charge-sharing for low power circuits. In this
paper we review the performance of significant charge sharing logic styles.
Performance advantage, problems and overheads associated with each
technique are discussed and compared with other circuit techniques.
KEYWORDS: Low Power, Charge Recycling, Charge Sharing."
}

@INPROCEEDINGS{Arsh0405:Power,
AUTHOR="Muhammad Arshad and Syed Islam",
TITLE="Power Transformer Critical Diagnostics for Reliability and Life Extension",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Power transformers have significant role in the power delivery system.
Being critical and expensive component its safe operation with good
reliability is always deemed by the asset owners. In many utilities the
asset is serving either close or beyond its design life (25-30 years). The
majority of the asset in particular the older are operating with full load
with no significant condition assessment. Also many failures reported even
before reaching to their design life. Due the complexity of the asset, the
insulation (chain) under goes thermal, electrical and mechanical stresses.
Asset fails where its insulation system could not withstand the designed
(normal) electrical and thermal stresses. Materials with different
dielectric properties (solids and gases) with in the insulation system will
discharge energy and may lead to breakdown. Technical assessment based on
critical diagnostics stands vital for both new and old assets. The ageing
asset needs strict surveillance to monitor the asset closely for its
behavior. It is important to develop and implement diagnostics techniques
according to the condition as well as age of the asset. To predict the
breakdown time, aging effect on the insulation chain with accurate trend
analysis is required to be monitored. Online monitoring (dissolved gas
analysis, moisture contents, temperature and partial discharge detection)
and diagnostics (winding deformation, local breakdown and inter-turn
faults) are the important tools for asset assessment. The key evaluation is
the trend analysis for the insulation behaviors with respect to time,
temperature and loading pattern. Temperature, moisture and oxygen are the
main parameters for accelerated aging. New asset (<5 years) exhibits 0.5\%
moisture content in the insulation and in the aged asset (>20 years) it is
found from 3-4\%, where as the asset with 5\% of moisture is declared not
fit for service. Also dissolved gas analysis (DGA) with correct
interpretation can identify several faults before becoming active and
catastrophic failures can be averted. By applying realistic operating
criteria and in-time effective condition based maintenance, asset aging can
be controlled effectively. This paper presents a detailed case study of a
power transformer failure, before reaching to its design life in the
absence of critical component monitoring and diagnostics. Keywords:
Diagnostics, Reliability, Life-extension"
}

@INPROCEEDINGS{Arsh0406:VLSI,
AUTHOR="Ahmed Arshad and Ralf Koetter and Naresh Shanbhag",
TITLE="{VLSI} architectures for soft-decision decoding of {Reed-Solomon} codes",
BOOKTITLE="Signal Processing in Communications Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="In this paper, we present architectures for bivariate polynomial
interpolation and factorization; the two main steps in soft-decision
decoding of Reed-Solomon codes. We present an efficient formulation of the
interpolation algorithm in which dependencies among the required
computations are used to reduce complexity. Interpolation and factorization
complexity is also reduced by using an FFT-like formulation for univariate
polynomial translation. The architectures incorporate recently proposed
algorithm level modifications for efficient interpolation and
factorization. We determine the latency and hardware requirements for
soft-decoding a [255,239] Reed-Solomon code using the proposed
architectures."
}

@INPROCEEDINGS{Arsl0406:Multi,
AUTHOR="Huseyin Arslan",
TITLE="Multi-access Interference Cancellation Receiver for {Time-Hopping}
Ultra-wideband Communication",
BOOKTITLE="Wireless Communications Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="In this paper, a low complexity coherent joint maximum-likelihood detection
receiver is developed for cancelling multi-access interference in
Ultra-wideband (UWB) wireless communication systems. Unlike previous joint
demodulation receivers, where the complexity is enormous and the other
users' codes are required, the proposed approach does not need to know the
time hopping (TH) codes of the other users which makes it very attractive
solution. The performance of joint demodulation receiver depends on the
ability to estimate the channel coefficients of desired and interfering
users. A novel and practical algorithm for estimating multiple users'
channel responses is developed. The performance of the proposed algorithms
are tested through computer simulations and the results are compared with
the performance of the conventional single user UWB receiver. It is
observed that the proposed joint demodulation receiver provides significant
performance gains with respect to conventional single user receiver."
}

@INPROCEEDINGS{Arth0409:Effects,
AUTHOR="Colin Arthur and Demessie Girma",
TITLE="The Effects of Packet Reordering in a Wireless Multimedia Environment",
BOOKTITLE="International Symposium on Wireless Communication Systems",
ADDRESS="MAURITIUS",
DAYS=20,
MONTH=sep,
YEAR=2004,
ABSTRACT="Packet Reordering has been shown as an ever increasing phenomenon on the
internet, and is a consequence of increased parallelism within switch
equipment architecture. Packet reordering is also a symptom of wireless
networks, where link-layer retransmissions, appear as 'reordering events'
to the protocol transport layer above. TCP has been shown to suffer
degraded performance in situations of high packet reordering. This paper
will illustrate why video traffic over UDP also performs badly, due to the
temporal inter-packet dependencies introduced by the MPEG video encoding
structure. An experimental investigation into the effects of video packet
reordering is presented, using the Windows Media streaming format. A
scheduling method is then discussed, which unlike previous frame-based
methods, is optimised for a multi-frame per packet structure that the
majority of streaming media formats use. This will provide real-world
performance benefits for video streaming formats such as Windows Media,
under situations of high packet reordering."
}

@INPROCEEDINGS{Arti0404:Digital,
AUTHOR="Olivier Artigue and Jean Pierre Enguent and Claude {Tételin}",
TITLE="Digital demodulator at low sampling frequency for contactless smart cards
transceiver",
BOOKTITLE="2004 IEEE Sarnoff Symposium",
ADDRESS="Princeton, New Jersey",
DAYS=26,
MONTH=apr,
YEAR=2004,
ABSTRACT="Smart Card applications are very widespread today. The adaptation of
contactless technology to smart cards suppresses expensive systems with
electric contacts. However, the messing of an embedded power source induces
the use of simple and low power circuits. The chips supply is obtained by
tele-supply. Communication from the contactless smart card to the reader
can be performed by load modulation. The informative signal detected by the
reader is an amplitude modulated signal. The modulation coefficient is low
near any percent. Classic analog demodulators need amplifications
step-matched at the carrier frequency. This article presents a complete
digital architecture to the reader system in order to suppress all analog
convenient."
}

@INPROCEEDINGS{Arti0405:Connectivity,
AUTHOR="Maen Artimy and Bill Robertson and William Phillips",
TITLE="Connectivity in Inter-vehicle Ad Hoc Networks",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="A two-stage simulation model is developed to investigate the effects of
free-flow traffic on connectivity in inter-vehicle ad hoc networks. A
traffic microsimulator generates vehicles movement in multi-lane,
unidirectional highway, and a simple network model maintains connectivity
graphs between the moving vehicles. The free-flow conditions allow vehicles
to travel at their maximum velocities, virtually unobstructed by other
vehicles because of low vehicle density. We examine some factors that
determine the networks ability to maintain an active communication sessions
between a pair of vehicles. Vehicle density, relative velocity, and number
of lanes are found to have a key influence on connectivity. The effect of
distance, however, depends on the communication range. We also find that
the probability distribution of connection lifetime resembles a power law
function."
}

@INPROCEEDINGS{Arum0405:Adaptive,
AUTHOR="Nallanathan Arumugam",
TITLE="Adaptive Channel Estimation and Interference Cancellation in {Space-Time}
Coded {OFDM} Systems",
BOOKTITLE="Wireless Access",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="This paper presents an LSE-RLS interference suppression scheme for
space-time block coded orthogonal frequency division multiplexing (ST-OFDM)
systems over frequency selective fading channels. We consider a multi-user
environment with K synchronous co-channel users, each equipped with n
transmit antennas. The receiver is equipped with m(\&#61619;K) receive
antennas. The proposed scheme utilizes OFDM to transform frequency
selective fading channels into multiple flat fading subchannels on which
space-time coding is applied. It is shown that by applying the LSE-RLS
algorithm over each sub channel at the receiver, the proposed scheme is
capable of suppressing the interference from the K co-channel users without
any explicit knowledge of the channel or the interference. The proposed
scheme is computationally less intensive than the MMSE scheme which assumes
perfect channel knowledge and retains the simple linear decoding property
of space-time block codes with acceptable performance degradation due to
imperfect channel estimation."
}

@INPROCEEDINGS{Arum0405:Performance,
AUTHOR="Nallanathan Arumugam",
TITLE="On the Performance of {MC-CDMA} with Transmit Diversity over Fast Frequency
Selective Fading Channels",
BOOKTITLE="Wireless Access",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="Space-time (ST) block coded multi-carrier code division multiple access
(MC-CDMA) has been proposed as an attractive solution for high data rate
transmission in a multipath fading environment. It is a transmitter
diversity system which makes use of block codes formed across the space and
time domains. If the encoding is done across space and frequency instead,
the scheme obtained would be known as space-frequency (SF) block coded
MC-CDMA. In this paper, a space-time-frequency (STF) block coded MC-CDMA
scheme is presented. The proposed scheme is a four-branch transmitter
diversity system which utilizes block codes formed over the space, time and
frequency domains. The performance of STF block coded MC-CDMA scheme is
then compared with that of the ST block coded MC-CDMA and SF block coded
MC-CDMA systems with four transmitting antennas. It is shown that the
proposed STF block coded MC-CDMA scheme gives better performance over fast
frequency selective fading channels."
}

@INPROCEEDINGS{Arum0411:Eigenbeam,
AUTHOR="Nallanathan Arumugam",
TITLE="Eigenbeam- Space Division Mutiplexing for {OFDM} Systems with Optimum
Resource Allocation",
BOOKTITLE="IEEE Globecom 2004 - Signal Processing for Communications",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="A promising solution for significant increase of bandwidth efficiency and
system capacity is the exploitation of special dimension, by using space
division multiplexing. When the channel state information is known at a
transmitter of multiple-input multiple-output systems, the optimum capacity
is achieved by eigen mode channel division with water-pouring power
control. In this paper, frequency domain eigenbeam-space division
multiplexing is proposed for orthogonal frequency division multiplexing
(OFDM) with a method to assign both bits and transmit power to each
substream subcarriers. This assignment is based on the criterion of
minimizing error rate. SER performance of the proposed E-SDM-OFDM system is
numerically analyzed and compared with SDM-OFDM system. It is shown that
the proposed E-SDM-OFDM scheme can significantly reduce bit error rate
compared to the conventional SDM-OFDM system. Maximum Likelihood Decoding
is used to ensure maximum diversity gain."
}

@INPROCEEDINGS{Arya0403:Wireless,
AUTHOR="Farshid Aryanfar",
TITLE="Wireless Channel Modeling Using Miniaturized City and {MM-Wave}
Transceivers",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="A scaled propagation measurement system (SPMS) has been developed as an
alternate to the time consuming and expensive measurements for wireless
channel characterization. This system allows accurate measurements of
well-defined channels in a laboratory environment. Confining the desired
range of frequency to systems operating at UHF to L-Band (0.5-2 GHz),
dimensions of the scatterers and terrain features can be reduced by a
factor of 50-200 for the SPMS that operates at around 100 GHz. The system
includes a probe positioner, scaled model of city, miniaturized millimeter
wave transceivers probes, and a network analyzer. SPMS is capable of
measuring path loss as well as power delay profile (PDP) for any desired
environment. It can be used to verify available channel models or collect
data for developing new models. The system has a dynamic range around 85 dB
and average spurious level of -40dBc."
}

@INPROCEEDINGS{Asai0405:Performance,
AUTHOR="Kikuo Asai and Noritaka Osawa and Kimio Kondo and Kazuo Ishihara",
TITLE="Performance Estimation of Asymmetric Satellite-closed Network for
Inter-univeristy Communication System",
BOOKTITLE="Satellite Networks and Services",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="We made performance estimates of reliable data transmission in an
asymmetric satellite network for the inter-university communication system.
Satellite-terrestrial connections have been used in asymmetric networks
such as hybrid Internet access. However, the inter-university satellite
network that we have constructed, switches transmitting stations, and the
network topology dynamically changes. This makes a router setting
complicated at each station. To solve this problem, we have considered a
satellite-closed network. The simple configuration may enable users to
manage data transmission without detail knowledge on the network
equipments, but the throughput performance probably drops. We then
simulated throughput performance of multicast communications with a SR
(Selective-Repeat) protocol for error control in the application level,
using FDM for multiple downstream links and TDMA for feedback links. The
simulation results show traffic of the feedback link dominates the
throughput of the whole network, and the amount of traffic is important,
rather than channel efficiency in the feedback link. The multiple feedback
links improve the throughput efficiency by avoiding traffic congestion."
}

@INPROCEEDINGS{Asai0409:Experimental,
AUTHOR="Yusuke Asai and Daisei Uchida and Satoshi Kurosaki and Takatoshi Sugiyama
and Masahiro Umehira",
TITLE="Experimental Evaluation of {SDM-COFDM} Using Hierarchical {ICI} canceller
with Pilot-based Channel Tracking in Fast Multipath Fading",
BOOKTITLE="VTC'F04 Transmission Technology",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="We have developed the SDM-COFDM prototype using the hierarchical ICI
canceller with the pilot-based channel tracking scheme. We have evaluated
the experimental performances of the prototype when the subcarrier
modulation scheme is 16QAM, the coding rate is 3/4 and the maximum Doppler
frequency is 50Hz in 5GHz band. PER performances are dramatically improved
by using the channel tracking scheme. PER degradation compared to the case
when pilot symbol interval is 3, which is the best performance case, at PER
of 0.1 is less than 2dB when the pilot symbol interval is less than 72. We
have also evaluated the relation between the pilot symbol interval and the
required CNR. The degradation of CNR is less than 1dB when pilog symbol
interval is less than 70. We have calculated the throughput performances.
We found that pilot symbol interval which provide the optimum throughput
ranges from 48 to 60 and it depends on CNRs."
}

@INPROCEEDINGS{Asai0411:3D,
AUTHOR="Toshihiro Asai and Masayuki Kanbara and Naokazu Yokoya",
TITLE="{3D} modeling of wide area outdoor envirnments by integrating
omniderectional range and color images",
BOOKTITLE="ISMAR'04",
ADDRESS="Arlington, VA,",
DAYS=2,
MONTH=nov,
YEAR=2004,
ABSTRACT="This paper describes a method for modeling wide area outdoor environments
by integrating omnidirectional range and color images. The proposed method
effectively reconstructs the 3D model of outdoor environments by using
omnidirectional laser rangefinder and omnidirectional multicamera system
(OMS). In this paper, we also give experimental result of 3D wide area
reconstruction using the data acquired at 50 points in our campus"
}

@INPROCEEDINGS{Asai0411:3D,
AUTHOR="Toshihiro Asai and Masayuki Kanbara and Naokazu Yokoya",
TITLE="{3D} modeling of wide area outdoor envirnments by integrating
omniderectional range and color images - video",
BOOKTITLE="ISMAR'04",
ADDRESS="Arlington, VA,",
DAYS=2,
MONTH=nov,
YEAR=2004,
ABSTRACT="This movie shows the experimental result of 3D reconstruction using the
data acquired at 50 points in our campus"
}

@INPROCEEDINGS{Asan0404:Quality,
AUTHOR="Toshio Asano and Akihito Tsuno and Toshihiro Nishizono",
TITLE="Quality Management System for Network Provisioning and Customer Service in
Content Delivery",
BOOKTITLE="IEEE/IFIP Network Operations and Management Symposium",
ADDRESS="Seoul, Korea",
DAYS=19,
MONTH=apr,
YEAR=2004,
ABSTRACT="We propose a quality management system enabling efficient, accurate
measurement of streaming video quality to meet the requirements of network
provisioning and customer service. Streaming video is delivered through a
content delivery network (CDN) consisting of a content server, network, and
customersf personal computers (client PCs). In the digital content delivery
business, it is thus necessary to manage the overall quality for all these
elements.      
The proposed system employs both active measurement and passive
monitoring. Active measurement is used to periodically estimate quality
along the delivery route and identify bottlenecks in either the network or
server if degradation occurs. On the other hand, passive monitoring is sued
to measure quality for individual users and take improvement measures
proactively, before customers complain.
In this paper we discuss three aspects of this system. We first analyze
the requirements of quality management in terms of network provisioning and
customer service for streaming video delivery. We then explain the
architecture and configuration of the quality management system we
developed to meet these requirements. Finally, we demonstrate the
effectiveness of our system experimentally."
}

@INPROCEEDINGS{Asgh0411:Automatic,
AUTHOR="Ziad Asghar and Ashwin Sampath and Gibong Jeong",
TITLE="Automatic Threshold Control for Improved Paging Detection Performance in
Wireless Systems",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="Wireless systems such as UMTS, use a paging indication channel (PICH) to
signal whether a mobile is being paged. The threshold for PICH detection
must be set to balance the tradeoff between missed calls (due to missed
page) and lowered battery life (due to false alarms). Threshold selection
is one of many factors that affect those metrics and, often, the
sensitivity of those metrics to the PICH detection performance is highly
dependent on the operating SNR. This paper provides a methodology for
automatically setting the PICH detection threshold by taking such an SNR
dependent sensitivity of the performance metrics into account in order to
achieve the right tradeoff across all SNRs. Furthermore, we correctly
account for imperfect channel estimation in the threshold setting. For each
SNR value, we determine which metric (the metrics are false alarm
probability and missed PICH probability) is the binding constraint and
determine what its value should be. Using an analytic approach that
correctly accounts for channel estimation error, we then determine the
appropriate threshold to use at that SNR. Simulation results are presented
for a UMTS system and show that substantial improvements in battery life
can be obtained while also improving missed call rate compared to Maximum
Likelihood (ML) detection. Significant gains over a Neyman-Pearson (NP)
based approach are also obtained."
}

@INPROCEEDINGS{Asif0409:Parallel,
AUTHOR="Saad Asif",
TITLE="Parallel Interference Cancellation Technique for cdma2000 {(3G)} Systems",
BOOKTITLE="VTC'F04 Poster Papers",
ADDRESS="Los Angeles, CA",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="The recent forecasts on wireless applications and services are challenging
the North American operators to enhance the capacity of their networks.
Keeping this challenge in mind, Sprint is devoting its resources to explore
the possibilities that exist with the incorporation of Parallel
Interference Cancellation (PIC) scheme in the 3G mobile terminals. The
technology is discussed in context of downlink (base station to mobile)
since commercial CDMA systems are mainly downlink limited. This paper
discusses a potential solution for reducing the forward link interference
that inhibits the performance of cdma2000 systems. One of the major sources
of interference is intra-cell interference, which PIC technique works to
resolve. Sprint has conducted lab testing with a prototype handset and
cdma2000 base station to understand this technique and its impact on the
voice capacity of the CDMA system. The tests showed that a PIC capable
handset would provide voice capacity gains in the range of 0.1-4.3dB in the
downlink."
}

@INPROCEEDINGS{Asla0405:Qos,
AUTHOR="Nauman Aslam and Bill Robertson and William Phillips",
TITLE="Composite Metric For {QoS} Routing In {OLSR}",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="Quality of Service (QoS) support in mobile ad hoc networks (MANETs) is a
very challenging task because of the dynamic topology, limited resources
and wireless link characteristics. The Optimized Link State Routing
Protocol (OLSR) is a pro-active routing protocol for MANETs. The metric
used in OLSR protocol is hop count, which is not suitable for the wireless
environment due to its inherent dynamic link characteristics. In this paper
we discuss the different approaches used to add QoS functionality in OLSR.
Most of these techniques are centered on using one or two performance
metrics. We propose a composite metric using multiple parameters to find
the optimal route given the QoS constraints."
}

@ARTICLE{Asla0408:Parallel,
AUTHOR="Ahmed Aslam and Kenneth Christensen",
TITLE="A parallel packet switch with multiplexors containing virtual input queues",
JOURNAL="Computer Communications",
VOLUME=27,
NUMBER=13,
PAGES="1248-1263",
MONTH=aug,
YEAR=2004,
REFERENCES=24,
KEYWORDS="Packet switching; Switch architecture; Parallel packet switches; Virtual
input queues",
ABSTRACT="A packet switch with parallel switching planes is a parallel packet switch
(PPS). A PPS can scale-up to faster line speeds than can a single-plane
switch. It is an open problem to design a PPS that is feasible to implement
using existing low-cost hardware components where no component runs faster
than line speed. A PPS must be able to internally load balance traffic,
have packet delays comparable to a reference single-plane switch, and
provide QoS (bandwidth, delay, and loss guarantees) to flows. We
investigate a new architecture for a PPS that uses virtual input queues
(VIQ) in the output multiplexors to achieve packet-level load balancing. A
VIQ at an output multiplexor consists of one FIFO queue for each input. For
K planes and N ports, our VIQ PPS requires KN cells of buffering in the
input demultiplexors and 2NK+2K cells of buffering in the output
multiplexors to achieve guaranteed loss-free operation and in-order cell
delivery. Using simulation models, the new VIQ PPS is shown to offer
improved delay performance compared to existing PPS designs. For balanced
and unbalanced loads the VIQ PPS is stable where a reference iSLIP
single-plane switch is unstable.",
URL="http://www.sciencedirect.com/science?\_ob=MImg\&\_imagekey=B6TYP-4C0HSX9-1-72\&\_cdi=5624\&\_orig=browse\&\_coverDate=08\%2F15\%2F2004\&\_sk=999729986\&view=c\&wchp=dGLbVlz-zSkzV\&\_acct=C000002018\&\_version=1\&\_userid=18704\&md5=37aba74cc8ff867d74ab3d3bfe849a55\&ie=f.pdf"
}

@INPROCEEDINGS{Asma0405:Smarslam,
AUTHOR="Daniel Asmar",
TITLE="{SmartSLAM:} a context-based approach to landmark representation using
vision",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="With the absence of absolute localization techniques, such as GPS, it is
still possible for a robot to localize itself in an unknown environment.
Simultaneous Localization and Mapping (SLAM) is the process of localizing a
robot, while building a map of the environment in which it is navigating.
All SLAM algorithms build their navigation maps by detecting landmarks, or
salient features. These features must be recognizable in order for SLAM to
function. In all SLAM algorithms, the programmer specifies the parameters
of the landmarks a priori to the robot, and in none of them does the robot
attempt to suggest a landmark, according to the surrounding milieu it is
in. Our work is concerned with developing an algorithm that: (1) recognizes
the environment it is in, (2) suggests landmarks to use according to its
environment and (3) detects if the robot has navigated out of its
environment and into a new one; if so it will suggest new features to track
that are appropriate for the new environment. To this date, we have
segregated environments into four groups. One hundred images for each of
these environments have been collected. Low level features from these
images will be extracted by first filtering them with a Gabor filter and
then by reducing their dimensionality by applying Principal Component
Analysis. Environments will be represented by these low level vectors.
Landmarks will be suggested that are suitable for each recognized
environment. A database will be set up containing features that are most
probable for each environment. During implementation, the robot will
collect images of its milieu; low level features will be extracted and fed
into a Bayesian network that will subsequently infer the environment.
Landmarks that are most appropriate for the robot's setting will be chosen
from the database and used to perform SLAM."
}

@INPROCEEDINGS{Asos0412:VOICE,
AUTHOR="Abbas Asosheh",
TITLE="{VOICE} {OVER} {ADAPTIVE} {IP} {NETWORK} {(VoAIP)}",
BOOKTITLE="Australian Telecommunication Networks  and Applications Conference",
ADDRESS="Sydney, Australia",
DAYS=8,
MONTH=dec,
YEAR=2004,
ABSTRACT="We will focus our attention on providing adaptability and propose an
algorithm for adaptation of the network in the IP telephony applications.
Play out delay time and number of independent transmission paths are used
as two degrees of freedom in optimizing the quality of service on the VoIP
networks. While, the time of onset of the congestion is indicated through
Random early detection (RED) method, the de-jitter buffer length start
increasing to mitigate the effect of early congestion in the network, and a
backup channel for transmission of redundant voice stream is employed to
accommodate a reasonable de-jitter buffer length, whereas the strongly
congested period is detected. We show that the overall average packet loss
probability will be reduced by applying our proposed adaptive technique."
}

@INPROCEEDINGS{Aspl0405:Measurements,
AUTHOR="Henrik Asplund and Fredrik Harrysson and Jonas Medbo and Jan-Erik Berg",
TITLE="Measurements and analysis of a {MIMO} macrocell outdoor-indoor scenario at
1947 {MHz}",
BOOKTITLE="Antennas and Propagation",
ADDRESS="Genoa, Italy",
DAYS=10,
MONTH=may,
YEAR=2004,
ABSTRACT="Narrowband MIMO channel measurements at 1947 MHz have been performed in an
urban macrocellular outdoor-indoor scenario. The spatial characteristics of
the channel have been analyzed, showing an angular spread of 5-10 degrees
at the base station and 30-60 degrees at the mobile station. The maximum
theoretical capacity that the channel can support has been evaluated for
various antenna spacings and system sizes. A 4x4 MIMO system at 10 dB SNR
with 0.7 lambda spacing at the BS and 0.2 lambda spacing at the MS can
reach 75\% of the ideal (i.i.d. Rayleigh) capacity. Correlation over the
transmit and receive array due to limited angular spread is identified as
one factor reducing the capacity, another is Ricean fading."
}

@INPROCEEDINGS{Assa0405:Agent,
AUTHOR="Abderrahmane Assal and Voicu Groza",
TITLE="Agent-based Resource Management Framework for Smart Robotic Sensors",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT="In this paper, we propose an agent-based architecture for managing the
resources of smart robotic sensors. The idea is to share all the available
sensors among the entire society of agents, in such a way, that even though
some of the agents do not have the required physical sensor or actuator
on-board, they can always use other agents resources to overcome this
deficiency"
}

@INPROCEEDINGS{Assa0411:Analysis,
AUTHOR="Antonio Assalini and Andrea Tonello and Silvano Pupolin",
TITLE="Analysis of the Effects of Phase Noise in Filtered Multitone {(FMT)}
Modulated Systems",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="In this paper, we study the effects of phase noise in a multicarrier
system. We show that the phase noise introduces interference components,
and we evaluate their second order statistics. The analysis is then applied
to two particular multicarrier architectures: discrete multitone (DMT)
modulation, and filtered multitone (FMT) modulation. For the DMT case our
results are in agreement with other related work that considers DMT only.
For FMT modulation we demonstrate that the phase noise power spectral
density as well as the frequency response of the prototype filters play a
key role on the resulting interference power value. Finally, we show that
the analytical performance results are close to the simulation results."
}

@INPROCEEDINGS{Assa0411:Effect,
AUTHOR="Mohamad Assaad and Badii Jouaber and Djamal Zeghlache",
TITLE="Effect of {TCP} on {UMTS-HSDPA} System Performance and Capacity",
BOOKTITLE="IEEE Globecom 2004 - Wireless Communications, Networks, and Systems",
ADDRESS="Dallas, Texas",
DAYS=29,
MONTH=nov,
YEAR=2004,
ABSTRACT="An analytical model to evaluate the impact of TCP on the UMTS-HSDPA
capacity is presented. A method to minimize the effect of TCP on wireless
networks using shared channels is also proposed. HSDPA (High Speed Downlink
Packet Access) achieves higher aggregate bit rates through the introduction
of adaptive modulation and coding, Hybrid ARQ, fast scheduling, fast cell
selection and MIMO (space time coding and Blast) techniques. The proposed
model is used to evaluate the effect of the TCP protocol on the bit rate of
various data services (at 64 and 128kbps). As expected the bit rate per
flow decreases strongly if congestion in the wired network increases.
However, the capacity achieved by HSDPA is not as affected by TCP. Using
this result, a method to maintain the bit rate per TCP flow at a given
value without loosing much cell capacity is proposed. The findings are
supported by simulation results."
}

@INPROCEEDINGS{Assi0404:RDF,
AUTHOR="Pedro Assis and Joaquim Arnaldo Martins",
TITLE="A {RDF} Schema For {CIM} Compliant Models",
BOOKTITLE="IEEE/IFIP Network Operations and Management Symposium",
ADDRESS="Seoul, Korea",
DAYS=19,
MONTH=apr,
YEAR=2004,
ABSTRACT="The present work advocates the alignment of network management
data/information modeling with the proposals made in the aim of the W3C
Semantic Web initiative. It is propose a feasible methodology to build an
OWL-based management ontology. This methodology is based on a layered
model, which foundations are the DMTF CIM model and the W3C RDF language.
The primary goal, in proposing such ontology, is to make a contribution to
the network management tools R\&D targeting the interoperability of
heterogeneous management environments. Such tools will benefit from the
common, neutral, high-level representation of the exchanged management
data."
}

@INPROCEEDINGS{Aste0410:Performance,
AUTHOR="Maurizio Aste and Achille Pattavina",
TITLE="Performance of Optical Packet Switching Nodes in {IP} Transport Networks",
BOOKTITLE="Broadband Networks 2004 - Broadband Optical Networking Symposium",
ADDRESS="San Jose, CA, USA",
DAYS=25,
MONTH=oct,
YEAR=2004,
ABSTRACT="This paper deals with optical packet switching in a full-IP transport
network scenario. For the switching of IP packet flows different node
architectures are considered that are based on current optical routing
devices. The traffic performance of a mesh network is evaluated with the
various node structures, assuming that nodes employ either shortest path
routing or deflection routing to forward packets to the addressed
destinations. The paper shows how the different node structures behave in
terms of packet loss probability with different network configurations when
the node parameters are varied."
}

@INPROCEEDINGS{Astr0405:Simulation,
AUTHOR="Igor Astrov",
TITLE="Simulation of {Two-Rate} Adaptive Neural Network and Fuzzy Logic Hybrid
Control for Stochastic Model of an Experimental Aircraft",
BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2004",
ADDRESS="Niagara Falls, Ontario, Canada",
DAYS=2,
MONTH=may,
YEAR=2004,
ABSTRACT={The nature of the multirate dynamics of the process makes it very
attractive for applications. In [1]is described the problem of
linear-quadratic optimal control for state-space (SS) type stochastic
continuous-time multi-input/multi-output (MIMO) decomposed model of a
tracked vehicle. This paper expands the basic ideas presented in [1]for the
field of two-rate adaptive neural network (NN) and fuzzy logic (FL) hybrid
control. The goal of this paper is to show the applicability of the
proposed two-rate NN and FL hybrid control technique to the stochastic MIMO
model of a tracking system for an experimental aircraft. The control NN
with Many ADAptive LINear Elements (MADALINE) of three neurons and
neuro-fuzzy networks of adaptive control structure for {"}fast{"}
subsystem, and control MADALINE NN of three neurons for {"}slow{"}
subsystem are designed. A FL control structure is designed to achieve the
two-rate control goal. This FL controller uses Mamdani-style fuzzy
inference with the nine rules base. The block diagrams both the original
control system and decomposed low-order MIMO autonomous control subsystems
with various speeds of actuation and with the real number as a relation of
discretization periods were designed. The obtained results show that the
control tasks for the subsystems can be solved more qualitatively than for
the original system. The contribution of the paper is twofold: to develop
new decomposition schemes appropriate for real-time multirate adaptive NN
and FL hybrid control applications, and to present the results of two-rate
adaptive NN and FL hybrid control for any chosen SS type of MIMO stochastic
model in simulation form using the MATLAB/Simulink environment. [1] I.
Astrov, J. Em and E. Rüstern, Two-Rate State-Space Mathematical Models
for Stochastic Multivariable Continuous-Time Control Systems and their
Simulation{"}, Proc. 6th International Conference on Methods and Models in
Automation and Robotics, Miedzyzdroje, Poland, Vol. 1, 2000, pp. 471-476.}
}

@INPROCEEDINGS{Atay0403:Exploiting,
AUTHOR="Furuzan {Atay Onat} and Christopher Rose",
TITLE="Exploiting Mobility in Multi-hop Infostation Networks to Decrease Transmit
Power",
BOOKTITLE="IEEE Wireless Communications and Networking Conference 2004",
ADDRESS="Atlanta, Georgia",
DAYS=21,
MONTH=mar,
YEAR=2004,
ABSTRACT="Mobility, rather than being a liability, can be an asset. If delay
constraints are loose, it is possible for a given packet to observe many
different network topologies as nodes move relative one another, and these
different topologies can be treated as diversity. Opportunistic strategies
can exploit these large scale changes in the channel quality to decrease
transmit power at the expense of greater delay. We study the tradeoff
between mobility, transmit power and delay and along the way develop simple
greedy (packet-based) threshold rules for packet transmission."
}

@INPROCEEDINGS{Atha0406:Adaptive,
AUTHOR="Chandra Athaudage and Vikram Krishnamurthy",
TITLE="Adaptive Symbol Tracking Using Discrete Stochastic Approximation for
Wireless {OFDM} Systems",
BOOKTITLE="Signal Processing in Communications Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="This paper presents discrete stochastic approximation (DSA) algorithms for
symbol time synchronization in OFDM systems. It is shown that the discrete
stochastic approximation algorithms can be effectively used to achieve a
significant reduction in computational complexity compared to brute force
maximum-likelihood (ML) methods for OFDM synchronization. The most
important property of the proposed algorithms is their recursive
self-learning capability - most of the computational effort is spent at the
global or a local optimizer of the objective function. An adaptive version
of the discrete stochastic approximation algorithm is also presented for
tracking time-varying time delays and frequency offsets in time selective
fading channels. Detailed numerical examples illustrate the performance
gains of these DSA based synchronization algorithms."
}

@INPROCEEDINGS{Atha0409:Deterministic,
AUTHOR="Georgia Athanasiadou",
TITLE="Deterministic propagation modelling and measurements for the broadband
fixed wireless access channel",
BOOKTITLE="VTC'F04 Antenna and Propagation",
DAYS=26,
MONTH=sep,
YEAR=2004,
ABSTRACT="A three-dimensional (3D) ray-tracing propagation model is presented in this
paper. The algorithm is optimised for Broadband Fixed Wireless Access
(BFWA) operational scenarios. The model works with raster terrain as well
as 3D vector building and foliage databases. It also considers reflections
off building walls, off-axis roof top and terrain diffractions and foliage
attenuation. Outputs include the received power and the impulse response of
the wireless channel, and as such the tool permits a detailed and realistic
assessment of the performance of a broadband system including network
planning and deployment issues. Field trial measurements carried out for
different scenarios (propagation conditions, antenna heights, distance from
the access point, etc.) in the city of Cambridge (UK) with a commercial
BFWA operating system (3.5GHz), are compared with ray tracing simulation
results. The analysis studies the propagation characteristics of the BFWA
radio channel and the accuracy of the presented deterministic propagation
modelling approach."
}

@INPROCEEDINGS{Athu0411:Enhanced,
AUTHOR="Sanjeewa Athuraliya and Harsha Sirisena",
TITLE="An Enhanced Token Bucket Marker for {DiffServ} Networks",
BOOKTITLE="IEEE International Conference on Networks 2004",
ADDRESS="Singapore",
DAYS=17,
MONTH=nov,
YEAR=2004,
ABSTRACT="The DiffServ architecture has been widely accepted as a scalable framework
for providing Quality of Service in the Internet. However there are still
unresolved issues, in particular the inability of TCP aggregates to reach
their guaranteed rates, within some Per-Hop-Behaviors proposed for use in
DiffServ. We propose an enhanced token bucket marker, that is simple,
efficient and effective compared to other proposed schemes, in realizing
throughput guarantees of TCP aggregates. We provide a theoretical analysis
and simulation studies that support this claim."
}

@INPROCEEDINGS{Atki0409:Location,
AUTHOR="Robert Atkinson and Swee Goo and James Irvine and John Dunlop",
TITLE="Location Privacy and the Personal Distributed Environment",
BOOKTITLE="International Symposium on Wireless Communication Systems",
ADDRESS="MAURITIUS",
DAYS=20,
MONTH=sep,
YEAR=2004,
ABSTRACT="The Personal Distributed Environment is a new concept being developed
within the Mobile VCE project whereby users have access to their services
and data through a distributed set of terminals, wherever they happen to
be. Devices are co-ordinated by Device Management Entities (DMEs), which
are either Local DMEs, controlling devices within a single PDE-subnetwork
at users home or office, for example, and an overall Root DME providing
universal co-ordination and a single point of contact. While such a
structure allows very flexible service delivery, it has serious security
concerns, as the presence of signalling between Root and Local DMEs will
allow the location of the user to be determined at all times. In this
paper, we analyse the security threats to the DME structure proposed for
the PDE, and introduce a system of tunnelling and mix networks to provide
security and privacy."
}

@INPROCEEDINGS{Atla0406:Compact,
AUTHOR="El-Sayed Atlam",
TITLE="A Compact Memory Space of Dynamic {Full-Text} Search using {Bi-Gram} Index",
BOOKTITLE="The Ninth IEEE Symposium on Computers and Communications",
ADDRESS="Alexandria, Egypt",
DAYS=29,
MONTH=jun,
YEAR=2004,
ABSTRACT="Full-text search is widely used for various services of the Internet. A
more high-speed and a more efficient full-text search technology are
necessary because of the amount of increasing handled document and
corresponding document data every day. This paper proposes an adaptive
block management algorithm that is efficient for dynamic data management
method. This algorithm is applied for inverted file searching. The new
method is speeding up character string retrieval by first making the
full-text search of Uni-gram and by the full-text search of Bi-gram. This
paper proposes a method of enhancing the static full-text search system of
Bi-gram to the dynamic full-text search system of Bi-gram. Moreover, this
paper presents an efficient achievement method of the dynamic full-text
search system of Bi-gram using effectiveness of the adaptive block
management structure."
}

@INPROCEEDINGS{Atov0411:Capacity,
AUTHOR="Irena Atov and Richard Harris",
TITLE="Capacity Planning of Multiservice {IP} Networks",
BOOKTITLE="IEEE International Conference on Networks 2004",
ADDRESS="Singapore",
DAYS=17,
MONTH=nov,
YEAR=2004,
ABSTRACT={Traffic demands on the Internet today include delay-sensitive traffic that
requires better than the standard ``best effort{"} service provided by IP
networks. As a result, various new technologies and mechanisms to support
the many different types of traffic - each having various performance
requirements - are being developed and implemented. Traditional methods for
capacity planning of IP networks are limited in that they only consider
``best effort{"} service, or else a single delay constraint for all
traffic. In this paper, we propose a framework for a capacity planning tool
that takes account of these new technologies and provides Quality of
Service (QoS) based on multiple delay constraints so that guaranteed
performance can be achieved for each of the traffic classes. To provide a
foundation for the capacity planning procedure, we first overview and
categorize the QoS mechanisms deployed in IP-based networks and identify
their implications for network planning. We then describe some specific
features and algorithms that have been incorporated into a capacity
planning tool for multiservice IP networks. The planning tool is briefly
described and the solution to a simple network problem is demonstrated
based on the tool.}
}

@INPROCEEDINGS{Atre0410:Probability,
AUTHOR="Pradeep Atrey and Mohan Kankanhalli",
TITLE="Probability Fusion for Correlated Multimedia Streams",
BOOKTITLE="ACM Multimedia 2004 Short Papers",
ADDRESS="New York, NY",
DAYS=10,
MONTH=oct,
YEAR=2004,
ABSTRACT="The fusion of multiple correlated observations of a multimedia system is a
research problem arising in many multimedia applications. In this paper, we
propose a novel framework for the probabilistic fusion of correlated
multimedia observations. Assuming that each of the media stream has a
priori probability of achieving the goal and their underlying correlations
are known, our framework fuses the individual probabilities using the
quantitative correlation based on Bayesian approach. The simulation results
show that fewer highly positively correlated observations better achieve a
specified goal when compared to the use of a larger number of observations
with low correlation."
}

@INPROCEEDINGS{Atti0406:Reliability,
AUTHOR="Gamal Attiya",
TITLE="Reliability Oriented Task Allocation in Heterogeneous Distributed Computing
Systems",
BOOKTITLE="The Ninth IEEE Symposium on Computers and Communications",
ADDRESS="Alexandria, Egypt",
DAYS=29,
MONTH=jun,
YEAR=2004,
ABSTRACT="This paper investigates the problem of task allocation in heterogeneous
distributed computing systems with the goal of maximizing the system
reliability. It first develops a mathematical model for reliability based
on a cost function representing the unreliability caused by the execution
of tasks on the system processors and the unreliability caused by the
interprocessor communication costs subject to constraints imposed by both
the application and the system resources. It then proposes an optimal,
memory efficient, hybrid algorithm to this problem. The algorithm first
finds a near optimal allocation by applying the well known Simulated
Annealing (SA) and then finds an optimal distribution by applying the
Branch-and-Bound (BB) technique considering the solution of the SA as the
initial solution. The proposed algorithm overcomes the low solutions
quality that may be obtained by using heuristics. It also overcomes the
computational time complexity of the exact algorithms."
}

@INPROCEEDINGS{Auer0406:Analysis,
AUTHOR="Gunther Auer",
TITLE="Analysis of {Pilot-Symbol} Aided Channel Estimation for {OFDM} Systems with
Multiple Transmit Antennas",
BOOKTITLE="Wireless Communications Symposium",
ADDRESS="Paris, France",
DAYS=20,
MONTH=jun,
YEAR=2004,
ABSTRACT="We address pilot-symbol aided channel estimation (PACE) for OFDM based
systems employing multiple transmit antennas. Two approaches are
ivestigated: first, all N transmit antennas use all available pilot symbols
simultanously, resulting in N superimposed signals; second, a subset of
available pilots is allocated for each transmit antenna exclusively. The
Wiener filter and the corresponding mean square error (MSE) are derived for
both approaches. Furthermore, by applying the sampling theorem, the minimum
number of pilots required to estimate the channel response of N waveforms
is derived."
}

@INPROCEEDINGS{Auer0409:Channel,
AUTHOR="Gunther Auer",
TITLE="Channel Estimation by Set Partitioning for {OFDM} with Cyclic Delay
Diversity",
BOOKTITLE="VTC'F04 Wireless Access",
DAYS=27,
MONTH=sep,
YEAR=2004,
ABSTRACT="For OFDM based systems using cyclic delay diversity (CDD), a multiple input
channel is transformed to a single input channel, with increased frequency
selectivity. While CDD provides additional frequency diversity which can be
utilized by the outer channel decoder, a conventional channel estimator may
have difficulties to track the increased dynamics of the received signal.
However, the knowledge about the cyclic delays can be utilized by the
channel estimator. We show that for maximum cyclic delays, adjacent
subcarriers become uncorrelated. By partitioning uncorrelated subcarriers
into sets, and performing channel estimation for each set separately, a
simple and yet very efficient channel estimation scheme can be derived."
}

@INPROCEEDINGS{Augu0410:Efficient,
AUTHOR="Nathaniel August and Dong Ha",
TITLE="An Efficient {UWB} Radio Architecture for Busy Signal {MAC} Protocols",
BOOKTITLE="The First IEEE International Conference on Sensor and Ad hoc Communications
and Networks",
ADDRESS="Santa Clara, CA",
DAYS=4,
MONTH=oct,
YEAR=2004,
ABSTRACT="Large wireless ad hoc and sensor networks impose tight constraints on cost
and power dissipation, so nodes usually adopt a single transceiver
approach. Since a single transceiver cannot assess the status of existing
transmissions, it wastes valuable time and energy on handshaking packets
and corrupted packets. To avoid such overhead, we propose a single
transceiver approach based on ultra wideband (UWB) and a companion medium
access control (MAC) layer based on busy tone multiple access (BTMA). BTMA
reduces the time and energy spent on collisions as compared to handshaking
protocols. It is well suited for ad hoc and sensor networks since it
permits random, distributed medium access with no central point of failure.
The single transceiver leverages the inherently low duty cycle of
impulse-based UWB (I-UWB) to assess the status of a packet during its
transmission. This paper describes the I-UWB system architecture, and
simulations show that it effectively detects a busy signal without
affecting data transmission"
}

@INPROCEEDINGS{Auh0404:Analysis,
AUTHOR="Yun-Bong Auh and Eun-Kyung Lee