@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, Tex