@INPROCEEDINGS{Roch9803:Cost, AUTHOR="R. Guerin and L. Li and Steve Nadas and Ping Pan and V. Peris", TITLE="The Cost of {QoS} Support in Edge Devices: An Experimental Study", BOOKTITLE=infocom, INSTITUTION="IBM Research Center", MONTH="March/April", YEAR=1999, } @BOOK{Stall99:Cryptography, AUTHOR="W. Stallings", TITLE="Cryptography and Network Security: principles and practice", ISBN="0-13-869017-0", PUBLISHER="Prentice Hall", ADDRESS="Upper Saddle River, New Jersey", YEAR=1999, KEYWORDS="security; firewall", } @ARTICLE{Hand99XX:Large, AUTHOR="Mark Handley and Jon Crowcroft and Carsten Bormann and Joerg Ott", TITLE="Very Large Conferences on the Internet: the {Internet} Multimedia Conferencing Architecture", JOURNAL=cn, VOLUME=31, YEAR=1999, ABSTRACT="In this paper we provide an overview of multimedia conferencing on the Internet. The protocols mentioned are all specified elsewhere as Internet-Drafts or RFCs. Each RFC gives details of the protocol itself, how it works and what it does. This document attempts to provide the reader with an overview of how the components fit together and of some of the assumptions made, as well as some statement of direction for those components still in a nascent stage.", } @BOOK{Stei99:Multimedia, AUTHOR="R. Steinmetz", TITLE="Multimedia-Technologie: Grundlagen, Komponenten und Systeme", ISBN="3-540-62060-5", PUBLISHER="Springer", ADDRESS="Berlin", YEAR=1999, KEYWORDS="multimedia; packet audio; packet video", } @BOOK{Daco99:Java, AUTHOR="Michael C. Daconta and Al Saganich and Eric Monk", TITLE="Java 2 and JavaScript for C and {C++} Programmers", ISBN="0-471-32719-0", PUBLISHER="Wiley", ADDRESS="New York, New York", YEAR=1999, KEYWORDS="Java; programming languages; JMF; JFC; RMI; JDBC", } @BOOK{Gonc99:IP, AUTHOR="Marcus Goncalves and Kitty Niles", TITLE="{IP} Multicasting Concepts and Applications", ISBN="0-07-913791-1", PUBLISHER="McGraw-Hill", ADDRESS="New York, New York", YEAR=1999, KEYWORDS="multicasting; IP multicast; IGMP; DVMRP", } @MISC{Metr99:Ricochet, AUTHOR="Metricom", TITLE="The Ricochet Wireless Network Overview", YEAR=1999, URL="http://www.metricom.com/ricochet/netoverview.html", } @ARTICLE{Good9905:Internet, AUTHOR="Bill Goodman", TITLE="{Internet} Telephony and Modem Delay", JOURNAL=ieeenet, VOLUME=13, NUMBER=3, PAGES="8-17", MONTH="May/June", YEAR=1999, KEYWORDS="modem delay; Internet telephony", ABSTRACT="The author focuses on causes of delay within analog modems, with the objective of developing recommendations for VoIP applications.", URL="http://207.127.135.8/ni/private/1999/may/Goodman.html", } @ARTICLE{Rose9905:IETF, AUTHOR="J. Rosenberg and Henning Schulzrinne", TITLE="The {IETF} {Internet} Telephony Architecture and Protocols", JOURNAL=ieeenet, VOLUME=13, NUMBER=3, PAGES="18-23", MONTH="May/June", YEAR=1999, KEYWORDS="Internet telephony; SIP", ABSTRACT="Protocols that provide a partial solution for interworking Internet telephony and traditional circuit-switched telephony are presented.", URL="http://207.127.135.8/ni/private/1999/may/Schulzrinne.html", } @ARTICLE{Rose9905:Programming, AUTHOR="J. Rosenberg and J. Lennox and Henning Schulzrinne", TITLE="Programming {Internet} Telephony Services", JOURNAL=ieeenet, VOLUME=13, NUMBER=3, PAGES="42-49", MONTH="May/June", YEAR=1999, KEYWORDS="Internet telephony; SIP; CPL; cgi", ABSTRACT="Internet telephony enables a wealth of new service possibilities. Traditional telephony services, such as call forwarding, transfer, and 800 number services can be enhanced by interaction with email, web, and directory services. Additional media types, like video and interactive chat, can be added as well. One of the challenges in providing these services is how to effectively program them. Programming these services requires decisions regarding where the code executes, how it interfaces with the protocols that deliver the services, and what level of control the code has. In this paper, we consider this problem in detail. We develop requirements for programming Internet telephony services, and we show that at least two solutions are required \_ one geared for service creation by trusted users (such as administra- tors), and one geared for service creation by untrusted users (such as consumers). We review existing techniques for service programmability in the Internet and in the telephone network, and extract the best components of both. The result is a Common Gateway Interface (CGI) that allows trusted users to de- velop services, and the Call Processing Language (CPL) that allows untrusted users to develop services.", URL="http://www.cs.columbia.edu/~hgs/papers/Rose9905\_Programming.ps", } @ARTICLE{Huit9905:Architecture, AUTHOR="C. Huitema and Jane Cameron and Petros N. Mouchtaris and Darek Smyk", TITLE="An architecture for {Internet} Telephony Service for Residential Customers", JOURNAL=ieeenet, VOLUME=13, NUMBER=3, PAGES="50-57", MONTH="May/June", YEAR=1999, KEYWORDS="MGCP; Internet telephony", ABSTRACT="A new architecture that can be used for offering Internet telephony service to residential customers is introduced.", URL="http://207.127.135.8/ni/private/1999/may/Mouch.html", } @ARTICLE{Goya9905:Integration, AUTHOR="P. Goyal and A. G. Greenberg and C. R. Kalmanek and Bill Marshall and P. Mishra and Doug Nortz and Kadangode K. Ramakrishnan", TITLE="Integration of Call Signaling and Resource Management for {IP} Telephony", JOURNAL=ieeenet, VOLUME=13, NUMBER=3, PAGES="24-33", MONTH="May/June", YEAR=1999, REFERENCES=10, KEYWORDS="Internet telephony; resource reservation", ABSTRACT="IP telephony presents a tremendous opportunity to service providers to offer both traditional services as well as a range of creative new services. However, there are substantial challenges to be faced in supporting a resource management framework that is adequate for telephony, and in providing a signaling architecture that enables these services while preserving user privacy and preventing theft of service. This paper describes the Distributed Open Signaling Architecture (DOSA), a framework for call signaling and resource management, that meets these needs. A key contribution of our work is a recognition of the need for coordination between call signaling, which controls access to telephony specific services, and resource management, which controls access to network-layer resources. We evaluate one approach to resource management in the backbone, consistent with our architecture, using signaling for aggregates of flows. Using traces from calls on the AT\&T long distance network, we show that the multiplexing gains achieved by such aggregation can achieve most of the benefits of per-flow signaling, while avoiding its overheads. We also evaluate scheduling algorithms in order to understand their effect on the end-to-end delay experienced by voice packets.", URL="http://207.127.135.8/ni/private/1999/may/Mishra.html", } @ARTICLE{Rizz9905:Voice, AUTHOR="Daniele Rizzetto and Claudio Catania", TITLE="A Voice over {IP} Service Architecture for Integrated Communications", JOURNAL=ieeenet, VOLUME=13, NUMBER=3, PAGES="34-41", MONTH="May/June", YEAR=1999, KEYWORDS="Internet telephony", ABSTRACT="Integrating IP-based telephony with the legacy circuit-switched intelligent network may be achieved with this novel service architecture.", URL="http://207.127.135.8/ni/private/1999/may/Rizzetto.html", } @ARTICLE{Poly9905:POTS, AUTHOR="Christos A. Polyzois and K. Hal Purdy and P. Q. Yang and D. C. Shrader and Henry Sinnreich and François Ménard and Henning Schulzrinne", TITLE="From {POTS} to {PANS} -- A Commentary on the Evolution to {Internet} Telephony", JOURNAL=ieeenet, VOLUME=13, NUMBER=3, PAGES="58-64", MONTH="May/June", YEAR=1999, REFERENCES=24, KEYWORDS="Internet telephony architecture; billing; XML", ABSTRACT="We describe some of the challenges and problems as we move from the world of plain old telephony services (POTS) to the promise of Internet-based pretty amazing new services (PANS). We present a set of ideas that relate the architectural evolution of networks and services to the underlying changes in technology. After examining the motivations behind the drive to Internet multimedia communications, we discuss the distribution of service intelligence in the future communications architecture. As with any period of evolution, thorny problems arise regarding interworking between the two network architectures. A brief exploration of the Intelligent Network (IN) is presented as a solution to address interworking. Finally, we examine how the transition to an Internet-based system might affect how transport and services are billed for.", URL="http://www.cs.columbia.edu/~hgs/papers/Poly9905\_POTS.pdf", } @INPROCEEDINGS{Hilt99:Generic, AUTHOR="Volker Hilt and M. Mauve and Christoph Kuhmünch and W. Effelsberg", TITLE="A Generic Scheme for the Recording of Interactive Media Streams", BOOKTITLE="Interactive Distributed Multimedia Systems and Telecommunication Services (IDMS)", INSTITUTION="Universität Mannheim", ADDRESS="Toulouse, France", YEAR=1999, KEYWORDS="RTP", ABSTRACT="Interactive media streams with real-time characteristics, such as those produced by shared whiteboards, distributed Java applets or shared VRML viewers, are rapidly gaining importance. Current solutions to the recording of interactive media streams are limited to one specific application (e.g. one specific shared whiteboard). In this paper we present a generic recording service that enables the recording and playback of this new class of media. To facilitate the generic recording we have defined a profile for the Real-Time Transport Protocol (RTP) that covers common aspects of the interactive media class in analogy to the profile for audio and video. Based on this profile we introduce a generalized recording service that enables the recording and playback of arbitrary interactive media.", URL="http://www.informatik.uni-mannheim.de/informatik/pi4/projects/RTPI/papers/RTPIRecording.pdf", } @ARTICLE{Cace99:Fast, AUTHOR="R. Caceres and Venkata N. Padmanabhan", TITLE="Fast and Scalable Handoffs in Support of Mobile {Internet} Audio", JOURNAL=monet, YEAR=1999, REFERENCES=38, KEYWORDS="mobile IP; handoff; mobility management; packet audio", ABSTRACT="Future internetworks will include large numbers of portable devices moving among small wireless cells. We propose a hierarchical mobility management scheme for such networks. Our scheme exploits locality in user movement to restrict handoff processing to the vicinity of a mobile node. It reduces handoff latency and the load on the internetwork. Our design is bead on the Internet Protocol (IP) and is compatible with the Mobile IP standard. We also present experimental results for the lowest level of the hierarchy. We implemented our local handoff mechanism on Unix-based portable computers and base stations, and evaluated its performance on a WaveLAN network. These experiments show that our handoffs are fast enough to avoid noticeable disruptions in interactive audio traffic. For example, our handoff protocol completes in less than 10 milliseconds after a mobile node initiates it. Our mechanism also recovers from packet losses suffered during the transition from one cell to another. This work helps extend Internet telephony and teleconferencing to mobile devices that communicate over wireless networks.", URL="http://www-daedalus.cs.berkeley.edu/publications/monet99-handoff.ps.gz", } @ARTICLE{McCa99:Low, AUTHOR="Steve McCanne and M. Vetterli and V. Jacobson", TITLE="Low-complexity Video Coding for Receiver-driven Layered Multicast", JOURNAL=ieeejsac, VOLUME=8, YEAR=1999, REFERENCES=50, KEYWORDS="packet video; Mbone; multicast", ABSTRACT="In recent years the ``Internet Multicast Backbone'', or MBone, has risen from a small, research curiosity to a large scale and widely used communications infrastructure. A driving force behind this growth was the development of multipoint audio, video, and shared whiteboard conferencing applications. Because these real-time media are transmitted at a uniform rate to all the receivers in the network, a source must either run at the bottleneck rate or overload portions of its multicast distribution tree. We overcome this limitation by moving the burden of rate-adaptation from the source to the receivers with a scheme we call Receiver-driven Layered Multicast, or RLM. In RLM, a source distributes a hierarchical signal by striping the different layers across multiple multicast groups and receivers adjust their reception rate by simply joining and leaving multicast groups. In this paper we describe a layered video compression algorithm which, when combined with RLM, provides a comprehensive solution for scalable multicast video transmission in heterogeneous networks. In addition to a layered representation, our coder has low-complexity (admitting an efficient software implementation) and high loss resilience (admitting robust operation in loosely controlled environments like the Internet). Even with these constraints, our hybrid DCT/wavelet-based coder exhibits good compression performance. It outperforms all publicly available Internet video codecs while maintaining comparable run-time performance. We have implemented our coder in a ``real'' application -- the UCB/LBL video conferencing tool vic. Unlike previous work on layered video compression and transmission, we have built a fully operational system that is currently being deployed on a very large scale over the MBone.", URL="http://www.cs.umn.edu/~zhzhang/cs8299/Readings/McCa96:Low-Complexity-Coding.ps", } @ARTICLE{Jele9902:Asymptotic, AUTHOR="Predrag Jelenkovic and Aurel A. Lazar", TITLE="Asymptotic Results for Multiplexing Subexponential On-Off Processes", JOURNAL=aap, VOLUME=31, NUMBER=2, YEAR=1999, KEYWORDS="Non-Cramer type conditions; Subexponential distributions; Long-tailed distributions; Long-range dependency; Network multiplexer; Fluid ow queue; M/G/1 queue", ABSTRACT="Consider an aggregate arrival process $A^N$ obtained by multiplexing $N$ on-off sources with exponential off periods at rate $\lambda$ and subexponential on periods $\tau^{on}$. As $N$ goes to infinity, with $\lambda N \rightarrow \Lambda$, $A^N$ approaches an $M/G/\infty$ type process. Both for finite and infinite $N$, we obtain the asymptotic characterization of the arrival process activity period. Using these results, we investigate a fluid queue with limiting $M/G/\infty$ arrival process $A\_i^\infty$ and capacity $c$. When on periods are regularly varying (with non-integer exponent), we derive a precise asymptotic behavior of the queue length variable $Q\_t^P$ observed at the beginning of the arrival process activity periods. The asymptotic (time average) queue distribution lower bound is obtained under more general assumptions on on periods than regular variation. In addition, we analyze a queueing system in which on on-off process whose on period belongs to a subclass of subexponential distributions, is multiplexed with independent exponential processes with aggregate expected rate $E$. This system is shown to be asymptotically equivalent to the same queueing system with the exponential arrival processes being replaced by their total mean value $E$.", URL="http://www.ctr.columbia.edu/~predrag/mypub/aapRevisedShort.ps", } @BOOK{Kilkk99:Differentiated, AUTHOR="K. Kilkki", TITLE="Differentiated Services for the {Internet}", ISBN="1-57870-132-5", PUBLISHER="MacMillan", ADDRESS="Indianapolis", YEAR=1999, KEYWORDS="differentiated services; quality of service; diff-serv", } @INCOLLECTION{Ford99:Quality, AUTHOR="Merilee Ford and Henry Lew and Steve Spanier and Tim Stevenson", TITLE="Quality of Service (QoS) Networking", BOOKTITLE="Internetworking Technology Overview", PUBLISHER="Cisco Systems", YEAR=1999, KEYWORDS="QOS; fair queueing; priority queueing; RSVP; MPLS; differentiated services", ABSTRACT="This chapter outlines the features and benefits of the QoS provided by the Cisco IOS QoS.", URL="http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito\_doc/index.htm", } @MISC{Suci99:Semistructured, AUTHOR="Dan Suciu", TITLE="From Semistructured Data to {XML}", INSTITUTION="AT\\&T Labs", NOTE="VLDB 1999 tutorial slides", YEAR=1999, KEYWORDS="XML; databases; RDF; tutorial", URL="http://www.research.att.com/~suciu/tutorial-vldb99.ppt", } @MISC{Surv99:Project, AUTHOR="Advanced Networks and Services", TITLE="The Surveyor Project Home Page", NOTE="http://www.advanced.org/csg-ipmm", YEAR=1999, KEYWORDS="measurement; GPS; packet delay", } @BOOK{Kuro99:Computer, AUTHOR="James F. Kurose and Keith W. Ross", TITLE="Computer Networking: A Top-Down Approach featuring the {Internet}", PUBLISHER="Addison-Wesley-Longman", YEAR=1999, KEYWORDS="tutorial; Internet; computer networks", URL="http://gaia.cs.umass.edu/kurose/Contents.htm, http://occ.awlonline.com/bookbind/pubbooks/kurose-ross1/", } @TECHREPORT{Micr99:IP, AUTHOR="Microsoft", TITLE="{IP} Telephony with {TAPI} 3.0", TYPE="White paper", INSTITUTION="Microsoft", ADDRESS="Redmond, Washington", YEAR=1999, KEYWORDS="Internet telephony; TAPI", ABSTRACT="TAPI 3.0 is an evolutionary API that supports convergence of both traditional PSTN telephony and telephony over IP networks.", URL="http://www.microsoft.com/Windows/server/Technical/networking/iptelephony.asp", } @BOOK{Crow99:Internetworking, AUTHOR="Jon Crowcroft and Mark Handley and Ian Wakeman", TITLE="Internetworking Multimedia", ISBN="1-55860-584-3", PUBLISHER="Morgan-Kaufman", ADDRESS="San Francisco, California", YEAR=1999, KEYWORDS="multimedia; packet audio; packet video", } @MASTERSTHESIS{Agbo99:Study, AUTHOR="Charles Agboh", TITLE="A study of two main {IP} telephony signaling protocols: {H.323} signaling and {SIP;} a comparison and a signaling gateway specification", SCHOOL="Unversite Libre de Bruxelles (ULB), Facutés des Science, Départment Informatique", ADDRESS="Brussels, Belgium", NOTE="supervised by Eric Manie", YEAR=1999, KEYWORDS="H.323; SIP", } @ARTICLE{Xiao9903:Internet, AUTHOR="XiPeng Xiao and Lionel M Ni", TITLE="{Internet} QoS: A Big Picture", JOURNAL=ieeenet, VOLUME=13, NUMBER=2, PAGES="8-18", YEAR=1999, LANGUAGE="English", KEYWORDS="Internet; QoS; Integrated Services; RSVP; Differentiated Services; MPLS; constraint based routing; traffic engineering", ABSTRACT="In this paper we present a framework for the emerging Internet Quality of Service (QoS). All the important components of this framework, i.e., Integrated Services, RSVP, Differentiated Services, Multi-Protocol Label Switching (MPLS) and Constraint Based Routing are covered. We describe what Integrated Services and Differentiated Services are, how they can be implemented, and the problems they have. We then describe why MPLS and Constraint Based Routing have been introduced into this framework, how they differ from and relate to each other, and where they fit into the Differentiated Services architecture. Two likely service architectures are presented, and the end-to-end service deliveries in these two architectures are illustrated. We also compare ATM networks to router networks with Differentiated Services and MPLS. Putting all these together, we give the readers a grasp of the big picture of the emerging Internet QoS.", URL="http://www.cse.msu.edu/~xiaoxipe/papers/inet.qos.bigpicture.pdf", } @ARTICLE{Knig9903:Admission, AUTHOR="Edward W. Knightly and Ness Shroff", TITLE="Admission Control for Statistical QoS: Theory and Practice", JOURNAL=ieeenet, VOLUME=13, NUMBER=2, PAGES="20-29", MONTH="March/April", YEAR=1999, ABSTRACT="In networks that support Quality of Service (QoS), an admission control algorithm determines whether or not a new traffic flow can be admitted to the network such that all users will receive their required performance. Such an algorithm is a key component of future multi-service networks as it determines the extent to which network resources are utilized and whether the promised QoS parameters are actually delivered. Our goals in this paper are threefold. First, we describe and classify a broad set of proposed admission control algorithms. Second, we evaluate the accuracy of these algorithms via experiments using both on-off sources and long traces of compressed video; we compare the admissible regions and QoS parameters predicted by our implementations of the algorithms with those obtained from trace-driven simulations. Finally, we identify the key aspects of an admission control algorithm necessary for achieving a high degree of accuracy and hence a high statistical multiplexing gain.", URL="http://www.ece.rice.edu/networks/papers/KniShr99.ps.gz", } @ARTICLE{Teit9909:Internet2, AUTHOR="Benjamin Teitelbaum and Sue Hares and Larry Dunn and Robetr Neilson and Raytheon Vishy Narayan and Francis Reichmeyer", TITLE="Internet2 {QBone:} Building a Testbed for Differentiated Services", JOURNAL=ieeenet, VOLUME=13, NUMBER=5, PAGES="8-16", MONTH="September/October", YEAR=1999, REFERENCES=22, ABSTRACT="The Internet2 project is partnership of over 130 U.S. universities, 40 corporations, and 30 other organizations. Since its inception, one of the primary technical objectives of Internet2 has been to engineer scalable, interoperable, and administrable interdomain QoS to support an evolving set of new advanced networked applications. Applications like distance learning, remote instrument access and control, advanced scientific visualization, and networked collaboratories will allow universities to fulfill their research and education missions into the future, but only if the network QoS these applications require can be ensured. To meet this challenge, the Internet2 QBone initiative[1] has brought together a dedicated group of U.S. university and federal agency networks, international research networks, engineers, researchers, and applications developers to build a testbed for interdomain IP differentiated services. This article presents the engineering motivations behind DiffServ and its adoption by Internet2, provides an overview of the QBone architecture, and describes its anticipated deployment, including plans for a trial interdomain bandwidth brokering architecture.", URL="http://www.comsoc.org/~ni/public/1999/sep/index.html", } @ARTICLE{Dovr9909:Case, AUTHOR="C. Dovrolis and P. Ramanathan", TITLE="A Case for Relative Differentiated Services and the Proportional Differentiation Model", JOURNAL=ieeenet, VOLUME=13, NUMBER=5, PAGES="26-34", MONTH="September/October", YEAR=1999, REFERENCES=24, ABSTRACT="Internet applications and users have very diverse quality-of-service expectations, making the same-service-to-all model of the current Internet inadequate and limiting. There is a widespread consensus today that the Internet architecture has to be extended with service differentiation mechanisms, so that certain users and applications can get a better service than others at a higher cost. One approach, referred to as absolute differentiated services, is based on sophisticated admission control and resource reservation mechanisms in order to provide guarantees or statistical assurances for absolute performance measures, such as a minimum service rate or a maximum end-to-end delay. Another approach, which is simpler in terms of implementation, deployment, and network manageability, is to offer relative differentiated services between a small number of classes of service. These classes are ordered based on their packet forwarding quality, in terms of per-hop metrics for the queueing delays and packet losses, giving the assurance that higher classes are better than lower classes. The applications and users, in this context, can dynamically select the class that best meets their quality and pricing constraints, without a priori guarantees for the actual performance level of each class. The relative differentiation approach can be further refined and quantified using the Proportional Differentiation Model. This model aims to provide the network operator with the `tuning knobs' for adjusting the quality spacing between classes, independent of the class loads. When this spacing is feasible in short time scales, it can lead to predictable and controllable class differentiation, which are two important features for any relative differentiation model. The proportional differentiation model can be approximated in practice with simple forwarding mechanisms (packet scheduling and buffer management), that we briefly describe here.", URL="http://www.cae.wisc.edu/~dovrolis/case.ps, http://www.comsoc.org/~ni/public/1999/sep/index.html", } @ARTICLE{Raja9909:Policy, AUTHOR="R. Rajan and Dinesh Verma and S. Kamat and E. Felstaine and S. Herzog", TITLE="A Policy Framework for Integrated and Differentiated Services in the {Internet}", JOURNAL=ieeenet, VOLUME=13, NUMBER=5, PAGES="36-41", MONTH="September/October", YEAR=1999, REFERENCES=10, ABSTRACT="In this article, we examine the issues that arise in the definition, deployment, and management of policies related to QoS in an IP network. The article provides an overview of requirements for QoS policies, alternative policy architectures that can be deployed in a network, different protocols that can be used to exchange policy information, and exchange of policy information among different administrative domains. We discuss current issues being examined in IETF and other standards bodies, as well as issues explored in ongoing policy-related research at different universities and research laboratories.", URL="http://www.comsoc.org/~ni/public/1999/sep/index.html", } @ARTICLE{Bhat9909:Web, AUTHOR="N. T. Bhatti and Rich Friedrich", TITLE="Web Server Support for Tiered Services", JOURNAL=ieeenet, VOLUME=13, NUMBER=5, PAGES="64-71", MONTH="September/October", YEAR=1999, REFERENCES=12, ABSTRACT="The evolving needs of conducting commerce using the Internet requires more than just network quality of service mechanisms for differentiated services. Empirical evidence suggests that overloaded servers can have significant impact on user perceived response times. Furthermore, FIFO scheduling done by servers can eliminate any QoS improvements made by network-differentiated services. Consequently, server QoS is a key component in delivering end to end predicatable, stable, and tiered services to end users. This article describes our research and results for WebQoS, an architecture for supporting server QoS. We demonstrate that through classification, admission control, and scheduling, we can support distinct performance levels for different classes of users and maintain predictable performance even when the server is subjected to a client request rate that is several times greater than server's maximum processing rate.", URL="http://www.comsoc.org/~ni/public/1999/sep/index.html", } @TECHREPORT{Micr99:Quality, AUTHOR="Microsoft", TITLE="Quality of Service Technical White Paper", INSTITUTION="Microsoft", ADDRESS="Redmond, Washington", YEAR=1999, KEYWORDS="quality of service; RSVP; resource reservation", ABSTRACT="Within the past few years, there has been a rapid growth in network traffic. New applications, particularly multimedia applications, have placed increasing demands on networks, straining their ability to provide customers with a satisfactory experience. In answer to this situation, numerous mechanisms have surfaced for providing quality of service (QoS) networks. The ultimate goal of these mechanisms is to provide improved network service to the applications at the edges of the network. This white paper reviews emerging QoS mechanisms and how they are integrated to optimize the utilization of network resources. It then specifically discusses Microsoft's QoS mechanisms.", URL="http://www.microsoft.com/windows2000/library/howitworks/communications/trafficmgmt/QoSOver.asp", } @TECHREPORT{Lazz99:JPEG, AUTHOR="John Lazzaro and John Wawryznek", TITLE="{JPEG} Quality Transcoders", TYPE="web page", INSTITUTION="UC Berkeley", ADDRESS="Berkeley, California", YEAR=1999, KEYWORDS="JPEG; packet video", ABSTRACT="JPEG is a lossy compression standard for digital images. The JPEG encoding process lets users trade off reduced compressed filesize for degraded image quality. We have developed a JPEG Quality Transcoder (JQT) that converts a JPEG image file that was encoded with low image quality to a larger JPEG image file with reduced visual artifacts, without access to the original uncompressed image. In this website, we show how JQTs can be used in networked systems to: Reduce bandwidth while maintaining perceptual quality. Enhance perceptual quality at a constant bandwidth. while maintaining compatibility with the JPEG standard.", URL="http://www.cs.berkeley.edu/~lazzaro/jqt/", } @INPROCEEDINGS{Terz99:Prototype, AUTHOR="Andreas Terzis and J. Ogawa and Sonia Tsui and Lei Wang and L. Zhang", TITLE="A Prototype Implementation of the Two-Tier Architecture for Differentiated Services", BOOKTITLE="RTAS", ADDRESS="Vancouver, Canada", YEAR=1999, } @ARTICLE{Cela9912:Simulation, AUTHOR="N. Celandroni and E. Ferro and Invalid Invalid", TITLE="A simulation tool to validate and compare satellite {TDMA} access schemes", JOURNAL="Real-Time Systems", VOLUME=12, NUMBER=1, PAGES="21-37", YEAR=1999, KEYWORDS="emulator; simulator; satellite access schemes; performance comparison; TDMA; aggregate traffic", ABSTRACT="This paper proposes an architecture design for a tool suitable for emulating DA­TDMA (demand­assignment­time division multiple access) satellite access schemes. The tool presented, named FRACAS 1 , is particularly suitable for comparing the performance of different satellite channel allocation policies. Using FRACAS, a service provider can choose from different policies for sharing a satellite channel among a number of users. Some allocation policies, selected from those available in the literature, are built­in, while others can be designed from scratch and added without much effort. The parameters of the built­in allocation policies can easily be changed in order to exploit the full potential of the allocation schemes. FRACAS's features permit the optimisation of satellite resource usage in accordance with the traffic pattern supported. FRACAS enables research teams and students to explore and compare different multiple access schemes, and to develop simulation runs for various kinds of service­induced traffic, including aggregate traffic, which is typical in a local area network (LAN) interconnection environment.", URL="mailto:F.Potorti@cnuce.cnr.it", } @ARTICLE{Bald9909:Application, AUTHOR="M. Baldi and A. Macii and E. Macii and M. Poncino", TITLE="Application of symbolic {FSM} Markovian analysis to protocol verification", JOURNAL="IEEE Proceedings on Computers and Digital Techniques", VOLUME=146, NUMBER=5, PAGES="221-226", MONTH="Sep", YEAR=1999, } @ARTICLE{Bald9912:CLIMAX, AUTHOR="M. Baldi and D. Bergamasco and Silvano Gai and D. Malagrinø", TITLE="{CLIMAX:} CeLl-Interleaved Merged {ATM} ConneXions", JOURNAL=ts, VOLUME=1, NUMBER=12, YEAR=1999, } @INPROCEEDINGS{Mukh9911:Passive, AUTHOR="Sugata Mukhopadhyay and Babington Smith", TITLE="Passive Capture and Structuring of Lectures", BOOKTITLE="ACM Multimedia", INSTITUTION="Cornell University", ADDRESS="Orlando, Florida", MONTH="October/November", YEAR=1999, REFERENCES=19, KEYWORDS="distance learning; capture; multimedia; teleteaching", ABSTRACT="Despite recent advances in authoring systems and tools, creating multimedia presentations remains a labor-intensive process. This paper describes a system for automatically constructing structured multimedia documents from live presentations. The automatically produced documents contain synchronized and edited audio, video, images, and text. Two essential problems, synchronization of captured data and automatic editing, are identified and solved.", URL="http://www4.cs.cornell.edu/LectureBrowser/lb-mm99-final.pdf", } @INPROCEEDINGS{Fan99:Web, AUTHOR="L. Fan and P. Cao and W. Lin and Quinn Jacobson", TITLE="Web prefetching between low-bandwidth clients and proxies: Potential and performance", BOOKTITLE="International Conference on Measurement and Modeling of Computer Systems", PAGES="178-187", YEAR=1999, } @ARTICLE{Foot9901:Overview, AUTHOR="Jonathan Foote", TITLE="An overview of audio information retrieval", JOURNAL=mms, VOLUME=7, NUMBER=1, PAGES="2-10", YEAR=1999, ABSTRACT="The problem of audio information retrieval is familiar to anyone who has returned from vacation to find an answering machine full of messages. While there is not yet an", } @ARTICLE{Sche9901:Structured, AUTHOR="Eric D. Scheirer", TITLE="Structured audio and effects processing in the {MPEG-4} multimedia standard", JOURNAL=mms, VOLUME=7, NUMBER=1, PAGES="11-22", YEAR=1999, ABSTRACT="While previous generations of the MPEG multimedia standard have focused primarily on coding and transmission of content digitally sampled from the real world, MPEG-4 contains extensive support for structured, synthetic and synthetic/natural hybrid coding methods. An overview is presented of the", } @ARTICLE{Barr9901:Using, AUTHOR="Stephen Barrass and Glen Kramer", TITLE="Using sonification", JOURNAL=mms, VOLUME=7, NUMBER=1, PAGES="23-31", YEAR=1999, KEYWORDS="Sonification;Visualisation;Multi-modal;Multimedia;Perceptual display;Human-computer interaction;Information design;Auditory display", ABSTRACT="The idea behind sonification is that synthetic non-verbal sounds can represent numerical data and provide support for information processing activities of many different kinds. This article describes some of the ways that sonification has been used in assistive technologies, remote collaboration, engineering analyses, scientific visualisations, emergency services and aircraft cockpits. Approaches for designing sonifications are surveyed, and issues raised by the existing approaches and applications are outlined. Relations are drawn to other areas of knowledge where similar issues have also arisen, such as human-computer interaction, scientific visualisation, and computer music. At the end is a list of resources that will help you delve further into the topic.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007001/90070023.pdf", } @ARTICLE{Camu9901:Interactive, AUTHOR="Antonio Camurri and Pasqualino Ferrentino", TITLE="Interactive environments for music and multimedia", JOURNAL=mms, VOLUME=7, NUMBER=1, PAGES="32-47", YEAR=1999, ABSTRACT="Multimodal Environments (MEs) are systems capable of establishing creative, multimodal user interaction by exhibiting real-time adaptive behaviour. In a typical scenario, one or more users are immersed in an environment allowing them to communicate by means of full-body movement, singing or playing. Users get feedback from the environment in real time in terms of sound, music, visual media, and actuators, i.e. movement of semi-autonomous mobile systems including mobile scenography, on-stage robots behaving as actors or players, possibly equipped with music and multimedia output. MEs are therefore a sort of extension of augmented reality environments. From another viewpoint, an ME can be seen as a sort of prolongation of the human mind and senses. From an artificial intelligence perspective, an ME consists of a population of physical and as software agents capable of changing their reactions and their social interaction over time. For example, a gesture of the user(s) can mean different things in different situations, and can produce changes in the agents populating the ME. The paradigm adopted for movement recognition is that of a human observer of the dance, where the focus of attention changes according to the evolution of the dance itself and of the music produced. MEs are therefore agents able to observe the user, extract", } @ARTICLE{Wyse9901:Embedding, AUTHOR="Lonce Wyse and Peter Kellock", TITLE="Embedding interactive sounds in multimedia applications", JOURNAL=mms, VOLUME=7, NUMBER=1, PAGES="48-54", YEAR=1999, KEYWORDS="Interactivity;Realtime sound;Multimedia;Interface;Sound synthesis;Developer tools", ABSTRACT="We describe a system for generating and controlling sound effects from within applications. We discuss performance demands and current technology constraints on sound synthesis methods, highlight several distinct interactive control strategies, and demonstrate a development environment for making a large database of heterogeneous sound models manageable by developers who are not sound synthesis experts.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007001/90070048.pdf", } @ARTICLE{Jot9901:Real, AUTHOR="Jean-Marc Jot", TITLE="Real-time spatial processing of sounds for music, multimedia and interactive human-computer interfaces", JOURNAL=mms, VOLUME=7, NUMBER=1, PAGES="55-69", YEAR=1999, KEYWORDS="3D sound;Multimedia sound spatialization;Environmental audio", ABSTRACT="This paper gives an overview of the principles and methods for synthesizing complex 3D sound scenes by processing multiple individual source signals. Signal-processing techniques for directional sound encoding and rendering over loudspeakers or headphones are reviewed, as well as algorithms and interface models for synthesizing and dynamically controling room reverberation and distance effects. A real-time modular spatial-sound-processing software system, called Spat, is presented. It allows reproducing and controling the localization of sound sources in three dimensions and the reverberation of sounds in an existing or virtual space. A particular aim of the Spatialisateur project is to provide direct and computationally efficient control over perceptually relevant parameters describing the interaction of each sound source with the virtual space, irrespective of the chosen reproduction format over loudspeakers or headphones. The advantages of this approach are illustrated in practical contexts, including professional audio, computer music, multimodal immersive simulation systems, and architectural acoustics.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007001/90070055.pdf", } @ARTICLE{Tsun9902:Dynamic, AUTHOR="Babak Hamidzadeh Tsun-Ping J. To", TITLE="Dynamic real-time scheduling strategies for interactive continuous media servers", JOURNAL=mms, VOLUME=7, NUMBER=2, PAGES="91-106", YEAR=1999, KEYWORDS="Video on demand;Continuous media file server;Multimedia scheduling;Admission control;Variable bit-rate", ABSTRACT="In this paper, we propose and study a dynamic approach to schedule real-time requests in a video-on-demand (VOD) server. Providing quality of service in such servers requires uninterrupted and on-time retrieval of motion video data. VOD services and multimedia applications further require access to the storage devices to be shared among multiple concurrent streams. Most of the previous VOD scheduling approaches use limited run-time,0 information and thus cannot exploit the potential capacity of the system fully. Our approach improves throughput by making use of run-time information to relax admission control. It maintains excellent quality of service under varying playout rates by observing deadlines and by reallocating resources to guarantee continuous service. It also reduces start-up latency by beginning service as soon as it is detected that deadlines of all real-time requests will be met. We establish safe conditions for greedy admission, dynamic control of disk read sizes, fast initial service, and sporadic services. We conduct thorough simulations over a wide range of buffer capacities, load settings, and over varying playout rates to demonstrate the significant improvements in quality of service, throughput and start-up latency of our approach relative to a static approach.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007002/90070091.pdf", } @ARTICLE{Chan9902:Circular, AUTHOR="Chi-ching Chang and C. Jimmy Shih", TITLE="A circular skip-cluster scheme to support video-on-demand services", JOURNAL=mms, VOLUME=7, NUMBER=2, PAGES="107-118", YEAR=1999, KEYWORDS="Admission control;CD-ROM;Disk array;Cluster;Popularity;Video-on-demand (VOD) systems", ABSTRACT="The major drawback of the existing cluster placement scheme is the long response time caused by admission control if the number of clusters and the number of users are large. A circular skip-cluster placement scheme is proposed to reduce the size of the data buffer as well as the system response time. Furthermore, the popularity of each video is different in the real world. We propose a new popularity-based data allocation scheme to allocate data units within a cluster such that the corresponding data units of these popular videos are stored in those cylinders at one end of each cluster. Due to a higher spatial locality within these hot cylinders, some data units requested by the users are stored in the same cylinder such that one seek operation, one rotation, and one transfer operation are required to retrieve these data units. Therefore, the time required to retrieve data for these requests can be reduced, thus also reducing the system response time. Based on our results, the buffer size and the system response time can be reduced by half or more. These findings are essential for constructing video-on-demand systems that provide satisfactory performance.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007002/90070107.pdf", } @ARTICLE{Zabi9902:Feature, AUTHOR="Ramin Zabih and J. M. Miller and Kevin Mai", TITLE="A feature-based algorithm for detecting and classifying production effects", JOURNAL=mms, VOLUME=7, NUMBER=2, PAGES="119-128", YEAR=1999, KEYWORDS="Content-based indexing and retrieval;Scene break detection", ABSTRACT="We describe a new approach to the detection and classification of production effects in video sequences. Our method can detect and classify a variety of effects, including cuts, fades, dissolves, wipes and captions, even in sequences involving significant motion. We detect the appearance of intensity edges that are distant from edges in the previous frame. A global motion computation is used to handle camera or object motion. The algorithm we propose withstands JPEG and MPEG artifacts, even at high compression rates. Experimental evidence demonstrates that our method can detect and classify production effects that are difficult to detect with previous approaches.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007002/90070119.pdf", } @ARTICLE{Smit9902:Integrated, AUTHOR="Jr. Smith and Shih-Fu Chang", TITLE="Integrated spatial and feature image query", JOURNAL=mms, VOLUME=7, NUMBER=2, PAGES="129-140", YEAR=1999, KEYWORDS="Database management;Content analysis and indexing;Information storage and retrieval", ABSTRACT="We present a new system for querying for images by regions and their spatial and feature attributes. The system enables the user to find the images that contain arrangements of regions similar to those diagrammed in a query image. By indexing the attributes of regions, such as sizes, locations and visual features, a wide variety of complex joint spatial and feature queries are efficiently computed. In order to demonstrate the utility of the system, we develop a process for the extracting color regions from photographic images. We demonstrate that integrated spatial and feature querying using color regions improves image search capabilities over non-spatial content-based image retrieval methods.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007002/90070129.pdf", } @ARTICLE{Han9902:Progressively, AUTHOR="Richard Han and D. Messerschmitt", TITLE="A progressively reliable transport protocol for interactive wireless multimedia", JOURNAL=mms, VOLUME=7, NUMBER=2, PAGES="141-156", YEAR=1999, ABSTRACT="We propose a progressively reliable transport protocol for delivery of delay-sensitive multimedia over Internet connections with wireless access links. The protocol, termed", } @ARTICLE{Jaco9902:Silence, AUTHOR="Stephan Jacobs and Alexandros Eleftheriadis and Dimitris Anastassiou", TITLE="Silence detection for multimedia communication systems", JOURNAL=mms, VOLUME=7, NUMBER=2, PAGES="157-164", YEAR=1999, ABSTRACT="Silence detection and removal is an essential building block of any multimedia video conferencing system. It reduces the bandwidth requirements of the underlying network transport service and helps to maintain an acceptable end-to-end delay for audio. We analyze the requirements for a silence detection algorithm hosted on a multimedia communication system, and propose a novel low-complexity algorithm operating in the non-linear domain. After discussing the constraints which are imposed by the architecture of the system hardware (computer, packet-based network), we show that several recently proposed silence detection algorithms fail to meet all of these constraints. A new approach is then introduced, based on the small- and large-signal behavior of the speech waveform in the $\mu$-law domain. The new algorithm is compared with a recent design that meets several of our requirements; experimental results indicate that it performs significantly better in the particular environment at hand.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007002/90070157.pdf", } @ARTICLE{Lu9902:Region, AUTHOR="Guofeng Lu and Atul Sajjanhar", TITLE="Region-based shape representation and similarity measure suitable for content-based image retrieval", JOURNAL=mms, VOLUME=7, NUMBER=2, PAGES="165-174", YEAR=1999, KEYWORDS="Shape representation;Shape similarity measure;Pattern recognition;Image retrieval", ABSTRACT="A region-based approach to shape representation and similarity measure is presented. The shape representation is invariant to translation, scale and rotation. The similarity measure conforms to human similarity perception, i.e., perceptually similar shapes have high similarity measure. An experimental shape retrieval system has been developed and its performance has been studied. The shape retrieval performance of the proposed approach is better than that of the more established Fourier descriptor method.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007002/90070165.pdf", } @ARTICLE{Corr9903:Special, AUTHOR="Jacopo M. Corridoni and A. Del Bimbo and P. Pala", TITLE="Image retrieval by color semantics", JOURNAL=mms, VOLUME=7, NUMBER=3, PAGES="175-183", YEAR=1999, KEYWORDS="Image retrieval by content;Color semantics;Image databases", ABSTRACT="The development of a system supporting querying of image databases by color content tackles a major design choice about properties of colors which are referenced within user queries. On the one hand, low-level properties directly reflect numerical features and concepts tied to the machine representation of color information. On the other hand, high-level properties address concepts such as the perceptual quality of colors and the sensations that they convey. Color-induced sensations include warmth, accordance or contrast, harmony, excitement, depression, anguish, etc. In other words, they refer to the semantics of color usage. In particular, paintings are an example where the message is contained more in the high-level color qualities and spatial arrangements than in the physical properties of colors. Starting from this observation, Johannes Itten introduced a formalism to analyze the use of color in art and the effects that this induces on the user's psyche. In this paper, we present a system which translates the Itten theory into a formal language that expresses the semantics associated with the combination of chromatic properties of color images. The system exploits a competitive learning technique to segment images into regions with homogeneous colors. Fuzzy sets are used to represent low-level region properties such as hue, saturation, luminance, warmth, size and position. A formal language and a set of model-checking rules are implemented to define semantic clauses and verify the degree of truth by which they hold over an image.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007003/90070175.pdf", } @ARTICLE{Ma9903:Special, AUTHOR="Wei-hsiu Ma and B. S. Manjunath", TITLE="NeTra: A toolbox for navigating large image databases", JOURNAL=mms, VOLUME=7, NUMBER=3, PAGES="184-198", YEAR=1999, ABSTRACT="We present here an implementation of NeTra, a prototype image retrieval system that uses color, texture, shape and spatial location information in segmented image regions to search and retrieve similar regions from the database. A distinguishing aspect of this system is its incorporation of a robust automated image segmentation algorithm that allows object- or region-based search. Image segmentation significantly improves the quality of image retrieval when images contain multiple complex objects. Images are segmented into homogeneous regions at the time of ingest into the database, and image attributes that represent each of these regions are computed. In addition to image segmentation, other important components of the system include an efficient color representation, and indexing of color, texture, and shape features for fast search and retrieval. This representation allows the user to compose interesting queries such as", } @ARTICLE{Izqu9903:Regular, AUTHOR="M. R. Izquierdo and Douglas Reeves", TITLE="A survey of statistical source models for variable-bit-rate compressed video", JOURNAL=mms, VOLUME=7, NUMBER=3, PAGES="199-213", YEAR=1999, KEYWORDS="Video modeling;VBR;Variable bit rate;MPEG;H.261;TES;Self-similar", ABSTRACT="It is predicted that, in the near future, the transport of compressed video will pervade computer networks. Variable-bit-rate (VBR) encoded video is expected to become a significant source of network traffic, due to its advantages in statistical multiplexing gain and consistent video quality. Both systems analysts and developers need to assess and study the impact these sources will have on their networks and networking products. To this end, suitable statistical source models are required to analyze performance metrics such as packet loss, delay and jitter. This paper provides a survey of VBR source models which can be used to drive network simulations. The models are categorized into four groups: Markov chain/linear regression, TES, self-similar and i.i.d/analytical. We present models which have been used for VBR sources containing moderate-to-significant scene changes and moderate-to-full motion. A description of each model is given along with corresponding advantages and shortcomings. Comparisons are made based on the complexity of each model.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007003/90070199.pdf", } @ARTICLE{Gibb9903:Regular, AUTHOR="S. Gibbs and Costas Arapis and Christian Breiteneder", TITLE="{TELEPORT:} Towards immersive copresence", JOURNAL=mms, VOLUME=7, NUMBER=3, PAGES="214-221", YEAR=1999, ABSTRACT="TELEPORT is an experimental teleconferencing system with the goal of enabling small groups of people, although geographically separated, to meet as if face to face. The innovative features of the system include the use of full-wall display surfaces.", } @ARTICLE{Rao9903:Regular, AUTHOR="Santosh Rao and S. V. Raghavan", TITLE="Fast techniques for the optimal smoothing of stored video", JOURNAL=mms, VOLUME=7, NUMBER=3, PAGES="222-233", YEAR=1999, KEYWORDS="Video-on-demand;Bandwidth smoothing;Video compression;Prefetching", ABSTRACT="Work-ahead smoothing is a technique whereby a server, transmitting stored compressed video to a client, utilizes client buffer space to reduce the rate variability of the transmitted stream. The technique requires the server to compute a schedule of transfer under the constraints that the client buffer neither overflows nor underflows. Recent work established an optimal off-line algorithm (which minimizes peak, variance and rate variability of the transmitted stream) under the assumptions of fixed client buffer size, known worst case network jitter, and strict playback of the client video. In this paper, we examine the practical considerations of heterogeneous and dynamically variable client buffer sizes, variable worst case network jitter estimates, and client interactivity. These conditions require on-line computation of the optimal transfer schedule. We focus on techniques for reducing on-line computation time. Specifically, (i) we present an algorithm for precomputing and storing the optimal schedules for all possible client buffer sizes in a compact manner; (ii) we show that it is theoretically possible to precompute and store compactly the optimal schedules for all possible estimates of worst case network jitter; (iii) in the context of playback resumption after client interactivity, we show convergence of the recomputed schedule with the original schedule, implying greatly reduced on-line computation time; and (iv) we propose and empirically evaluate an", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007003/90070222.pdf", } @ARTICLE{Pass9903:Regular, AUTHOR="Greg Pass and Ramin Zabih", TITLE="Comparing images using joint histograms", JOURNAL=mms, VOLUME=7, NUMBER=3, PAGES="234-240", YEAR=1999, KEYWORDS="Content-based indexing and retrieval;Color histograms;Color-spatial indexing", ABSTRACT="Color histograms are widely used for content-based image retrieval due to their efficiency and robustness. However, a color histogram only records an image's overall color composition, so images with very different appearances can have similar color histograms. This problem is especially critical in large image databases, where many images have similar color histograms. In this paper, we propose an alternative to color histograms called a joint histogram, which incorporates additional information without sacrificing the robustness of color histograms. We create a joint histogram by selecting a set of local pixel features and constructing a multidimensional histogram. Each entry in a joint histogram contains the number of pixels in the image that are described by a particular combination of feature values. We describe a number of different joint histograms, and evaluate their performance for image retrieval on a database with over 210,000 images. On our benchmarks, joint histograms outperform color histograms by an order of magnitude.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007003/90070234.pdf", } @ARTICLE{Shen9903:Regular, AUTHOR="Prashant Shenoy and Harrick Vin", TITLE="Efficient support for interactive operations in multi-resolution video servers", JOURNAL=mms, VOLUME=7, NUMBER=3, PAGES="241-253", YEAR=1999, KEYWORDS="Multi-resolution video servers;Multi-resolution playback;Scan operations;Fast-forward;Rewind;Disk arrays;Scalable compression", ABSTRACT="In this paper, we present a placement algorithm that interleaves multi-resolution video streams on a disk array and enables a video server to efficiently support playback of these streams at different resolution levels. We then combine this placement algorithm with a scalable compression technique to efficiently support interactive scan operations (i.e., fast-forward and rewind). We present an analytical model for evaluating the impact of the scan operations on the performance of disk-arr ay-based servers. Our experiments demonstrate that: (1) employing our placement algorithm substantially reduces seek and rotational latency overhead during playback, and (2) exploiting the characteristics of video streams and human perceptual tolerances enables a server to support interactive scan operations without any additional overhead.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007003/90070241.pdf", } @ARTICLE{Liou9904:Special, AUTHOR="Shih-Ping Liou and Rune Hjelsvold and Remi Depommier and Arding Hsu", TITLE="Efficient and reliable digital media archive for content-based retrieval", JOURNAL=mms, VOLUME=7, NUMBER=4, PAGES="256-268", YEAR=1999, KEYWORDS="Shot detection;Structured logging;Multimedia database;Semantic modeling;Card-based query", ABSTRACT="Recent years have witnessed a significant price reduction in many enabling technologies for wide-spread deployment of multimedia to desktop PCs and workstations. This advancement has lead to an increasing demand for systems that can store, retrieve, and manipulate large volumes of multimedia information. For a multimedia information system to better meet information users' needs, it must provide suitable access structures and methods. The answers to this demand fall into the research area of what most people called content-based multimedia indexing and retrieval. Existing approaches to content-based indexing and retrieval have limitations. What we need is a digital-media-archiving system that is both efficient and reliable. By reliable, we mean that users should be able to retrieve documents that have the most potential for being relevant to their queries. On the other hand, an efficient digital-media-archiving system should provide an environment that allows human operators to create document indices without the need to manually watch every multimedia object and enter keyword descriptions. This can be done by providing initial structure information of the video to the user, by guiding the human operator through the indexing process, and by offering tools to create multiple media representations in a hierarchical structure.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007004/90070256.pdf", } @ARTICLE{Yeo9904:Special, AUTHOR="Boon-Lock Yeo", TITLE="On fast microscopic browsing of {MPEG-compressed} video", JOURNAL=mms, VOLUME=7, NUMBER=4, PAGES="269-281", YEAR=1999, KEYWORDS="Video browsing;Compressed-domain processing;Video analysis;Video database;DC images", ABSTRACT="MPEG has been established as a compression standard for efficient storage and transmission of digital video. However, users are limited to VCR-like (and tedious) functionalities when viewing MPEG video. The usefulness of MPEG video is presently limited by the lack of tools available for fast browsing, manipulation and processing of MPEG video. In this paper, we first address the problem of rapid access to individual shots and frames in MPEG video. We build upon the compressed-video-processing framework proposed in [1, 8], and propose new and fast algorithms based on an adaptive mixture of approximation techniques for extracting spatially reduced image sequence of uniform quality from MPEG video across different frame types and also under different motion activities in the scenes. The algorithms execute faster than real time on a Pentium personal computer. We demonstrate how the reduced images facilitate fast and convenient shot- and frame-level video browsing and access, shot-level editing and annotation, without the need for frequent decompression of MPEG video. We further propose methods for reducing the auxiliary data size associated with the reduced images through exploitation of spatial and temporal redundancy. We also address how the reduced images lead to computationally efficient algorithms for video analysis based on intra- and inter-shot processing for video database and browsing applications. The algorithms, tools for browsing and techniques for video processing presented in this paper have been used by many in IBM Research on more than 30 h of MPEG-1 video for video browsing and analysis.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007004/90070269.pdf", } @ARTICLE{Meng9904:Special, AUTHOR="Horace J. Meng and Di Zhong and Shih-Fu Chang", TITLE="Searching and editing {MPEG-compressed} video in a distributed online environment", JOURNAL=mms, VOLUME=7, NUMBER=4, PAGES="282-293", YEAR=1999, KEYWORDS="Video content analysis;Video indexing;Compressed domain video manipulations;Network based video editing", ABSTRACT="WebClip (on-line demo at http://www.ctr.columbia.edu/webclip) is a compressed video searching and editing system operating over the World Wide Web. WebClip uses a distributed client-server model including a server engine for content analysis/editing, and clients for interactive controls of video browsing/editing. It specializes several unique features, including compressed-domain video feature extraction and manipulation, multi-resolution video access, content based video browsing/retrieval, and a distributed network architecture.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007004/90070282.pdf", } @ARTICLE{Jian9904:Regular, AUTHOR="X. Jiang and P. Mohapatra", TITLE="Efficient admission control algorithms for multimedia servers", JOURNAL=mms, VOLUME=7, NUMBER=4, PAGES="294-304", YEAR=1999, KEYWORDS="Admission control;Future-Max algorithm;Interval estimation algorithm;Multimedia storage server;Quality of service", ABSTRACT="In this paper, we have proposed efficient admission control algorithms for multimedia storage servers that are providers of variable-bit-rate media streams. The proposed schemes are based on a slicing technique and use aggressive methods for admission control. We have developed two types of admission control schemes: Future-Max (FM) and Interval Estimation (IE). The FM algorithm uses the maximum bandwidth requirement of the future to estimate the bandwidth requirement. The IE algorithm defines a class of admission control schemes that use a combination of the maximum and average bandwidths within each interval to estimate the bandwidth requirement of the interval. The performance evaluations done through simulations show that the server utilization is improved by using the FM and IE algorithms. Furthermore, the quality of service is also improved by using the FM and IE algorithms. Several results depicting the trade-off between the implementation complexity, the desired accuracy, the number of accepted requests, and the quality of service are presented.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007004/90070294.pdf", } @ARTICLE{Lee9904:Regular, AUTHOR="K. Y. Lee and Heon Yeom", TITLE="An effective admission control mechanism for variable-bit-rate video streams", JOURNAL=mms, VOLUME=7, NUMBER=4, PAGES="305-311", YEAR=1999, KEYWORDS="Admission control;Video-on-demand systems;Variable bit rate;Disk scheduling;Buffer management", ABSTRACT="For admission control in real-time multimedia systems, buffer space, disk bandwidth and network bandwidth must be considered. The CBR-based mechanisms do not use system resources effectively, since media data is usually encoded with VBR compression techniques. We propose an admission control mechanism based on a VBR data model that has a dynamic period length. In our mechanism, the period can be adaptively changed to maximize the performance, considering both disk bandwidth and buffer space. To compare the performance, extensive simulations are conducted on RR, SCAN, and GSS schemes which have the dynamic period length and the static period length.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007004/90070305.pdf", } @ARTICLE{John9904:Dynamic, AUTHOR="T. Johnson and A. Zhang", TITLE="Dynamic playout scheduling algorithms for continuous multimedia streams", JOURNAL=mms, VOLUME=7, NUMBER=4, PAGES="312-325", YEAR=1999, KEYWORDS="Multimedia;Presentation;Synchronization", ABSTRACT="In this paper, we investigate a playout scheduling framework for supporting the continuous and synchronized presentations of multimedia streams in a distributed multimedia presentation system. We assume a situation in which the server and network transmissions provide sufficient support for the delivery of media objects. In this context, major issues regarding the enforcement of the smooth presentation of multimedia streams at client sites must be addressed to deal with rate variance of stream presentations and delay variance of networks. We develop various playout-scheduling algorithms that are adaptable to quality-of-service parameters. The proposed algorithms permit the local adjustment of unsynchronized presentations by gradually accelerating or retarding presentation components, rather than abruptly skipping or pausing the presentation materials. A comprehensive experimental analysis of the proposed algorithms demonstrates that our algorithms can effectively avoid playout gaps (or hiccups) in the presentations. This scheduling framework can be readily used to support customized multimedia presentations.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007004/90070312.pdf", } @ARTICLE{Xie9904:Regular, AUTHOR="Yongzhe Xie and Chao-Ming Liu and M. J. Lee and T. N. Saadawi", TITLE="Adaptive multimedia synchronization in a teleconference system", JOURNAL=mms, VOLUME=7, NUMBER=4, PAGES="326-337", YEAR=1999, KEYWORDS="Multimedia synchronization;QOS", ABSTRACT="In this paper, we present an adaptive buffering scheme for implementing intra-stream and inter-stream synchronization in real-time multimedia applications. The essence of the proposed scheme is to dynamically enforce equalized delays to incoming media streams, in order to piece-wise smooth the network delay variations and to synchronize the streams at the sink. An adaptive control mechanism based on an event-counting algorithm is employed to calibrate the PlayOut Clocks (POCs), which manages the presentations of multimedia data. The algorithm does not rely on globally synchronized clock and makes minimal assumption on underlying network delay distribution. Also, the user defined quality of service (QoS) specifications can be directly incorporated into the design parameters of the synchronization algorithm. The proposed synchronization scheme has been experimentally implemented in a teleconference system which consists of separately controllable audio, video, and data channels. The modular structure of the synchronization control provides the flexibility to maintain an arbitrary synchronization group in conjunction with a distributed conference management scheme. This paper also shows the experimental results of the test implementation and the suitability of the proposed scheme with respect to the multimedia traffic across an FDDI/Ethernet network.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007004/90070326.pdf", } @ARTICLE{Hirz9904:Regular, AUTHOR="Nael Hirzalla and Ahmed Karmouch", TITLE="A data model and a query language for multimedia documents databases", JOURNAL=mms, VOLUME=7, NUMBER=4, PAGES="338-348", YEAR=1999, KEYWORDS="Multimedia database;Database schema;Multimedia query language;Object oriented", ABSTRACT="A multimedia application involves information that may be in a form of video, images, audio, text and graphics, need to be stored, retrieved and manipulated in large databases. In this paper, we propose an object-oriented database schema that supports multimedia documents and their temporal, spatial and logical structures. We present a document example and show how the schema can adress all the structures described. We also present a multimedia query specification language that can be used to describe a multimedia content portion to be retrieved from the database. The language provides means by which the user can specify the information on the media as well as the temoral and spatial relationships among these media.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007004/90070338.pdf", } @ARTICLE{Wen9905:Special, AUTHOR="Xiaodong Wen and Theodore D. Huffmire and Helen H. Hu and A. Finkelstein", TITLE="Wavelet-based video indexing and querying", JOURNAL=mms, VOLUME=7, NUMBER=5, PAGES="350-358", YEAR=1999, ABSTRACT="We present several algorithms suitable for analysis of broadcast video. First, we show how wavelet analysis of frames of video can be used to detect transitions between shots in a video stream, thereby dividing the stream into segments. Next we describe how each segment can be inserted into a video database using an indexing scheme that involves a wavelet-based", } @ARTICLE{Rui9905:Special, AUTHOR="Yong Rui and Tien-Yu Huang and Sharad Mehrotra", TITLE="Constructing table-of-content for videos", JOURNAL=mms, VOLUME=7, NUMBER=5, PAGES="359-368", YEAR=1999, KEYWORDS="Video accessing;Scene-level ToC construction", ABSTRACT="A fundamental task in video analysis is to extract structures from the video to facilitate user's access (browsing and retrieval). Motivated by the important role that the table of content (ToC) plays in a book, in this paper, we introduce the concept of ToC in the video domain. Some existing approaches implicitly use the ToC, but are mainly limited to low-level entities (e.g., shots and key frames). The drawbacks are that low-level structures (1) contain too many entries to be efficiently presented to the user; and (2) do not capture the underlying semantic structure of the video based on which the user may wish to browse/retrieve. To address these limitations, in this paper, we present an effective semantic-level ToC construction technique based on intelligent unsupervised clustering. It has the characteristics of better modeling the time locality and scene structure. Experiments based on real-world movie videos validate the effectiveness of the proposed approach. Examples are given to demonstrate the usage of the scene-based ToC in facilitating user's access to the video.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007005/90070359.pdf", } @ARTICLE{Jain9905:Special, AUTHOR="A. K. Jain and Aditya Vailaya and Xiong Wei", TITLE="Query by video clip", JOURNAL=mms, VOLUME=7, NUMBER=5, PAGES="369-384", YEAR=1999, KEYWORDS="Video database;Key frames;Retrieval;Video clips;Clip similarity;Color;Texture;Motion", ABSTRACT="Typical digital video search is based on queries involving a single shot. We generalize this problem by allowing queries that involve a video clip (say, a 10-s video segment). We propose two schemes: (i) retrieval based on key frames follows the traditional approach of identifying shots, computing key frames from a video, and then extracting image features around the key frames. For each key frame in the query, a similarity value (using color, texture, and motion) is obtained with respect to the key frames in the database video. Consecutive key frames in the database video that are highly similar to the query key frames are then used to generate the set of retrieved video clips. (ii) In retrieval using sub-sampled frames, we uniformly sub-sample the query clip as well as the database video. Retrieval is based on matching color and texture features of the sub-sampled frames. Initial experiments on two video databases (basketball video with approximately 16,000 frames and a CNN news video with approximately 20,000 frames) show promising results. Additional experiments using segments from one basketball video as query and a different basketball video as the database show the effectiveness of feature representation and matching schemes.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007005/90070369.pdf", } @ARTICLE{Sato9905:Special, AUTHOR="T. Sato and Takeo Kanade and Ellen K. Hughes and Malcolm Smith and S. Satoh", TITLE="Video {OCR:} indexing digital news libraries by recognition of superimposed captions", JOURNAL=mms, VOLUME=7, NUMBER=5, PAGES="385-395", YEAR=1999, KEYWORDS="Digital video library;Caption;Index;OCR;Image enhancement", ABSTRACT="The automatic extraction and recognition of news captions and annotations can be of great help locating topics of interest in digital news video libraries. To achieve this goal, we present a technique, called Video OCR (Optical Character Reader), which detects, extracts, and reads text areas in digital video data. In this paper, we address problems, describe the method by which Video OCR operates, and suggest applications for its use in digital news archives. To solve two problems of character recognition for videos, low-resolution characters and extremely complex backgrounds, we apply an interpolation filter, multi-frame integration and character extraction filters. Character segmentation is performed by a recognition-based segmentation method, and intermediate character recognition results are used to improve the segmentation. We also include a method for locating text areas using text-like properties and the use of a language-based postprocessing technique to increase word recognition rates. The overall recognition results are satisfactory for use in news indexing. Performing Video OCR on news video and combining its results with other video understanding techniques will improve the overall understanding of the news video content.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007005/90070385.pdf", } @ARTICLE{Hua9905:Special, AUTHOR="Kien Hua and Wallapak Tavanapong and Jin-Tuu Wang", TITLE="{2PSM:} an efficient framework for searching video information in a limited-bandwidth environment", JOURNAL=mms, VOLUME=7, NUMBER=5, PAGES="396-408", YEAR=1999, KEYWORDS="Data organization;Video library;Previewing;VCR-style interaction;Video on demand;World Wide Web", ABSTRACT="We present a novel technique, called 2-Phase Service Model, for streaming videos to home users in a limited-bandwidth environment. This scheme first delivers some number of non-adjacent data fragments to the client in Phase 1. The missing fragments are then transmitted in Phase 2 as the client is playing back the video. This approach offers many benefits. The isochronous bandwidth required for Phase 2 can be controlled within the capability of the transport medium. The data fragments received during Phase 1 can be used to provide an excellent preview of the video. They can also be used to facilitate VCR-style operations such as fast-forward and fast-reverse. Systems designed based on this method are less expensive because the fast-forward and fast-reverse versions of the video files are no longer needed. Eliminating these files also improves system performance because mapping between the regular files and their fast-forward and fast-reverse versions is no longer part of the VCR operations. Furthermore, since each client machine handles its own VCR-style interaction, this technique is very scalable. We provide simulation results to show that 2-Phase Service Model is able to handle VCR functions efficiently. We also implement a video player called {\em FRVplayer}. With this prototype, we are able to judge that the visual quality of the previews and VCR-style operations is excellent. These features are essential to many important applications. We discuss the application of FRVplayer in the design of a video management system, called VideoCenter. This system is intended for Internet applications such as digital video libraries.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007005/90070396.pdf", } @ARTICLE{Day9905:Regular, AUTHOR="Young Francis Day and Ashfaq Khokhar and Serhan Dagtas and A. Ghafoor", TITLE="A multi-level abstraction and modeling in video databases", JOURNAL=mms, VOLUME=7, NUMBER=5, PAGES="409-423", YEAR=1999, KEYWORDS="Semantic modeling;Video databases;Content-based retrieval;Spatio-temporal logic;Object-oriented modeling", ABSTRACT="In this paper, we propose a multi-level abstraction mechanism for capturing the spatial and temporal semantics associated with various objects in an input image or in a sequence of video frames. This abstraction can manifest itself effectively in conceptualizing events and views in multimedia data as perceived by individual users. The objective is to provide an efficient mechanism for handling content-based queries, with the minimum amount of processing performed on raw data during query evaluation. We introduce a multi-level architecture for video data management at different levels of abstraction. The architecture facilitates a multi-level indexing/searching mechanism. At the finest level of granularity, video data can be indexed based on mere appearance of objects and faces. For management of information at higher levels of abstractions, an object-oriented paradigm is proposed which is capable of supporting domain specific views.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007005/90070409.pdf", } @ARTICLE{Song9905:Regular, AUTHOR="J. Song and G. Ramalingam and R. G. Miller and Byoung-Kee Yi", TITLE="Interactive authoring of multimedia documents in a constraint-based authoring system", JOURNAL=mms, VOLUME=7, NUMBER=5, PAGES="424-437", YEAR=1999, ABSTRACT="As multimedia applications spread widely, it is crucial for programming and design support systems to handle", } @ARTICLE{Agga9906:Regular, AUTHOR="Charu Aggarwal and J. Wolf and P. S. Yu", TITLE="Design and analysis of permutation-based pyramid broadcasting", JOURNAL=mms, VOLUME=7, NUMBER=6, PAGES="439-448", YEAR=1999, KEYWORDS="Broadcasting;Video-on-demand;Pyramid schemes", ABSTRACT="Periodic broadcasting can be used to support near-video-on-demand for popular videos. For a given bandwidth allocation, pyramid broadcasting schemes substantially reduce the viewer latency (waiting) time compared to conventional broadcasting schemes. Nevertheless, such pyramid schemes typically have substantial storage requirements at the client end, and this results in set-top boxes needing disks with high transfer rate capabilities. In this paper, we present a permutation-based pyramid scheme in which the storage requirements and disk transfer rates are greatly reduced, and yet the viewer latency is also smaller. Under the proposed approach, each video is partitioned into contiguous segments of geometrically increasing sizes, and each segment is further divided into blocks, where a block is the basic unit of transmission. As in the original pyramid scheme, frequencies of transmission for the different segments of a video vary in a manner inversely proportional to their size. Instead of transmitting the blocks in each segment in sequential order, the proposed scheme transmits these blocks in a prespecified cyclic permutation to save on storage requirements in the client end. Performance analyses are provided to quantify the benefits of the new scheme.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007006/90070439.pdf", } @ARTICLE{Gong9906:Regular, AUTHOR="Yi Gong", TITLE="Advancing content-based image retrieval by exploiting image color and region features", JOURNAL=mms, VOLUME=7, NUMBER=6, PAGES="449-457", YEAR=1999, KEYWORDS="Content-based image retrieval.;Color clustering.;Region-based image matching.;Human color perceptions", ABSTRACT="In this paper, we propose a novel system that strives to achieve advanced content-based image retrieval using seamless combination of two complementary approaches: on the one hand, we propose a new color-clustering method to better capture color properties of the original images; on the other hand, expecting that image regions acquired from the original images inevitably contain many errors, we make use of the available erroneous, ill-segmented image regions to accomplish the object-region-based image retrieval. We also propose an effective image-indexing scheme to facilitate fast and efficient image matching and retrieval. The carefully designed experimental evaluation shows that our proposed image retrieval system surpasses other methods under comparison in terms of not only quantitative measures, but also image retrieval capabilities.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007006/90070449.pdf", } @ARTICLE{Wu9906:Regular, AUTHOR="Chengke Wu and Gin-Kou Ma and Minkui Liu", TITLE="A scalable storage supporting multistream real-time data retrieval", JOURNAL=mms, VOLUME=7, NUMBER=6, PAGES="458-466", YEAR=1999, KEYWORDS="Data placement;Multimedia system;Storage system", ABSTRACT="This paper presents a new data placement scheme for continuous-media playback via a scalable storage system. Multimedia contents are segmented into data blocks for the purpose of being stored, retrieved, and manipulated. If these data blocks belong to some continuous media, then they must be handled in a timely manner, for example, being retrieved before some deadline. One of the main challenges in implementing the above system is the simultaneous retrieval of a great number of different media streams from a very large storage system. The proposed scheme efficiently reduces the seeking delay by a very simple placement method and a retrieval scheduler. Thus, both the storage capacity and the number of concurrent accesses to the storage are scalable. The performance of the proposed scheme is evaluated through a simple analytical model and a practical prototype implementation.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007006/90070458.pdf", } @ARTICLE{Abba9906:Regular, AUTHOR="Sadegh Abbasi and Farzin Mokhtarian and J. Kittler", TITLE="Curvature scale space image in shape similarity retrieval", JOURNAL=mms, VOLUME=7, NUMBER=6, PAGES="467-476", YEAR=1999, KEYWORDS="Multi-scale analysis;Shape similarity;Curvature scale space;Image database retrieval;Performance characterisation", ABSTRACT="In many applications, the user of an image database system points to an image, and wishes to retrieve similar images from the database. Computer vision researchers aim to capture image information in feature vectors which describe shape, texture and color properties of the image. These vectors are indexed or compared to one another during query processing to find images from the database. This paper is concerned with the problem of shape similarity retrieval in image databases. Curvature scale space (CSS) image representation along with a small number of global parameters are used for this purpose. The CSS image consists of several arch-shape contours representing the inflection points of the shape as it is smoothed. The maxima of these contours are used to represent a shape. The method is then tested on a database of 1100 images of marine creatures. A classified subset of this database is used to evaluate the method and compare it with other methods. The results show the promising performance of the method and its superiority over Fourier descriptors and moment invariants.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007006/90070467.pdf", } @ARTICLE{Knig9906:Regular, AUTHOR="Edward W. Knightly", TITLE="Resource allocation for multimedia traffic flows using rate variance envelopes", JOURNAL=mms, VOLUME=7, NUMBER=6, PAGES="477-485", YEAR=1999, ABSTRACT="In order for networks to support the delay and loss requirements of interactive multimedia applications, resource management algorithms are needed that efficiently allocate network resources. In this paper, we introduce a new resource allocation scheme based on rate variance envelopes. Such envelopes capture a flow's burstiness properties and autocorrelation structure by characterizing the variance of its rate distribution over intervals of different length. From this traffic characterization, we develop a simple and efficient resource allocation algorithm for static priority schedulers by employing a Gaussian approximation over intervals and considering a maximal busy period. Our approach supports heterogeneous quality-of-service requirements via our consideration of prioritized service disciplines, and supports heterogeneous and bursty traffic flows via our general framework of traffic envelopes. To evaluate the scheme, we perform trace-driven simulation experiments with long traces of compressed video and show that our approach is accurate enough to capture most of the available statistical multiplexing gain, achieving average network utilizations of up to 90\% for these traces and substantially outperforming alternate schemes.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007006/90070477.pdf", } @ARTICLE{Wije9906:Regular, AUTHOR="Duminda Wijesekera and J. Srivastava and Anil Nerode and Mark Foresti", TITLE="Experimental evaluation of loss perception in continuous media", JOURNAL=mms, VOLUME=7, NUMBER=6, PAGES="486-499", YEAR=1999, KEYWORDS="Quality of service;User studies;Media losses;Metrics", ABSTRACT="Perception of multimedia quality, specified by quality-of-service (QoS) metrics, can be used by system designers to optimize customer satisfaction within resource bounds enforced by general-purpose computing platforms. Media losses, rate variations and transient synchronization losses have been suspected to affect human perception of multimedia quality. This paper presents metrics to measure such defects, and results of a series of user experiments that justify such speculations. Results of the study provide bounds on losses, rate variations and transient synchronization losses as a function of user satisfaction, in the form of Likert values. It is shown how these results can be used by algorithm designers of underlying multimedia systems.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007006/90070486.pdf", } @ARTICLE{Hakk9906:Regular, AUTHOR="Veli Hakkoymaz and J. Kraft and Gultekin Ozsoyoglu", TITLE="Constraint-based automation of multimedia presentation assembly", JOURNAL=mms, VOLUME=7, NUMBER=6, PAGES="500-518", YEAR=1999, ABSTRACT="In this paper, we present a methodology for automated construction of multimedia presentations. Semantic coherency of a multimedia presentation is expressed in terms of presentation inclusion and exclusion constraints. When a user specifies a set of segments for a presentation, the multimedia database system adds segments into and/or deletes segments from the set in order to satisfy the inclusion and exclusion constraints. We discuss the consistency and the satisfiability of inclusion and exclusion constraints when exclusion is allowed. Users express a presentation query by (a) pointing and clicking to an initial set of desired multimedia segments to be included into the presentation, and (b) specifying an upper bound on the time length of the presentation. The multimedia database system then finds the set of segments satisfying the inclusion-exclusion constraints and the time bound. Using priorities for segments and inclusion constraints, we give two algorithms for automated presentation assembly and discuss their complexity. To automate the assembly of a presentation with concurrent presentation streams, we introduce presentation organization constraints that are incorporated into the multimedia data model, independent of any presentation. We define four types of presentation organization constraints that, together with an underlying database ordering, allow us to obtain a unique presentation graph for a given set of multimedia segments. We briefly summarize a prototype system that fully incorporates the algorithms for the segment selection problem.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007006/90070500.pdf", } @INPROCEEDINGS{Davi99:Bandwidth, AUTHOR="Donald W. Davies and Robetr Neilson and Juha Heinanen and Jean-Marc Uze and A. Danthine and Craig Labovitz", TITLE="Debate: Bandwidth overprovisioning vs. {QoS}", BOOKTITLE="QoS Summit", ADDRESS="Paris, France", YEAR=1999, KEYWORDS="quality of service; overprovisioning", ABSTRACT="Debate transcript", URL="http://www.upperside.fr/qos99/qosdeb.doc", } @INPROCEEDINGS{Fank9903:Reservation, AUTHOR="G. Fankhauser and B. Stiller and C. Vogtli and B. Plattner", TITLE="Reservation-based Charging in an Integrated Services Network", BOOKTITLE="4th Informs Telecommunications Conference", ADDRESS="Boca Raton", MONTH="Mar", YEAR=1999, REFERENCES=19, KEYWORDS="Charging; Accouting; Internet Protocol; Economic Models; Usage-based Pricing; resource Reservation; Service Class Model; Quality of Service (QoS)", ABSTRACT="Valuable high-end communication services cannot be assigned in a cooperative fashion, they must be rather granted on grounds of economic admission policies. Usagebased pricing models for an integrated services Internet have been proposed, but on a theoretical level only. In this paper, a control protocol for charging and accounting resource reservations in the integrated services Internet is presented, highlighting implementation issues and performance aspects with such usage-based pricing models. The general design decisions as well as a first implementation are described. They are based on a simple version of the resource reservation protocol RSVP. The pricing models employed were (1) an auction-based pricing model (delta auction) and (2) an adaptive, load-sensitive, volume pricing model. The protocol can handle these pricing models concurrently, i.e., it supports local pricing decisions. Furthermore, sender and receiver of a connection can share the cost of a transmission. Finally, the prototype implementation was used to obtain first results and measurements concerning the overhead in terms of network and computing resources.", URL="www.tik.ee.ethz.ch/~gfa/papers/informs98.pdf", } @ARTICLE{Gibb99:Resource, AUTHOR="R. J. Gibbens and F. P. Kelly", TITLE="Resource pricing and the evolution of congestion control", JOURNAL="Automatica", VOLUME=35, PAGES="1969-1985", YEAR=1999, REFERENCES=28, KEYWORDS="charging; critical congestion interval; game theory; Internet; proportionally fair pricing; rate control; sample path shadow prices", ABSTRACT="We describe ways in which the transmission control protocol of the Internet may evolve to support heterogeneous applications. We show that by appropriately marking packets at overloaded resources and by charging a fixed small amount for each mark received, end-nodes are provided with the necessary information and the correct incentive to use the network efficiently.", URL="http://www.statslab.cam.ac.uk/~frank/evol.html", } @INPROCEEDINGS{Reic9909:Auction, AUTHOR="P. Reichl and G. Fankhauser and B. Stiller", TITLE="Auction Models for Multi-Provider {Internet} Connections", BOOKTITLE="Tagungsband zur 10. GI/ITG-Fachtagung Messung, Modellierung und Bewertung von Rechen- und Kommunikationssystemen (MMB)", MONTH="Sep", YEAR=1999, ABSTRACT="Auctions are a widely used approach for determing the current market price for congested resources. However, using them for real systems, such as the Internet, the auction algorithms require modifications as soon as connections cover links from more than one Internet Service Provider. This paper presents work in progress on two new auction schemes that have been designed to overcome this problem.", URL="http://www.tik.ee.ethz.ch/~gfa/paper/mmb99.pdf", } @ARTICLE{Sato9901:Name, AUTHOR="S. Satoh and Yasuaki Nakamura and Takeo Kanade", TITLE="Name-It: Naming and Detecting Faces in News Videos", JOURNAL=ieeemm, VOLUME=6, NUMBER=1, MONTH="January-March", YEAR=1999, ABSTRACT="We developed Name-It, a system that associates faces and names in news videos. It processes information from the videos and can infer possible name candidates for a given face or locate a face in news videos by name. To accomplish this task, the system takes a multimodal video analysis approach: face sequence extraction and similarity evaluation from videos, name extraction from transcripts, and video-caption recognition.", URL="http://www.computer.org/multimedia/mu1999/u1toc.htm", } @ARTICLE{Ratc9901:Remote, AUTHOR="Mark Ratcliffe and Tim Paul Davies and Gillian Price", TITLE="Remote Advisory Services: A {NEAT} Approach", JOURNAL=ieeemm, VOLUME=6, NUMBER=1, MONTH="January-March", YEAR=1999, ABSTRACT="The Networked Expertise, Advice, and Tuition (NEAT) project has produced and evaluated a networked computer-based system that lets students contact and communicate remotely with help desk staff, tutors, or advisors over the Internet. The system uses public domain technology that facilitates video, audio, and text-based communication, whiteboarding, and application sharing. Here we discuss the system requirements, architecture, evaluation, and usability.", URL="http://www.computer.org/multimedia/mu1999/u1toc.htm", } @ARTICLE{Wang9901:Integrating, AUTHOR="Fei-Yue Wang and Shaidah Jusoh", TITLE="Integrating Multiple Web-based Geographic Information Systems", JOURNAL=ieeemm, VOLUME=6, NUMBER=1, MONTH="January-March", YEAR=1999, ABSTRACT="Most Web-based geographic information systems (GISs) are stand-alone. Our technique aims to integrate a collection of Web GISs into a system, providing more transparent and efficient access. Users can access the data stored at any of the participating sites as though all the data come from one site. We based our technique on Common Object Request Broker Architecture (Corba) and Java.", URL="http://www.computer.org/multimedia/mu1999/u1toc.htm", } @ARTICLE{Coul9901:Configurable, AUTHOR="G. Coulson", TITLE="A Configurable Multimedia Middleware Platform", JOURNAL=ieeemm, VOLUME=6, NUMBER=1, MONTH="January-March", YEAR=1999, ABSTRACT="Experience demonstrates the benefits and feasibility of supporting multimedia applications in distributed middleware architectures. However, deployment of multimedia-capable middleware platforms has not yet occurred on a large scale. This article describes designing such a platform and its attempts to maximize performance, predictability, and configurability in a standard workstation operating-system environment.", URL="http://www.computer.org/multimedia/mu1999/u1toc.htm", } @ARTICLE{Naka9904:FreeWalk, AUTHOR="H. Nakanishi and Chikara Yoshida and T. Nishimura and Toru Ishida", TITLE="FreeWalk: A {3D} Virtual Space for Casual Meetings", JOURNAL=ieeemm, VOLUME=6, NUMBER=2, MONTH="April-June", YEAR=1999, ABSTRACT="A meeting environment for casual communication in a networked community, FreeWalk provides a 3D common area where everyone can meet and talk freely. FreeWalk represents participants as 3D polygon pyramids, on which their live video is mapped. Voice volume remains proportional to the distance between sender and receiver. For evaluation, we compared communications in FreeWalk to a conventional desktop videoconferencing system and a face-to-face meeting.", URL="http://www.computer.org/multimedia/mu1999/u2toc.htm", } @ARTICLE{Ohya9904:Virtual, AUTHOR="Jun Ohya and Jun Kurumisawa and Ryohei Nakatsu and Kazuyuki Ebihara and Shoichiro Iwasawa and David Harwood and Thanarat Horprasert", TITLE="Virtual Metamorphosis", JOURNAL=ieeemm, VOLUME=6, NUMBER=2, MONTH="April-June", YEAR=1999, ABSTRACT="The virtual metamorphosis system lets people change their forms into any other form in a virtual scene. To realize these changes, a computer vision system estimates facial expressions and body postures and reproduces them in a computer graphics avatar in real time. We introduce three systems in order of their development: the Virtual Kabuki system, Networked Theater, and ``Shall We Dance?''", URL="http://www.computer.org/multimedia/mu1999/u2toc.htm", } @ARTICLE{Ram9904:PML, AUTHOR="Ashwin Ram and Richard Catrambone and Mark J. Guzdial and Colleen M. Kehoe and D. Scott McCrickard and J. T. Stasko", TITLE="{PML:} Adding Flexibility to Multimedia Presentations", JOURNAL=ieeemm, VOLUME=6, NUMBER=2, MONTH="April-June", YEAR=1999, ABSTRACT="In multimedia systems, designers typically link content and presentation. A new markup language, Procedural Markup Language (PML), decouples content and presentation. It lets users specify the knowledge structures, underlying physical media, and relationships between them using cognitive media roles. This approach fosters modular system design and dynamic multimedia systems that can determine appropriate presentations for a given situation by allowing knowledge specification to be done separately from knowledge presentation.", URL="http://www.computer.org/multimedia/mu1999/u2toc.htm", } @ARTICLE{Chen9904:Representing, AUTHOR="Chi-Ming Chen and Linda Thomas and J. B. Cole and Chiladda Chennawasin", TITLE="Representing the Semantics of Virtual Spaces", JOURNAL=ieeemm, VOLUME=6, NUMBER=2, MONTH="April-June", YEAR=1999, KEYWORDS="Knowledge-based media space modeling; information visualization; collaborative virtual environments; social navigation", ABSTRACT="In the StarWalker virtual environment, users explore a shared semantic space and collaborate with concurrent visitors. StarWalker's design illustrates the potential of unifying spatial models, semantic structures, and social navigation metaphors in the development of multiuser virtual environments.", URL="http://www.computer.org/multimedia/mu1999/u2toc.htm", } @ARTICLE{Rous9904:Mediascape, AUTHOR="Nicolas Roussel", TITLE="Mediascape: A Web-Based Media Space", JOURNAL=ieeemm, VOLUME=6, NUMBER=2, MONTH="April-June", YEAR=1999, ABSTRACT="Mediascape provides a Web-based media space--an audio, video, and computing environment that supports distributed groups. Using Web standards and protocols it supports creating a software infrastructure that incorporates three important design principles: integrability, flexibility, and privacy. The Videoserver component handles digital video communication. This Web-based environment offers benefits to users and developers greater than traditional media spaces.", URL="http://www.computer.org/multimedia/mu1999/u2toc.htm", } @ARTICLE{Hiro9907:Integrating, AUTHOR="Michitaka Hirose and Tetsuro Ogi and Toshio Yamada", TITLE="Integrating Live Video for Immersive Environments", JOURNAL=ieeemm, VOLUME=6, NUMBER=3, MONTH="July-September", YEAR=1999, ABSTRACT="Cabin, an immersive projection display, is a room-sized, five-screen system that can display both computer graphics and video images. Several Cabins connected via a broadband network form the Cabinet system. Cabinet includes video avatars-a key new technology for sharing virtual worlds. Using video avatars, we have experimentally evaluated the ability to express positional information between distant users.", URL="http://www.computer.org/multimedia/mu1999/u3toc.htm", } @ARTICLE{Vazi9907:Specifying, AUTHOR="M. Vazirgiannis and Ioannis Kostalas and Timos Sellis", TITLE="Specifying and Authoring Multimedia Scenarios", JOURNAL=ieeemm, VOLUME=6, NUMBER=3, MONTH="July-September", YEAR=1999, ABSTRACT="An authoring methodology and a set of checking tools let authors specify the spatial and temporal features of an application and verify the application prior to its execution. The checking tools include an animation tool, spatial and temporal layouts, and the execution table.", URL="http://www.computer.org/multimedia/mu1999/u3toc.htm", } @ARTICLE{Colo9907:Semantics, AUTHOR="Carlo Colombo and A. Del Bimbo and P. Pala", TITLE="Semantics in Visual Information Retrieval", JOURNAL=ieeemm, VOLUME=6, NUMBER=3, MONTH="July-September", YEAR=1999, ABSTRACT="A compositional approach increases the level of representation that can be automatically extracted and used in a visual information retrieval system. Visual information at the perceptual level is aggregated according to a set of rules. These rules reflect the specific context and transform perceptual words into phrases capturing pictorial content at a higher, and closer to the human, semantic level.", URL="http://www.computer.org/multimedia/mu1999/u3toc.htm", } @ARTICLE{Kons9907:Distributed, AUTHOR="Dimitri Konstantas and Yann Orlarey and Olivier Carbonel and S. Gibbs", TITLE="The Distributed Musical Rehearsal Environment", JOURNAL=ieeemm, VOLUME=6, NUMBER=3, MONTH="July-September", YEAR=1999, ABSTRACT="We developed an asynchronous transfer mode-based environment for distributed musical rehearsals in an immersive teleconference environment. This article describes the technical specifications of the installations and the organization and studio setup of these rehearsals. We present our implementation of the environment and give the results obtained from the organized distributed musical rehearsal trials.", URL="http://www.computer.org/multimedia/mu1999/u3toc.htm", } @ARTICLE{Nack9907:Everything, AUTHOR="Frank Nack and Adam T. Lindsay", TITLE="Everything You Wanted to Know About {MPEG-7:} Part 1", JOURNAL=ieeemm, VOLUME=6, NUMBER=3, MONTH="July-September", YEAR=1999, ABSTRACT="Audio-visual information must allow some degree of interpretation, which can be passed onto, or accessed by, a device or a computer code. MPEG-7 aims to create a standard for describing these operational requirements. We provide an overview on the development, functionality, and applicability of MPEG-7. We present the role of MPEG-7 and outline ideas for using MPEG-7 technology based on examples of improved versions of existing applications as well as completely new ones.", } @ARTICLE{Nack9907:Everything2, AUTHOR="Frank Nack and Adam T. Lindsay", TITLE="Everything You Wanted to Know About {MPEG-7:} Part 2", JOURNAL=ieeemm, VOLUME=6, NUMBER=4, MONTH="July-September", YEAR=1999, ABSTRACT="Audio-visual information must allow some degree of interpretation, which can be passed onto, or accessed by a device or a computer code. MPEG-7 aims to create a standard for describing these operational requirements. This article describes MPEG-7's concepts, terminology, and requirements. We also describe the influence of other approaches on multimedia content description on the development of the MPEG-7 standard and conclude with a short outlook on the time schedule for the standard.", URL="http://www.computer.org/multimedia/mu1999/u4toc.htm", } @ARTICLE{Fran9907:Multimedia, AUTHOR="Antonio Franchi and Eyal Trachtman and Louis Christodoulides and Jay Sengupta", TITLE="Multimedia via Inmarsat", JOURNAL=ieeemm, VOLUME=6, NUMBER=4, MONTH="July-September", YEAR=1999, ABSTRACT="Inmarsat's provision of multimedia services over its current satellites, as well as over a possible new generation of satellites, will enable technologies for support of higher data rates for mobile terminals. Inmarsat's next-generation satellite communications system will extend current capabilities by supporting fully interactive multimedia communications to small portable user terminals.", URL="http://www.computer.org/multimedia/mu1999/u4toc.htm", } @ARTICLE{Holz9907:Aeronautical, AUTHOR="Matthias Holzbock and Christian Senninger", TITLE="An Aeronautical Multimedia Service Demonstration at High Frequencies", JOURNAL=ieeemm, VOLUME=6, NUMBER=4, MONTH="July-September", YEAR=1999, ABSTRACT="An aeronautical measurement campaign for the satellite channel at the K band and an aeronautical multimedia service demonstration campaign for high data rate satellite services at the K/Ka band aim to provide high data rate services for all kinds of mobile terminals", URL="http://www.computer.org/multimedia/mu1999/u4toc.htm", } @ARTICLE{Mari9907:Regenerative, AUTHOR="Mauro Marinelli and Riccardo Giubilei", TITLE="A Regenerative Payload for Satellite Multimedia Communications", JOURNAL=ieeemm, VOLUME=6, NUMBER=4, MONTH="July-September", YEAR=1999, ABSTRACT="We describe a large-capacity on-board processing payload, designed for next-generation satellite systems. It provides broadband multimedia services to mobile and fixed users, and assigns data rates ranging from a few Kbps up to 2 Mbps for an aggregate traffic capacity of about 9 Gbps. This regenerative payload is the key element of the EuroSkyWay communication system.", URL="http://www.computer.org/multimedia/mu1999/u4toc.htm", } @ARTICLE{Pris9907:UMTS, AUTHOR="F. D. Priscoli", TITLE="{UMTS} Architecture for Integrating Terrestrial and Satellite Systems", JOURNAL=ieeemm, VOLUME=6, NUMBER=4, MONTH="July-September", YEAR=1999, ABSTRACT="This architecture proposal for the Universal Mobile Telecommunication System harmonizes several approaches to the evolving European Union mobile-systems standard. The architecture accommodates both satellite and terrestrial networks and allows a smooth transition from existing systems to UMTS.", URL="http://www.computer.org/multimedia/mu1999/u4toc.htm", } @ARTICLE{Iera9907:QoS, AUTHOR="A. Iera and A. Molinaro and S. Marano and Miriam Petrone", TITLE="{QoS} for Multimedia Applications in Satellite Systems", JOURNAL=ieeemm, VOLUME=6, NUMBER=4, MONTH="July-September", YEAR=1999, ABSTRACT="We present a policy for handling multimedia traffic over satellite air interfaces. It extends the advantages of ATM to satellite by the statistical multiplexing of variable-rate traffic sources. Effectiveness is assessed within a multimedia satellite platform called EuroSkyWay, based on Ka-band payload and on-board processing.", URL="http://www.computer.org/multimedia/mu1999/u4toc.htm", } @ARTICLE{Blef9907:Resource, AUTHOR="N. Blefari-Melazzi and G. Reali", TITLE="A Resource Management Scheme for Satellite Networks", JOURNAL=ieeemm, VOLUME=6, NUMBER=4, MONTH="July-September", YEAR=1999, ABSTRACT="Satellite networks with dynamic bandwidth allocation capabilities (DBAC) are based on classical circuit switches. The DBAC payload allows changing the capacity of each connection dynamically, without tearing down and setting up the connection. An analysis of our DBAC satellite system performance shows a significant increase in the overall utilization factor of our system compared to a plain circuit switching solution.", URL="http://www.computer.org/multimedia/mu1999/u4toc.htm", } @ARTICLE{Turn9901:Terabit, AUTHOR="J. S. Turner", TITLE="Terabit burst switching", JOURNAL=jhsn, VOLUME=8, NUMBER=1, PAGES="3-16", YEAR=1999, ABSTRACT="Demand for network bandwidth is growing at unprecedented rates, placing growing demands on switching and transmission technologies. Wavelength division multiplexing will soon make it possible to combine hundreds of gigabit channels on a single fiber. This paper presents an architecture for Burst Switching Systems designed to switch data among WDM links, treating each link as a shared resource rather than just a collection of independent channels. The proposed network architecture separates burst level data and control, allowing major simplifications in the data path in order to facilitate all-optical implementations. To handle short data bursts efficiently, the burst level control mechanisms in burst switching systems must keep track of future resource availability when assigning arriving data bursts to channels or storage locations. The resulting Lookahead Resource Management problems raise new issues and require the invention of completely new types of high speed control mechanisms. This paper introduces these problems and describes approaches to burst level resource management that attempt to strike an appropriate balance between high speed operation and efficiency of resource usage.", URL="http://www.iospress.nl/site/html/09266801.html", } @ARTICLE{Chao9901:Terabit, AUTHOR="Hung-Po Chao and Xiaolei Guo and C. F. Lam and T. Wang", TITLE="A terabit {IP} switch router using optoelectronic technology", JOURNAL=jhsn, VOLUME=8, NUMBER=1, PAGES="35-57", YEAR=1999, KEYWORDS="Terabit IP router; optical packet switch; input---output queued packet switching; speedup; optical interconnection network(OIN); wavelength division multiplexing(WDM); tunable filter", ABSTRACT="N=256the arbitration can be completed in 11 gates delay, less than 5 ns using the current CMOS technology, showing that the PPA scheme can support multiple terabit/s switch capacity.", URL="http://www.iospress.nl/site/html/09266801.html", } @ARTICLE{Lin9901:Optical, AUTHOR="Lang Lin and Evan L. Goldstein and L. M. Lunardi and R. W. Tkach", TITLE="Optical crossconnects for high-capacity lightwave networks", JOURNAL=jhsn, VOLUME=8, NUMBER=1, PAGES="17-34", YEAR=1999, ABSTRACT="Optical crossconnects are rapidly emerging as critical elements for provisioning and restoration in high-capacity wavelength-division-multiplexed optical networks. High port count appears to be emerging as particularly important in this core-network application, with 500-port optical crossconnects(OXC's)widely expected to be needed within about five years. This requirement severely strains current optical-switching technologies. The emergence of this new application is, however, beginning to stimulate new device technologies. One of these is the free-space micromachined optical switch(FS-MOS). This approach combines the advantages of free-space interconnection and monolithic integrated optics, thus offering the possibility of achieving high port-count in a small, low-cost system with excellent optical quality. In this paper, we review the fundamental principles, fabrication, and performance of the FS-MOS, and discuss both its port-count scalability and its ability to incorporate advanced optical-networking functionality within the switch fabric itself.", URL="http://www.iospress.nl/site/html/09266801.html", } @ARTICLE{Sinn9902:Distributed, AUTHOR="Christian Sinner and M. Wolf", TITLE="Distributed and dynamic resource allocation in wireless {ATM} access networks", JOURNAL=jhsn, VOLUME=8, NUMBER=2, PAGES="113-133", YEAR=1999, ABSTRACT="Wireless ATM access networks are currently discussed intensely. In this article, the dynamic resource allocation within the MAC layer of WATM systems is discussed. Emphasizing ease of implementation, the protocols of WATMnet, MEDIAN, MBS and Magic WAND are compared. Based upon this, a novel MAC protocol is outlined that attempts to combine the benefits while avoiding some of the drawbacks of these projects. Central to this new scheme called Distributed and Dynamic Resource Allocation(DADRA)is the move of uplink traffic prediction and computation into the mobile terminals(MT), leaving the base station to collect precise demand requests and to coordinate media access. The reduced processing demand on the base station may lower equipment costs and increase the number of supported connections while the load on the individual MT is increased marginally.", URL="http://www.iospress.nl/site/html/09266801.html", } @ARTICLE{Bart9902:Error, AUTHOR="M. Barton and L. F. Chang", TITLE="Error protection for {ATM-based} wireless networking systems", JOURNAL=jhsn, VOLUME=8, NUMBER=2, PAGES="87-100", YEAR=1999, KEYWORDS="Wireless ATM; punctured coding; forward error correction; personal communications system; protocol data unit; bit error rate", ABSTRACT="Variable rate error protection is required to support the broad range of quality of service(QoS)requirements for multimedia services in future Asynchronous Transfer Mode(ATM)-based wireless networking systems known as wireless ATM(WATM). In this paper, the performance of a rate-compatible punctured convolution(RCPC)coding scheme is examined. It provides adaptive forward error correction(FEC)at the physical(PHY)layer of the(non-ATM)wireless access segment, that interworks with the fixed ATM transport network. Bit error rate(BER)performance of the RCPC codes is evaluated for a range of wireless protocol data unit(PDU)formats. The throughput is also compared with well known Bose-Chaudhuri-Hocquenghem(BCH)and Reed-Solomon(RS)block codes. An hybrid automatic repeat request(ARQ)/FEC protocol that uses RCPC coding to distribute error protection between the wireless PHY and data link control(DLC)layers is also presented. Issues relating to complexity/cost trade-off, and effects of multipath fading, require further study.", URL="http://www.iospress.nl/site/html/09266801.html", } @ARTICLE{Sheu9902:Reducing, AUTHOR="S. T. Sheu", TITLE="Reducing clean cell loss rate in wireless {ATM} networks", JOURNAL=jhsn, VOLUME=8, NUMBER=2, PAGES="101-111", YEAR=1999, KEYWORDS="HEC; interleaving; wireless ATM; HEC", ABSTRACT="In wireless asynchronous transfer mode(ATM)networks, the bit error rate is high and burst errors may occur in transmission due to jamming and fading. When single-bit error occurs in cell header, it can be easily corrected by the CRC-8 code in the HEC(Header Error Correction)field. However, HEC can not recover the cells with burst errors, and they will be lost or mis-routed accordingly. A strategy to spread each bit of a header field over the entire data field has been proposed to reduce the cell loss probability in wireless ATM networks. In such method, most burst errors are transformed into single-bit errors in header and the HEC is able to recover it. Intuitively, each corrected cell has a higher probability to contain incorrect payload due to burst errors. When network becomes congested, these dirty cells should be dropped first to reduce the number of error cells received by receiver. Meanwhile, the number of retransmitted cells is also reduced. In this paper, the cell payload error probability of a corrected cell is analyzed. A simple cell priority swapping mechanism and the cell discarding strategy are also introduced to reduce the clean cell loss rate on wireless ATM networks. To precisely recognize dirty cells, an efficient hybrid data/header interleaving strategy is proposed. The performance of proposed strategies are investigated by simulation. The simulation results show that the proposed strategies substantially reducing the clean cell loss rate.", URL="http://www.iospress.nl/site/html/09266801.html", } @ARTICLE{Liu9902:Congestion, AUTHOR="Te-Kai Liu and J. A. Silvester", TITLE="Congestion control policies for wireless multimedia {CDMA} networks", JOURNAL=jhsn, VOLUME=8, NUMBER=2, PAGES="135-147", YEAR=1999, KEYWORDS="CDMA; multimedia; traffic control; quality of service; wireless networks", ABSTRACT="The issues of integrating multimedia traffic in the reverse(mobile to base station)link of wireless CDMA networks are studied. Due to their delay constraint, realtime(voice/video)services are subject to connection-level admission control. In order to maintain the quality of realtime voice/video traffic while fully utilizing the unused channel capacity, non-realtime data traffic follows burst-level congestion control. Two congestion control policies are introduced and their performance under 3 types of feedback information is compared. The impact of various system parameters, such as the traffic parameters(especially video)and the processing gain of the CDMA system are also quantified.", URL="http://www.iospress.nl/site/html/09266801.html", } @ARTICLE{Yau9903:CA, AUTHOR="Victor Yau and Krzysztof Pawlikowski", TITLE="{CA-STAR:} a centrally-arbitrated broadcast-and-select star architecture for lightwave networks", JOURNAL=jhsn, VOLUME=8, NUMBER=3, PAGES="173-193", YEAR=1999, KEYWORDS="Lightwave networks; network architectures; media access control protocols; destination conflicts; photonic switching systems", ABSTRACT="Parallel use of multiple channels in WDM star networks requires that either each station is equipped with one receiver per channel or we have to deal with destination conflicts whenever a station is reached by more packets than it is able to receive. Earlier proposed networks resolved destination conflicts either after they occur(applying the detect-and-retransmit-if-lost principle)or before packets are transmitted(applying the request-schedule-then-transmit principle). This paper introduces networks in which such conflicts are resolved whilst packets are en route to their destinations, using a central arbiter station(CA)located at the star coupler. CA detects destination conflicts, buffers packets which would otherwise be lost, and forwards them to their destinations as soon as their destinations are free to receive them. Buffer operations at CA are streamlined, allowing either electronic implementation or a simple optical delay-line implementation. Their performance is evaluated by studying their delay and throughput characteristics, protocol computational complexity, E/O conversion overhead, and hardware demands.", URL="http://www.iospress.nl/site/html/09266801.html", } @ARTICLE{Cido9903:OPENET, AUTHOR="I. Cidon and T. Hsiao and Asad Khamisy and Abhay Parekh and R. Rom and M. Sidi", TITLE="{OPENET:} an open and efficient control platform for {ATM} networks", JOURNAL=jhsn, VOLUME=8, NUMBER=3, PAGES="195-210", YEAR=1999, ABSTRACT="ATM networks are currently moving from the experimental stage of test-beds to a commercial state where production networks are deployed and operated. The ATM Forum PNNI (Private Network to Network Interface) standard introduces an architecture suited for an internetwork which, in principle, can also be used as an intra-network nodal interface. However, the current PNNI falls short in providing an acceptable solution due to severe performance limitations in intra-network operation, limited functionality and the lack of open interfaces for functional extensions and services.

OPENET is a common, open and high-performance network control platform based on performance and functional enhancements to the PNNI platform. It is designed to address the issues of interoperability (being vendor independent), scalability (in terms of network size and volume of calls), high performance (in terms of call processing latency and throughput) and functionality. OPENET is mainly an intra-networking extension to current PNNI. It is compatible with PNNI in the internetwork environment where large networks must be partitioned according to natural topological or organizational boundaries. The major novelty of the OPENET architecture (compared to the current PNNI) is its focus on network control performance. A particular emphasis is given to the increase of the overall rate of connection handling, to the reduction of the call establishment latency and to the efficient utilization of the network resources. These performance enhancements are achieved by the use of a native ATM distribution tree for the dissemination of utilization update, light-weight call setup, take down and modification signaling, the use of fast setup and takedown with the future option to implement them in hardware, and extensive use of caching and pre-calculation for route computation. OPENET also extends PNNI in terms of functionality. It utilizes a new signaling paradigm that better supports fast reservation and multicast services, a rich control communication infrastructure which enables the development of augmented services leveraging the existing functions, messaging system and information of the network control platform.", URL="http://www.iospress.nl/site/html/09266801.html", } @ARTICLE{Yoo9903:Traffic, AUTHOR="S. W. Yoo and S. Kim", TITLE="Traffic modeling and {QoS} prediction for {MPEG-coded} video services over {ATM} networks using scene level statistical characteristics", JOURNAL=jhsn, VOLUME=8, NUMBER=3, PAGES="211-224", YEAR=1999, KEYWORDS="MPEG; traffic modeling; QoS", ABSTRACT="In this paper, we propose a new traffic model and its queueing solution for MPEG-coded video sequences, which are now widely used for many types of video applications. The MPEG variable bit rate(VBR)video traffic has both very strong short-range correlations and long-range dependence. To capture the long-range dependence, we model the overall scene-level cell rate flow with a scene-level state transition diagram. At the same time, we use a frame-level chain to reflect the short-range correlation effects between the frames of the same frame type and between the different frame types within a scene state. Thus scene changes and frame sequences are modeled by a two-dimensional continuous time Markov chain. We provide an analytic queueing solution in terms of the maximum cell transfer delay and the cell loss ratio. The simulation results show that our analytical model accurately approximates the queueing performance of the original videos. Finally, with an asymptotic approximation, we provide a method for estimating the effective bandwidth for MPEG video sources with a guarantee of the user's quality of service requirements.", URL="http://www.iospress.nl/site/html/09266801.html", } @ARTICLE{Malt9903:TCP, AUTHOR="David A. Maltz and P. Bhagwat", TITLE="{TCP} Splice for application layer proxy performance", JOURNAL=jhsn, VOLUME=8, NUMBER=3, PAGES="225-240", YEAR=1999, KEYWORDS="TCP; firewalls; SOCKS; application layer proxies; performance", ABSTRACT="Application layer proxies already play an important role in today's networks, serving as firewalls and HTTP caches---and their role is being expanded to include encryption, compression, and mobility support services. Current application layer proxies suffer major performance penalties as they spend most of their time moving data back and forth between connections;context switching and crossing protection boundaries for each chunk of data they handle. We present a technique called TCP Splice that provides kernel support for data relaying operations which runs at near router speeds. In our lab testing, we find SOCKS firewalls using TCP Splice can sustain a data throughput twice that of normal firewalls, with an average packet forwarding latency 30 times less.", URL="http://www.iospress.nl/site/html/09266801.html", } @ARTICLE{Park9904:Novel, AUTHOR="Jongseung Park and H. Yoon", TITLE="Novel recursive multicast algorithms in multistage interconnection networks for {ATM} switches", JOURNAL=jhsn, VOLUME=8, NUMBER=4, PAGES="265-280", YEAR=1999, KEYWORDS="Multicast algorithms; multistage interconnection networks; ATM switch architectures; recursive scheme; header encoding schemes; deadlock freedom", ABSTRACT="In this paper, we study the multicast communication in the self-routing multistage interconnection network(MIN)for constructing asynchronous transfer mode(ATM)switch architectures. Many of these applications require multicast communications in addition to conventional point-to-point communications. Multicast communication which the same message is delivered from a source to an arbitrary number of destinations, is fundamental in supporting collective communication primitives including cable TV, teleconferencing, and video-on-demand services. This paper presents a novel approach to supporting multicast communication, on the basis of the restricted address encoding scheme which constructs a short fixed-size multicast header and the recursive scheme that recycles a multicast packet one or more times through the network to reach at desired destinations. We also propose novel recursive multicast algorithms providing deadlock-freedom in MIN-based ATM switches. The emphasis is on evaluating the performance of these algorithms in terms of the number of recycling passes, the complexity of switching elements, and the number of links used. The proposed algorithms can be easily applicable to buffered MIN-based ATM switches.", URL="http://www.iospress.nl/site/html/09266801.html", } @ARTICLE{Vutu9904:Practical, AUTHOR="Srinivas Vutukury and J. J. Garcia-Luna-Aceves", TITLE="A practical framework for minimum-delay routing in computer networks", JOURNAL=jhsn, VOLUME=8, NUMBER=4, PAGES="241-263", YEAR=1999, ABSTRACT="The conventional approach to routing in computer networks consists of using a heuristic to compute a single shortest path from a source to a destination. Single-path routing is very responsive to topological and link-cost changes: however, except under light traffic loads, the delays obtained with this type of routing are far from optimal. Furthermore, if link costs are associated with delays, single-path routing exhibits oscillatory behavior and becomes unstable as traffic loads increase. On the other hand, minimum-delay routing approaches can minimize delays only when traffic is stationary or very slowly changing. We present a 'near-optimal'routing framework that offers delays comparable to those of optimal routing and that is as flexible and responsive as single-path routing protocols proposed to date. First, an approximation to the Gallager's minimum-delay routing problem is derived, and then algorithms that implement the approximation scheme are presented and verified. We describe the first routing algorithm based on link-state information that provides multiple paths of unequal cost to each destination that are loop-free at every instant. We show through simulations that the delays obtained in our framework for minimum-delay routing are comparable to those obtained using Gallager's algorithm for minimum-delay routing. Also, we show that our framework renders far smaller delays and makes better use of resources than traditional single-path routing.", URL="http://www.iospress.nl/site/html/09266801.html", } @ARTICLE{Jou9904:Modeling, AUTHOR="Y. F. Jou and A. Nilsson and F.-Y. Lai", TITLE="Performance modeling of a finite capacity polling system with {ATM} bursty and correlated input traffic", JOURNAL=jhsn, VOLUME=8, NUMBER=4, PAGES="281-301", YEAR=1999, ABSTRACT="This paper is concerned with the mean delay and the probability of cell loss that bursty and correlated arrivals incur in an ATM switching system which can be modeled as a finite capacity polling system with nonexhaustive cyclic service. The arrival process to each input port of the system is modeled by a Markov Modulated Bernoulli Process(MMBP)which is able to describe the bursty and correlated nature of the ATM traffic. A practical polling system with finite capacity, as the one we deal with here, does not lend itself to an exact solution. In this paper, we introduce a tractable approach to provide an analytical approximation. This approach is validated extensively by comparing it against simulation results under different configurations. It is shown that both the mean delays and the cell loss probabilities obtained from this analysis provide highly accurate estimates.", URL="http://www.iospress.nl/site/html/09266801.html", } @ARTICLE{Veli9904:Practical, AUTHOR="John Velissarios and Roberto Santarossa", TITLE="Practical security issues with high-speed networks", JOURNAL=jhsn, VOLUME=8, NUMBER=4, PAGES="311-324", YEAR=1999, ABSTRACT="As corporate networks evolve in step with the Internet, an increasing number of networks are being connected through controlled access points. The deployment of end-to-end high-speed connections in corporate LANs have resulted in as yet untamed security issues directly attributable to the increased throughput(100+Mbits/s). This paper attempts to identify some of the potential issues and communicate these to those responsible for the administration and development of IT and security infrastructures. Limitations of Intrusion Detection Systems, information leakage of encrypted channels, reduced features of hardware in order to enable faster switching, have all contributed to effectively diminish overall security. Despite the endless need for faster networks engendered by streaming video and audio, 3D worlds, voice over data and video conferencing, we must pause and ask ourselves if we are prepared to trade security for speed.", URL="http://www.iospress.nl/site/html/09266801.html", } @ARTICLE{Li9904:Bounds, AUTHOR="Gang Li and R. Simha", TITLE="On bounds for the wavelength assignment problem on optical ring networks", JOURNAL=jhsn, VOLUME=8, NUMBER=4, PAGES="303-309", YEAR=1999, KEYWORDS="Optical networks; wavelength division multiplexing; wavelength assignment problems", ABSTRACT="k.", URL="http://www.iospress.nl/site/html/09266801.html", } @ARTICLE{Tami9901:Optical, AUTHOR="Lakshman S. Tamil and F. Masetti and Tom McDermott and Gerardo Castanon and An Ge and Ljubisa Tancevski", TITLE="Optical {IP} routers:design and performance issues under self-similar traffic", JOURNAL=jhsn, VOLUME=8, NUMBER=1, PAGES="59-67", YEAR=1999, ABSTRACT="The increased data traffic experienced today and the projected increase in the data traffic in the future demand exploration of novel approaches to IP transport such as transport of IP traffic over optics. The bimodal nature of the IP traffic\: short packets which are typical of transactional-style flows and large packets or bursts which are encountered in the transport of large data blocks requires, design of routers that are capable of routing packets with variable lengths efficiently. In this paper, we discuss the design aspects of such all-optical IP-routers. The broadcast and select architecture is a prime candidate for implementing optical IP routers. Construction of optical routers with buffering, wavelength conversion and multipath routing are considered. The merits and demerits of all these cases and the effect of buffer size, wavelength conversion and multiple-path routing on the blocking probability and probability of packet loss are discussed.", URL="http://www.iospress.nl/site/html/09266801.html", } @ARTICLE{Qiao9901:Optical, AUTHOR="C. Qiao and Myungsik Yoo", TITLE="Optical burst switching(OBS)---a new paradigm for an Optical {Internet}", JOURNAL=jhsn, VOLUME=8, NUMBER=1, PAGES="69-84", YEAR=1999, KEYWORDS="Bursty traffic; fiber delay line(FDL); IP; optical networks; reservation; WDM", ABSTRACT="To support bursty traffic on the Internet(and especially WWW)efficiently, optical burst switching(OBS)is proposed as a way to streamline both protocols and hardware in building the future generation Optical Internet. By leveraging the attractive properties of optical communications and at the same time, taking into account its limitations, OBS combines the best of optical circuit-switching and packet/cell switching. In this paper, the general concept of OBS protocols and in particular, those based on Just-Enough-Time(JET), is described, along with the applicability of OBS protocols to IP over WDM. Specific issues such as the use of fiber delay-lines(FDLs)for accommodating processing delay and/or resolving conflicts are also discussed. In addition, the performance of JET-based OBS protocols which use an offset time along with delayed reservation to achieve efficient utilization of both bandwidth and FDLs as well as to support priority-based routing is evaluated.", URL="http://www.iospress.nl/site/html/09266801.html", } @INPROCEEDINGS{Hump99:Distributed, AUTHOR="G. Humphreys and Pat Hanrahan", TITLE="A Distributed Graphics System for Large Tiled Displays", BOOKTITLE="IEEE Visualization", YEAR=1999, } @BOOK{Walr99:JFC, AUTHOR="K. Walrath and M. Campione", TITLE="The {JFC} Swing Tutorial: A Guide to Constructing {GUIs}", PUBLISHER="Addison-Wesley", ADDRESS="Reading, Massachusetts", YEAR=1999, } @INPROCEEDINGS{Mann99:Interpolating, AUTHOR="R. A. Manning and C. R. Dyer", TITLE="Interpolating View and Scene Motion by Dynamic View Morphing", BOOKTITLE="Computer Vision and Pattern Recognition Conf", PAGES="388-394", YEAR=1999, } @ARTICLE{Seit9902:Photorealistic, AUTHOR="Steven Seitz and C. R. Dyer", TITLE="Photorealistic scene reconstruction by voxel coloring", JOURNAL="International Journal of Computer Vision", VOLUME=35, NUMBER=2, PAGES="151-173", YEAR=1999, } @INPROCEEDINGS{Rao99:Cache, AUTHOR="Jai R. Rao and Keith W. Ross", TITLE="Cache Conscious Indexing for Decision-Support in Main Memory", BOOKTITLE="25th VLDB Conference", PAGES="78-89", YEAR=1999, } @INCOLLECTION{Blaz99:Role, AUTHOR="Matt Blaze and J. Feigenbaum and J. Ioannidis and Angelos Keromytis", TITLE="The Role of Trust Management in Distributed Systems Security", BOOKTITLE="Secure Internet Programming: Security Issues for Mobile and Distributed Objects", EDITOR="Jan Vitek and Christian Jensen", SERIES="Lecture Notes in Computer Science", ISBN="3-540-66130-1", PUBLISHER="Springer-Verlag", ADDRESS="New York, New York", VOLUME=1603, PAGES="185-210", YEAR=1999, KEYWORDS="Computer security; Electronic data processing - Distributed processing - Security; Intelligent agents (Computer software) - Security measures; measures; Mobile agents (Computer software)", } @INPROCEEDINGS{Bonc99:Database, AUTHOR="Peter Boncz and Stefan Manegold and Martin L. Kersten", TITLE="Database Architecture Optimized for the New Bottleneck: Memory Access", BOOKTITLE="25th VLDB Conference", PAGES="54-65", YEAR=1999, } @ARTICLE{Koen9902:Bidirectional, AUTHOR="J. J. Koenderink and A. J. van~Doorn and K. J. Dana and Shree K. Nayar", TITLE="Bidirectional Reflection Distribution Function of thoroughly pitted surfaces", JOURNAL="International Journal of Computer Vision", VOLUME=31, NUMBER="2/3", PAGES="129-144", YEAR=1999, } @UNPUBLISHED{Perl99:Deployed, AUTHOR="R. Perlman and Charlie Kaufman", TITLE="Deployed and Emerging Security Systems for the {Internet}", NOTE="lecture slides", YEAR=1999, KEYWORDS="network security; cryptography; tutorial", ABSTRACT="What network security protocols need to do; toolkit of crypto tricks; design pitfalls; conceptual overview of standards and deployed systems", } @ARTICLE{Roth99:Cost, AUTHOR="Mary Tork Roth and Fatma Özcan and Laura M. Haas", TITLE="Cost Models {DO} Matter: Providing Cost Information for Diverse Data Sources in a Federated System", JOURNAL="The VLDB Journal", YEAR=1999, LANGUAGE="English", } @INPROCEEDINGS{Joac99:Transductive, AUTHOR="Thorsten Joachims", TITLE="Transductive Inference for Text Classification using Support Vector Machines", BOOKTITLE="16th International Conference on Machine Learning", YEAR=1999, LANGUAGE="English", } @INPROCEEDINGS{Ilve99:Performance, AUTHOR="Mika Ilvesmäki and Marko Luoma", TITLE="Performance Analysis of Multi-Class {Internet} Traffic Classifier in a Connection Oriented Router Environment", BOOKTITLE="Internet II: Quality of Service and Future Directions", ORGANIZATION="SPIE", YEAR=1999, LANGUAGE="English", ABSTRACT="1. In this work, we analyze the performance of multi-class Internet traffic classifier primarily in a connection-oriented IP router environment. We define the tasks and related concepts of traffic classification in the Internet and then proceed to construct a multi-class traffic classifier using the Learning Vector Quantization algorithm classifier that has been previously used to divide the traffic into two classes. We show how the functionality of the 2-class LVQ classifier can easily be extended to an arbitrary amount of classes, in this work to three: the hard-interactive, the elastic and the best effort service classes. This is done by consecutive 2-class classifications and unanimous decisions on classification. The multi-class LVQ classifier is observed to perform adequately being able to provide network service profiles, sets of classified services, with characteristics relating to respective classes. The multi-class classifier also performs well within the hardware performance limits and is still able to provide the forwarding component of the Internet router a substantial workload reduction. We also observe the individual service class performance and conclude that separately defined service architectures are needed to limit the use of QoS resources in the network. Our belief is that in order to provide end-to-end QoS a connection oriented link layer technology is needed. These technologies are able to offer dedicated forwarding paths for individual packets thus reducing the processor intensive hop count and flattening the network.", } @TECHREPORT{Pele99:Glif3, AUTHOR="Mor Peleg and Aziz A. Boxwala and Omolola Ogunyemi and Qing Zeng and Samson Tu and Ronilda Lacson and Elmer Bernstam and Nachman Ash", TITLE="{GLIF3:} The Evolution of a Guideline Representation Format", INSTITUTION="Department of Medical Informatics, Columbia University", YEAR=1999, LANGUAGE="English", } @INPROCEEDINGS{Cao99:Distributed, AUTHOR="Guohong Cao", TITLE="Distributed Fault-Tolerant Channel Allocation for Mobile Cellular Networks", BOOKTITLE=infocom, YEAR=1999, LANGUAGE="English", KEYWORDS="fault tolerance; channel allocation; cellular networks", ABSTRACT="Distributed channel allocation algorithms have received considerable attention due to their high reliability and scalability. However, in these algorithms, a borrower needs to consult with its interference neighbors in order to borrow a channel. Thus, a borrower fails to borrow channels when it cannot communicate with anyone of its interference neighbors. In real-life networks, under heavy traffic load, a cell has a large probability to experience an intermittent network congestion or even a communication link failure. In these algorithms, since a cell has to consult with a large number of interference neighbors to borrow a channel, the failure rate will be much higher under heavy traffic load. In this paper, we first propose a fault-tolerant channel acquisition algorithm which tolerates communication link failures and node ($MH$ or $MSS$) failures. Then, we present a channel selection algorithm and integrate it into the distributed acquisition algorithm. Simulation results show that our algorithm significantly reduces the failure rate under network congestion, communication link failures, and node failures compared to non-fault-tolerant channel allocation algorithms.", URL="http://www.cse.psu.edu/~gcao", } @BOOK{Verm99:Supporting, AUTHOR="Dinesh Verma", TITLE="Supporting Service Level Agreements on {{IP}} Networks", PUBLISHER="Macmillan Technical Publishing", YEAR=1999, LANGUAGE="English", KEYWORDS="service level agreement; SLA", } @TECHREPORT{Semiconductor:crystal, AUTHOR="Dallas Semiconductor", TITLE="{{DS1553}:} 64k {{NV}} {{Y2KC}} {Timekeeping} {{RAM}} {Manual}", INSTITUTION="Dallas Semiconductor", YEAR=1999, LANGUAGE="English", URL="http://pdfserv.maxim-ic.com/arpdf/DS1553-DS1553P.pdf", } @TECHREPORT{Cher99:Speech, AUTHOR="Michael Chernick and Stefan Leigh and Kevin Mills and Robert Toense", TITLE="Can Speech Recognizers Measure the Effectiveness of Encoding Algorithms for Digital Speech Transmission?", INSTITUTION="National Institute of Standards and Technology", YEAR=1999, LANGUAGE="English", } @TECHREPORT{Abra99:Traffic, AUTHOR="Henrik Abrahamsson", TITLE="Traffic Measurement and Analysis", INSTITUTION="SICS -- Swedish Institute of Computer Science", NUMBER="T99:05", MONTH="SEP", YEAR=1999, ABSTRACT="Measurement and analysis of real traffic is important to gain knowledge about the characteristics of the traffic. Without measurement, it is impossible to build realistic traffic models. It is recent that data traffic was found to have self-similar properties. In this thesis work traffic captured on the network at SICS and on the Supernet, is shown to have this fractal-like behaviour. The traffic is also examined with respect to which protocols and packet sizes are present and in what proportions. In the SICS trace most packets are small, TCP is shown to be the predominant transport protocol and NNTP the most common application. In contrast to this, large UDP packets sent between not well-known ports dominates the Supernet traffic. Finally, characteristics of the client side of the WWW traffic are examined more closely. In order to extract useful information from the packet trace, web browsers use of TCP and HTTP is investigated including new features in HTTP/1.1 such as persistent connections and pipelining. Empirical probability distributions are derived describing session lengths, time between user clicks and the amount of data transferred due to a single user click. These probability distributions make up a simple model of WWW-sessions.", URL="http://www.sics.se/~henrik/t9905.ps", } @TECHREPORT{Feen99:Taxonomy, AUTHOR="Laura Feeney", TITLE="A Taxonomy for Routing Protocols in Mobile Ad Hoc Networks", INSTITUTION="SICS -- Swedish Institute of Computer Science", NUMBER="T1999:07", MONTH="OCT", YEAR=1999, ABSTRACT="A Mobile Ad hoc NETwork (manet) is a mobile, multi-hop wireless network which is capable of autonomous operation. It is characterized by energy-constrained nodes, bandwidth-constrained, variable-capacity wireless links and dynamic topology, leading to frequent and unpredictable connectivity changes. In the absence of a fixed infrastructure, manet nodes cooperate to provide routing services, relying on each other to forward packets to their destination. Routing protocols designed for the fixed network are not effective in the dynamic and resource-constrained manet environment; many alternative routing protocols have been suggested. This report provides an overview of a number of manet routing protocols. More importantly, it defines a taxonomy that is suitable for examining a wide variety of protocols in a structured way and exploring tradeoffs associated with various design choices. The emphasis is on practical design and implementation issues rather than complexity analysis.", URL="http://www.sics.se/cna/publications/survey-tax.ps", } @INPROCEEDINGS{Grön99:Design, AUTHOR="Björn Grönvall and Assar Westerlund and Stephen Pink", TITLE="The Design of a Multicast-based Distributed File System", BOOKTITLE="Third Symposium on Operating System Design and Implementation", ADDRESS="New Orleans, USA", MONTH="FEB", YEAR=1999, URL="http://www.sics.se/cna/publications/osdi99.ps", } @INPROCEEDINGS{KarlssonG:IWQOS99, AUTHOR="Gunnar Karlsson and Fredrik Orava", TITLE="The {DIY} approach to {QoS}", BOOKTITLE="Seventh International Workshop on Quality of Service", ADDRESS="London", MONTH="JUN", YEAR=1999, } @INPROCEEDINGS{MarshI:globecom99, AUTHOR="Ian Robin Marsh", TITLE="Measuring {Internet} Telephony Quality: Where are we today?", BOOKTITLE="of IEEE Globecom: Global Internet", ADDRESS="Rio De Janeiro, Brazil", MONTH="DEC", YEAR=1999, URL="http://www.sics.se/~ianm/Publications/ipquality.ps", } @INPROCEEDINGS{Voi:nemtcp, AUTHOR="Thiemo Voigt and Bengt Ahlgren", TITLE="Scheduling {TCP} in the Nemesis Operating System", BOOKTITLE="IFIP WG~6.1/WG~6.4 International Workshop on Protocols for High-Speed Networks", MONTH="AUG", YEAR=1999, ABSTRACT="The Nemesis operating system is designed to provide Quality of Service to applications. Nemesis also allows applications to reserve CPU time and transmit bandwidth on network interfaces. We have implemented a TCP for Nemesis that makes use of these guarantees. We show that the Nemesis transmit scheduler rate-controls TCP traffic and thus leads to predictable traffic behavior when applications choose not to utilize non-allocated bandwidth. Applications that want to make use of the non-allocated transmit bandwidth receive the guaranteed bandwidth plus a share of the non-allocated bandwidth. We also study the impact of the guaranteed fraction of CPU time on the throughput that networked applications achieve. We measure the amount of CPU time applications have to reserve in order to run the TCP protocol stack and send data at a particular speed. We show that these values hold even when several applications strive for CPU time and transmit bandwidth.", URL="http://www.sics.se/~thiemo/pfhsn.ps", } @MISC{Voi:lic, AUTHOR="Thiemo Voigt", TITLE="Providing Quality of Service Guarantees to Networked Applications Using the Nemesis Operating System", HOWPUBLISHED="Licentiate thesis", MONTH="OCT", YEAR=1999, ABSTRACT="As the Internet grows, more and more applications are being networked. In this thesis, we use the Nemesis operating system to provide networked applications with service guarantees from both the network and the end system. The Nemesis operating system is designed from scratch to provide applications with service guarantees. Nemesis allows applications to reserve resources such as CPU time, transmit bandwidth on network interfaces and disk I/O bandwidth. We have implemented communication protocols in Nemesis. The ability of Nemesis to reserve CPU time enables applications to run the protocol stack within a guaranteed time and the ability to rserve transmit bandwidth enables applications to transmit data into the network at guaranteed rates. Experiments with the Nemesis TCP show, that networked applications with CPU time and transmit bandwidth reservations transmit at desired rates even when several applications contend for both CPU time and transmit bandwidth. We have also implemented the resource reservation protocol RSVP that reserves resources in the network. Nemesis is thus able to provide networked applications with end-to-end service guarantees.", URL="http://www.sics.se/~thiemo/lic.ps", } @INPROCEEDINGS{WesterlundA:usenix99, AUTHOR="Assar Westerlund and Love Hörnquist-Åstrand and Johan Danielsson", TITLE="Meta: A Freely Available Scalable {MTA}", BOOKTITLE="Usenix 1999 Annual Technical Conference", ADDRESS="Monterey, USA", MONTH="JUN", YEAR=1999, URL="http://www.sics.se/cna/publications/meta.ps", } @INPROCEEDINGS{Bhag99:Bluesky, AUTHOR="Pravin Bhagwat and Ibrahim Korpeoglu and Chatschik Bisdikian and Mahmoud Naghshineh and Satish K. Tripathi", TITLE="BlueSky: A Cordless Networking Solution for Palmtop Computers", BOOKTITLE="Fifth Annual ACM/IEEE International Conference on Mobile Computing and Networking", PAGES="69-76", YEAR=1999, } @INPROCEEDINGS{Fiko99:Performance, AUTHOR="N. Fikouras and K. Malki and Srba Cvetkovic and M. Kraner", TITLE="Performance Analysis of Mobile {IP} Handoffs", BOOKTITLE="Asia Pacific Microwave Conference", VOLUME=3, PAGES="770-773", YEAR=1999, } @PHDTHESIS{Yap99:Itinerant, AUTHOR="Chern Nam Yap", TITLE="Itinerant {Internet} Protocol", TYPE="Master in Research Dissertation", SCHOOL="University of Sheffield", ADDRESS="Department of Computer Science, Regent Court, 211 Portobello Street, Sheffield S14DP, UK", YEAR=1999, } @INPROCEEDINGS{Ramj99:HAWAII, AUTHOR="Ramachandran Ramjee and T. La Port and Sandra Thuel and Kannan Varadhan and Shie-Yuan Wang", TITLE="{HAWAII:} A Domain-based Approach for Supporting Mobility in Wide-area Wireless Networks", BOOKTITLE="IEEE International Conference on Network Protocols", YEAR=1999, } @INPROCEEDINGS{Have99:Implementation, AUTHOR="H. Haverinen and Jussi Lemilainen", TITLE="Implementation of a Multimode Mobile Computer", BOOKTITLE="of International Conference on Telecommunications ICT '99", YEAR=1999, } @TECHREPORT{Olov99:Effect, AUTHOR="J. Olov and Gerald (Chip) Maguire", TITLE="The Effect of Using Co-Located Care-of-Addresses on Macro Handover Latency", TYPE="Technical Report", INSTITUTION="Department of Teleinformatics, Royal Institute of Technology", ADDRESS="Kista, Sweden", YEAR=1999, } @INPROCEEDINGS{McAu99:Mobile, AUTHOR="Anthony McAuley and Ethendranath Bommaiah and Arun K Misra and Rajesh Talpade and Sue Thomson and K. C. Young", TITLE="Mobile Multicast Proxy", BOOKTITLE="IEEE 1999 Military Communications Conference", VOLUME=1, PAGES="631-635", MONTH="October November", YEAR=1999, } @INPROCEEDINGS{Park99:Anycast, AUTHOR="Vincent D. Park and Joe Macker", TITLE="Anycast Routing for Mobile Networking", BOOKTITLE="IEEE Military Communications Conference, MILCOM 1999", VOLUME=1, PAGES="1-5", MONTH="October November", YEAR=1999, } @INPROCEEDINGS{Endl99:Atomic, AUTHOR="Markus Endler", TITLE="An Atomic Multicast Protocol for Mobile Computing", BOOKTITLE="Third International Workshop on Discrete Algorithms and Methods for Mobile Computing and Communications, DIALM 99", ADDRESS="Seattle WA", YEAR=1999, } @ARTICLE{Lee99:Simulation, AUTHOR="Sung Lee and Mario Gerla and Ck Toh", TITLE="A Simulation Study of Table-Driven and On-Demand Routing Protocols for Mobile Ad Hoc Networks", JOURNAL="IEEE Networks", VOLUME=13, NUMBER=4, PAGES="48-54", MONTH="July-August", YEAR=1999, } @ARTICLE{Gerl99:Tree, AUTHOR="Mario Gerla and Chuan-wen Chiang and Liang Zhang", TITLE="Tree Multicast Strategies in Mobile, Multihop Wireless Networks", JOURNAL="ACM/Baltzer Mobile Networks and Applications", VOLUME=4, NUMBER=3, YEAR=1999, } @INPROCEEDINGS{Nasi99:Multipath, AUTHOR="Asis Nasipuri and Samir Das", TITLE="On-Demand Multipath Routing for Mobile Ad Hoc Networks", BOOKTITLE="8th International Conference on Computer Communications and Networks, IC3N", ADDRESS="Boston, MA", YEAR=1999, } @INPROCEEDINGS{Labo99:Origins, AUTHOR="Craig Labovitz and Gerald R. Malan and Farnam Jahanian", TITLE="Origins of {Internet} Routing Instability", BOOKTITLE="of INFOCOM99", YEAR=1999, } @ARTICLE{Pomm99:Testbed, AUTHOR="Joerg Pommnitz and Wolfgang Schoenfeld", TITLE="A Testbed for Mobile Multimedia Applications", JOURNAL="Journal of Multimedia Tools and Applications", VOLUME=9, NUMBER=1, PAGES="29-42", YEAR=1999, } @ARTICLE{Zao99:Public, AUTHOR="John K. Zao and Joshua Gahm and Gregory D. Troxel and Matthew Condell and Pam Helinek and Nina Yuan and Isidro M. Castineyra and Stephen T. Kent", TITLE="A Public-Key Based Secure Mobile {IP}", JOURNAL=wln, VOLUME=5, NUMBER=5, YEAR=1999, } @INPROCEEDINGS{Wu99:AMRIS, AUTHOR="Cheng-Shong Wu and Y.C. Tay", TITLE="{AMRIS:} A Multicast Protocol for Ad Hoc Wireless Networks", BOOKTITLE="of IEEE Military Communications Conference", VOLUME=1, PAGES="25-29", YEAR=1999, } @INPROCEEDINGS{Sufa99:Mobile, AUTHOR="Sufatrio and Kook Yan Lam", TITLE="Mobile {IP} Registration Protocol: A Security Attack and New Secure Minimal Public-key Based Authentication", BOOKTITLE="Fourth International Symposium on Parallel Architectures, Algorithms and Networks, I-SPAN '99", PAGES="364-369", YEAR=1999, } @INPROCEEDINGS{Hend99:Distributed, AUTHOR="Thomas R. Henderson and Randy H. Katz", TITLE="On Distributed, Geographic-Based Packet Routing for {LEO} Satellite Networks", BOOKTITLE="Globecom 2000", YEAR=1999, } @INPROCEEDINGS{Cheu99:Effect, AUTHOR="Michael Cheung and Jon Mark", TITLE="Effect of Mobility on {QoS} Provisioning in Wireless Communications Networks", BOOKTITLE="Wireless Communications and Networking Conference", VOLUME=1, PAGES="306-310", YEAR=1999, } @TECHREPORT{Liu99:Ad, AUTHOR="Mingyan Liu and Rajesh Talpade and Anthony McAuley and Ethendranath Bommaiah", TITLE="Ad Hoc Multicast Routing Protocol (AMroute)", TYPE="Tech Report", INSTITUTION="UMD", NUMBER="99-8", YEAR=1999, } @INPROCEEDINGS{Ko99:Geocasting, AUTHOR="Young-bae Ko and Nitin Vaidya", TITLE="Geocasting in Mobile Ad Hoc Networks: Location-Based Multicast Algorithms", BOOKTITLE="Second IEEE Workshop on Mobile Computing Systems and Applications, WMCSA '99", PAGES="101-110", YEAR=1999, } @INPROCEEDINGS{Garc99:Efficient, AUTHOR="J.J. Garcia-Luna-Aceves and Marcelo Spohn", TITLE="Efficient Routing in Packet-Radio Networks Using Link-State Information", BOOKTITLE="IEEE Wireless Communications and Networking Conference, WCNC", VOLUME=3, PAGES="1308-1312", YEAR=1999, } @INPROCEEDINGS{Hein99:Adaptive, AUTHOR="Wendi Heinzelman and Joanna Kulik and Hari Balakrishnan", TITLE="Adaptive Protocols for Information Dissemination in Wireless Sensor Networks", BOOKTITLE="International Conference on Mobile Computing and Networking, Mobicom 1999", YEAR=1999, } @ARTICLE{Chi99:Framework, AUTHOR="Kuang-Hwei Chi and Chien-Chao Tseng and Ting-Lu Huang", TITLE="A Framework for Mobile Multicast Using Dynamic Route Reconstructions", JOURNAL="The Computer Journal", VOLUME=42, NUMBER=6, YEAR=1999, } @INPROCEEDINGS{McDo99:Path, AUTHOR="Bruce McDonald and Taieb Znati", TITLE="A Path Availability Model for Wireless Ad-Hoc Networks", BOOKTITLE="of IEEE Wireless Communications and Networking Conference", ADDRESS="New Orleans, LA", VOLUME=1, PAGES="35-40", YEAR=1999, } @INPROCEEDINGS{Stoj99:Voronoi, AUTHOR="Ivan Stojmenovic", TITLE="Voronoi Diagram and Convex Hull based Geocasting and Routing in Wireless Networks", BOOKTITLE="citeseer, researchindex", YEAR=1999, } @INPROCEEDINGS{Ni99:Broadcast, AUTHOR="Sze-Yao Ni and Yu-Chee Tseng and Yuh-Shyan Chen and Jang-Ping Sheu", TITLE="The Broadcast Storm Problem in a Mobile Ad Hoc Network", BOOKTITLE="MobiCom", YEAR=1999, } @INPROCEEDINGS{Staj99:Resurrecting, AUTHOR="Frank Stajano and R. R. Anderson", TITLE="The Resurrecting Ducking: Security Issues for Ad-Hoc Wireless Networks", BOOKTITLE="7th International Workshop on Security Protocols, LNCS", YEAR=1999, } @INPROCEEDINGS{Wei99:Just, AUTHOR="John Wei and Jorge Pastor and Ramu Ramamurthy and Yukun Tsai", TITLE="Just-in-time Optical Burst Switching for Multiwavelength Networks.", BOOKTITLE="Broadband Communications", PAGES="339-352", YEAR=1999, LANGUAGE="English", } @TECHREPORT{Micr99:Jini, AUTHOR="Sun Microsystems", TITLE="Jini Architectural Overview", YEAR=1999, LANGUAGE="English", } @TECHREPORT{Cons99:Salutation, AUTHOR="The Salutation Consortium", TITLE="Salutation Architecture Specification Version 2.1", YEAR=1999, LANGUAGE="English", } @ARTICLE{Zube99:Timed, AUTHOR="W. M. Zuberek and W. Kubiak", TITLE="Timed Petri nets in Modeling and analysis of simple schedules for manufacturing cellss", JOURNAL="Elsevier Science, Computers and Mathematics with Applications", VOLUME="Volume 37", YEAR=1999, LANGUAGE="English", KEYWORDS="Performance evaluation, timed Petri nets, net variant analysis", ABSTRACT="It is shown that a large class of flexible manufacturing cells can be modeled using time Petri nets. Net models of simple schedules (i.e., schedules in which exactly one part enters and one leaves the cell during each cycle) are conflict-free nets. Two complementary approaches to analysis of such models are presented: invriant analysis and throughput analysis. Invariant analysis provides analytic (or symoblic) solutions for the cycle time of a cell analyzing (invariant) subnets of the original net. Throughput analysis performs a series of performance-preserving net reductions to simplify the original model. Several directions for further research are indicated.", URL="http://www.cs.mun.ca/~wlodek/abstracts/99-JCMA-a.html", } @INPROCEEDINGS{Holb9908:IP, AUTHOR="H. W. Holbrook and D. R. Cheriton", TITLE="{IP} Multicast Channels: {EXPRESS} Support for Large-scale Single-source Applications", BOOKTITLE=sigcomm, ADDRESS="Cambridge, Massachusetts", DAYS=1, MONTH="August/September", YEAR=1999, KEYWORDS="multicast; SSM; single-source multicast; PIM", ABSTRACT="In the IP multicast model, a set of hosts can be aggregated into a group of hosts with one address, to which any host can send. However, Internet TV, distance learning, file distribution and other emerging large-scale multicast applications strain the current realization of this model, which lacks a basis for charging, lacks access control, and is diffcult to scale. This paper proposes an extension to IP multicast to support the channel model of multicast and describes a specific realization called EXPlicitly REquested Single-Source (EXPRESS) multicast. In this model, a multicast channel has exactly one explicitly designated source, and zero or more channel subscribers. A single protocol supports both channel subscription and efficient collection of channel information such as subscriber count. We argue that EXPRESS addresses the aforementioned problems, justifying this multicast service model in the Internet.", URL="http://www.acm.org/sigcomm/sigcomm99/papers/session2-3.html", } @INPROCEEDINGS{Petr9906:Implementing, AUTHOR="David Petrou", TITLE="Implementing Lottery Scheduling: Matching the Specializations in Traditional Schedulers", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=22, ABSTRACT="We describe extensions to lottery scheduling, a proportional share resource management algorithm, to provide the performance assurances present in traditional non-real time process schedulers. Lottery scheduling enables flexible control over relative process execution rates with a ticket abstraction and provides load insulation among groups of processes using currencies. We first show that a straightforward implementation of lottery scheduling does not provide the responsiveness for a mixed interactive and CPU­bound workload offered by the decay usage priority scheduler of the FreeBSD operating system. Moreover, standard lottery scheduling ignores kernel priorities used in the FreeBSD scheduler to reduce kernel lock contention. In this paper, we show how to use dynamic ticket adjustments to incorporate into a lottery scheduler the specializations present in the FreeBSD scheduler to improve interactive response time and reduce kernel lock contention. We achieve this while maintaining lottery scheduling's flexible control over relative execution rates and load insulation. In spite of added scheduling overhead, the throughput of CPU­bound workloads under our scheduler is within one percent of the FreeBSD scheduler for all but one test. We describe our design, evaluate our implementation, and relate our experience in deploying our hybrid lottery scheduler on production machines.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/petrou/petrou.ps", } @INPROCEEDINGS{Brun9906:Retrofitting, AUTHOR="J. Bruno and José Carlos Brustoloni and Eran Gabber and Banu Özden and Avi Silberschatz", TITLE="Retrofitting Quality of Service into a Time-Sharing Operating System", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=24, ABSTRACT="Theoretical aspects of proportional share schedulers have received considerable attention recently. We contribute practical considerations on how to retrofit such schedulers into mainstream time-sharing systems. In particular, we propose /reserv, a uniform API for hierarchical proportional resource sharing. The central idea in /reserv is associating resource reservations with references to shared objects (and not with the objects themselves). We discuss in detail the implementation of /reserv and several proportional share schedulers on FreeBSD; the modified system is called Eclipse/BSD. Our experiments demonstrate that the proposed modifications allow selected applications to isolate their (or their clients') performance from CPU, disk, or network overloads caused by other applications. This capability is increasingly important for soft real-time, multimedia, Web, and distributed client-server applications.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/bruno/bruno.ps", } @INPROCEEDINGS{Doug9906:Adaptive, AUTHOR="F. Douglis and Tom Killian", TITLE="Adaptive Modem Connection Lifetimes", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=10, ABSTRACT="Internet Service Providers sometimes go to great lengths to minimize dial-up connection times, in order to make the best use of limited resources. Typically they disconnect users after a fixed period of complete inactivity, such as 10-15 minutes. We propose adaptive time-out policies that take past history into account, and we evaluate some of these policies using a trace from a production environment. We find that adaptive policies can reduce cumulative connection times and average simultaneous usage by about 10-20\% compared to a conservative fixed threshold, in exchange for a moderate increase in the number of disconnections that inconvenience the user.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/douglis/douglis.ps", } @INPROCEEDINGS{Lee9906:Operation, AUTHOR="Yeonwoo Lee and K. K. Leung and M. Satyanarayanan", TITLE="Operation-based Update Propagation in a Mobile File System", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=24, ABSTRACT="In this paper we describe a technique called operation-based update propagation for efficiently transmitting updates to large files that have been modified on a weakly connected client of a distributed file system. In this technique, modifications are captured above the file-system layer at the client, shipped to a surrogate client that is strongly connected to a server, re-executed at the surrogate, and the resulting files transmitted from the surrogate to the server. If re-execution fails to produce a file identical to the original, the system falls back to shipping the file from the client over the slow network. We have implemented a prototype of this mechanism in the Coda File System on Linux, and demonstrated performance improvements ranging from 40 percents to nearly three orders of magnitude in reduced network traffic and elapsed time. We also found a novel use of forward error correction in this context.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_paper/lee/lee.ps", } @INPROCEEDINGS{Zado9906:Extending, AUTHOR="Erez Zadok and Ion Badulescu and Alex Shender", TITLE="Extending File Systems Using Stackable Templates", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=24, ABSTRACT="Extending file system functionality is not a new idea, but a desirable one nonetheless[6,14,18]. In the several years since stackable file systems were first proposed, only a handful are in use[12,19]. Impediments to writing new file systems include the complexity of operating systems, the difficulty of writing kernel-based code, the lack of a true stackable vnode interface[14], and the challenges of porting one file system to another operating system. We advocate writing new stackable file systems as kernel modules. As a starting point, we propose a portable, stackable template file system we call Wrapfs (wrapper file system). Wrapfs is a canonical, minimal stackable file system that can be used as a pattern across a wide range of operating systems and file systems. Given Wrapfs, developers can add or modify only that which is necessary to achieve the desired functionality. Wrapfs takes care of the rest, and frees developers from the details of operating systems. Wrapfs templates exist for several common operating systems (Solaris, Linux, and FreeBSD), thus alleviating portability concerns. Wrapfs can be ported to any operating system with a vnode interface that provides a private data pointer for each data structure used in the interface. The overhead imposed by Wrapfs is only 5-7\%. This paper describes the design and implementation of Wrapfs, explores portability issues, and shows how the implementation was achieved without changing client file systems or operating systems. We discuss several examples of file systems written using Wrapfs.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/zadok/zadok.ps", } @INPROCEEDINGS{Shri9906:Why, AUTHOR="Elizabeth Shriver and Christopher Small and Keith A. Smith", TITLE="Why does file system prefetching work?", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=34, ABSTRACT="Most file systems attempt to predict which disk blocks will be needed in the near future and prefetch them into memory; this technique can improve application throughput as much as 50\%. But why? The reasons include that the disk cache comes into play, the device driver amortizes the fixed cost of an I/O operation over a larger amount of data, total disk seek time can be decreased, and that programs can overlap computation and I/O. However, intuition does not tell us the relative benefit of each of these causes, or techniques for increasing the effectiveness of prefetching. To answer these questions, we constructed an analytic performance model for file system reads. The model is based on a 4.4BSD-derived file system, and parameterized by the access patterns of the files, layout of files on disk, and the design characteristics of the file system and of the underlying disk. We then validated the model against several simple workloads; the predictions of our model were typically within 4\% of measured values, and differed at most by 9\% from measured values. Using the model and experiments, we explain why and when prefetching works, and make proposals for how to tune file system and disk parameters to improve overall system throughput.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/shriver/shriver.ps", } @INPROCEEDINGS{Brec9906:Region, AUTHOR="T. B. Brecht and Harjinder Sandhu", TITLE="The Region Trap Library: Handling Traps on Application-Defined Regions of Memory", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=28, ABSTRACT="User-level virtual memory (VM) primitives are used in many different application domains including distributed shared memory, persistent objects, garbage collection, and checkpointing. Unfortunately, VM primitives only allow traps to be handled at the granularity of fixed-sized pages defined by the operating system and architecture. In many cases, this results in a size mismatch between pages and application-defined objects that can lead to a significant loss in performance. In this paper we describe the design and implementation of a library that provides, at the granularity of application-defined regions, the same set of services that are commonly available at a page-granularity using VM primitives. Applications that employ the interface of this library, called the Region Trap Library (RTL), can create and use multiple objects with different levels of protection (i.e., invalid, read-only, or read-write) that reside on the same virtual memory page and trap only on read/write references to objects in an invalid state or write references to objects in a read-only state. All other references to these objects proceed at hardware speeds. Benchmarks of an implementation on five different OS/architecture combinations are presented along with a case study using region trapping within a distributed shared memory (DSM) system, to implement a region-based version of the lazy release consistency (LRC) coherence protocol. Together, the benchmark results and the DSM case study suggest that region trapping mechanisms provide a feasible region- granularity alternative for application domains that commonly rely on page-based virtual memory primitives.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/brecht/brecht.ps", } @INPROCEEDINGS{Wils9906:Case, AUTHOR="Paul Wilson and Scott Kaplan and Yannis Smaragdakis", TITLE="The Case for Compressed Caching in Virtual Memory Systems", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=17, ABSTRACT="Compressed caching uses part of the available RAM to hold pages in compressed form, effectively adding a new level to the virtual memory hierarchy. This level attempts to bridge the huge performance gap between normal (uncompressed) RAM and disk. Unfortunately, previous studies did not show a consistent benefit from the use of compressed virtual memory. In this study, we show that technology trends favor compressed virtual memory--it is attractive now, offering reduction of paging costs of several tens of percent, and it will be increasingly attractive as CPU speeds increase faster than disk speeds. Two of the elements of our approach are innovative. First, we introduce novel compression algorithms suited to compressing in-memory data representations. These algorithms are competitive with more mature Ziv-Lempel compressors, and complement them. Second, we adaptively determine how much memory (if at all) should be compressed by keeping track of recent program behavior. This solves the problem of different programs, or phases within the same program, performing best for different amounts of compressed memory.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/wilson/wilson.ps", } @INPROCEEDINGS{Cran9906:UVM, AUTHOR="C. Cranor and G. M. Parulkar", TITLE="The {UVM} Virtual Memory System", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=21, ABSTRACT="We introduce UVM, a new virtual memory system for the BSD kernel that has an improved design that increases system performance over the old Mach-based 4.4BSD VM system. In this paper we present an overview of both UVM and the BSD VM system. We focus our discussion on the design decisions made when creating UVM and contrast the UVM design with the less efficient BSD VM design. Topics covered include mapping, memory object management, anonymous memory and copy-on-write mechanisms, and pager design. We also present an overview of virtual memory based data movement mechanisms that have been introduced in BSD by UVM. We believe that the lessons we learned from designing and implementing UVM can be applied to other kernels and large software systems. Implemented in the NetBSD operating system, UVM will completely replace BSD VM in NetBSD 1.4.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/cranor/cranor.ps", } @INPROCEEDINGS{Mill9906:Lightweight, AUTHOR="Russ Miller and Brad Myers", TITLE="Lightweight Structured Text Processing", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=27, ABSTRACT="Text is a popular storage and distribution format for information, partly due to generic text­processing tools like Unix grep and sort. Unfortunately, existing generic tools make assumptions about text format (e.g., each line is a record) that limit their applicability. Custom­built tools are one alternative, but they require substantial time investment and programming expertise. We describe a new approach, lightweight structured text processing, which overcomes these difficulties by enabling users to define text structure interactively and manipulate the structure with generic tools. Our prototype system, LAPIS, is a web browser that can highlight, filter, and sort text regions described by the user. LAPIS has several advantages over other systems: (1) the ability to define custom structure with a simple, intuitive pattern language; (2) interactive specification, showing pattern matches in context and letting users choose the most convenient combination of manual selection and pattern matching; and (3) external parsers for standard text formats. The pattern language in LAPIS, text constraints, describes text structure in high­level terms, with region relationships like before, after, in, and contains. We describe an implementation of text constraints using a novel, compact representation of region sets as collections of rectangles, or region intervals. We also illustrate some examples of applying LAPIS to web pages, text files, and source code.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/miller/miller.ps", } @INPROCEEDINGS{Stei9906:SBOX, AUTHOR="Lincoln Stein", TITLE="{SBOX:} Put {CGI} Scripts in a Box", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=16, ABSTRACT="sbox is a CGI wrapper script that allows Web sites to safely grant CGI authoring privileges to untrusted or naive authors. The script increases security in several ways. It changes the process privileges of CGI scripts to match their owners, preventing one script from interfering with another's data files or operations. It establishes configurable ceilings on script resource usage, avoiding intentional or unintentional denial of service attacks. Most importantly, sbox can also be used to run untrusted CGI scripts within a chroot()-ed directory, thereby preventing CGI scripts from accessing sensitive portions of the file system. sbox is written in ANSI C and compiles on multiple flavors of Unix. It can be used and redistributed freely. The complete package is available for download at http://stein.cshl.org/WWW/software/sbox/", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/stein/stein.ps", } @INPROCEEDINGS{Grib9906:MultiSpace, AUTHOR="Steven D. Gribble and Matt Welsh and Eric Brewer and David Culler", TITLE="The MultiSpace: an Evolutionary Platform for Infrastructural Services", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=34, ABSTRACT="This paper presents the architecture for a Base, a clustered environment for building and executing highly available, scalable, but flexible and adaptable infrastructure services. Our architecture has three organizing principles: addressing all of the difficult service fault-tolerance, availability, and consistency problems in a carefully controlled environment, building that environment out of a collection of execution environments that are receptive to mobile code, and using dynamically generated code to introduce run-time- generated levels of indirection separating clients from services. We present a prototype Java implementation of a Base called the MultiSpace, and talk about two applications written on this prototype: the Ninja Jukebox (a cluster based music warehouse), and Keiretsu (an instant messaging service that supports heterogeneous clients). We show that the MultiSpace implementation successfully reduces the complexity of implementing services, and that the platform is conducive to rapid service evolution.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/gribble/gribble.ps", } @INPROCEEDINGS{Ving9906:Web, AUTHOR="Radek Vingralek and Yuri Breitbart and Mehmet Sayal and P. Scheuermann", TITLE="Web++: A System For Fast and Reliable Web Service", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=44, ABSTRACT="We describe the design of a system for a fast and reliable HTTP service termed Web++. Web++ achieves high reliability by dynamically replicating Web data among multiple Web servers. Web++selects a server which is available and that is expected to provide the fastest response time. Furthermore, Web++ guarantees data delivery, provided that at least one server containing the requested data is available. After detecting a server failure, Web++ client requests are satisfied transparently to the client by another server. Web++ is built on top of the standard HTTP protocol and does not require any changes either in existing Web browsers, or the installation of any software on the client side. We implement a Web++prototype; performance experiments indicate that Web++improves the client response time on average by 36.6\%, and in many cases by as much as 59\%, when compared with the current Web performance.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/vingralek/vingralek.ps", } @INPROCEEDINGS{Aron9906:Efficient, AUTHOR="Mohit Aron and P. Druschel and W. Zwaenepoel", TITLE="Efficient Support for {P-HTTP} in Cluster-Based Web Servers", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=31, ABSTRACT="This paper studies mechanisms and policies for supporting HTTP/1.1 persistent connections in cluster-based Web servers that employ content-based request distribution. We present two mechanisms for the efficient, content-based distribution of HTTP/1.1 requests among the back-end nodes of a cluster server. A trace-driven simulation shows that these mechanisms, combined with an extension of the locality-aware request distribution (LARD) policy, are effective in yielding scalable performance for HTTP/1.1 requests. We implemented the simpler of these two mechanisms, back-end forwarding. Measurements of this mechanism in connection with extended LARD on a prototype cluster, driven with traces from actual Web servers, confirm the simulation results. The throughput of the prototype is up to four times better than that achieved by conventional weighted round-robin request distribution. In addition, throughput with persistent connections is up to 26\% better than without.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/aron/aron.ps", } @INPROCEEDINGS{Pai9906:Flash, AUTHOR="Vivek Pai and P. Druschel and W. Zwaenepoel", TITLE="Flash: An efficient and portable Web server", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=32, ABSTRACT="This paper presents the design of a new Web server architecture called the asymmetric multi-process event-driven (AMPED) architecture, and evaluates the performance of an implementation of this architecture, the Flash Web server. The Flash Web server combines the high performance of single-process event-driven servers on cached workloads with the performance of multi-process and multi-threaded servers on disk-bound workloads. Furthermore, the Flash Web server is easily portable since it achieves these results using facilities available in all modern operating systems. The performance of different Web server architectures is evaluated in the context of a single implementation in order to quantify the impact of a server's concurrency architecture on its performance. Furthermore, the performance of Flash is compared with two widely-used Web servers, Apache and Zeus. Results indicate that Flash can match or exceed the performance of existing Web servers by up to 50\% across a wide range of real workloads. We also present results that show the contribution of various optimizations embedded in Flash.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/pai/pai.ps", } @INPROCEEDINGS{Gsch9906:NewsCache, AUTHOR="Thomas Gschwind and Manfred Hauswirth", TITLE="NewsCache - A High Performance Cache Implementation for Usenet News", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=17, ABSTRACT="Usenet News is reaching its limits as current traffic strains the available infrastructure. News data volume increases steadily and competition with other Internet services has intensified. Consequently bandwidth requirements are often beyond that provided by typical links and the processing power needed exceeds a single system's capabilities. A rapidly growing number of users, especially attracted by WWW, overloads communication links and makes bandwidth a scarce resource. While an elaborate caching infrastructure was adopted for the WWW, Usenet News still uses most of its originally defined infrastructure. Caching techniques have not yet been adopted on a large scale. We believe that this is due to the lack of efficient cache implementations. In this paper we present a high performance cache server for Usenet News that helps to conserve network bandwidth, computing power, and disk storage and is compatible with the current infrastructure and standards. After a thorough comparison of existing news database formats and replacement strategies we designed and implemented NEWSCACHE to remedy Usenet News bottlenecks. We present an empirical comparison of different cache replacement strategies as well as an evaluation of the use of NEWSCACHE as a news server.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/gschwind/gschwind.ps", } @INPROCEEDINGS{Choi9906:Study, AUTHOR="J. D. Choi and Sam Noh and Sang Min and Yong Soo Cho", TITLE="An Implementation Study of a Detection-Based Adaptive Block Replacement Scheme", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=21, ABSTRACT="In this paper, we propose a new adaptive buffer management scheme called DEAR (DEtection based Adaptive Replacement) that automatically detects the block reference patterns of applications and applies different replacement policies to different applications based on the detected reference pattern. The proposed DEAR scheme uses a periodic process. Detection is made by associating block attribute values such as backward distance and frequency gathered at the (i-1)-th invocation with forward distances of blocks referenced between the (i-1)-th and i-th invocations. We implemented the DEAR scheme in FreeBSD 2.2.5 and measured its performance using several real applications. The results show that compared with the LRU buffer management scheme, the proposed scheme reduces the number of disk I/Os by up to 51\% (with an average of 23\%) and the response time by up to 35\% (with an average of 12\%) in the case of single application executions. For multiple applications, the proposed scheme reduces the number of disk I/Os by up to 20\% (with an average of 12\%) and the overall response time by up to 18\% (with an average of 8\%).", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/choi/choi.ps", } @INPROCEEDINGS{Bang9906:Scalable, AUTHOR="Gaurav Banga and J. C. Mogul and P. Druschel", TITLE="A scalable and explicit event delivery mechanism for {UNIX}", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=24, ABSTRACT="UNIX applications not wishing to block when doing I/O often use the select() system call, to wait for events on multiple file descriptors. The select() mechanism works well for small-scale applications, but scales poorly as the number of file descriptors increases. Many modern applications, such as Internet servers, use hundreds or thousands of file descriptors, and suffer greatly from the poor scalability of select(). Previous work has shown that while the traditional implementation of select() can be improved, the poor scalability is inherent in the design. We present a new event-delivery mechanism, which allows the application to register interest in one or more sources of events, and to efficiently dequeue new events. We show that this mechanism, which requires only minor changes to applications, performs independently of the number of file descriptors.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/banga/banga.ps", } @INPROCEEDINGS{Gabb9906:Pebble, AUTHOR="Eran Gabber and Christopher Small and J. Bruno and José Carlos Brustoloni and Avi Silberschatz", TITLE="The Pebble Component-Based Operating System", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=26, ABSTRACT="Pebble is a new operating system designed with the goals of flexibility, safety, and performance. Its architecture combines a set of features heretofore not found in a single system, including (a) a minimal privileged mode nucleus, responsible for switching between protection domains, (b) implementation of all system services by replaceable user-level components with minimal privileges (including the scheduler and all device drivers) that run in separate protection domains enforced by hardware memory protection, and (c) generation of code specialized for each possible cross-domain transfer. The combination of these techniques results in a system with extremely inexpensive cross-domain calls that makes it well-suited for both efficiently specializing the operating system on a per-application basis and supporting modern component-based applications.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/gabber/gabber.ps", } @INPROCEEDINGS{Dell9906:Linking, AUTHOR="Luke Deller and Gernot Heiser", TITLE="Linking Programs in a Single Address Space", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=20, ABSTRACT="Linking and loading are the final steps in preparing a program for execution. This paper assesses issues concerning dynamic and static linking in traditional as well as single-address-space operating systems (SASOS). Related loading issues are also addressed. We present the dynamic linking model implemented in the Mungi SASOS and discuss its strengths and limitations. Benchmarking shows that dynamic linking in a SASOS carries significantly less overhead than dynamic linking in SGI's Irix operating system. The same performance advantages could be achieved in Unix systems, if they reserved a portion of the address space for dynamically linked libraries, and ensured that each library is always mapped at the same address.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/delller/deller.ps", } @INPROCEEDINGS{Nigh9906:DCD, AUTHOR="Tycho Nightingale and Yu Hen Hu and Q. Yang", TITLE="The Design and Implementation of a {DCD} Device Driver for Unix", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=14, ABSTRACT="Recent research results [1,2] using simulation have demonstrated that Disk Caching Disk (DCD), a new disk I/O architecture, has the potential for drastically improving disk write performance besides its higher reliability than traditional disk systems. To validate whether DCD can live up to its promise in the real world environment, we have designed and implemented a DCD device driver for the Sun's Solaris operating system. Measured performance results are very promising. For metadata intensive benchmarks, our DCD driver outperforms the traditional system by a factor of 2-6 in terms of program execution speeds. The driver also guarantees file system integrity in the events of system crashes or failures. Moreover, unlike other approaches such as Log-structured File Systems or Soft Updates, the DCD driver is completely transparent to the OS. It does not require any changes to the OS or the on-disk data layout. As a result, it can be used as a ``drop-in'' replacement for the traditional disk device driver in an existing system to obtain immediate performance improvement. Our multi-layered device-driver approach significantly reduces the implementation overhead and improves portability.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/nightingale/nightingale.ps", } @INPROCEEDINGS{Ande9906:Application, AUTHOR="Tom Anderson and James Griffioen", TITLE="An Application-Aware Data Storage Model", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=25, ABSTRACT="We describe a new application-controlled file persistence model in which applications select the desired stability from a range of persistence guarantees. This new abstraction extends conventional abstractions by allowing applications to specify a file's volatility and methods for automatic reconstruction in case of loss. The model allows applications, particularly ones with weak persistence requirements, to leverage the memory space of other machines to improve their performance. An automated (filename-matching) interface permits legacy applications to take advantage of the variable persistence guarantees without being modified. Our prototype implementation shows significant speed-ups, in some cases more than an order of magnitude over conventional network file systems such as NFS version 3.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/anderson/anderson.ps", } @INPROCEEDINGS{McKu9906:Soft, AUTHOR="Marshall K. McKusick and Gregory R. Ganger", TITLE="Soft Updates: A Technique for Eliminating Most Synchronous Writes in the Fast Filesystem", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=16, ABSTRACT="Traditionally, filesystem consistency has been maintained across system failures either by using synchronous writes to sequence dependent metadata updates or by using write-ahead logging to atomically group them. Soft updates, an alternative to these approaches, is an implementation mechanism that tracks and enforces metadata update dependencies to ensure that the disk image is always kept consistent. The use of soft updates obviates the need for a separate log or for most synchronous writes. Indeed, the ability of soft updates to aggregate many operations previously done individually and synchronously reduces the number of disk writes by 40 to 70\% for file-intensive environments (e.g., program development, mail servers, etc.). In addition to performance enhancement, soft updates can also maintain better disk consistency. By ensuring that the only inconsistencies are unclaimed blocks or inodes, soft updates can eliminate the need to run a filesystem check program after every system crash. Instead, the system is brought up immediately. When it is convenient, a background task can be run on the active filesystem to reclaim any lost blocks and inodes. This paper describes an implementation of soft updates and its incorporation into the 4.4BSD fast filesystem. It details the changes that were needed, both to the original research prototype and to the BSD system, to create a production-quality system. It also discusses the experiences, difficulties, and lessons learned in moving soft updates from research to reality; as is often the case, non-focal operations (e.g., fsck and ``fsync'') required rethinking and additional code. Experiences with the resulting system validate the earlier research: soft updates integrates well with existing filesystems and enforces metadata dependencies with performance that is within a few percent of optimal.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/mckusick/mckusick.ps", } @INPROCEEDINGS{Evan9906:Transaction, AUTHOR="Joseph B. Evans", TITLE="Design and Implementation of a Transaction-Based Filesystem on {FreeBSD}", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=5, ABSTRACT="Transactional database management systems (DBMS's) have special data integrity requirements that standard filesystems such as the Berkeley Fast Filesystem do not address. This paper briefly describes the requirements a transactional DBMS makes of a transaction-based filesystem, then goes on to describe the design and implementation of such a filesystem, referred to as a block repository 1 , which is part of the SQRL DBMS project. The implementation of SQRL's block repository is different than most traditional filesystems in that it is purposely implemented in user-land using raw devices and threads. Its performance is more tunable to the needs of transaction processing than would be the case if it were integrated into the kernel.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/evans/evans.ps", } @INPROCEEDINGS{Tso9906:Standalone, AUTHOR="Theodore Ts'o", TITLE="Standalone Device Drivers in Linux", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, ABSTRACT="Traditionally, Unix device drivers have been developed and distributed inside the kernel. There are a number of good reasons why this method is the predominant way most device drivers are distributed. First of all, it simplifies the packaging and distribution issues for the device driver. Secondly, it makes it easier to make changes to the interfaces between the kernel and the device drivers. However, this traditional scheme has a number of major disadvantages. First of all, it means that each version of the device driver is linked to a specific version of the kernel. So if a device is only supported in a development release, a customer who might otherwise want to use a stable, production release might be forced to use a bleeding-edge system. Alternatively, there may be bugs present in the device driver as included in the stable release of the kernel, but which are fixed in the development kernel. Moreover, including device drivers with the kernel is not scalable in the long term. If Linux-like 1 systems are ever to be able to support as many devices as various OS's from Redmond, Washington, hardware manufacturers will have to be able to support and distribute drivers separately from the main kernel distribution. Currently, the size of the total Linux kernel source base has been doubling (roughly) every 18 months. Almost all of this growth has been the result of new device drivers. If Linux is to be successful at Linus Torvald's goal of Total World Domination, it will be essential that we remove any limits to growth, and an exponential growth in the size of the Linux kernel is an obviously a long-term growth limitation.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/tso/tso.pdf", } @INPROCEEDINGS{Koba9906:Firewire, AUTHOR="Kazutomo Kobayashi", TITLE="Design and Implementation of Firewire Device Driver on {FreeBSD}", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=8, ABSTRACT="A Firewire device driver has been implemented on FreeBSD system. The driver provides IP network stack, native socket system interface, and stream device interface suchas a DV video. The device driver shows enough performance on the IP over Firewire environment at 30Mbps. Also, DV video communication application using IP has been developed with the device driver and it enebles DV quality communication between US and Japan only with the consumer market products.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/kobayashi/kobayashi.ps", } @INPROCEEDINGS{Furu9906:Newconfig, AUTHOR="Atsushi Furuta and Jun-ichiro Itojun Hagino", TITLE="newconfig: A Dynamic-Configuration Framework for {FreeBSD}", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=2, URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/furuta/furuta.pdf", } @INPROCEEDINGS{Lehe9906:Vinum, AUTHOR="Greg Lehey", TITLE="The Vinum Volume Manager", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=13, ABSTRACT="The Vinum Volume Manager is a block device driver which implements virtual disk drives. It isolates disk hardware from the block device interface and maps data in ways which result in an increase in flexibility, performance and reliability compared to the traditional slice view of disk storage. Vinum implements the RAID-0, RAID-1 and RAID-5 models, both individually and in combination.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/lehey/lehey.ps", } @INPROCEEDINGS{Braa9906:Porting, AUTHOR="Peter J. Braam and Mike Callahan and M. Satyanarayanan and Marc Schnieder", TITLE="Porting the Coda File System to Windows", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=18, ABSTRACT="We first describe how the Coda distributed filesystem was ported to Windows 95 and 98. Coda consists of user level cache managers and servers and kernel level code for filesystem support. Severe reentrancy difficulties in the Win32 environment on this platform were overcome by extending the DJGPP DOS C compiler package with kernel level support for sockets and more flexible memory management. With this support library and kernel modules for Windows 9x filesystems in place, the Coda file system client could be ported with very little patching and will likely soon run as well on Windows 9x as on Linux. We ported Coda file servers to Windows NT. For fileservers the Cygwin32 kit was used. We will not report here on the port of the Coda client to Windows NT, which is in an early stage. In both cases cross compilation from a Linux environment was most helpful to get a good development environment.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/braam/braam.pdf", } @INPROCEEDINGS{Kise9906:Network, AUTHOR="Oleg Kiselyov", TITLE="A Network File System over {HTTP:} Remote Access and Modification of Files and files", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=6, ABSTRACT="The goal of the present HTTPFS project is to enable access to remote files, directories, and other containers through an HTTP pipe. HTTPFS system permits retrieval, creation and modification of these resources as if they were regular files and directories on a local filesystem. The remote host can be any UNIX or Win9x/WinNT box that is capable of running a Perl CGI script and accessible either directly or via a web proxy or a gateway. HTTPFS runs entirely in user space. The current implementation fully supports reading as well as creating, writing, appending, and truncating of files on a remote HTTP host. HTTPFS provides an isolation level for concurrent file access stronger than the one mandated by POSIX file system semantics, closer to that of AFS. Both a programmatic interface with familiar open(), read(), write(), close(), etc. calls, and an interactive interface, via the popular Midnight Commander file browser, are provided.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/kiselyov/kiselyov.ps", } @INPROCEEDINGS{Prov9906:Future, AUTHOR="Niels Provos and David Mazières", TITLE="A Future-Adaptable Password Scheme", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=17, ABSTRACT="Many authentication schemes depend on secret passwords. Unfortunately, the length and randomness of user-chosen passwords remain fixed over time. In contrast, hardware improvements constantly give attackers increasing computational power. As a result, password schemes such as the traditional UNIX user-authentication system are failing with time. This paper discusses ways of building systems in which password security keeps up with hardware speeds. We formalize the properties desirable in a good password system, and show that the computational cost of any secure password scheme must increase as hardware improves. We present two algorithms with adaptable cost--eksblowfish, a block cipher with a purposefully expensive key schedule, and bcrypt, a related hash function. Failing a major breakthrough in complexity theory, these algorithms should allow password-based systems to adapt to hardware improvements and remain secure well into the future.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/provos/provos.ps", } @INPROCEEDINGS{Raad99:Cryptography, AUTHOR="Theo de Raadt and Niklas Hallqvist and Artur Grabowski and Angelos Keromytis and Niels Provos", TITLE="Cryptography in OpenBSD: An Overview", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=38, ABSTRACT="Cryptographic mechanisms are an important security component of an operating system in securing the system itself and its communication paths. Indeed, in many situations, cryptography is the only tool that can solve a particular problem, e.g., network-level security. While cryptography by itself does not guarantee security, when applied correctly, it can significantly improve overall security. Since one of the main foci of the OpenBSD system is security, various cryptographic mechanisms are employed in a number of different roles. This paper gives an overview of the cryptography employed in OpenBSD. We discuss the various components (IPsec, SSL libraries, stronger password encryption, Kerberos IV, random number generators, etc.), their role in system security, and their interactions with the rest of the system (and, where applicable, the network).", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/deraadt/deraadt\_html/index.html", } @INPROCEEDINGS{Cran9906:Minding, AUTHOR="Lorrie Cranor", TITLE="Minding Your Own Business: The Platform for Privacy Preferences Project and Privacy Minder", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, URL="http://www.usenix.org/publications/library/proceedings/usenix99/technical\_freenix.html", } @INPROCEEDINGS{Pres9906:Global, AUTHOR="Kenneth Preslan and Matthew T. O'Keefe and John Lekashman", TITLE="The Global File System: A Shared Disk File System for {*BSD} and Linux", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, URL="http://www.usenix.org/publications/library/proceedings/usenix99/technical\_freenix.html", } @INPROCEEDINGS{Gall9906:Trapeze, AUTHOR="Andrew J. Gallatin and Jeffrey S. Chase and Kenneth Yocum", TITLE="Trapeze/IP: {TCP/IP} at Near-Gigabit Speeds", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=10, ABSTRACT="This paper presents experiences with high-speed TCP/IP networking on a gigabit-per-second Myrinet network, using a Myrinet messaging system called Trapeze. We explore the effects of common optimizations above and below the TCP/IP protocol stack, including zero-copy sockets, large packets with scatter/gather I/O, checksum offloading, message pipelining, and interrupt suppression. Our experiments use extended FreeBSD 4.0 kernels on a range of Intel and Compaq Alpha platforms. These experiments give a snapshot of the FreeBSD TCP/IP implementation running at bandwidths as high as 956 Mb/s. We also report some results using Gigabit Ethernet products from Alteon Networks, which yielded a TCP bandwidth of 988 Mb/s using zero-copy sockets on a 500 MHz Compaq Alpha 21264 workstation.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/gallatin/gallatin.pdf", } @INPROCEEDINGS{Cho9906:Managing, AUTHOR="K. Cho", TITLE="Managing Traffic with {ALTQ}", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=12, ABSTRACT="ALTQ is a package for traffic management. ALTQ includes a queueing framework and several advanced queueing disciplines such as CBQ, RED, WFQ and RIO. ALTQ also supports RSVP and diffserv. ALTQ can be configured in a variety of ways for both research and operation. However, it requires understanding of the technologies to set up things correctly. In this paper, I summarize the design trade-offs, the available technologies and their limitations, and how they can be applied to typical network settings.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/cho/cho.ps", } @INPROCEEDINGS{Cran9906:Opening, AUTHOR="C. Cranor", TITLE="Opening the Source Repository with Anonymous {CVS}", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=13, ABSTRACT="Anonymous CVS is an advanced source file distribution mechanism we created to allow open source software projects to distribute source code and information about code to Internet users. Built on top of the Concurrent Versions System (CVS) revision control system, Anonymous CVS safely allows anonymous read-only access to a CVS source repository. Prior to the introduction of Anonymous CVS, access to a CVS repository had to be restricted to a select group of privileged software developers. The advantage of open source software is that it promotes reliability and quality by allowing independent peer review and rapid evolution of source code. By introducing Anonymous CVS, we have extended the concept of open source software projects to open source repository projects. Having an open source repository allows users to take a more active role in the debugging and development of open source projects. In this paper we will examine and compare the mechanisms used by open source projects to distribute source code. We will present the design and implementation of the first Anonymous CVS server (used to distribute the OpenBSD operating system). We will explain some of our concerns (e.g., security) and some of the problems we faced when trying to adapt CVS for anonymous use. We also will present other more recent source file distribution mechanisms that make use of an open CVS repository. Anonymous CVS is currently bring used by a number of projects including OpenBSD, FreeBSD, Mozilla, Ecgs, Gnome, Python, and GNUstep.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/cranor\_f/cranor\_f.ps", } @INPROCEEDINGS{Snch9906:Open, AUTHOR="Wilfredo Sánchez", TITLE="Open Software in a Commercial Operating System", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, ABSTRACT="Apple Computer has been working for the past couple of years to build a new and modern operating system to advance the Macintosh platform. The Macintosh platform, developed at Apple, while strong in many areas (in particular human interface), lacks the solid and modern foundation best exemplified in current variants of the Unix operating system. Apple acquired NeXT Software, Inc. in early 1997 largely in order to gain NeXT's experience in making an operating system based on a modern foundation which also had made advances in user interfaces, programming models, enterprise software, and other areas in which Apple was not traditionally strong. Thus began the development of Mac OS X Server, Apple's server operating system offering, which is also the basis for parts of Mac OS X, which we will be rolling out later in 1999. This session will discuss this new foundation: the ``Core Operating System'', which is largely based on software which was developed at the University of California at Berkeley and Carnegie-Mellon University, and was made freely available with open licensing terms. In addition much of the Core OS utilizes software available from the present-day BSD efforts, the Free Software Foundation, M.I.T., the Apache Group, and countless other groups and individuals who create and publish software under open licenses.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/sanchez/sanchez\_html/index.html", } @INPROCEEDINGS{Rose9906:Business, AUTHOR="Donald K. Rosenberg", TITLE="Business Issues in Free Software Licensing", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, ABSTRACT="There are some odd ideas circulating about Linux and the Free Software or Open Source movements. We can call these ideas primitive because they are simplistic and not well thought-out, and because they go back to the reductio ad absurdum of the primitive peoples who believed (and still believe, we hear) in what anthropologists like to talk about as the ``cargo cults.'' According to the anthropologists, these movements began among South Seas peoples in the 19th century, when they awaited the arrival of large ships which would restore to them all the wonderful goods their peoples had owned once, long ago. After World War II these cults took the form of waiting for aircraft to descend from the skies with their abundant cargoes. We are told that the believers even constructed runways with mock aircraft on them, hoping to attract the passing air traffic. We all smile--how much more we know than they--but today there is a firm body of thought on the one hand that eventually all software in the future will be produced, shared, and enjoyed on the Bazaar model: freely developed and given away by loosely-organized programmers around the world, and superior in quality and design to the commercial products of today. Given the behavior of much modern commercial software, one can understand why the believers hope so fervently for the millennium. But commercial vendors are just as likely to make the same mistake: we see articles and columnists hyping the idea that if a software firm can just take the leap of faith into arms of Open Source, they will attract legions of the world's smartest programmers, working ceaselessly and without compensation to improve the code the vendor has thrown among them. It does not help that any announcement that a company is releasing source code is regarded by the business community as a desperate act of last resort. What should be the approach of a commercial software vendor to the Open Source space? And what do they really want, anyway?", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/rosenberg/rosenberg.ps", } @INPROCEEDINGS{Bore9906:Doing, AUTHOR="N. Borenstein and Joseph Hardin and Marshall Van Alstyne", TITLE="Doing Well, Doing Good, and Staying Sane: A Hybrid Model for Sustainably Producing Innovative Open Software", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, URL="http://www.usenix.org/publications/library/proceedings/usenix99/technical\_freenix.html", } @INPROCEEDINGS{Shap9906:Sendmail, AUTHOR="G. Shapiro and E. Allman", TITLE="Sendmail Evolution: 8.10 and Beyond", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=18, ABSTRACT="Sendmail^TM has been the de facto mail transfer agent implementation since the dawn of the Internet. Today, sendmail development is still driven by a continually changing set of network requirements and user demands. Lately,two new driving forces have also contributed to sendmail development. First, as more open source mail transfer agents, such as Exim and Postfix, become available, a new friendly competition has developed in which the authors of the various MTAs share their ideas via open source and help to advance open standards as opposed to advancing their own particular implementation. Second, a new", } @INPROCEEDINGS{Icaz99:GNOME, AUTHOR="Miguel de Icaza", TITLE="The {GNOME} Desktop Project", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, URL="http://www.usenix.org/publications/library/proceedings/usenix99/technical\_freenix.html", } @INPROCEEDINGS{West9906:Meta, AUTHOR="Assar Westerlund and Love Hörnquist-Åstrand and Johan Danielsson", TITLE="Meta: A Freely Available Scalable {MTA}", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, URL="http://www.usenix.org/publications/library/proceedings/usenix99/technical\_freenix.html", } @INPROCEEDINGS{Metz9906:Porting, AUTHOR="Craig W. Metz", TITLE="Porting Kernel Code to Four {BSDs} and Linux", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=3, ABSTRACT="The U.S. Naval Research Laboratory develops and maintains a freely available IPv6 and IP Security distribution. All of the software builds and runs on BSD/OS, FreeBSD, NetBSD, and OpenBSD, and a growing portion of the software builds and runs on Linux. Each of the four BSDs has evolved signicantly from their original 4.4BSD-Lite ancestor, and increasingly more of that evolution is along divergent paths. Linux shares no signicant ancestry with the BSDs, but is still a POSIX system, which means that many of the same high-level facilities are available even though their implementation might be completely different. This paper discusses many of the differences and many of the similarities we encountered in the internals of these systems. It also discusses the techniques and glue software that we developed for isolating and abstracting the differences so that we could build a significant base of system code that is portable between all five systems.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/metz/metz.ps", } @INPROCEEDINGS{Mill9906:Strlcpy, AUTHOR="Todd Miller and Theo de Raadt", TITLE="strlcpy and strlcat--Consistent, Safe, String Copy and Concatenation", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=9, ABSTRACT="As the prevalence of buffer overflow attacks has increased, more and more programmers are using size or length-bounded string functions such as strncpy() and strncat(). While this is certainly an encouraging trend, the standard C string functions generally used were not really designed for the task. This paper describes an alternate, intuitive, and consistent API designed with safe string copies in mind. There are several problems encountered when strncpy() and strncat() are used as safe versions of strcpy() and strcat(). Both functions deal with NUL-termination and the length parameter in different and non-intuitive ways that confuse even experienced programmers. They also provide no easy way to detect when truncation occurs. Finally, strncpy() zero-fills the remainder of the destination string, incurring a performance penalty. Of all these issues, the confusion caused by the length parameters and the related issue of NUL-termination are most important. When we audited the OpenBSD source tree for potential security holes we found rampant misuse of strncpy() and strncat(). While not all of these resulted in exploitable security holes, they made it clear that the rules for using strncpy() and strncat() in safe string operations are widely misunderstood. The proposed replacement functions, strlcpy() and strlcat(), address these problems by presenting an API designed for safe string copies (see Figure 1 for function prototypes). Both functions guarantee NUL-termination, take as a length parameter the size of the string in bytes, and provide an easy way to detect truncation. Neither function zero-fills unused bytes in the destination.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/millert/millert.ps", } @INPROCEEDINGS{Mill9906:Pk, AUTHOR="Frank Miller", TITLE="pk: A {POSIX} Threads Kernel", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=4, ABSTRACT="pk is a new operating system kernel targeted for use in real-time and embedded applications. There are two novel aspects to the pk design: Documentation: The kernel is documented using literate programming techniques and the noweb tool in particular. POSIX Threads with Memory Protection: The concurrency model is based on the POSIX Threads (aka Pthreads) standard, however, the kernel also provides page-based memory protection using Memory Management Unit (MMU) hardware. This short paper discusses these facets of the pk kernel project. The use of literate programming is presented rst, followed by a brief description of some of the pk design issues.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/millerf\_millerf.ps", } @INPROCEEDINGS{Olso9906:Berkeley, AUTHOR="Michael A. Olson and Keith Bostic and Margo Seltzer", TITLE="Berkeley {DB}", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=10, ABSTRACT="Berkeley DB is an Open Source embedded database system with a number of key advantages over comparable systems. It is simple to use, supports concurrent access by multiple users, and provides industrial- strength transaction support, including surviving system and disk crashes. This paper describes the design and technical features of Berkeley DB, the distribution, and its license.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/olson/olson.ps", } @INPROCEEDINGS{Asam9906:FreeBSD, AUTHOR="Satoshi Asami", TITLE="The {FreeBSD} Ports Collection", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, ABSTRACT="FreeBSD is an open source operating system based on 4.4BSD-Lite2, a version of UNIX from the University of California at Berkeley. It is maintained by a group of volunteers from around the world. In addition to providing a complete operating system, the FreeBSD project supports an extensive collection of sanctioned third-party software called the Ports Collection, many of which were contributed by the users. In addition to the source form, most of the ports are provided as binary packages too.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/asami/asami.ps", } @INPROCEEDINGS{Hagi99:Multilingual, AUTHOR="Jun-ichiro Itojun Hagino and Yoshitaka Tokugawa", TITLE="Multilingual vi Clones: Past, Now and the Future", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=4, URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/hagino/hagino.pdf", } @INPROCEEDINGS{RCer9906:Improving, AUTHOR="R. Cervera and T. Cortes and Y. Bercerra", TITLE="Improving Application Performance Through Swap Compression", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, REFERENCES=17, ABSTRACT="There are many applications that use large amounts of memory. These large applications take advantage of the swapping mechanism to run on the system as the available physical memory is not enough for them to run. The same problem appears when we try to run, on a laptop, the same applications we run on a desktop computer. These applications will relay on the swapping mechanism as laptop computers usually have less physical memory than desktop ones. Finally, multi-user environments tend to be very loaded and their applications have to swap out part of their memory so that all applications can run concurrently. In all these cases, the performance of the applications is much lower than the one they would achieve if no swapping was needed. This happens because the swapping mechanism has to access the disk to keep the pages that do not fit in memory. It is clear that these applications, and the whole system, would benefit from a faster swapping system. If we examine the same problem from a different point of view, we observe that increasing the number of pages that fit in the swap space without increasing the number of blocks in the swap partition would also be quite beneficial. We could run the same applications on a laptop than on a desktop system. Remember that laptops also have smaller disks if compared to desktop ones. This increase in swap space would also help multi-user systems to avoid getting out of memory. Finally, out-of-core applications could be programmed more easily as the global-memory restriction would not be so important. Now a days it is quite normal to continue the office work at home. This usually means the use of large applications on a Linux box. These large applications fit well in the office machines but are too large to run efficiently on a smaller Linux box. In these cases, a fast swapping mechanism would be very beneficial as those applications would run faster and working at home would be less ``painful''. Furthermore, increasing the swap space at no cost would allow these kind of users to run applications that would normally not fit in their home machines. These performance and space problems have motivated this work and its objectives. The first, and most important, objective is to speedup the swap mechanism. This will increase the performance of the applications that, for whatever reason, have to keep part of their memory in the swap space. It is also an objective of this paper to increase the size of the memory offered to the applications without increasing the number of disk blocks in the swap partition. It is important to notice that should these two objectives be in conflict, we will favor performance over capacity. Finally, we want to achieve both improvements with the minimum number of changes in the original Linux kernel. The main idea used to accomplish both objectives consists of compressing the pages that have to be swapped out. This will increase the number of pages that can be placed in the swap partition. Furthermore, it will also allow us to build a cache of compressed pages that will decrease the number of times the system has to access the swap device. It is important to notice that previous studies show that good compression ratios can be achieved when compressing memory pages. The idea we present in this paper is similar, in essence, to the one proposed by Douglis, but some improvements and modifications have been done (see Section 5. We believe that now is a good time to reevaluate the results obtained in this previous work as the technology has improved significantly which means that compressing and decompressing pages can be done much more efficiently. This paper is divided into 6 sections. In Section 2, we describe the concepts and ideas in which this work has been based. In this section, we also present some preliminary results that will lead the final design. Section 3 gives a detailed overview of the way the mechanism works. Section 4 presents the benchmarks used and the results obtained while running them on our system. In Section 5, we present the most significant work already done in the area. Finally, Section 6 presents the main conclusions that can be extracted from this paper.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/cervera/cervera.ps", } @INPROCEEDINGS{Fisc9906:New, AUTHOR="Eric Fischer", TITLE="New Tricks for an Old Terminal Driver", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, ABSTRACT="Users expect more out of command lines than they did fifteen years ago, but the terminal interface has not evolved to keep up with their expectations. With a few modifications, though, the terminal driver can provide every program with support for the arrow keys and several common Emacs commands.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/fischer/fischer.pdf", } @INPROCEEDINGS{Lewi9906:Dents, AUTHOR="T. G. Lewis", TITLE="The Design of the Dents {DNS} Server", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, ABSTRACT="Dents is a server implementation of the Internet's Domain name System. Dents main features are a modular driver architecture, a CORBA-based control facility, a replaceable tree system, a clean design and good karma. Dents is free software, licensed under version 2 of the GPL. In this paper, I describe the design of Dents, concentrating on the innovations and evolutions it embodies, and including the future directions in which we hope to take the server. I describe some of the problems we've had. Finally, I summarize some lessons about server design which Dents reflects.", URL="http://www.usenix.org/publications/library/proceedings/usenix99/full\_papers/lewis/lewis.ps", } @INPROCEEDINGS{Shor9906:IP, AUTHOR="Melinda Shore", TITLE="{IP} Telephony - Protocols and Architectures", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, URL="http://www.usenix.org/publications/library/proceedings/usenix99/invited\_talks/shore.pdf", } @INPROCEEDINGS{Mank9906:There, AUTHOR="A. Mankin", TITLE="Will There Be an {IPv6} Transition?", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, URL="http://www.usenix.org/publications/library/proceedings/usenix99/invited\_talks/mankin\_html/", } @INPROCEEDINGS{Dunc9906:Paving, AUTHOR="J. S. Duncan", TITLE="Paving over Road-Kill on the Info Superhighway: Observations on the State of the Art in Incident Handling", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, URL="http://www.usenix.org/publications/library/proceedings/usenix99/invitedtalks.html", } @INPROCEEDINGS{Selt9906:Gizmo, AUTHOR="Margo Seltzer", TITLE="Gizmo Databases", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, URL="http://www.usenix.org/publications/library/proceedings/usenix99/invited\_talks/seltzer.pdf", } @INPROCEEDINGS{Meye9906:Deploying, AUTHOR="D. L. Meyer", TITLE="Deploying {IP} Multicast", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, URL="http://www.usenix.org/publications/library/proceedings/usenix99/invitedtalks.html", } @INPROCEEDINGS{Spen9906:Joys, AUTHOR="Henry Spencer", TITLE="The Joys of Interpretive Languages: Real Programmers Don't Always Use C", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, URL="http://www.usenix.org/publications/library/proceedings/usenix99/invitedtalks.html", } @INPROCEEDINGS{Bass9906:Bombs, AUTHOR="Tim Bass", TITLE="E-mail Bombs, Countermeasures, and the Langley Cyber Attack", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, URL="http://www.usenix.org/publications/library/proceedings/usenix99/invitedtalks.html", } @INPROCEEDINGS{Mash9906:Big, AUTHOR="John R. Mashey", TITLE="Big Data and the Next Wave of InfraStress Problems, Solutions, Opportunities", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, URL="http://www.usenix.org/publications/library/proceedings/usenix99/invited\_talks/mashey.pdf", } @INPROCEEDINGS{Mogu9906:What, AUTHOR="J. C. Mogul", TITLE="What's Wrong with {HTTP} and Why It Doesn't Matter", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, URL="http://www.usenix.org/publications/library/proceedings/usenix99/invited\_talks/mogul.pdf", } @INPROCEEDINGS{Salu9906:UNIX, AUTHOR="Peter Salus", TITLE="{UNIX} to Linux in Perspective", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=6, MONTH="Jun", YEAR=1999, URL="http://www.usenix.org/publications/library/proceedings/usenix99/invitedtalks.html", } @INPROCEEDINGS{Ries9906:Cplant, AUTHOR="Rolf Riesen and Ron Brightwell and Lee Ann Fisk and Tramm Hudson and J. Otto and A. Maccabe", TITLE="Cplant", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, REFERENCES=6, ABSTRACT="The Computational Plant project at Sandia National Laboratories is developing a large-scale, massively parallel computing resource from a cluster of commodity computing and networking components. We are combining the knowledge and research of previous and ongoing commodity cluster projects with our expertise in designing, developing, using, and maintaining large-scale MPP machines. This paper describes the main parts of the architecture and discusses the most important design choices and decisions. Scaling to hundreds and thousands of nodes requires more than simply combining readily- available software and hardware. We will highlight some of the more crucial pieces that make Cplant scalable.", URL="http://www.extremelinux.org/activities/usenix99/docs/cplant/index.html", } @INPROCEEDINGS{Feld9906:Generation, AUTHOR="Bob Felderman", TITLE="The Next Generation: {GM,} {LANai7} and 64-bit {PCI}", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, ABSTRACT="Myricom has been shipping GM software for the past several months. This paper will describe the current status of the software, some performance results and expectations for software deliveries on new platforms and new Myricom hardware.", URL="http://www.extremelinux.org/activities/usenix99/docs/myrinet/index.html", } @INPROCEEDINGS{Hals9906:Giga, AUTHOR="David M. Halstead and Brett Bode and D. Turner and Vasily Lewis", TITLE="Giga-Plant Scalable Cluster", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, REFERENCES=20, ABSTRACT="The Giga-Plant is a next generation compute cluster architecture under construction within the Scalable Computing Laboratory (SCL). This work describes the general cluster design philosophy utilized on this machine and others, and illustrates the performance evaluation process that was exercised in order to make an informed hardware purchasing decision. We present network communication throughput results taken from several hardware platforms using Fast Ethernet and Gigabit Ethernet with and without Jumbo Frames. We show that, despite throughput in excess of 800Mbit/s, communication latency is the critical factor in determining the viability of commodity network hardware in parallel processing applications.", URL="http://www.extremelinux.org/activities/usenix99/docs/gigaplant/gigaplant.pdf", } @INPROCEEDINGS{Ishi9906:RWCP, AUTHOR="Yasushi Ishikawa and Atsushi Hori and Hiroshi Tezuka and Shinji Sumimoto and T. Takahashi and H. Harada", TITLE="{RWCP} {PC} Cluster Programming Environment", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, REFERENCES=11, ABSTRACT="We have been developing the SCore cluster system software running on top of Linux. As shown in Figure 1, the SCore System software consists of a global operating system called SCore-D, a communication facility called PM, MPI implemented on PM called MPICH-PM/CLUMP, a software distributed shared memory system called SCASH, and a multithreaded programming language called MPC++. To realize the high performance system using commodity hardware and software, the following key technologies have been employed:  A user-level zero-copy message transfer mechanism between nodes and one copy message transfer mechanism within a SMP node by a high performance communication facility called PM,  A high performance MPI implementation called MPICH-PM/CLUMP that integrates both zero-copy message transfer and messagepassing facilities in order to maximize performance, and  A multi-user environment using gang scheduling without degrading the communication performance realized by an operating system daemon called SCore-D.", URL="http://www.extremelinux.org/activities/usenix99/docs/rwcp/rwcp.pdf", } @INPROCEEDINGS{Bal9906:Parallel, AUTHOR="Henri E. Bal and Aske Plaat and Thilo Kielmann and Jason Maassen and Rob van Nieuwpoort and Ronald Veldema", TITLE="Parallel Computing on Wide-Area Clusters: the Albatross Project", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, REFERENCES=17, ABSTRACT="The aim of the Albatross project is to study applications and programming environments for wide-area cluster computers, which consist of multiple clusters connected by wide-area networks. Parallel processing on such systems is useful but challenging, given the large differences in latency and bandwidth between LANs and WANs. We apply application- level optimizations that exploit the hierarchical structure of wide-area clusters to minimize communication over the WANs. In addition, we use highly efficient local-area communication protocols. We illustrate this approach using a high-performance Java system that is implemented on a collection of four Myrinet-based clusters connected by wide-area ATM networks. The optimized applications obtain high speedups on this wide- area system.", URL="http://www.extremelinux.org/activities/usenix99/docs/albatross/albatross.pdf", } @INPROCEEDINGS{Shen9906:Profiling, AUTHOR="Sameer Shende", TITLE="Profiling and Tracing in Linux", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, REFERENCES=20, ABSTRACT="Profiling and tracing tools can help make application parallelization more effective and identify performance bottlenecks. Profiling presents summary statistics of performance metrics while tracing highlights the temporal aspect of performance variations, showing when and where in the code performance is achieved. A complex challenge is the mapping of performance data gathered during execution to high-level parallel language constructs in the application source code. Presenting performance data in a meaningful way to the user is equally important. This paper presents a brief overview of profiling and tracing tools in the context of Linux - the operating system most commonly used to build clusters of workstations for high performance computing.", URL="http://www.extremelinux.org/activities/usenix99/docs/shende/index.html", } @INPROCEEDINGS{Ahre9906:Using, AUTHOR="J. Ahrens", TITLE="Using Linux Clusters for Parallel Visualization and Rendering", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, URL="http://www.extremelinux.org/activities/usenix99/docs/ahrens/index.htm", } @INPROCEEDINGS{Braa9906:File, AUTHOR="Peter J. Braam", TITLE="File Systems for Clusters from a Protocol Perspective", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, REFERENCES=12, ABSTRACT="The protocols used by distributed file systems vary widely. The aim of this talk is to give an overview of these protocols and discuss their applicability for a cluster environment. File systems like NFS have weak semantics, making tight sharing difficult. AFS, Coda and InterMezzo give a great deal of autonomy to cluster members, and involve a persistent file cache for each system. True cluster file systems such as found in VMS VAXClusters, XFS, GFS introduce a shared single image, but introduce complex dependencies on cluster membership.", URL="http://www.extremelinux.org/activities/usenix99/docs/braam/braam.html", } @INPROCEEDINGS{Pres9906:Shared, AUTHOR="Kenneth Preslan and M. Agarwal and Andrew P. Barry and Jonathan E. Brassow and Russell Cattelan and Grant M. Erickson and Erling Nygaard and Seth Van Oort", TITLE="A 64-bit, Shared Disk File System for Linux", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, REFERENCES=13, ABSTRACT="In computer systems today, speed and responsiveness is often determined by network and storage subsystem performance. Faster, more scalable networking interfaces like Fibre Channel and Gigabit Ethernet provide the scaf-folding from which higher performance implementations may be constructed, but new thinking is required about how machines interact with network-enabled storage devices. We have developed a Linux file system called GFS (the Global File System) that allows multiple Linux machines to access and share disk and tape devices on a Fibre Channel or SCSI storage network. We plan to extend GFS by transporting packetized SCSI commands over IP so that any GFS-enabled Linux machine can access shared network devices. GFS will perform well as a local file system, as a traditional network file system running over IP, and as a high-performance cluster file system running over storage networks like Fibre Channel. GFS device sharing provides a key cluster-enabling technology for Linux, helping to bring the availability, scalability, and load balancing benefits of clustering to Linux. Our goal is to develop a scalable, (in number of clients and devices, capacity, connectivity, and bandwidth) server-less file system that integrates IP-based network attached storage (NAS) and Fibre-Channel-based storage area networks (SAN). We call this new architecture Storage Area InterNetworking (SAINT). It exploits the speed and device scalability of SAN clusters, and provides the client scalability and network interoperability of NAS appliances. Our Linux port shows that the GFS architecture is portable across different platforms, and we are currently working on a port to FreeBSD. The GFS code is open source (GPL) software freely available on the Internet at http://www.globalfilesystem.org.", URL="http://www.extremelinux.org/activities/usenix99/docs/gfs/gfs.pdf", } @INPROCEEDINGS{Hanr9906:Multi, AUTHOR="Pat Hanrahan", TITLE="Multi-graphics: Towards Scalable, Distributed Visualization", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, URL="http://www.extremelinux.org/activities/usenix99/docs/hanrahan/index.htm", } @INPROCEEDINGS{Ligo9906:Overview, AUTHOR="Walter B. Ligon and Robert Ross", TITLE="An Overview of the Parallel Virtual File System", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, REFERENCES=4, ABSTRACT="As the PC cluster has grown in popularity as a parallel computing platform, the demand for system software for this platform has grown as well. One common piece of system software available for many commercial parallel machines is the parallel file system. Parallel file systems offer higher I/O performance than single disk or RAID systems, provide users with a convenient and consistent name space across the parallel machine, support physical distribution of data across multiple disks and network entities (I/O nodes), and typically include additional I/O interfaces to support larger files and control of file parameters. The Parallel Virtual File System (PVFS) Project is an effort to provide a parallel file system for PC clusters. As a parallel file system, PVFS provides a global name space, striping of data across multiple I/O nodes, and multiple user interfaces. The system is implemented at the user level, so no kernel modifications are necessary to install or run the system. All communication is performed using TCP/IP, so no additional message passing libraries are needed, and support is included for using existing binaries on PVFS files. This paper describes the key aspects of the PVFS system and presents recent performance results on a 64 node Beowulf workstation. Conclusions are drawn and areas of future work are discussed.", URL="http://www.extremelinux.org/activities/usenix99/docs/pvfs/pvfs.html", } @INPROCEEDINGS{Thak9906:MPI, AUTHOR="Rajeev Thakur and William Gropp and Ewing Lusk", TITLE="{MPI-IO:} A Standard, Portable {API} for High-Performance Parallel {I/O}", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, REFERENCES=7, ABSTRACT="Although a standard API for message-passing, namely MPI, has existed for a while, a similar standard API hasn't been available for performing I/O from parallel programs. Most parallel le systems (and therefore parallel programs) simply use the Unix I/O API as the interface for parallel I/O. The Unix API, although portable, is not appropriate as an API for high-performance parallel I/O. With the Unix API, one cannot express (in a single function) the kinds of accesses that are common in parallel programs, namely, each process accessing a noncontiguous data set and a group of processes accessing a file simultaneously. Without this information, the file system cannot perform certain optimizations that can otherwise improve performance dramatically. Furthermore, many vendors support vendor-specific extensions to the basic Unix API, and using any of these extensions makes programs nonportable. A solution to these problems is MPI-IO, the I/O interface defined in the MPI-2 standard [2].", URL="http://www.extremelinux.org/activities/usenix99/docs/mpiio/mpiio.pdf", } @INPROCEEDINGS{Arch9906:Patrick, AUTHOR="A Modular High Performance Implementation Architecture", TITLE="Patrick Bozeman", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, REFERENCES=17, URL="http://www.extremelinux.org/activities/usenix99/docs/mvia/mvia.pdf", } @INPROCEEDINGS{Fost9906:Beta, AUTHOR="Ian Foster", TITLE="The Beta Grid: A National Infrastructure for Computer Systems Research", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, REFERENCES=7, URL="http://www.extremelinux.org/activities/usenix99/docs/betagrid/betagrid.pdf", } @INPROCEEDINGS{Clin9906:Compaq, AUTHOR="Joel L. Clinkenbeard", TITLE="Compaq’s High Performance Programming Environment for Linux", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, URL="http://www.extremelinux.org/activities/usenix99/docs/compaq/index.htm", } @INPROCEEDINGS{Ches9906:SGI, AUTHOR="G. L. Chesson", TITLE="{SGI,} Linux, Scaleable Systems", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, URL="http://www.extremelinux.org/activities/usenix99/docs/chesson/index.htm", } @INPROCEEDINGS{Stev9906:High, AUTHOR="Rick Stevens", TITLE="The High Performance Computing, Extreme Linux, Open Source, and Systems Software Initiative", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, URL="http://www.extremelinux.org/activities/usenix99/docs/betagrid/StevensEL99/index.htm", } @INPROCEEDINGS{Evar9906:Chiba, AUTHOR="Rémy Evard", TITLE="Chiba City", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, URL="http://www.extremelinux.org/activities/usenix99/docs/betagrid/EvardEL99/index.htm", } @INPROCEEDINGS{Hump9906:Using, AUTHOR="William Humphrey and Susan Coghlan", TITLE="Using a Linux Cluster for Linear Accelerator Modeling", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, ABSTRACT="Large-scale scientific parallel computations, traditionally performed on specialized, expensive supercomputers and massively- parallel-processing computers, are being performed more and more on relatively inexpensive Linux-based clusters of computers. The rapid improvement in the performance and memory capacity of commodity processors from Intel and DEC, coupled with the stability and performance of the Linux operating system, has made it possible to assemble networked clusters of PC’s at a fraction of the cost of supercomputers. Compute power is only part of the story, however; very large scientific simulation codes often also require large memory and network bandwidth resources, and this must be taken into account when developing a Linux cluster for these types of problems. Researchers at Los Alamos National Laboratory, studying the dynamics of intense particle beams in accelerators, have developed a parallel simulation code to model the motion of charge particles through linear accelerator components, and have studied the performance of this code on a 128-processor, 64-node cluster of PC’s running Linux as well as on a 128-node Origin 2000 SMP supercomputer. The Linux cluster includes two forms of interprocessor networking: inexpensive 100-BT Ethernet, with a maximum per-node bandwidth of 100 Mb/s, and Myrinet networking, with a maximum per-node bandwidth of 1 Gb/s. We compare the time to compute a typical problem in parallel on the Linux cluster and on the Origin 2000 platform, for increasing numbers of processors. We also compare the price/performance of these systems, taking into account the cost of the networking equipment when running across Myrinet vs. 100-BT, and the use of single- or dual-processor PC’s. For this hardware and application, the Linux-based PC cluster performs at two-third to three-fourths of the performance of the Origin 2000 machine, but at much lower total cost. Use of Myrinet hardware, it is seen, improves total performance, but the added cost of the Myrinet network hardware does not always lead to better price/performance value.", URL="http://www.extremelinux.org/activities/usenix99/docs/linacc/LinuxAcc2.html", } @INPROCEEDINGS{Gibs9906:NASD, AUTHOR="G. A. Gibson and David F. Nagle and William Courtright I. I. and Nat Lanza and Paul Mazaitis and Marc Unangst and Jim Zelenka", TITLE="{NASD} Scalable Storage Systems", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, REFERENCES=25, ABSTRACT="The goal of CMU's Network-Attached Secure Disks (NASD) project is to define the next era of storage system interfaces and architectures. To encourage industry standardization of a compliant storage device/ subsystem interface, we are working closely with the National Storage Industry Consortium’s working group on network-attached storage. Our experimental demonstration of the NASD interface’s value is device and filesystem prototype software that delivers the scalability inherent in a NASD storage architecture. To engage the academic community and to provide a reference implementation for industry development, CMU is releasing its Linux and Digital UNIX ports of this software. In this paper, we overview the NASD scalable storage architecture and the code-base we are releasing for Linux.", URL="http://www.extremelinux.org/activities/usenix99/docs/gibson/index.html", } @INPROCEEDINGS{Nitz9906:PBS, AUTHOR="Bill Nitzberg and B. Henderson", TITLE="{PBS} on Extreme Linux: An Overview", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, ABSTRACT="PBS, the Portable Batch System, was developed at NASA Ames Research Center as a successor to the widely-used Network Queuing System (NQS). PBS provides sophisticated resource management facilities for a wide range of systems: • POSIX 1003.2d Batch Environment Standard compliant • separate, fully tunable, scheduler in C (also supports tcl \& BASL) - production schedulers available supporting priorities, dedicated time, and dynamic backfilling • production hardened and demonstrated scalability - 256 processor IBM SP, 352 processor SGI Origin cluster, and 130 processor Linux cluster • both serial and parallel jobs are fully supported in a mixed time-shared and space-shared environment • fault isolation, crash recovery, and support for logging and accounting. Although fully configurable, the typical PBS installation on an Extreme Linux cluster consists of a few ``front-end'' nodes running: the PBS client code, a single PBS server, and a single PBS scheduler. The rest of the cluster (the ``back-end'' nodes) run the PBS MOM daemon, which actually executes the jobs. A job (e.g., ``mpirun -np 4 ./hello'') is submitted along with a resource specification (e.g., ``4 nodes with 256 MB for 10 minutes'') on one of the front-ends, handed to the server, scheduled, run by the MOMs, and has output placed back on the front-end. Active development work is continuing at NASA Ames and elsewhere, including: support for Kerberos authentication, porting the Maui scheduler, providing a bi-directional inter-face to Globus - allowing PBS jobs to be run via Globus, and adding advance reservation support. In addition, a web client interface is planned. PBS is an ``open source'' package, and runs on nearly every UNIX variant; there is cur-rently no support for Windows. An RPM of the current release (version 2.1) is available via pbs.mrj.com.", URL="http://www.extremelinux.org/activities/usenix99/docs/pbs/index.htm", } @INPROCEEDINGS{Schu9906:Linux, AUTHOR="Vincent Schuster", TITLE="Linux {SMP} and Tool Support", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, URL="http://www.extremelinux.org/activities/usenix99/docs/pgroup/index.htm", } @INPROCEEDINGS{Lind9906:Supercomputing, AUTHOR="Greg Lindahl and Luke Lonergan", TITLE="Supercomputing on Linux Alpha", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, URL="http://www.extremelinux.org/activities/usenix99/docs/alphalinux/alphalinux.pdf", } @INPROCEEDINGS{Jack9906:Maui, AUTHOR="Daniel Jackson", TITLE="Maui Scheduler on Linux", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, ABSTRACT="As Linux clusters continue to establish themselves as effective high performance computing (HPC) platforms, system administrators are finding themselves in need of advanced scheduling and resource management capabilities. The Maui scheduler was designed as an HPC scheduler with advanced features such as aggressive backfill, fairshare scheduling, multiple fairness policies, dynamic prioritization, dedicated consumable resource tracking and enforcement, and a very extensive advance reservation system. These features allow the scheduler administer to control and optimally utilize the system resources available. This presentation discusses some of the features of the maui scheduler as well as experiences using the maui scheduler on Linux clusters.", URL="http://www.extremelinux.org/activities/usenix99/docs/maui/maui.html", } @INPROCEEDINGS{Kueh9906:Ptools, AUTHOR="Jeffery A. Kuehn", TITLE="Ptools Support for Linux", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, URL="http://www.extremelinux.org/activities/usenix99/docs/ptools/index.htm", } @INPROCEEDINGS{Buet9906:Metrowerks, AUTHOR="Kevin Buettner", TITLE="Metrowerks Linux Technology Roadmap", BOOKTITLE="USENIX Annual Technical Conference", ADDRESS="Montery, California, USA", DAYS=8, MONTH="Jun", YEAR=1999, URL="http://www.extremelinux.org/activities/usenix99/docs/metrowerks/metrowerks.pdf", } @INPROCEEDINGS{Li9910:Scalable, AUTHOR="Dong Li and D. R. Cheriton", TITLE="Scalable Web Caching of Frequently Updated Objects using Reliable Multicast", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=6, ABSTRACT="Frequently updated web objects reduce the benefit of caching, increase the problem of cache inconsistency, and aggravate the inefficiency of the conventional ``repeated unicast'' delivery model. In this paper, we investigate multicast invalidation and delivery of popular, frequently updated objects to web cache proxies. Our protocol, MMO, groups objects into volumes, each of which maps to one IP multicast group. We show that, by forming volumes of the appropriate size and/or object correlation, the benefit from reliable multicast outweighs the cost of delivering extraneous data as well as the overhead of multicast reliability. Moreover, trace-driven simulations show that the bandwidth saving over conventional approaches increases significantly as the audience size grows. We conclude that MMO provides efficient bandwidth utilization and service scalability, and makes strong web cache consistency for dynamic objects practical.", URL="http://www.usenix.org/publications/library/proceedings/usits99/li.html", } @INPROCEEDINGS{Yin9910:Hierarchical, AUTHOR="Jiahnsheng Yin and Lorenzo Alvisi and Michael D. Dahlin and Ching-Yung Lin", TITLE="Hierarchical Cache Consistency in a {WAN}", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=21, ABSTRACT="This paper explores ways to provide improved consistency for Internet applications that scale to millions of clients. We make four contributions. First, we identify how workloads affect the scalability of cache consistency algorithms. Second, we define two primitive mechanisms, split and join, for growing and shrinking consistency hierarchies, and we present a simple mechanism for implementing them. Third, we describe and evaluate policies for using split and join to address the fault tolerance and performance challenges of consistency hierarchies. Fourth, using synthetic workload and trace-based simulation, we compare various algorithms for maintaining strong consistency in a range of hierarchy configurations. Our results indicate that a promising configuration for providing strong consistency in a WAN is a two-level consistency hierarchy where servers and proxies work to maintain consistency for data cached at clients. Specifically, by adapting to clients' access patterns, two-level hierarchies reduce the read latency for demanding workloads without introducing excessive overhead for nondemanding workloads. Also, they can improve scalability by orders of magnitude. Furthermore, this configuration is easy to deploy by augmenting proxies, and it allows invalidation messages to traverse firewalls.", URL="http://www.usenix.org/publications/library/proceedings/usits99/yin.html", } @INPROCEEDINGS{Wolm9910:Organization, AUTHOR="Alec Wolman and Geoff Voelker and N. K. Sharma and Neal Cardwell and M. R. Brown and Tashana Landray and Denise Pinnel and Anna R. Karlin", TITLE="Organization-Based Analysis of Web-Object Sharing and Caching", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=27, ABSTRACT="Performance-enhancing mechanisms in the World Wide Web primarily exploit repeated requests to Web documents by multiple clients. However, little is known about patterns of shared document access, particularly from diverse client populations. The principal goal of this paper is to examine the sharing of Web documents from an organizational point of view. An organizational analysis of sharing is important, because caching is often performed on an organizational basis; i.e., proxies are typically placed in front of large and small companies, universities, departments, and so on. Unfortunately, simultaneous multi-organizational traces do not currently exist and are difficult to obtain in practice. The goal of this paper is to explore the extent of document sharing (1) among clients within single organizations, and (2) among clients across different organizations. To perform the study, we use a large university as a model of a diverse collection of organizations. Within our university, we have traced all external Web requests and responses, anonymizing the data but preserving organizational membership information. This permits us to analyze both inter- and intra-organization document sharing and to test whether organization membership is significant. As well, we characterize a number of parameters of our data, including basic object characteristics, object cacheability, and server distributions.", URL="http://www.usenix.org/publications/library/proceedings/usits99/wolman.html", } @INPROCEEDINGS{Gold9910:Ninja, AUTHOR="Ian Goldberg and Steven D. Gribble and D. B. Wagner and Eric Brewer", TITLE="The Ninja Jukebox", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=22, ABSTRACT="We present the design and implementation of the ``Ninja Jukebox'', an infrastructural service that allows a community of users to build a distributed, collaborative music repository that delivers digital music to Internet clients, and that performs simple collaborative filtering based on users' song preferences inferred by the service. The Jukebox, implemented in Java, was designed to allow rapid service evolution and reconfiguration, simplicity in participation, and extensibility. We demonstrate that our careful use of a distributed component architecture enabled rapid prototyping of the service, and that our use of carefully designed, strongly typed interfaces enabled the smooth evolution of the service from a simple prototype to a more complex, mature system.", URL="http://www.usenix.org/publications/library/proceedings/usits99/goldberg.html", } @INPROCEEDINGS{Chen9910:Cha, AUTHOR="M.-S. Chen and J. P. Hong and Jung-Lung Lin and Marti Hearst", TITLE="Cha-Cha: A System for Organizing Intranet Search Results", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=30, ABSTRACT="Although search over World Wide Web pages has recently received much academic and commercial attention, surprisingly little research has been done on how to search the web pages within large, diverse intranets. Intranets contain the information associated with the internal workings of an organization. A standard search engine retrieves web pages that fall within a widely diverse range of information contexts, but presents these results uniformly, in a ranked list. As an alternative, the Cha-Cha system organizes web search results in such a way as to reflect the underlying structure of the intranet. In our approach, an ``outline'' or ``table of contents'' is created by first recording the shortest paths in hyperlinks from root pages to every page within the web intranet. After the user issues a query, these shortest paths are dynamically combined to form a hierarchical outline of the context in which the search results occur. The system is designed to be helpful for users with a wide range of computer skills. Preliminary user study and survey results suggest that some users find the resulting structure more helpful than the standard retrieval results display for intranet search.", URL="http://www.usenix.org/publications/library/proceedings/usits99/chen.html", } @INPROCEEDINGS{Hode9910:Document, AUTHOR="Todd D. Hodes and Randy H. Katz", TITLE="A Document-based Framework for {Internet} Application Control", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=31, ABSTRACT="This paper motivates and details a document-based framework for manipulating the components that comprise distributed Internet applications. In the framework, XML documents are used to describe both server-side functionality and the mapping between a client's applications and the servers it accesses. Our system model contrasts with explicitly context-aware application designs, where location information must be explicitly manipulated by the application to affect change; instead, a middleware layer is interposed between client applications and services so that invocations between the two can be transparently remapped. This approach is useful for a subset of application domains, including our example domain of ``remote control'' of local resources (e.g., lights, stereo components, etc.). We illustrate how the framework allows for 1) remapping of a portion of an existing user interface to a new service, 2) viewing of arbitrary subsets and combinations of the available functionality, and 3) mixing dynamically-generated user interfaces with existing user interfaces. The use of a document-based framework in addition to a conventional object-oriented programming language provides a number of key features. One of the most useful is that it exposes the mappings between programs/UIs and the objects to which they refer, thereby providing a standard location for manipulation of this indirection.", URL="http://www.usenix.org/publications/library/proceedings/usits99/hodes.html", } @INPROCEEDINGS{Sava9910:Sting, AUTHOR="Stefan Savage", TITLE="Sting: a {TCP-based} Network Measurement Tool", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=17, ABSTRACT="Understanding wide-area network characteristics is critical for evaluating the performance of Internet applications. Unfortunately, measuring the end-to-end network behavior between two hosts can be problematic. Traditional ICMP-based tools, such as ping, are easy to use and work universally, but produce results that are limited and inaccurate. Measurement infrastructures, such as NIMI, can produce highly detailed and accurate results, but require specialized software to be deployed at both the sender and the receiver. In this paper we explore using the TCP protocol to provide more accurate network measurements than traditional tools, while still preserving their near-universal applicability. Our first prototype, a tool called sting, is able to accurately measure the packet loss rate on both the forward and reverse paths between a pair of hosts. We describe the techniques used to accomplish this, how they were validated, and present our preliminary experience measuring the packet loss rates to and from a variety of Web servers.", URL="http://www.usenix.org/publications/library/proceedings/usits99/savage.html", } @INPROCEEDINGS{Chan9910:JPEG, AUTHOR="S. Chandra and Carla Ellis", TITLE="{JPEG} Compression Metric as a Quality Aware Image Transcoding", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=22, ABSTRACT="Transcoding is becoming a preferred technique to tailor multimedia objects for delivery across variable network bandwidth and for storage and display on the destination device. This paper presents techniques to quantify the quality-versus-size tradeoff characteristics for transcoding JPEG images. We analyze the characteristics of images available in typical Web sites and explore how we can perform informed transcoding using the JPEG compression metric. We present the effects of this transcoding on the image storage size and image information quality. We also present ways of predicting the computational cost as well as potential space benefits achieved by the transcoding. These results are useful in any system that uses transcoding to reduce access latencies, increase effective storage space as well as reduce access costs.", URL="http://www.usenix.org/publications/library/proceedings/usits99/chandra.html", } @INPROCEEDINGS{Mark9910:Secondary, AUTHOR="Evangelos Markatos and M. Katevenis and Dionisis Pnevmatikatos and Michail D. Flouris", TITLE="Secondary Storage Management for Web Proxies", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=42, ABSTRACT="World-Wide Web proxies are being increasingly used to provide Internet access to users behind a firewall and to reduce wide-area network traffic. Recent results suggest that disk I/O is increasingly becoming the limiting factor for the performance of web proxies. In this paper we study the overheads associated with disk I/O for web proxies, and propose secondary storage management alternatives that improve performance. We use a combination of experimental evaluation and simulation based on traces from busy web proxies. We show that web proxies experience significant overheads due to disk I/O. We propose several file management methods that reduce the disk I/O overhead overhead by a factor of 25 overall, resulting in a single-disk service rate that exceeds 500 (URL-get) operations per second.", URL="http://www.usenix.org/publications/library/proceedings/usits99/markatos.html", } @INPROCEEDINGS{Chi9910:Compression, AUTHOR="C.-H. Chi and J. Deng and Y. Lim", TITLE="Compression Proxy Server: Design and Implementation", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=26, ABSTRACT="Automatic data compression in the web proxy server is an important mechanism that can potentially reduce network bandwidth consumption and web access latency significantly. However, unlike traditional data compression, web protocols and data have unique characteristics that make compression challenging. These include data block streaming, wide range of data object sizes and types, and real-time response. In this paper, we focus on automatic web data compression in the HTTP proxy server. A new classification of web data compression based on system complexity and HTTP requirements is proposed: stream, block and file compression. Then, the concept of hybrid web data compression is introduced. To understand the potentials of web data compression better, an implementation of the proposed hybrid compression in the Squid proxy server is described. The result is very promising, as about 30\% of the bandwidth can be saved easily. Furthermore, even with a low end Pentium 266 MHz PC as the proxy machine, the compression overhead is less than 1\% of the transfer time.", URL="http://www.usenix.org/publications/library/proceedings/usits99/chi.html", } @INPROCEEDINGS{Cohe9910:TCP, AUTHOR="A. C. Cohen and Sampath Rangarajan and Hamilton Slye", TITLE="On the Performance of {TCP} Splicing for {URL-aware} Redirection", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=13, ABSTRACT="This paper describes the design, implementation and performance of a layer-7 switch which supports URL-aware redirection of HTTP traffic. Currently, there are several vendors who are beginning to announce the availability of such switches in the market, but little or no implementation and performance information is available. We discuss design issues pertaining to such switches through a prototype implementation of a URL-aware switch in the Linux kernel, and analyze the performance of our implementation. We investigate the use of TCP splicing as a mechanism for improving the performance of the switch; we explore whether TCP splicing will benefit URL-aware redirection even though HTTP connections, on average, are short-lived and transfer small amounts of data. Results from our implementation show that TCP splicing does improve the performance of URL-aware switches that handle short- lived HTTP connections. Our results also re-affirm earlier findings that TCP splicing substantially improves the performance of any application-layer proxy when large amounts of data are transferred through the splice.", URL="http://www.usenix.org/publications/library/proceedings/usits99/cohen.html", } @INPROCEEDINGS{Duch9910:Prefetching, AUTHOR="Dan Duchamp", TITLE="Prefetching Hyperlinks", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=28, ABSTRACT="This paper develops a new method for prefetching Web pages into the client cache. Clients send reference information to Web servers, which aggregate the reference information in near-real-time and then disperse the aggregated information to all clients, piggybacked on GET responses. The information indicates how often hyperlink URLs embedded in pages have been previously accessed relative to the embedding page. Based on knowledge about which hyperlinks are generally popular, clients initiate prefetching of the hyperlinks and their embedded images according to any algorithm they prefer. Both client and server may cap the prefetching mechanism's space overhead and waste of network resources due to speculation. The result of these differences is improved prefetching: lower client latency (by 52.3\%) and less wasted network bandwidth (24.0\%).", URL="http://www.usenix.org/publications/library/proceedings/usits99/duchamp.html", } @INPROCEEDINGS{Pitk9910:Mining, AUTHOR="Jim Pitkow and Peter Pirolli", TITLE="Mining Longest Repeating Subsequences to Predict World Wide Web Surfing", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=20, ABSTRACT="Modeling and predicting user surfing paths involves tradeoffs between model complexity and predictive accuracy. In this paper we explore predictive modeling techniques that attempt to reduce model complexity while retaining predictive accuracy. We show that compared to various Markov models, longest repeating subsequence models are able to significantly reduce model size while retaining the ability to make accurate predictions. In addition, sharp increases in the overall predictive capabilities of these models are achievable by modest increases to the number of predictions made.", URL="http://www.usenix.org/publications/library/proceedings/usits99/pitkow.html", } @INPROCEEDINGS{Vahd9910:Active, AUTHOR="Amin Vahdat and Michael D. Dahlin and T. W. Anderson and Anshu Aggarwal", TITLE="Active Names: Flexible Location and Transport of Wide-Area Resources", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=57, ABSTRACT="In this paper, we explore flexible name resolution as a way of supporting extensibility for wide-area distributed services. Our approach, called Active Names, maps names to a chain of mobile programs that can customize how a service is located and how its results are transformed and transported back to the client. To illustrate the properties of our system, we implemented prototypes of server selection based on end-to-end performance measurements, location-independent data transformation, and caching of composable active objects and demonstrate up to a five-fold performance improvement to end users relative to protocols in widespread use. We show how these new services are developed, composed, and secured in our framework. Finally, we develop a set of algorithms to control how mobile Active Name programs are mapped onto available wide-area resources to optimize performance and availability.", URL="http://www.usenix.org/publications/library/proceedings/usits99/vahdat.html", } @INPROCEEDINGS{Rous9910:Person, AUTHOR="Mema Roussopoulos and Petros Maniatis and Edward Swierk and Kuen-Chu Lai and Guido Appenzeller and Maurice Baker", TITLE="Person-level Routing in the Mobile People Architecture", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=12, ABSTRACT="Ubiquitous network connectivity for devices does not automatically imply continuous reachability for people. People move from place to place and switch from one network device to another. As a result, phones ring in empty offices, email cannot reach most cell phones, and spam clogs expensive, low-bandwidth links to laptops. Whereas existing mechanisms have addressed host mobility or the mobility of people within one network, few have allowed people, the ultimate and most important endpoints of communication, to roam freely, without being constrained to one location, one application, one device, or one network. We have designed the Mobile People Architecture (MPA) to maintain person-to-person reachability. The central component of MPA is a person-level router called the Personal Proxy. It tracks a mobile person's location, accepts communications on his behalf, converts them into different application formats according to his preferences, and forwards the resulting communications to him. In contrast to similar systems, the Personal Proxy protects the user's privacy, is easily extensible to new network devices and applications, and has been deployed with no modifications to the existing network and telecommunications infrastructure. In this paper, we describe the design, implementation, and preliminary evaluation of our prototype Personal Proxy, a service that integrates Internet and telephone communication and addresses the need for person-to-person reachability.", URL="http://www.usenix.org/publications/library/proceedings/usits99/roussopoulos.html", } @INPROCEEDINGS{Anup9910:User, AUTHOR="Vinod Anupam and David Kristol and Alain Mayer", TITLE="A User's and Programmer's View of the New JavaScript Security Model", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=11, ABSTRACT="In this paper we introduce a new security model for JavaScript in Mozilla, as well as its programming interface. We present important concepts via examples from electronic commerce applications. We also describe our experience of implementing the model in the publicly available Mozilla source code. This model is likely to be integrated into Navigator 5.0, which, as of this writing, is scheduled to be released in late fall, 1999.", URL="http://www.usenix.org/publications/library/proceedings/usits99/anupam.html", } @INPROCEEDINGS{Bahn9910:Using, AUTHOR="Hyokyung Bahn and Sam Noh and Kern Koh and Sang Min", TITLE="Using Full Reference History for Efficient Document Replacement in Web Caches", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=15, ABSTRACT="With the increase in popularity of the World Wide Web, the research community has recently seen a proliferation of Web caching algorithms. This paper presents a new such algorithm, that is efficient and robust, called Least Unified-Value (LUV). LUV evaluates a Web document based on its cost normalized by the likelihood of it being re-referenced. This results in a normalized assessment of the contribution to the value of a document, leading to a fair replacement policy. LUV can conform to arbitrary cost functions of Web documents, so it can optimize any particular performance measure of interest, such as the hit rate, the byte hit rate, or the delay-savings ratio. Unlike most existing algorithms, LUV exploits complete reference history of documents, in terms of reference frequency and recency, to estimate the likelihood of being re-referenced. Nevertheless, LUV allows for an efficient implementation in both space and time complexities. The space needed to maintain the reference history of a document is only a few bytes and furthermore, the time complexity of the algorithm is O(log\_2 n), where n is the number of documents in the cache. Trace-driven simulations show that the LUV algorithm outperforms existing algorithms for various performance measures for a wide range of cache configurations.", URL="http://www.usenix.org/publications/library/proceedings/usits99/bahn.html", } @INPROCEEDINGS{Barn9910:Providing, AUTHOR="Julie Barnes and R. Pandey", TITLE="Providing Dynamic and Customizable Caching Policies", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=25, ABSTRACT="Web caching has emerged as one solution for improving client latency on the web. Cache effectiveness depends on the policies used to route requests to other caches and servers, to maintain up-to-date web objects and to remove objects from the cache. Traditional caches apply one set of policies, which determines the efficiency as well as the effectiveness of the caches. This set of policies often does not exploit the diversity inherent in different web objects, caches and clients. Policies that do exploit this diversity result in convoluted caching policies that attempt to combine multiple policies and guess at the unknown characteristics of web objects, caches and clients. In this paper, we present an extensible caching infrastructure in which cache administrators, servers, and end users can customize how web objects are cached, replaced, and kept consistent. The infrastructure includes a domain-specific language, CacheL, for defining customizable caching policies that can be changed dynamically. Analysis of our prototype, PoliSquid, shows the benefits of the infrastructure for variable coherency policies, localized removal policies, and early removal of objects from servers.", URL="http://www.usenix.org/publications/library/proceedings/usits99/barnes.html", } @INPROCEEDINGS{Smit9910:Exploiting, AUTHOR="Babington Smith and Arup Acharya and T. Yang and H. Zhu", TITLE="Exploiting Result Equivalence in Caching Dynamic Web Content", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=25, ABSTRACT="Caching is currently the primary mechanism for reducing the latency as well as bandwidth requirements for delivering Web content. Numerous techniques and tools have been proposed, evaluated and successfully used for caching static content. Recent studies show that requests for dynamic web content also contain substantial locality for identical requests. In this paper, we classify locality in dynamic web content into three kinds: identical requests, equivalent requests, and partially equivalent requests. Equivalent requests are not identical to previous requests but result in generation of identical dynamic content. The documents generated for partially equivalent requests are not identical but can be used as temporary place holders for each other while the real document is being generated. We present a new protocol, which we refer to as Dynamic Content Caching Protocol (DCCP), to allow individual content generating applications to exploit query semantics and specify how their results should be cached and/or delivered. We illustrate the usefulness of DCCP for several applications and evaluate its effectiveness using traces from the Alexandria Digital Library and NASA Kennedy Center as case studies.", URL="http://www.usenix.org/publications/library/proceedings/usits99/smith.html", } @INPROCEEDINGS{Yang9910:Efficient, AUTHOR="C.-L. Yang and Mon-Yen Luo", TITLE="Efficient Support for Content-Based Routing in Web Server Clusters", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=56, ABSTRACT="Clustered server architectures have been employed for many years on the Internet as a way to increase performance, reliability and scalability in the presence of the Internet's explosive growth. A routing mechanism for mapping requests to individual servers within cluster is at the heart of any server clustering techniques. In this paper, we first analyze the deficiencies of existing request-routing approaches. Based on these observations, we argue that the request routing mechanism in a cluster-based server should factor in the content of a request in making decisions. Thus, we designed and implemented a new mechanism to efficiently support content-aware routing in Web server clusters. With this mechanism, we also built in a number of sophisticated content-aware intelligence for making routing decision. Performance evaluation on a prototype implementation demonstrates substantial performance improvements over contemporary routing schemes. The proposed mechanism can also enable many new capabilities in cluster-based servers, such as sophisticated load balancing, differentiated service, special content deployment, session integrity, etc.", URL="http://www.usenix.org/publications/library/proceedings/usits99/yang.html", } @INPROCEEDINGS{LeFe9910:Rapid, AUTHOR="William LeFebvre and Ken Craig", TITLE="Rapid Reverse {DNS} Lookups for Web Servers", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=11, ABSTRACT="When a web server wants to learn the domain name of one of its clients, it must perform a lookup in the Domain Name System's ``reverse domain'', in-addr.arpa . These lookups can take time and may have an adverse impact on the web server's response to its clients. Rapid DNS is an intermediate client/server system that operates between a web server and a DNS server. It provides caching of the results and, more importantly, limits web server lookups to the data contained in the cache. This provides a significant improvement in response time for situations in which knowledge of the hostname is not critical to the web server's operation. The Rapid DNS system was implemented for use in the web farm that serves the collection of Cable News Network (CNN) sites. Its design is presented, along with measurements of its performance in the CNN environment.", URL="http://www.usenix.org/publications/library/proceedings/usits99/lefebvre.html", } @INPROCEEDINGS{Crov9910:Connection, AUTHOR="Mark Crovella and Robert Frangioso and Mor Harchol-Balter", TITLE="Connection Scheduling in Web Servers", BOOKTITLE="2nd USENIX Symposium on Internet Technologies and Systems", ADDRESS="Boulder, Colorado, USA", DAYS=11, MONTH="Oct", YEAR=1999, REFERENCES=18, ABSTRACT="Under high loads, a Web server may be servicing many hundreds of connections concurrently. In traditional Web servers, the question of the order in which concurrent connections are serviced has been left to the operating system. In this paper we ask whether servers might provide better service by using non-traditional service ordering. In particular, for the case when a Web server is serving static files, we examine the costs and benefits of a policy that gives preferential service to short connections. We start by assessing the scheduling behavior of a commonly used server (Apache running on Linux) with respect to connection size and show that it does not appear to provide preferential service to short connections. We then examine the potential performance improvements of a policy that does favor short connections (shortest-connection-first). We show that mean response time can be improved by factors of four or five under shortest-connection-first, as compared to an (Apache-like) size-independent policy. Finally we assess the costs of shortest- connection-first scheduling in terms of unfairness (i.e., the degree to which long connections suffer). We show that under shortest-connection- first scheduling, long connections pay very little penalty. This surprising result can be understood as a consequence of heavy-tailed Web server workloads, in which most connections are small, but most server load is due to the few large connections. We support this explanation using analysis.", URL="http://www.usenix.org/publications/library/proceedings/usits99/crovella.html", } @TECHREPORT{Lenn9901:Implementing, AUTHOR="J. Lennox and Henning Schulzrinne and Thomas La Porta", TITLE="Implementing Intelligent Network Services with the Session Initiation Protocol", TYPE="Technical Report", INSTITUTION="Columbia University", ADDRESS="New York, New York", NUMBER="CUCS-002-99", MONTH=jan, YEAR=1999, REFERENCES=11, KEYWORDS="Internet telephony; signaling; SIP; intelligent network", ABSTRACT="Internet telephony is receiving increasing interest as an alternative to traditional telephone networks. This article shows how the IETF's Session Initiation Protocol (SIP) can be used to perform the services of traditional Intelligent Network protocols, as well as additional services.", URL="ftp://ftp.cs.columbia.edu/reports/reports-1999/cucs-002-99.ps.gz", } @TECHREPORT{Sund9901:Schouter, AUTHOR="Jim Sundqvist", TITLE="Schouter - an {IP} network emulator", TYPE="Technical Note", INSTITUTION="Ericsson EPL", ADDRESS="Stockholm, Sweden", NUMBER="EPL/T/R-99:006", MONTH=jan, YEAR=1999, KEYWORDS="network emulator", ABSTRACT="This document describes the schouter, a point-to-point IP network emulator which produces a repeatable behavior of an IP network. It is used for evaluation of IP related technologies.", } @ARTICLE{Krun9901:Bandwidth, AUTHOR="Marwan Krunz", TITLE="Bandwidth Allocation Strategies for Transporting Variable-Bit-Rate Video Traffic", JOURNAL=ieeecm, VOLUME=37, NUMBER=1, PAGES="40-46", MONTH=jan, YEAR=1999, REFERENCES=10, ABSTRACT="Large-scale deployment and successful commercialization of digital video services over computer networks strongly depend on the cost effectiveness of these services. Network bandwidth is one of the major factors that impact the cost of a video service. In this article we survey various approaches to reducing the bandwidth requirement for transporting compressed video traffic over high-speed networks.", URL="http://207.127.135.8/ci1/private/1999/jan/Krunz.html", } @ARTICLE{Sahi9901:Self, AUTHOR="Z. Sahinoglu and S. Tekinay", TITLE="Self-Similar Traffic and Network Performance", JOURNAL=ieeecm, VOLUME=37, NUMBER=1, PAGES="48-52", MONTH=jan, YEAR=1999, REFERENCES=10, ABSTRACT="The main objective in telecommunications network engineering is to have as many happy users as possible. In other words, the network engineer has to resolve the trade-off between capacity and QoS requirements. Accurate modeling of the offered traffic load is the first step in optimizing resource allocation algorithms such that provision of services complies with the QoS constraints while maintaining maximum capacity. In recent years, as broadband multimedia services became popular, they necessitated new traffic models with self-similar characteristics. In this article we present a survey of the self-similarity phenomenon observed in multimedia traffic and its implications on network performance. Our current research aims to fill the gap between this new traffic model and network engineering. An immediate consequence of this study is the demonstration of the limitations or validity of conventional resource allocation methods in the presence of self-similar traffic.", URL="http://207.127.135.8/ci1/private/1999/jan/Tekinay.html", } @ARTICLE{Kuo9901:Achieving, AUTHOR="G.-S. Kuo and Po-Chang Ko", TITLE="Achieving Minimum Slice Loss for Real-Time {MPEG-2-Based} Video Networking in a Flow-Oriented Input-Queued {ATM} Switching Router System", JOURNAL=ieeecm, VOLUME=37, NUMBER=1, PAGES="58-62", MONTH=jan, YEAR=1999, REFERENCES=15, ABSTRACT="Since the slice is the basic reconstruction unit at the display device, the MPEG-2-based video traffic in an ATM network is treated as many slice flows. For a real-time MPEG-2-based video service, the most important restriction is that all cells in a slice flow must be transmitted to their destination node completely before the deadline; otherwise, they should be dropped totally. The main purpose of this article is to propose a flow-oriented input-queued ATM switching router architecture with a scheduling strategy, MCL-MSL, taking advantage of the above characteristics to achieve higher-quality video services and more efficient utilization of network bandwidth. If the needed bandwidth for transmitting slice flows exceeds the available network bandwidth, MCL-MSL selects the slice flow with minimum slice loss for transmission. Furthermore, if multiple choices exist, it selects the one with maximum cell loss among them to achieve the most efficient bandwidth utilization.", URL="http://207.127.135.8/ci1/private/1999/jan/Kuo.html", } @ARTICLE{Rabb9901:QoS, AUTHOR="R. Rabbat and K.-Y. Siu", TITLE="{QoS} Support for Integrated Services over {CATV}", JOURNAL=ieeecm, VOLUME=37, NUMBER=1, PAGES="64-68", MONTH=jan, YEAR=1999, REFERENCES=7, ABSTRACT="Cable TV has recently emerged as a promising access network infrastructure for the delivery of voice, video, and high-speed data traffic. A central issue in the design of protocols for CATV networks is to support different levels of QoS for diverse user applications. While CATV service providers and equipment have standardized, in the so-called MCNS protocol, the basic network architecture and interfaces, issues in the MAC layer for QoS support are likely to be left for differentiation in vendor products. This article first presents an overview of the basic CATV network architectural assumptions and the set of QoS requirements for supportig integrated services over CATV. It then discusses a MAC-layer scheduling protocol that can efficiently multiplex constant bit rate traffic, such as voice over IP with guaranteed delay bound, and best-effort traffic, such as data services with minimum bit rate guarantee, while achieving fairness on any excess available bandwidth. The performance of this algorithm is illustrated by simulation results using Opnet. We also discuss a dynamic polling mechanism that enhances the link utilization while preserving delay bounds for latency-critical traffic.", URL="http://207.127.135.8/ci1/private/1999/jan/Rabbat.html", } @ARTICLE{Mint9901:Developing, AUTHOR="Fred Mintzer", TITLE="Developing Digital Libraries of Cultural Content for {Internet} Access", JOURNAL=ieeecm, VOLUME=37, NUMBER=1, PAGES="72-78", MONTH=jan, YEAR=1999, REFERENCES=10, ABSTRACT="Over the past five years, interest in digital libraries and in the World Wide Web have both greatly increased as the result of a symbiotic relationship. For an even longer period, my IBM colleagues and I have been developing online digital libraries for cultural institutions. In this article, selected aspects of projects with the Vatican Library, the National Gallery of Art (United States), the Klau Library of Hebrew Union College, and Russia's State Hermitage Museum are reported. In these projects, both technical and institutional challenges were met. Three technical challenges are discussed: protecting the intellectual property rights of institutions to their online materials, producing high-quality images with data sizes that are suitable for Internet delivery, and achieving significant capture throughput. Finally, some opinions are offered on the outlook for digital libraries of cultural content.", URL="http://207.127.135.8/ci1/private/1999/jan/Mintzer.html", } @ARTICLE{Wong9901:Digital, AUTHOR="Stephen T. C. Wong and Donny A. Tjandra", TITLE="A Digital Library for Biomedical Imaging on the {Internet}", JOURNAL=ieeecm, VOLUME=37, NUMBER=1, PAGES="84-91", MONTH=jan, YEAR=1999, REFERENCES=12, ABSTRACT="Traditional medical image management systems, such as picture and archiving communication systems, are based on specialized workstations and closed systems architecture. Internet technology is being explored for the efficient and cost-effective distribution of biomedical images. This article discusses new issues of a digital library for medical imaging, presents two different architectures for a Web-based medical imaging library, and illustrates their utilization with implemented examples.", URL="http://207.127.135.8/ci1/private/1999/jan/Tjandra.html", } @ARTICLE{Smit9901:Digital, AUTHOR="Jr. Smith", TITLE="Digital Video Libraries and the {Internet}", JOURNAL=ieeecm, VOLUME=37, NUMBER=1, PAGES="92-97", MONTH=jan, YEAR=1999, REFERENCES=10, ABSTRACT="Digital video libraries are positioned to be a major driving application for the Next Generation Internet Initiative. Likewise, the advancements in the communications infrastructure will be of great benefit to digital video libraries. This report investigates some of the recent technologies for handling video in digital video libraries and reviews the NGII's planned advancements in network communications technologies in order to examine their impact on deploying digital video libraries on the Internet.", URL="http://207.127.135.8/ci1/private/1999/jan/Smith.html", } @ARTICLE{Ston9901:Image, AUTHOR="H. S. Stone", TITLE="Image Libraries and the {Internet}", JOURNAL=ieeecm, VOLUME=37, NUMBER=1, PAGES="99-106", MONTH=jan, YEAR=1999, REFERENCES=11, ABSTRACT="Digital imaging is becoming a major information resource within the Internet. Although image access tools are primitive today, they are evolving rapidly. In this article we look at content descriptor-based and pixel-based image queries for accessing large image libraries. The access methods will be combined and enhanced in future retrieval systems.", URL="http://207.127.135.8/ci1/private/1999/jan/Stone.html", } @ARTICLE{Wein9901:Agent, AUTHOR="Peter C. Weinstein and William P. Birmingham and Edmund H. Durfee", TITLE="Agent-Based Digital Libraries: Decentralization and Coordination", JOURNAL=ieeecm, VOLUME=37, NUMBER=1, PAGES="110-115", MONTH=jan, YEAR=1999, REFERENCES=14, ABSTRACT="This article describes agent-based systems and explains why digitallibraries should be built with this type of architecture. The primary advantage of agent-based architecture is decentralization, which enables scaling, flexibility, and extensibility. The corresponding requirement is the need to coordinate agent activity. We describe the approach taken by the University of Michigan Digital Library project.", URL="http://207.127.135.8/ci1/private/1999/jan/Weinstein.html", } @ARTICLE{Call9901:Packet, AUTHOR="F. Callegati and M. Casoni and Carla Raffaelli and B. Bostica", TITLE="Packet Optical Networks for High-Speed {TCP-IP} Backbones", JOURNAL=ieeecm, VOLUME=37, NUMBER=1, PAGES="124-129", MONTH=jan, YEAR=1999, REFERENCES=10, ABSTRACT="This article presents a new proposal for TCP-IP backbone implementation based on optical packet switching technology. The proposed network architecture merges the flexibility in resource management of packet switching with the high capacity offered by full optical technology.", URL="http://207.127.135.8/ci1/private/1999/jan/Casoni.html", } @ARTICLE{Dixi9901:Data, AUTHOR="Sudhir Dixit", TITLE="Data Rides High on High-Speed Remote Access", JOURNAL=ieeecm, VOLUME=37, NUMBER=1, PAGES="130-141", MONTH=jan, YEAR=1999, REFERENCES=5, ABSTRACT="Internet and remote access services are growing by leaps and bounds, and major efforts are currently underway to provide greater bandwidth to the user by a multitude of access technologies, both wired and wireless. This article discusses the key access technologies currently being developed by vendors and deployed by service providers. It is expected that xDSL, cable data networks, and fixed and mobile wireless networks will be the hotbeds of tough competition, while direct satellite networks will hover over them with the potential to completely change the way the access networks are built. Irrespective of the ongoing debate on which technology would win or loose, in the world of real networks different access solutions will coexist, finding their own niches to meet the varying demands of performance and cost objectives for the end user.", URL="http://207.127.135.8/ci1/private/1999/jan/Dixit.html", } @TECHREPORT{Jian9901:Detecting, AUTHOR="W. Jiang", TITLE="Detecting and Measuring Asymmetric Links in an {IP} Network", TYPE="Technical Report", INSTITUTION="Columbia University", ADDRESS="New York, New York", NUMBER="CUCS-009-99", MONTH=jan, YEAR=1999, REFERENCES=8, KEYWORDS="Network measurement; bandwidth measurement; asymmetric link", ABSTRACT="The rapid growth of the Web has caused a lot of congestion in the Internet. Pinpointing bottle- necks in a network is very helpful in congestion control and performance tuning. Measuring link bandwidths can help identifying such bottlenecks. Existing tools for bandwidth measurement like Pathchar, Bing and Bprobe assume symmetric links. Hence their results will be incomplete or incorrect in the presence of asymmetric links. It becomes important to consider asymmetric links, as they are gaining popularity in recent years. Examples are ADSL lines, Cable modems, Satellite links, and 56K modems. In this paper, we present an algorithm that can measure each hop's link bandwidth in both directions in an IP network. Therefore, it is trivial to detect asymmetry of a link. We performed several experiments to validate our algorithm. We also discuss some factors that can adversely a ect the precision and/or correctness of bandwidth measurement, and suggest possible solutions.", URL="ftp://ftp.cs.columbia.edu/reports/reports-1999/cucs-009-99.ps.gz", } @ARTICLE{Valk9901:Cellular, AUTHOR="András G. Valkó", TITLE="Cellular {IP:} A New Approach to {Internet} Host Mobility", JOURNAL=ccr, VOLUME=29, NUMBER=1, PAGES="50-65", MONTH=jan, YEAR=1999, REFERENCES=16, KEYWORDS="mobile IP; mobility", ABSTRACT="This paper describes a new approach to Internet host mobility. We argue that by separating local and wide area mobility, the performance of existing mobile host protocols (e.g. Mobile IP) can be significantly improved. We propose Cellular IP, a new lightweight and robust protocol that is optimized to support local mobility but efficiently interworks with Mobile IP to provide wide area mobility support. Cellular IP shows great benefit in comparison to existing host mobility proposals for environments where mobile hosts migrate frequently, which we argue, will be the rule rather than the exception as Internet wireless access becomes ubiquitous. Cellular IP maintains distributed cache for location management and routing purposes. Distributed paging cache coarsely maintains the position of 'idle' mobile hosts in a service area. Cellular IP uses this paging cache to quickly and efficiently pinpoint 'idle' mobile hosts that wish to engage in 'active' communications. This approach is beneficial because it can accommodate a large number of users attached to the network without overloading the location management system. Distributed routing cache maintains the position of active mobile hosts in the service area and dynamically refreshes the routing state in response to the handoff of active mobile hosts. These distributed location management and routing algorithms lend themselves to a simple and low cost implementation of Internet host mobility requiring no new packet formats, encapsulations or address space allocation beyond what is present in IP.", URL="http://www.acm.org/sigcomm/ccr/archive/1999/jan99/ccr-9901-valko.html", } @TECHREPORT{Bagc9901:Voice, AUTHOR="A. Bagchi", TITLE="Voice over Packet in Next Generation Networks: An architectural Framework", TYPE="Special Report", INSTITUTION="Bellcore", ADDRESS="Red Bank, New Jersey", NUMBER="SR-4717", MONTH=jan, YEAR=1999, KEYWORDS="voice over packet; VoIP; packet voice", } @TECHREPORT{Fran9901:IN, AUTHOR="France Telecom", TITLE="{IN} and {H.323}", INSTITUTION="European Telecommunications Standards Institute", ADDRESS="Sophia Antipolis, France", NUMBER="ETSI STC SPS3", MONTH=jan, YEAR=1999, KEYWORDS="Intelligent network; Internet telephony; H.323; call model", ABSTRACT="In a previous contribution it was proposed that SPS3 studies the mapping of IN models and protocols to H.323 telephony. This document further elaborates on this topic.", } @ARTICLE{Zhen9901:Traffic, AUTHOR="B. Zheng and M. Atiquzzaman", TITLE="Traffic Management of Multimedia over {ATM} Networks", JOURNAL=ieeecm, VOLUME=37, NUMBER=1, PAGES="33-38", MONTH=jan, YEAR=1999, REFERENCES=11, KEYWORDS="Multimedia transmission; traffic management; ATM Networks", ABSTRACT="Multimedia is characterized by bursty traffic and often with stringent real-time constraints. Multimedia traffic requires quality of service guarantees. This gives rise to traffic management issues in order to obtain a high network utilization and quality of service guarantee to the multimedia stream. The aim of this paper is to present an overview of the traffic management issues and their possible solutions for transmission of multimedia over Asynchronous Transfer Mode networks.", URL="http://www.engr.udayton.edu/faculty/matiquzz, http://207.127.135.8/ci1/private/1999/jan/Atiqu.html", } @TECHREPORT{Albe9901:Annual, AUTHOR="R. Albers", TITLE="Annual Report 1998", TYPE="Report", INSTITUTION="Network Reliability Steering Committee, Alliance for Telecommunications Industry Solutions", ADDRESS="Washington, DC", MONTH=jan, YEAR=1999, KEYWORDS="telephone system; reliability; outages", ABSTRACT="This Annual Report reviews the health of the wireline public telecommunications network during the past year. It also covers the six years since the beginning of our reporting process: six years in which all segments of our industry have cooperated closely in the common cause of reliable service to the American public.", URL="http://www.atis.org/atis/nrsc/view.htm", } @TECHREPORT{Sipu9901:Virtual, AUTHOR="Michael J. Sipusic and Robert L. Pannoni and Randall B. Smith and John Dutra and Jonathan Gibbons and William R. Sutherland", TITLE="Virtual Collaborative Learning: A Comparison between Face-to-Face Tutored Video Instruction {(TVI)} and Distributed Tutored Video Instruction {(DTVI)}", TYPE="Technical Report", INSTITUTION="Sun Microsystems Research", NUMBER="TR-99-72", MONTH=jan, YEAR=1999, KEYWORDS="distance learning", ABSTRACT="Tutored Video Instruction (TVI) is a collaborative learning methodology in which a small group of students studies a videotape of a lecture. We constructed a fully virtual version of TVI called Distributed Tutored Video Instruction (DTVI), in which each student has a networked computer with audio microphone-headset and video camera to support communication within the group. In this report, we compare survey questionnaires, observations of student interactions, and grade outcomes for students in the face-to-face TVI condition with those of students in the DTVI condition. Our analysis also includes comparisons with students in the original lecture. This two and a half year study involved approximately 700 students at two universities. Despite finding a few statistically significant process differences between TVI and DTVI, the interactions were for the most part quite similar. Course grade outcomes for TVI and DTVI were indistinguishable, and these collaborative conditions proved better than lecture. We conclude that this kind of highly interactive virtual collaboration can be an effective way to learn.", URL="http://www.sun.com/research/techrep/1999/abstract-72.html", } @ARTICLE{Srir9901:Anomalies, AUTHOR="K. Sriram and Terry G. Lyons and Yixin Wang", TITLE="Anomalies Due to Delay and Loss in {AAL2} Packet Voice Systems: Performance Models and Methods of Mitigation", JOURNAL=ieeejsac, VOLUME=17, NUMBER=1, PAGES="4-17", MONTH=jan, YEAR=1999, REFERENCES=17, ABSTRACT="This paper investigates the packet delay variation and packet loss probabilities to be expected in typical applications of voice trunking using ATM adaptation layer type 2 (AAL2) and the consequences these may have, such as the need for sequence numbers in voice packet headers. Simulations have been run for the case of 32-kb/s ADPCM encoded voice across a physical link whose bandwidth is 1/4, 1/2, or 1 times DS1 (1.536 Mb/s). The results show the number of calls that can be admitted while meeting the ninety-ninth percentile queuing delay objective of 20 ms or less. The delay budget that can be allocated to packet queuing delay at access is about 20 ms, given a one-way end-to-end delay budget of 100 to 150 ms for conversational voice. The number of calls is also limited so that the ratio of late or lost packets does not exceed 10^{-3}. Voice quality is known to be tolerant to packet losses of up to one in 100. When the packet delay variation is significant, as it threatens to be in this situation, sequence numbers can help a receiver to detect and to recover from anomalies--lost, early, or late packets--and make fewer reconstruction errors than if sequence numbers were absent or ignored. Three circumstances are identified where packet slips can occur with ripple effects. An analysis of these cases leads to lower bounds on the sequence number modulus. The appropriate value of the sequence number modulus depends on the desired call load and performance objectives, and can be deduced from the results presented in this paper.", } @ARTICLE{Srir9901:Voice, AUTHOR="K. Sriram and Yixin Wang", TITLE="Voice over {ATM} Using {AAL2} and Bit Dropping: Performance and Call Admission Control", JOURNAL=ieeejsac, VOLUME=17, NUMBER=1, PAGES="18-28", MONTH=jan, YEAR=1999, REFERENCES=23, ABSTRACT="Asynchronous transfer mode (ATM) adaptation layer 2 (AAL2) has been designed for efficient transport of voice, fax, and voiceband data (VBD) traffic over an ATM virtual circuit. The protocol helps achieve low latency and high bandwidth efficiency while applying suitable compression methods on voice/VBD/fax calls and silence elimination on voice calls. We analyze the performance and capacity of an ATM multiplexer based on AAL2 adaptation. We assume that embedded adaptive differential pulse code modulation (ADPCM) is used to compress voice, and silence elimination is used to achieve statistical multiplexing gain. The embedded ADPCM coding scheme allows selective dropping of less significant bits of voice during congestion in the ATM/AAL2 multiplexer. We compare the call capacities of voice multiplexers with and without bit dropping (BD). The performance models and results presented here are based on fairly general assumptions and can be used for traffic engineering and call admission contriol in land-line or wireless ATM systems for a variety of voice/voiceband compression algorithms. A generalized algorithm for call admission control is also described.", } @ARTICLE{Tien9901:Intelligent, AUTHOR="P. L. Tien and Maria C. Yuang", TITLE="Intelligent Voice Smoother for Silence-Suppressed Voice over {Internet}", JOURNAL=ieeejsac, VOLUME=17, NUMBER=1, PAGES="29-41", MONTH=jan, YEAR=1999, REFERENCES=21, ABSTRACT="When transporting voice data with silence suppression over the Internet, the problem of jitter introduced from the network often renders the speech unintelligible. It is thus indispensable to offer intramedia synchronization to remove jitter while retaining minimal playout delay (PD). In this paper, we propose a neural network (NN)-based intravoice synchronization mechanism, called the intelligent voice smoother (IVoS). IVoS is composed of three components: 1) the smoother buffer; 2)the NN traffic predictor; and 3) the constant bit rate (CBR) enforcer. Newly arriving frames, assumed to follow a generic Markov modulated Bernoulli process (MMBP), are queued in the smoother buffer. The NN traffic predictor employs an online-trained back propagation NN (BPNN) to predict three traffic characteristics of ever newly encountered talkspurt period. Based on the predicted characteristics, the CBR enforcer derives an adaptive buffering delay (ABD) by means of a near-optimal simple closed-form formula. It then imposes the delay on the playout of the first frame in the talkspurt period. The CBR enforcer in turn regulates CBR-based departures for the remaining frames of the talkspurt, aiming at assuring minimal mean and variance of distortion of talkspurts (DOT) and mean PD. Simulation results reveal that, compared to three other playout approaches, IVoS achieves superior playout, yielding negligible DOT and PD, irrespective of traffic variation.", } @ARTICLE{Chan9901:Reservation, AUTHOR="Hsun-Hung Chan and S.-H. Leung", TITLE="Reservation Arbitrated Access for Statistical Multiplexing Voice Traffic over Dual-Bus Metropolitan Area Networks", JOURNAL=ieeejsac, VOLUME=17, NUMBER=1, PAGES="42-50", MONTH=jan, YEAR=1999, REFERENCES=18, ABSTRACT="Metropolitan area networks (MAN's) are well suited to serve as broadband multiplexers for asynchronous transfer mode (ATM) networks, to facilitate enterprise networking and to support future wireless personal communication systems. We propose and analyze a novel reservation arbitrated (RA) access method which provides isochronous voice transport over dual-bus MAN's while enabling statistical multiplexing among voice calls. In combination with a new cyclic capturing (CC) mechanism, RA access allows stations to capture and reserve isochronous voice channels in a fair and distributive manner. This paper presents the RA access protocol, derives an analytical model for general waste-free voice reservation protocols, and analyzes the performance of RA access by computer simulations validated by analytical calculations. To assess the actual voice quality, simulation results based on a real voice signal are also presented. Results indicate that RA access offers significant improvements in channel utilization, as compared to prearbitrated (PA) access, while providing an acceptable quality of service. Therefore, RA access offers an efficient voice transport mechanism for existing switched multimegabit data service (SMDS) networks employing the IEEE 802.6 protocol, as well as emerging ATM/MAN-based broadband networks.", } @ARTICLE{Poch9901:Efficient, AUTHOR="Herve Le Pocher and Victor C. M. Leung and Duncan Gillies", TITLE="An Efficient {ATM} Voice Service with Flexible Jitter and Delay Guarantees", JOURNAL=ieeejsac, VOLUME=17, NUMBER=1, PAGES="51-62", MONTH=jan, YEAR=1999, REFERENCES=29, ABSTRACT="A transmission and multiplexing strategy appropriate for voice over asynchronous transfer mode (ATM), called delayed frame queueing (DFQ), is proposed. This frame-based strategy has features in common with the synchronous transfer mode and is thus well suited to service synchronous applications such as voice, while retaining the statistical multiplexing capabilities of ATM. In particular, the DFQ service discipline can provide explicit and nontrivial bounds for queue delay and jitter, for both bursty as well as continuous traffic streams. Furthermore, the DFQ discipline can combine a wide range of delay and jitter bounds while also managing the distribution of quality of service violations among the traffic streams when congestion occurs. Jitter control is performed at the network periphery and thus does not negatively influence multiplexing gain at intermediate nodes. This efficient strategy has major implications in terms of the preferred alternatives chosen by clients when implementing source clock recovery for voice. DFQ allows the entire range of implementation alternatives for voice over ATM to be appropriately serviced, such as ATM adaptation layer types 1 and 2 (AAL1/2), adaptive playout, and immediate playout.", } @ARTICLE{Beri9901:ATM, AUTHOR="F. Beritelli and A. Lombardo and S. Palazzo and G. Schembra", TITLE="Performance Analysis of an {ATM} Multiplexer Loaded with {VBR} Traffic Generated by Multimode Speech Coders", JOURNAL=ieeejsac, VOLUME=17, NUMBER=1, PAGES="63-81", MONTH=jan, YEAR=1999, REFERENCES=27, ABSTRACT="Multimode coders are able to exploit the different characteristics of the speech waveform and to take into account the different peculiarities of background noise, thus allowing improvements in both signal reconstruction and network-offered load. In this context the variable rate code excited linear prediction (VR-CELP) coding, that is, a multimode variable bit rate (VBR) coding based on the CELP technique, has been introduced in the literature and is currently being considered for use in various applications, especially in the third-generation UMTS cellular systems. The target of the paper is to introduce an efficient and accurate framework allowing a network designer to analyze the impact of multimode VBR speech coding on the quality of service (QoS) provided by a wireless/wired ATM network. In order to capture the coder output characteristics, we propose to model a VR-CELP voice source by using a switched batch Bernoulli process (SBBP). More specifically, three models are introduced and compared in terms of accuracy and simplicity in determining network performance. As a result of the comparison, a four-state model has been chosen as the best tradeoff. The model is then used to analytically derive the loss probability and the jitter probability density function of an ATM multiplexer loaded by a number of VR-CELP sources. Finally, the proposed paradigm has been assessed in a case study where we demonstrate that, for a given output ATM link capacity and for a number of telecommunication services involving voice transmission, VR-CELP coding performs better than traditional ON-OFF coding.", } @ARTICLE{Diga9901:Quantization, AUTHOR="Vassilios V. Digalakis and Leonardo G. Neumeyer and Manolis Perakakis", TITLE="Quantization of Cepstral Parameters for Speech Recognition over the World Wide Web", JOURNAL=ieeejsac, VOLUME=17, NUMBER=1, PAGES="82-90", MONTH=jan, YEAR=1999, REFERENCES=14, ABSTRACT="We examine alternative architectures for a client-server model of speech-enabled applications over the World Wide Web (WWW). We compare a server-only processing model where the client encodes and transmits the speech signal to the server, to a model where the recognition front end runs locally at the client and encodes and transmits the cepstral coefficients to the recognition server over the Internet. We follow a novel encoding paradigm, trying to maximize recognition performance instead of perceptual reproduction, and we find that by transmitting the cepstral coefficients we can achieve significantly higher recognition performance at a fraction of the bit rate required when encoding the speech signal directly. We find that the required bit rate to achieve the recognition performance of high-quality unquantized speech is just 2000 bits per second.", } @ARTICLE{Aner9901:TOPS, AUTHOR="N. G. Anerousis and R. Gopalakrishnan and C. R. Kalmanek and A. Kaplan and W. T. Marshall and P. Mishra and P. Z. Onufryk and Kadangode K. Ramakrishnan", TITLE="{TOPS:} An Architecture for Telephony over Packet Networks", JOURNAL=ieeejsac, VOLUME=17, NUMBER=1, PAGES="91-108", MONTH=jan, YEAR=1999, REFERENCES=22, ABSTRACT="Packet telephony is of increasing interest in both the telecommunications and internet communities. The emergence of packet telephony will create new services, and presents an opportunity to rethink how conventional telephony services are implemented. In this paper, we present an architecture for telephony over packet networks (TOPS). TOPS allows users to move between terminals or to use mobile terminals while being reachable by the same name. TOPS users can have multiple terminals and control how calls are routed to them. TOPS allows for terminals with a range of capabilities such as support for video, whiteboard, and other media with a variety of coding formats. TOPS retains the necessary information on terminal capabilities to determine the appropriate type of communication to be established with the remote terminal. The architecture assumes that the underlying network supports the establishment of end-to-end connectivity between terminals, with an appropriate quality of service. The components of TOPS are a directory service, an application layer signaling protocol, and a logical channel abstraction for communication between end-systems. The directory service maps a user's name to a set of terminals where the user may be reached. A user can control the translation operation by specifying profiles that customize how his name is mapped to a set of terminals where he can be reached. Terminal capabilities are also stored in the directory service. The application layer signaling protocol establishes and maintains call state between communicating terminals. The logical channel abstraction provides a shared end-to-end context for a call's constituent media and control streams, while isolating the applications from the details of the network transport mechanisms. In addition to supporting simple point-to-point calls, the architecture supports both centralized and decentralized conferencing. We also introduce a simple encapsulation format for voice.", } @ARTICLE{Valk9901:Voice, AUTHOR="Andras Valko and Andras Racz and György Fodor", TITLE="Voice {QoS} in Third-Generation Mobile Systems", JOURNAL=ieeejsac, VOLUME=17, NUMBER=1, PAGES="109-123", MONTH=jan, YEAR=1999, REFERENCES=51, ABSTRACT="In this paper we analyze voice quality and system performance in third-generation mobile communication systems. We argue that in these networks that are expected to integrate voice, data, and multimedia services, the transport network can no longer be considered as a lossless transparent traffic channel. Rather, proper dimensioning is needed even for plain voice services. Furthermore, the efficient utilization of the network resources shared by voice and data traffic requires sophisticated traffic management in the statistical multiplexing environment. The contribution of the paper is twofold: First, voice quality in the cellular transport network is analyzed and network dimensioning criteria are derived. Second, building on recent advances reported in the literature and taking into consideration current standardization activities, a joint performance model is established for the air interface (AI) and the transmission network (TN) allowing for the analysis of end-to-end service performance within a uniform framework. To demonstrate the applicability of this model, we point to some performance problems in the multiservice environment and suggest and evaluate traffic management actions to overcome these.", } @ARTICLE{Huan9901:Novel, AUTHOR="JianJang Huang and C.-L. Yang and Nai-Cheng Fang", TITLE="A novel congestion control mechanism for multicast real-time connections", JOURNAL=comcom, VOLUME=22, NUMBER=1, PAGES="56-72", MONTH=jan, YEAR=1999, KEYWORDS="Real-time; Stop- and -Go; MCF", ABSTRACT="Time framing strategies such as Stop-and-Go (S\&G) [Golestani S.J., Congestion-free transmission of real-time traffic of real-time traffic in packet networks, IEEE INFOCOM, 1990, pp.527-536; Golestani S.J., A framing strategy for congestion management, IEEE JSAC, 9(7), 1991, pp.1064-1077; Golestani S.J., Congestion-free communication in high-speed packet networks, IEEE Transactions on Communications, 39(12), 1991, pp.1802-1812; Golestani S.J., A stop-and-go queueing framework for congestion management, ACM SIGCOMM, 1992, pp.8-18] and Continuous Framing (CF) [Jau-Hsiung Huang, Biau-Jwo Tsaur, Continuous framing mechanism for congestion control in broadband networks, Computer Communications, 18(10), 1995, pp.718-724] are designed to support the end-to-end delay bound and jitter bound for unicast connections. Considering the features of real-time multicast connections, a new time framing mechanism named Multicast Continuous Framing (MCF) is proposed in this article. S\&G and CF allow only one time frame length per connection, but MCF allows changing of the time frame length of a connection at intermediate nodes so that the statistical multiplexing gain within a connection is increased, i.e., the bandwidth requirement can be reduced. We also present the multicast connection setup scheme for MCF in the article. Simulation results show that MCF has a much better performance than that of CF, and the tighter jitter bound a connection requests, the more performance improvement MCF can obtain.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/17/25/article.pdf", } @ARTICLE{Traj9901:Effect, AUTHOR="L. Trajkovic and A. Neidhardt", TITLE="Effect of Traffic Knowledge on the Efficiency of Admission- Control Policies", JOURNAL=ccr, VOLUME=29, NUMBER=1, MONTH=jan, YEAR=1999, REFERENCES=22, ABSTRACT="We investigate the importance of understanding traffic characteristics for admission-control policies in packet networks. We compare the network utilization achieved with admission policies based on a partial knowledge of admitted traffic against the utilization that could be achieved with complete knowledge of traffic characteristics. Our quantitative study demonstrates that for realistic traffic traces the level of traffic knowledge dramatically affects admission control and improves network utilization. Indeed, the knowledge of only a few elementary traffic characteristics can produce substantial improvement. Yet, at least for one trace, this improvement based on elementary traffic knowledge is modest in comparison with the improvement that could be produced with additional traffic knowledge and if traffic characterization on more than one time scale were available.", URL="http://www.acm.org/sigcomm/ccr/archive/1999/jan99/ccr-9901-trajkovic.ps", } @ARTICLE{Pier9901:Context, AUTHOR="Lyndon G. Pierson and E. L. Witzke and Mark O. Bean and Gerry J. Trombley", TITLE="Context-Agile Encryption for High Speed Communication Networks", JOURNAL=ccr, VOLUME=29, NUMBER=1, MONTH=jan, YEAR=1999, REFERENCES=23, ABSTRACT="Different applications have different security requirements for data privacy, data integrity, and authentication. Encryption is one technique that addresses these requirements. Encryption hardware, designed for use in high-speed communications networks, can satisfy a wide variety of security requirements if the hardware implementation is key-agile, key length-agile, mode-agile, and algorithm-agile. Hence, context-agile encryption provides enhanced solutions to the security, interoperability, and quality of service issues in high-speed networks. Moreover, having a single context-agile encryptor at an ATM aggregation point (such as a firewall) reduces hardware and administrative costs. While single-algorithm, key-agile encryptors exits, encryptors that are agile in a cryptographic robustness sense, are still research topics.", URL="http://www.acm.org/sigcomm/ccr/archive/1999/jan99/ccr-9901-pierson.ps", } @ARTICLE{Ng9901:MPEG, AUTHOR="Joseph Kee-Yin Ng", TITLE="{MPEG} Transmission Schemes for a Timed Token Medium Access Control Network", JOURNAL=ccr, VOLUME=29, NUMBER=1, MONTH=jan, YEAR=1999, REFERENCES=32, ABSTRACT="This paper presents three transmission schemes to improve the transmission of MPEG video over a timed token medium access control (MAC) network. Multiple classes of MPEG video are used in the study. These data captured from real video programmes and we categorized these video clips according to their traffic burstiness and workload characteristics. The performance measure of the timed token MAC network is in terms of the maximum number of MPEG video stream being transmitted without any frame missing its deadline. This simulation study observed that by employing the Regulated Scheme, we could improve the performance by 28 to 40\%. When applying the Group Scheme for the MPEG transmission, we can improve the performance between 142 and 149\%. When we combined the two schemes together, the Regulated Grouping Scheme can further improve the performance up to 153\% which is a dramatic improvement over the original transmission scheme.", URL="http://www.acm.org/sigcomm/ccr/archive/1999/jan99/ccr-9901-ng.ps", } @ARTICLE{Vivo9901:Internet, AUTHOR="Marco de Vivo and Gabriela de Vivo and Robert Koeneke and Germinal Isern", TITLE="{Internet} Vulnerability Related to {TCP/IP} and {T/TCP}", JOURNAL=ccr, VOLUME=29, NUMBER=1, MONTH=jan, YEAR=1999, REFERENCES=9, ABSTRACT="The internet put the rest of the world at the reach of our computers. In the same way it also made our computers reachable by the rest of the world. Good news and bad news! Over the last decade, the Internet has been subject to widespread security attacks. Besides the classical terms, new ones had to be found in order to designate a large collection of threats: Worms, break-ins, hackers, crackers, hijacking, phrackers, spoofing, man-in-the-middle, password-sniffing, denial-of- service, and so on. Since the Internet was born of academic efforts to share information, it never strove for high security measures. In fact in some of its components, security was consciously traded for easiness in sharing. Although the advent of electronic commerce has pushed for", } @ARTICLE{Hutc9901:Novel, AUTHOR="Ron Hutchins and Tray Camp and P. H. Enslow", TITLE="A Novel Approach to Mobility Management", JOURNAL=ccr, VOLUME=29, NUMBER=1, MONTH=jan, YEAR=1999, REFERENCES=31, ABSTRACT="In this paper, we propose a novel approach to computer mobility. Our approach allows mobility to be rapidly deployed, as the networking infrastructure required for deployment is available off the shelf. Furthermore, a mobile node does not require modifications in order to use these mobile services. While our approach provides rapid deployment and supports both IP and non-IP protocols, only a subset of mobile usage scenarios are offered. In other words, our approach does not solve all the problems of mobility. We discuss the characteristics of mobility usage, and we list the scenarios our approach supports. We believe that the mobile usage scenarios supported by this method are some of the more common usage scenarios. We also believe that investigations into this method will provide more insights into network and mobility research.", URL="http://www.acm.org/sigcomm/ccr/archive/1999/jan99/ccr-9901-hutchins.ps", } @ARTICLE{Camp9901:Open, AUTHOR="Andrew T Campbell and I. Katzela and Kazuho Miki and John Vicente", TITLE="Open Signaling for {ATM,} {Internet} and Mobile Networks {(OPENSIG'98)}", JOURNAL=ccr, VOLUME=29, NUMBER=1, MONTH=jan, YEAR=1999, REFERENCES=44, ABSTRACT="The ability to rapidly create and deploy new transport, control and management architectures in response to new service demands is a key factor driving the programmable networking community. Competition between service providers may hinge on the speed at which one providers may hinge on the speed at which one provider can respond to new market demands over another. The notion of open programmable networks is having broad impact on service providers and vendors across a range of telecommunication sectors calling for major advances in open network control architecture, network programmability and distributed systems technology. In this paper we discuss the origins of the Open Signalling Working Group (OPENSIG) and present a summary of the fifth Workshop on Open Signaling for ATM Internet and Mobile Networks (OPENSIG'98), which was held at the University of Toronto, Ontario, October, 1998. We also discuss a number of new initiatives in the area of open programmable networks that have recently emerged.", URL="http://www.acm.org/sigcomm/ccr/archive/1999/jan99/ccr-9901-campbell.ps", } @ARTICLE{Bier9901:Synchronized, AUTHOR="Ernst Biersack and W. Geyer", TITLE="Synchronized delivery and playout of distributed stored multimedia streams", JOURNAL=mms, VOLUME=7, NUMBER=1, PAGES="70-90", MONTH=jan, YEAR=1999, KEYWORDS="Multimedia streaming; Synchronization; multimedia streams; video server", ABSTRACT="Multimedia streams such as audio and video impose tight temporal constraints for their presentation. Often, related multimedia streams, such as audio and video, must be presented in a synchronized way. We introduce a novel scheme to ensure the continuous and synchronous delivery of distributed stored multimedia streams across a communications network. We propose a new protocol for synchronized playback and compute the buffer required to achieve both, the continuity within a single substream and the synchronization between related substreams. The scheme is very general and does not require synchronized clocks. Using a resynchronization protocol based on buffer level control, the scheme is able to cope with server drop-outs and clock drift. The synchronization scheme has been implemented and the paper concludes with our experimental results.", URL="http://www.link.springer.de/link/service/journals/00530/papers/9007001/90070070.pdf, http://www.eurecom.fr/~btroup", } @ARTICLE{Sahi9901:Multimedia, AUTHOR="Z. Sahinoglu and S. Tekinay", TITLE="On Multimedia Networks: Self-Similar Traffic and Network Performance", JOURNAL=ieeepcm, VOLUME=6, NUMBER=1, MONTH=jan, YEAR=1999, REFERENCES=10, ABSTRACT="The main objective in telecommunications network engineering is to have as many happy users as possible. In other words, the network engineer has to resolve the trade-off between capacity and QoS requirements. Accurate modeling of the offered traffic load is the first step in optimizing resource allocation algorithms such that provision of services complies with the QoS constraints while maintaining maximum capacity. In recent years, as broadband multimedia services became popular, they necessitated new traffic models with self-similar characteristics. In this article we present a survey of the self-similarity phenomenon observed in multimedia traffic and its implications on network performance. Our current research aims to fill the gap between this new traffic model and network engineering. An immediate consequence of this study is the demonstration of the limitations or validity of conventional resource allocation methods in the presence of self-similar traffic.", URL="http://www.comsoc.org/ci/private/1999/jan/Tekinay.html", } @ARTICLE{Sher9901:Electronic, AUTHOR="M. H. Sherif", TITLE="Electronic Commerce and Standardization", JOURNAL=ieeecm, VOLUME=37, NUMBER=1, MONTH=jan, YEAR=1999, REFERENCES=2, URL="http://www.comsoc.org/ci/private/1999/jan/standards.html", } @ARTICLE{Perk9901:Mobile, AUTHOR="C. E. Perkins", TITLE="Mobile networking in the {Internet}", JOURNAL="Mobile Networks and Applications", VOLUME=3, NUMBER=4, PAGES="319-334", MONTH=jan, YEAR=1999, REFERENCES=64, ABSTRACT="Computers capable of attaching to the Internet from many places are likely to grow in popularity until they dominate the population of the Internet. Consequently, protocol research has shifted into high gear to develop appropriate network protocols for supporting mobility. This introductory article attempts to outline some of the many promising and interesting research directions. The papers in this special issue indicate the diversity of viewpoints within the research community, and it is part of the purpose of this introduction to frame their place within the overall research area.", URL="http://www.baltzer.nl/monet/contents/3-4.html#mnt071", } @ARTICLE{Stem9901:Vertical, AUTHOR="M. Stemm and Randy H. Katz", TITLE="Vertical handoffs in wireless overlay networks", JOURNAL="Mobile Networks and Applications", VOLUME=3, NUMBER=4, PAGES="335-350", MONTH=jan, YEAR=1999, REFERENCES=28, ABSTRACT="No single wireless network technology simultaneously provides a low latency, high bandwidth, wide area data service to a large number of mobile users. Wireless Overlay Networks -- a hierarchical structure of room-size, building-size, and wide area data networks -- solve the problem of providing network connectivity to a large number of mobile users in an efficient and scalable way. The specific topology of cells and the wide variety of network technologies that comprise wireless overlay networks present new problems that have not been encountered in previous cellular handoff systems. We have implemented a vertical handoff system that allows users to roam between cells in wireless overlay networks. Our goal is to provide a user with the best possible connectivity for as long as possible with a minimum of disruption during handoff. Results of our initial implementation show that the handoff latency is bounded by the discovery time, the amount of time before the mobile host discovers that it has moved into or out of a new wireless overlay. This discovery time is measured in seconds: large enough to disrupt reliable transport protocols such as TCP and introduce significant disruptions in continuous multimedia transmission. To efficiently support applications that cannot tolerate these disruptions, we present enhancements to the basic scheme that significantly reduce the discovery time without assuming any knowledge about specific channel characteristics. For handoffs between room-size and building-size overlays, these enhancements lead to a best-case handoff latency of approximately 170 ms with a 1.5\% overhead in terms of network resources. For handoffs between building-size and wide-area data networks, the best-case handoff latency is approximately 800 ms with a similarly low overhead.", URL="http://www.baltzer.nl/monet/contents/3-4.html#mnt072", } @ARTICLE{Ccer9901:Fast, AUTHOR="Ramn Cßceres and Venkata N. Padmanabhan", TITLE="Fast and scalable wireless handoffs in support of mobile {Internet} audio", JOURNAL="Mobile Networks and Applications", VOLUME=3, NUMBER=4, PAGES="351-363", MONTH=jan, YEAR=1999, REFERENCES=38, ABSTRACT="Future internetworks will include large numbers of portable devices moving among small wireless cells. We propose a hierarchical mobility management scheme for such networks. Our scheme exploits locality in user mobility to restrict handoff processing to the vicinity of a mobile node. It thus reduces handoff latency and the load on the internetwork. Our design is based on the Internet Protocol (IP) and is compatible with the Mobile IP standard. We also present experimental results for the lowest level of the hierarchy. We implemented our local handoff mechanism on Unix-based portable computers and base stations, and evaluated its performance on a WaveLAN network. These experiments show that our handoffs are fast enough to avoid noticeable disruptions in interactive audio traffic. For example, our handoff protocol completes less than 10 milliseconds after a mobile node initiates it. Our mechanism also recovers from packet losses suffered during the transition from one cell to another. This work helps extend Internet telephony and teleconferencing to mobile devices that communicate over wireless networks.", URL="http://www.baltzer.nl/monet/contents/3-4.html#mnt073", } @ARTICLE{Chik9901:Multicast, AUTHOR="Vineet Chikarman and Carey Williamson and R. B. Bunt and Wayne L. Mackrell", TITLE="Multicast support for mobile hosts using Mobile {IP:} Design issues and proposed architecture", JOURNAL="Mobile Networks and Applications", VOLUME=3, NUMBER=4, PAGES="365-379", MONTH=jan, YEAR=1999, REFERENCES=30, ABSTRACT="In this paper, we consider the problem of providing multicast to mobile hosts using Mobile IP for network routing support. Providing multicast in an internetwork with mobile hosts is made difficult because many multicast protocols are inefficient when faced with frequent membership or location changes. This basic difficulty can be handled in a number of ways, but three main problems emerge with most solutions. The tunnel convergence problem, the duplication problem, and the scoping problem are identified in this paper and a set of solutions are proposed. The paper describes an architecture to support IP multicast for mobile hosts using Mobile IP. The basic unicast routing capability of Mobile IP is used to serve as the foundation for the design of a multicast service facility for mobile hosts. We believe that our scheme is transparent to higher layers, simple, flexible, robust, scalable, and, to the extent possible, independent of the underlying multicast routing facility. For example, our scheme could interoperate with DVMRP, MOSPF, CBT, or PIM in the current Internet. Where differences exist between the current version of IP (IPv4) and the next generation protocol (IPv6), these differences and any further optimizations are discussed.", URL="http://www.baltzer.nl/monet/contents/3-4.html#mnt074", } @ARTICLE{Gupt9901:Secure, AUTHOR="V. P. Gupta and G. Montenegro", TITLE="Secure and mobile networking", JOURNAL="Mobile Networks and Applications", VOLUME=3, NUMBER=4, PAGES="381-390", MONTH=jan, YEAR=1999, REFERENCES=25, ABSTRACT="The IETF Mobile IP protocol is a significant step towards enabling nomadic Internet users. It allows a mobile node to maintain and use the same IP address even as it changes its point of attachment to the Internet. Mobility implies higher security risks than static operation. Portable devices may be stolen or their traffic may, at times, pass through links with questionable security characteristics. Most commercial organizations use some combination of source-filtering routers, sophisticated firewalls, and private address spaces to protect their network from unauthorized users. The basic Mobile IP protocol fails in the presence of these mechanisms even for authorized users. This paper describes enhancements that enable Mobile IP operation in such environments, i.e., they allow a mobile user, out on a public portion of the Internet, to maintain a secure virtual presence within his firewall-protected office network. This constitutes what we call a Mobile Virtual Private Network (MVPN).", URL="http://www.baltzer.nl/monet/contents/3-4.html#mnt075", } @ARTICLE{Murt9901:Routing, AUTHOR="Siva Ram Murthy and J. J. Garcia-Luna-Aceves", TITLE="A routing architecture for mobile integrated services networks", JOURNAL="Mobile Networks and Applications", VOLUME=3, NUMBER=4, PAGES="391-407", MONTH=jan, YEAR=1999, REFERENCES=17, ABSTRACT="A drawback of the conventional Internet routing architecture is that its route computation and packet forwarding mechanisms are poorly integrated with congestion control mechanisms. Any datagram offered to the network is accepted; routers forward packets on a best-effort basis and react to congestion only after the network resources have already been wasted. A number of proposals improve on this to support multimedia applications; a promising example is the Integrated Services Packet Network (ISPN) architecture. However, these proposals are oriented to networks with fairly static topologies and rely on the same conventional Internet routing protocols to operate. This paper presents a routing architecture for mobile integrated services networks in which network nodes (routers) can move constantly while providing end-to-end performance guarantees. In the proposed connectionless routing architecture, packets are individually routed towards their destinations on a hop by hop basis. A packet intended for a given destination is allowed to enter the network if and only if there is at least one path of routers with enough resources to ensure its delivery within a finite time. Once a packet is accepted into the network, it is delivered to its destination, unless resource failures prevent it. Each router reserves resources for each active destination, rather than for each source--destination session, and forwards a received packet along one of multiple loop-free paths towards the destination. The resources and available paths for each destination are updated to adapt to congestion and topology changes. This mechanism could be extended to aggregate dissimilar flows as well.", URL="http://www.baltzer.nl/monet/contents/3-4.html#mnt076", } @ARTICLE{Rama9901:Interaction, AUTHOR="Sudhir Ramakrishna and J. M. Holtzman", TITLE="Interaction of {TCP} and data access control in an integrated voice/data {CDMA} system", JOURNAL="Mobile Networks and Applications", VOLUME=3, NUMBER=4, PAGES="409-417", MONTH=jan, YEAR=1999, REFERENCES=15, ABSTRACT="This paper considers the interaction between a proposed data access control scheme and the standardized error recovery schemes on the radio link of a voice/data CDMA system. A data access control scheme for combined voice-data CDMA systems has been proposed and studied in previous literature. The scheme aims to maintain a certain target voice signal to interference ratio (SIR); this is achieved by controlling the data load according to the measured voice SIR. The data users are allowed to transmit in a radio-link time slot with a certain permission probability, which is determined by the base station based on the measured voice SIR in the previous slot. As per the IS-99 standards, however, data transmission operates under the framework of TCP, which is a higher level end-to-end protocol. The TCP data unit, called a segment, is typically equivalent to several tens of physical layer frames; hence, a segment transmission takes up several tens of slots. Due to changes in the number of voice users in talkspurt (which occur on a time scale shorter than a segment transmission time), the slot level data access control scheme can introduce significant variability in the segment transmission time. The effect of such variability on the TCP timers, which operate at the segment level, is of interest. In this paper, an approximate upper bound on the data throughput, taking the presence of TCP into account, is computed. The results provide one with an insight into the interaction of the access control scheme with TCP; they also give practical pointers as to choosing suitable parameters and operating points for the scheme.", URL="http://www.baltzer.nl/monet/contents/3-4.html#mnt077", } @ARTICLE{Hous9901:WebExpress, AUTHOR="B. C. Housel and George Samaras and David B. Lindquist", TITLE="WebExpress: A client/intercept based system for optimizing Web browsing in a wireless environment", JOURNAL="Mobile Networks and Applications", VOLUME=3, NUMBER=4, PAGES="419-431", MONTH=jan, YEAR=1999, REFERENCES=33, ABSTRACT="This paper describes an application model and software technology that makes it possible to run World Wide Web applications in wide area wireless networks. Web technology in conjunction with today's mobile devices (e.g., laptops, notebooks, personal digital assistants) and the emerging wireless technologies (e.g., digital cellular, packet radio, CDPD) offer the potential for unprecedented access to data and applications by mobile workers. Yet, the limited bandwidth, high latency, high cost, and poor reliability of today's wireless wide-area networks greatly inhibits (to the point of infeasibility) supporting such applications over wireless networks. This paper presents the Client/Intercept computational model that makes it possible to run such distributed applications efficiently in wide area wireless networks. Furthermore, it presents WebExpress, a client/intercept based system for optimizing Web browsing, that reduces data volume and latency of wireless communications by intercepting the HTTP data stream and performing various optimizations including: file caching, forms differencing, protocol reduction, and the elimination of redundant HTTP header transmission. This paper describes these optimizations and presents some experimental results.", URL="http://www.baltzer.nl/monet/contents/3-4.html#mnt078", } @ARTICLE{Chen9901:Backtrack, AUTHOR="Sheng Chen", TITLE="Backtrack routing and priority-based wavelength assignment in {WDM} networks", JOURNAL=comcom, VOLUME=22, NUMBER=1, PAGES="1-10", MONTH=jan, YEAR=1999, KEYWORDS="Backtrack Routing; Priority-based; WDM Networks; Wavelength assignment; Performance evaluation", ABSTRACT="In this paper, we consider two key problems in the WDM networks: the wavelengh assignment and routing problems. The objective of the problems is to minimize the request blocking rate. We propose two priority-based methods for the wavelength assignment problem: static and dynamic strategies. Based on the priority of an incoming request, the proposed methods allocate a wavelength among the available wavelengths for the given priority. Analytic models and simulations are presented for the proposed wavelength assignment methods so as to analyse the link blocking rate. The simulation results show that the link blocking rate by the dynamic strategy is less than that by the assignment strategy. We also develop a routing algorithm that works together with the proposed wavelength assignment methods to reduce the overall blocking rates. The proposed routing method maintains a routing tree for a given connection request. Based on the routing tree, the algorithm finds a route with one available wavelength for each link along the route. We compare the proposed routing method with the fixed routing and fixed alternate routing algorithms. The experiments show that the proposed routing algorithm performs better than the fixed routing and the alternate routing methods.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/17/19/article.pdf", } @ARTICLE{Papa9901:Centralized, AUTHOR="Georgios Papadimitriou", TITLE="Centralized Packet Filtering protocols: a new family of {MAC} protocols for {WDM} Star Networks", JOURNAL=comcom, VOLUME=22, NUMBER=1, PAGES="11-19", MONTH=jan, YEAR=1999, KEYWORDS="WDM Star Networks; Channel collisions; Receiver conflicts; Electrooptic tunable filters; Centralized Packet Filtering", ABSTRACT="The small number of available wavelengths has been a limiting factor in the development of WDM Broadcast-and-Select Star Networks, since most protocols require the number of wavelengths be equal to the number of users. A new protocol which overcomes this limitation is introduced in this paper. According to the proposed Centralized Packet Filtering (CPF) protocol, more than one station share each wavelength and transmit their packets in a random access fashion. An array of electrooptic tunable filters, which is placed at the network hub, allows at most one packet per wavelength to pass to the Star Coupler, at each time slot. In this way, channel collisions are eliminated. Furthermore, the selection of the passing packets is implemented in such a way that receiver conflicts are avoided. Extensive analytical and simulation results are presented which indicate that a WDM Star Network operating under the CPF protocol achieves a high performance under any load conditions.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/17/20/article.pdf", } @ARTICLE{Tsin9901:Proactive, AUTHOR="P. Tsingotjidis and J. F. Hayes", TITLE="Proactive congestion controls for the support of variable bit rate services on broadband satellite networks-a feasibility study", JOURNAL=comcom, VOLUME=22, NUMBER=1, PAGES="20-29", MONTH=jan, YEAR=1999, KEYWORDS="Burst level controls; Overload prediction; First passage times; Connection admission control; Broadband satellite networks", ABSTRACT="The feasibility of proactive congestion controls for the support of real-time variable bit rate services on wideband-broadband networks with large bandwidth delay products, e.g. broadband satellite networks, is examined. The method is based on congestion anticipation which is made possible due to correlations that multimedia traffic exhibits. We have used realistic models for traffic in low-earth-orbit, medium-earth- orbit and geosynchronous-earth-orbit satellite systems. It has been shown that the approach is effective; this indicates matching of the time-scales of these correlations with the delays involved.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/17/21/article.pdf", } @ARTICLE{Golm9901:ATM, AUTHOR="N. Golmie and M. D. Corner and J. Liebeherr and David Su", TITLE="{ATM} traffic control in hybrid fiber-coax networks - problems and solutions", JOURNAL=comcom, VOLUME=22, NUMBER=1, PAGES="30-39", MONTH=jan, YEAR=1999, KEYWORDS="Hybrid fiber-coax; IEEE 802.14; Cable modems; ATM; Available Bit Rate (ABR); Community networks", ABSTRACT="The IEEE 802.14 working group is currently standardizing a new media access control (MAC) protocol for the emerging Hybrid Fiber-Coax (HFC) networks. Crucial for the success of 802.14 will be its ability to support higher layer traffic services, namely, ATM Constant Bit Rate (CBR), Variable Bit Rate (VBR) and Available Bit Rate (ABR) traffic classes. In this study, we investigate the inter-operation of the MAC protocol, defined by 802.14, with ABR transmissions. An important finding of our study is that the bandwidth contention on the upstream channel in the HFC network may interfere with the feedback congestion control mechanisms of ABR traffic control. This interference can result in unfairness between ABR sources and decreased utilization of the upstream HFC channel. As a solution to the problem we propose a scheme whereby the headend station of the HFC network returns congestion information contained in resource management (RM) cells to the ABR sources. The proposed mechanism can be incorporated into the ABR rate control scheme without modifying the current traffic management specifications. Numerous simulation scenarios are presented to illustrate our findings. Parts of the results have been presented to the IEEE 802.14 standardization committee.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/17/22/article.pdf", } @ARTICLE{Wang9901:Adaptive, AUTHOR="Xin Wang and J. S. Meditch", TITLE="Adaptive wavelet predictor to improve bandwidth allocation efficiency of {VBR} video traffic", JOURNAL=comcom, VOLUME=22, NUMBER=1, PAGES="40-45", MONTH=jan, YEAR=1999, KEYWORDS="Multimedia Communication; ATM Traffic Management", ABSTRACT="Dynamic bandwidth allocation using adaptive prediction can significantly improve the efficiency and QoS guarantees in transporting VBR video over ATM network. Conventionally, the time-domain least-mean-square (LMS) predictor is used, with the drawback of slow convergence. In VBR video traffic characterized by frequent scene changes, this slow convergence may result in extended periods of intractability and excessive cell loss during scene changes. In this article, we propose an adaptive wavelet predictor for dynamic bandwidth allocation. The wavelet predictor converges faster and hence, tracks scene changes better. Our simulation results show that, in comparison with LMS predictor, the wavelet predictor reduces the prediction error by an average of 11\% over the six half-an-hour-long empirical MPEG-1 traces. The dynamic bandwidth allocation using wavelet prediction significantly reduces the cell-loss-rate over various network settings, especially at large buffer sizes.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/17/23/article.pdf", } @ARTICLE{Shie9901:Optimal, AUTHOR="S.-P. Shieh and Ching-Yung Lin and Shiquan Wu", TITLE="Optimal assignment of mobile agents for software authorization and protection", JOURNAL=comcom, VOLUME=22, NUMBER=1, PAGES="46-55", MONTH=jan, YEAR=1999, KEYWORDS="Software protection; Mobile code; Remote execution; Java language; Proxy", ABSTRACT="In this paper, a model for software authorization and protection in mobile code systems is proposed. In the model, a software is partitioned into objects, called mobile agents, and the privileges to access these agents are separated and distributed to the user's local system and a number of trusted servers called trusted computational proxies. The execution of a program (software) is conducted by cooperation of the agents and the proxies that contain them. Two agents are dependent if there is a message passing between them. To reduce the risk of software being attacked, dependent agents are distributed to different proxies. In this way, if a proxy is compromized, minimal information of the software will be disclosed. Methods for assigning agents to proxies are also proposed to minimize, under the security constraints, computation load of the proxies as well as communication load between the user's local system and proxies.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/17/24/article.pdf", } @ARTICLE{Juan9901:Partially, AUTHOR="W.-S. Juang and C.-L. Lei", TITLE="Partially blind threshold signatures based on discrete logarithm", JOURNAL=comcom, VOLUME=22, NUMBER=1, PAGES="73-86", MONTH=jan, YEAR=1999, KEYWORDS="Partially blind signatures; Threshold signatures; Discrete logarithm; Secure; E-cash systems; Secure voting schemes; Privacy and security", ABSTRACT="In this paper, we propose a group-oriented partially blind (t, n) threshold signature scheme based on the discrete logarithm problem. By the scheme, any t out of n signers in a group can represent the group to sign partially blind threshold signatures, which can be used in anonymous digital e-cash systems or secure voting schemes. By our proposed scheme, the growth of the bank's database was successfully minimized and the issue of e-coins is controlled by several authorities. Our proposed scheme can greatly simplify the voting processes when several elections are to be held in a short period of time by embedding information about each election in a partially blind threshold signature. In our scheme, the size of a partially blind threshold signature is the same as that of an individual partially blind signature and the signature verification process is simplified by a group public key. The security of our scheme relies on the difficulty of computing discrete logarithm.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/17/17/article.pdf", } @ARTICLE{Lee9901:Comments, AUTHOR="N. Lee and Tzonelih Hwang", TITLE="Comments on `dynamic key management schemes for access control in a hierarchy'", JOURNAL=comcom, VOLUME=22, NUMBER=1, PAGES="87-89", MONTH=jan, YEAR=1999, KEYWORDS="Cryptanalysis; Cryptography; Security; Access control; User hierarchy system", ABSTRACT="In 1997, Lin proposed a new dynamic access control scheme with a central authority for users organized in a hierarchy. The author claimed that the new scheme has many advantages, e.g. any class can change its group key for security reasons without affecting the others. However, this paper will show that once the old group key of a class is exposed, the newly chosen group key can be easily derived by the old key. Moreover, we shall show that if the identity of a class has a few bits different from those of the other classes, a user in the class can easily derive the group keys of these classes to which he/she is not entitled.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/17/18/article.pdf", } @ARTICLE{Li9901:Measurement, AUTHOR="Jinyang Li and Adam M Wolisz and R. Popescu-Zeletin", TITLE="Measurement and performance evaluation of {NFS} traffic in {ATM} network", JOURNAL=comcom, VOLUME=22, NUMBER=2, PAGES="101-109", MONTH=jan, YEAR=1999, KEYWORDS="Traffic measurement; ATM; NFS", ABSTRACT="This article has three parts. At first, we explore traffic characterization of an ATM local area network and find the traffic presents both long and short range dependence in nature. Secondly, one long range dependent traffic model (fast fractional Gaussian noise) is constructed to explore influence of long-range dependence on the queuing performance of an infinite buffer-size queue. At last, we combine importance sampling scheme and long range dependent traffic models to simulate a finite buffer-size queue. The results show that both LRD and SRD play an important role in the queuing systems. Especially when LRD is strong, the more buffer solution is almost useless to improve the queuing performance. Multiplexing and enough capacity are better solutions for queuing performance.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/18/17/article.pdf", } @ARTICLE{Cam9901:High, AUTHOR="Hasan Cam", TITLE="A high-performance {ATM} switch based on modified shuffle-exchange network", JOURNAL=comcom, VOLUME=22, NUMBER=2, PAGES="110-119", MONTH=jan, YEAR=1999, KEYWORDS="Shuffle-exchange network; Internal conflict; Destination tag routing scheme; Output buffering ATM switch; Performance evaluation", ABSTRACT="This paper presents an output buffering ATM switch, called modified shuffle-exchange network (MSN) that is obtained by inserting a connection pattern just after every other shuffle-exchange stage. The purpose of modifying a shuffle-exchange network by inserting a connection pattern is to reduce significantly the number of its internal conflicts. Each link of every other stage of MSN has a filter to route successful packets to their destinations. Instead of employing the traditional destination tag routing scheme on MSN, we developed a fast destination tag routing scheme, called FDR, for MSN. In the traditional destination tag routing scheme, the routing tag of a packet is made equal to its destination address. In FDR, however, the routing tag of a packet is determined by its destination address as well as source address. FDR often requires less than log2 N stages to route a packet from its source to destination, which leads the traffic load to be reduced at the successive stages of the network. An analytical model is presented to analyze the performance of MSN under uniform traffic. Under a variety of traffic models, including uniform, hot-spot, ATM bursty, and output concentration, extensive simulations are run to examine and compare the performance of MSN with two existing similar networks. The simulation results show that MSN with FDR improves the packet loss probability substantially.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/18/18/article.pdf", } @ARTICLE{Hier9901:Minimizing, AUTHOR="Robert M. Hierons", TITLE="Minimizing the cost of fault location when testing from a finite state machine", JOURNAL=comcom, VOLUME=22, NUMBER=2, PAGES="120-127", MONTH=jan, YEAR=1999, KEYWORDS="Finite state machine; Fault location; Adaptive testing; Minimal length test", ABSTRACT="If a test does not produce the expected output, the incorrect output may have been caused by an earlier state transfer failure. Ghedamsi and coworkers generate a set of candidates and then produce further tests to locate the failures within this set. We consider a special case where there is a state identification process that is known to be correct. A number of preset and adaptive approaches to fault location are described and the problem of minimizing the cost is explored. Some of the approaches lead to NP-hard optimization problems for which possible heuristics are suggested.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/18/19/article.pdf", } @ARTICLE{Nord9901:Deterministic, AUTHOR="S. Norden and S. Balaji and G. Manimaran and Chandra Murthy", TITLE="Deterministic protocols for real-time communication in multiple access networks", JOURNAL=comcom, VOLUME=22, NUMBER=2, PAGES="128-136", MONTH=jan, YEAR=1999, KEYWORDS="Real-time protocols; Multiple access network; Collision resolution; Best effort protocols; Admission test", ABSTRACT="In a distributed real-time system, tasks scheduled on different nodes communicate by message passing mechanisms. In such a system, where messages are characterized by service times and deadlines, the timely delivery of messages before their deadlines, is of prime importance. In this article, we consider the problem of time-constrained communication over a multiple access network. Prior work in this area has resulted in very few protocols that can bound the worst case channel access time in order to ensure predictability of message transmission. These protocols cannot efficiently support messages having multiple packets (packet is a basic unit of transmission) which are needed in most peer-to-peer and client-server real-time applications. As a solution to the problem, we propose best effort protocols based on CSMA/CD protocol with deterministic collision resolution, that use a concept of message deferment, which is based on laxity (laxity is the maximum amount of time that the transmission of a message can be delayed). We study the effectiveness of the proposed protocols through extensive simulation studies by comparing them with well known protocols. The simulation results indicate the superiority of the proposed protocols.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/18/20/article.pdf", } @ARTICLE{Lee9901:Overload, AUTHOR="Yeonwoo Lee and J. Song", TITLE="An overload control of {SCP} in advanced intelligent network with fairness and priority", JOURNAL=comcom, VOLUME=22, NUMBER=2, PAGES="137-143", MONTH=jan, YEAR=1999, KEYWORDS="Overload control; Intelligent network; Priority", ABSTRACT="In this article we propose two mechanisms for overload control SCP in AIN; continuous gapping method and new arrival gapping method. They are all interactive mechanisms in which as SCP and SSPs exchange load information for overload control. These mechanisms are based on the general ACG, however different call gapping times are applied to each SSP under the fairness scheme. Also in the mechanisms, priority scheme is implemented. The analytic and simulation results show that the call throughput in the two mechanisms is almost same and fairness about the probability of rejection is maintained with the same value on all SSPs. On the priority scheme, new arrival gapping method has better priority achievement than continuous gapping method.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/18/21/article.pdf", } @ARTICLE{Lin9901:Comparison, AUTHOR="Jung-Lung Lin and R. F. Chang", TITLE="A comparison of the {Internet} multicast routing protocols", JOURNAL=comcom, VOLUME=22, NUMBER=2, PAGES="144-155", MONTH=jan, YEAR=1999, KEYWORDS="Multicasting routing protocols; Delivery tree; Datagrams", ABSTRACT="The exploding Internet has brought many novel network applications. These include teleconferencing, interactive games, the voice/video phone, real-time multimedia playing, distributed computing, web casting, and so on. One of the specific characteristics of these applications is that all involve interactions among multiple members in a single session. Unlike the traditional one-to-one message transmission (unicasting), if the underlying networks provide no suitable protocol supports, these applications may be costly and infeasible to implement. Multicasting is one technique proposed to efficiently distribute datagrams to a set of interested group members on the interconnected networks. In this article, we survey the multicast routing protocols on the Internet today. Four well-known multicast routing protocols, Distance Vector Multicast Routing Protocol (DVMRP), Multicast extensions to OSPF (MOSPF), Core Based Tree multicast routing protocol (CBT), and Protocol Independent Multicast routing protocol (PIM), are introduced. Different protocols have different design concepts and use different techniques to delivery datagrams and each has its special functions and properties. We provide a succinct explanation of their features. The advantages and weaknesses of these Internet protocols are also examined and compared in detail by several protocol characteristics.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/18/22/article.pdf", } @ARTICLE{Saha9901:Approach, AUTHOR="Debabrata Saha and M. D. Purkayastha and A. Mukherjee", TITLE="An approach to wide area {WDM} optical network design using genetic algorithm", JOURNAL=comcom, VOLUME=22, NUMBER=2, PAGES="156-172", MONTH=jan, YEAR=1999, KEYWORDS="Optical network; Physical topology; Virtual topology; Routing and wavelength assignment; Scaleup; Prufer number; Flow-deviation; Genetic algorithm", ABSTRACT="This article presents a systemic method to generate and map an optimal virtual topology onto a certain physical wide area optical fiber network so as to maximize the scaleup which provides an estimate of the network throughput. The problem is to find the best possible virtual topology over a given wavelength-routed all-optical physical topology for wide area coverage. The physical topology consists of wavelength-routing nodes interconnected by fiber links in the network. The virtual topology consists of a set of lightpaths. For a given physical topology and traffic matrix, our objective is to maximize the throughput as well as to minimize the delay. We have also studied the scalability of various parameters, such as queuing delay, propagation delay and average-hop-distance, with increase in throughput. We present a heuristic algorithm for embedding a virtual topology to the given physical fiber network when the number of wavelength channels supported on each fiber is limited. A number of feasible virtual topologies are generated randomly using Prufer number method, and the optimum one is selected. The problem being computationally intractable, we use genetic algorithm (GA)for optimization. As GAs are expected to converge to globally optimal solutions, the proposed approach yields better solutions than previous ones. As a result of immense practical importance of the issues addressed in this work, the algorithms are expected to be significant for practitioners", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/18/23/article.pdf", } @ARTICLE{Sooy9901:Transmission, AUTHOR="Kang Sooyong and Yeom Heon Y.", TITLE="Transmission of video streams with constant bandwidth allocation", JOURNAL=comcom, VOLUME=22, NUMBER=2, PAGES="173-180", MONTH=jan, YEAR=1999, KEYWORDS="Video-on-demand; Variable bit rate; Traffic smoothing; Bandwidth utilization", ABSTRACT="Encoded video streams present numerous problems in bandwidth allocation, multiplexing and admission control as a result of their Variable Bit Rate (VBR) characteristics. In particular, as video signals show a large range of variability, peak rate allocation results in very low bandwidth utilization. However, other allocation schemes tend to cause cell loss, delay and delay jitter, which make it difficult to guarantee quality of service (QoS). It is therefore necessary to develop a scheme that has no cell loss while guaranteeing QoS and achieving high bandwidth utilization at the same time. In this article, we propose a new scheme to accomplish this, which employs a 2-phase smoothing technique before transmitting VBR signal to produce an on-off signal with fixed bandwidth. Hence, it is possible to allocate a constant bandwidth for each stream, which results in high bandwidth utilization and a guaranteed deterministic QoS.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/18/24/article.pdf", } @ARTICLE{Low9901:Loop, AUTHOR="Colin Low", TITLE="Loop-free multicast routing with end-to-end delay constraint", JOURNAL=comcom, VOLUME=22, NUMBER=2, PAGES="181-192", MONTH=jan, YEAR=1999, KEYWORDS="Loop-freedom; Delay constrained multicast routing; Heuristic algorithms", ABSTRACT="We study the problem of constructing multicast trees for high-bandwidth delay-sensitive applications in a point-to-point communication network. This problem arises in real time multimedia applications, which often requires a guaranteed bandwidth and bounded end-to-end delay to ensure that the quality of service is met. This problem can be formulated as that of finding a minimum cost steiner tree with bounded end-to-end delay along the paths from source to each destination and is known to be computationally intractable, being NP-complete. In this article, we propose two loop-free routing heuristics for this problem. Loop-freedom is an important consideration in multicasting as loops in multicast routing duplicate looping packets, which in turn consumes additional bandwidths and other network resources. Simulation results show that both algorithms performed better in terms of cost (utilization of bandwidths) against an existing algorithm that was proposed by Kompella et al. without compromising on delay latency and running time.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/18/25/article.pdf", } @ARTICLE{Sun9901:Note, AUTHOR="Hung-Min Sun and S.-P. Shieh and Hung-Min Sun", TITLE="A note on breaking and repairing a secure broadcasting in large networks", JOURNAL=comcom, VOLUME=22, NUMBER=2, PAGES="193-194", MONTH=jan, YEAR=1999, KEYWORDS="Secure system; Broadcasting; Network security; Cryptography; Computer network", ABSTRACT="In this note, we show that a proposed secure broadcasting scheme is insecure. We also present a modified scheme to overcome this weakness. The modified scheme has the extra advantage that each participant can derive his group keys from group identities without the need of knowing other information.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/18/26/article.pdf", } @ARTICLE{Hong9901:ATM, AUTHOR="D. Hong and T. Suda", TITLE="Performance of {ATM} available bit rate for bursty {TCP} sources and interfering traffic", JOURNAL=cn, VOLUME=31, NUMBER="1-2", PAGES="7-18", MONTH=jan, YEAR=1999, KEYWORDS="TCP; ATM; ABR; EPRCA; ERICA; QFC; internet; webStone", ABSTRACT="The Available Bit Rate (ABR) service has been shown to enable persistent, greedy data sources to efficiently utilize ATM network resources. However, the throughput for bursty TCP over ABR data traffic in the presence of interfering traffic may not be as good as for persistent ABR sources without interfering traffic. This paper shows that in a comparison of rate based ABR schemes (EPRCA and ERICA) and a credit based ABR scheme (QFC), QFC performance is significantly better than rate based ABR schemes for bursty data traffic with bursty interfering traffic.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Bast9901:QoS, AUTHOR="E. Basturk and A. Birman and G. S. Delp and R. Guérin and R. W. Haas and S. Kamat and D. Kandlur and Ping Pan", TITLE="Design and implementation of a {QoS} capable switch-router", JOURNAL=cn, VOLUME=31, NUMBER="1-2", PAGES="19-32", MONTH=jan, YEAR=1999, KEYWORDS="IP switching; RSVP; QoS; MPLS", ABSTRACT="An important challenge for the future growth of the Internet is to design routers that can forward the exponentially increasing volume of traffic, and at the same time provide the service differentiation needed by new applications. In this paper, we describe the architecture, implementation, and initial experiences with a system designed to meet this challenge. This system, which we call a QoS capable Switch-Router (QSR), combines the salient features of switching and routing technologies to provide high throughput and support the different classes of service being defined by the IETF. It consists of a core (ATM) switch fabric connecting intelligent adapters, each capable of both routing and switching packets. A control engine is responsible for routing, RSVP signaling, and resource management. We have built a prototype network of 3 systems connected to several UNIX hosts, and have conducted preliminary performance measurements on this network.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Fern9901:Burst, AUTHOR="Joseph Fernandez and Matt Mutka", TITLE="A burst-level priority scheme for bursty traffic in {ATM} networks", JOURNAL=cn, VOLUME=31, NUMBER="1-2", PAGES="33-45", MONTH=jan, YEAR=1999, KEYWORDS="ATM networks; bandwidth reservation; burst-oriented traffic control; burst-level priority scheme; bursty traffic; call admission control", ABSTRACT="Statistical gain is achieved in asynchronous transfer mode (ATM) networks by making bursty connections share resources stochastically. To guarantee the quality of service (QOS) of established connections, a call admission control (CAC) scheme is used to limit the number of admitted connections based on their traffic characteristics and QOS requirements. When connections with different QOS requirements share the same resources, the highest QOS requirements would typically be the limiting factor in determining the admissible load at a link. This may lead to connections with low QOS requirements getting better service than they require, leading to an underutilization of the resources. To alleviate this problem, a burst-level priority scheme is proposed. In the proposal, burst of related cells are to be handled in the network on a burst-by-burst basis. Bandwidth is allocated to bursts on-the-fly according to their priorities. This proposal includes a two-level priority CAC scheme for controlling the burst-level blocking rates of independent heterogeneous on-off sources.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Kaly9901:Reliability, AUTHOR="M. Kalyanakrishnan and Ravishankar Iyer and J. H. Patel", TITLE="Reliability of {Internet} hosts: a case study from the end user's perspective", JOURNAL=cn, VOLUME=31, NUMBER="1-2", PAGES="47-57", MONTH=jan, YEAR=1999, KEYWORDS="internet; measurement; failure modes; downtimes; availability", ABSTRACT="This paper presents the results of a reliability study on a set of nearly 100 popular Web sites done from an end user's perspective. The study attempts to address the following issues: (a) What is the (stationary) probability that a user's request to access a Web site succeeds? (b) On average, what percentage of Web sites remain accessible to the user at a given moment? (c) What are the major causes of access failures as seen by the user? (d) Typically, how long could a Web site be unavailable to the user? (e) What parameters could be used to quantitatively describe the behavior of a host on the Internet? Data for the study was acquired by periodically attempting to fetch an HTML file from each Web site and recording the outcome of such attempts. Analysis of the acquired data revealed: (i) Over 94\% of the HTML file fetch requests succeed on average. (ii) Over 70\% of the failures last less than 15 min (iii) Network-related outages account for over half of the failures. (iv) Network-related outages can potentially render more than 70\% of the hosts inaccessible to the user. (v) Host-related failures tend to be of a shorter duration than failures that might involve the network. (vi) Network connectivity is good on average, with 93\% of the sites being accessible at any given time. (vii) Mean Availability of the hosts is high (0.993). (viii) On average, a host remains unavailable to a user for about 2.5 days per year. However, the total downtimes exhibited by individual hosts varied from about 2 h per year to nearly 20 days per year.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Thom9901:Analyzing, AUTHOR="E. Thomopoulos and L. E. Moser and P. M. Melliar-Smith", TITLE="Analyzing and measuring the latency of the Totem multicast protocols", JOURNAL=cn, VOLUME=31, NUMBER="1-2", PAGES="59-78", MONTH=jan, YEAR=1999, KEYWORDS="multicast protocols; performance modeling and analysis; message delivery latency; probability density functions; latency measurements; clock skew elimination; density estimation", ABSTRACT="This article presents, by analysis and measurement, the probability density functions (pdfs) for the latency from origination to message delivery for the Totem multicast protocols, in the presence of message loss and token loss. The Totem protocols provide reliable totally ordered delivery of messages across single and multiple local-area networks (LANs), using a logical token-passing ring on each LAN with gateways that forward messages selectively between LANs. The analysis of the pdfs for the latency involves decomposing the latency into independent components and convolving the pdfs of those components. A comparison of the performance of single-ring, two-ring and four-ring networks shows that, with message filtering in the gateways, multiple-ring networks achieve lower mean latency, less variability, and shorter tails of the latency distribution than an equivalent single ring. The experimental measurements of the pdfs for the latency are similar to those obtained from the analytical formulas, particularly for values of the latency with high probabilities. Limitations of the analytical model, and insight into communication and scheduling of the operating system, are discussed.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Huan9901:Improved, AUTHOR="Yao-yu Huang and Mart L. Molle", TITLE="An improved topology discovery algorithm for networks with wormhole routing and directed links", JOURNAL=cn, VOLUME=31, NUMBER="1-2", PAGES="79-88", MONTH=jan, YEAR=1999, KEYWORDS="wormhole routing; non-symmetric networks; topology discovery; distributed algorithms", ABSTRACT="We propose a new parallel topology discovery algorithm for irregular, mesh-connected networks with unidirectional links and wormhole routing. An algorithm of this type was developed for the ATOMIC high speed local area network to avoid the need for manually updating routing tables. Similar needs may arise in wireless networks where channels may be unidirectional because of limited transmission power, multipath, and similar effects. Like the ATOMIC topology discovery algorithm, our algorithm accumulates a map of the network at a distinguished node called the Address Consultant. However, our algorithm is much faster. In addition, our algorithm is more general, because it can correctly resolve topologies that contain multiple links between the same nodes. We implemented both algorithms in a concurrent simulation environment, and tested them on a variety of topologies.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Chow9901:Dynamic, AUTHOR="A. Chowdhury and O. Frieder and E. Burger and Daniel B. Grossman and K. Makki", TITLE="Dynamic Routing System {(DRS):} fault tolerance in network routing", JOURNAL=cn, VOLUME=31, NUMBER="1-2", PAGES="89-99", MONTH=jan, YEAR=1999, KEYWORDS="distributed routing; fault tolerent routing; dynamic routing; server clusters", ABSTRACT="We present a novel proactive routing algorithm that continuously searches for failures via frequent ICMP echo requests. Our approach differs from its predecessors in that it is proactive instead of reactive. That is, we continuously search for failures before they affect message transmissions. When a failure is detected, an alternative route is identified and used. The Dynamic Routing System (DRS) is currently deployed commercially by one of the top-three United States telecommunications companies in over 27 major cities nationwide. In production use, the use of DRS has improved availability by 13\%.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Jia9901:Distributed, AUTHOR="X. Jia and Y.-Q. Zhang and N. Pissinou and K. Makki", TITLE="A distributed multicast routing protocol for real-time multicast applications", JOURNAL=cn, VOLUME=31, NUMBER="1-2", PAGES="101-110", MONTH=jan, YEAR=1999, KEYWORDS="multicast routing; delay bounded routing; distributed routing; real-time communication", ABSTRACT="Multicast routing is establishing a tree which is rooted from the source node and contains all the multicast destinations. A delay bounded routing tree is a tree in which the accumulated delay from the source node to any destination along the tree does not exceed a pre-specified bound. This paper presents a distributed routing protocol which constructs delay bounded routing trees for real-time multicast connections. A constructed routing tree has a near optimal network cost under the delay bound constraint. The proposed algorithm is fully distributed, efficient in terms of the number of messages required, and flexible in multicast membership changes. A large number of simulations have been done to show the network cost of the routing trees generated by our method is better than the other major existing algorithms.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Cart9901:Improving, AUTHOR="S. Carter and D. Long", TITLE="Improving bandwidth efficiency of video-on-demand servers", JOURNAL=cn, VOLUME=31, NUMBER="1-2", PAGES="111-123", MONTH=jan, YEAR=1999, KEYWORDS="video-on-demand; efficiency; bandwidth", ABSTRACT={Video-on-demand (VOD) servers have a limited amount of bandwidth with which to service client requests. Conventional VOD servers dedicate a unique stream of data for each client, and that strategy can quickly allocate all of the available bandwidth on the server. We describe a system called stream tapping that allows clients to "tap" into existing streams on the VOD server. By using existing streams as much as possible, clients can reduce the amount of new bandwidth they require, and that allows more clients to use the server at once, reducing client latency. Stream tapping uses less than 20\% of the bandwidth required by a conventional VOD server for popular videos, and it performs better than many other strategies designed to improve VOD servers.}, URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Misi9901:Admission, AUTHOR="J. Misic and S. T. Chanson and F.-Y. Lai", TITLE="Admission control for wireless multimedia networks with hard call level quality of service bounds", JOURNAL=cn, VOLUME=31, NUMBER="1-2", PAGES="125-140", MONTH=jan, YEAR=1999, KEYWORDS="wireless cellular networks; call admission control; quality-of-service", ABSTRACT="In this paper, a new adaptive admission control scheme for wireless cellular network supporting mixed narrowband and wideband traffic is proposed. The scheme is event-based and provides hard constraints on hand-off dropping probability requirements. The role of the quality of service (QoS) regulation parameter Pov in the call admission process is analyzed and presented. The analytic results are validated by simulation. We also show that the analytic model is extensible to more than two types of traffic.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Shet9901:Scheduling, AUTHOR="Khalid H. Sheta and M. Singhal", TITLE="Scheduling support for multicasting sessions in broadband communication networks", JOURNAL=cn, VOLUME=31, NUMBER="1-2", PAGES="141-150", MONTH=jan, YEAR=1999, KEYWORDS="multicast; multiprocessors; session; broadband networks", ABSTRACT="Multimedia applications require support from the underlying broadband network at the end-to-end communication level. Multicasting is an important paradigm of end-to-end communication. The root node of a multicasting session is responsible for controlling the session including monitoring, maintenance, and the implementation of the multicasting protocol. The job that controls the multicasting session executes as a group of tasks at the root node of a multicasting tree. The scheduling scheme at the root node should give support to a multicasting session by improving the completion time of the jobs controlling the multicasting session, hence increasing throughput and the probability of admitting new multicast sessions into the system. In this paper, we model the tasks that carry out the multicasting session monitoring and maintenance as a fork-join job executing on a multiprocessor system. We assume that an executing task blocks for device I/O as a part of the activities associated with sending and receiving data packets. We develop two analytic models for scheduling a session control job on a multiprocessor system. The first model allows incoming job tasks to multiplex processors with existing tasks of another multicasting session, while the other model schedules a task of the incoming job to an idle processor. We assume that the overhead of rescheduling a task to another processor is large. We compare the performance of both models and show the range of conditions under which a model outperforms the other. We point out how the results can be used in the design of an adaptive scheduler that uses both models to improve throughput and consequently the probability of admitting new multicast sessions.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Bose9901:Impact, AUTHOR="V. Bose", TITLE="The Impact of Software Radio on Wireless Networking", JOURNAL="MC2R", VOLUME=3, NUMBER=1, PAGES="30-37", MONTH=jan, YEAR=1999, ABSTRACT="A software radio is a wireless communications device in which some or all of the physical layer functions are implemented in software. The flexibility provided by the software implementation enables a single device to interoperate with other devices using different wireless physical layer technologies, by simply invoking the appropriate software. A mobile computing device equipped with a software radio would have access to a wide range of connectivity options including cellular, wireless LAN and satellite systems. This would not only enable seamless anytime, anywhere connectivity, but also provide users the flexibility of choosing from the available connectivity options to best suit their price/performance requirements. Most software radio research to date has been driven by military and commercial cellular applications. Mobile networking applications require additional functionality present new software radio design constraints. This paper reviews existing software radio research, describes the SpectrumWare software radio system and identifies some important research challenges that must be addressed in order to apply software radio research to mobile networking applications.", URL="http://www.acm.org/sigmobile/MC2R/vol3\_toc.html#v3n1", } @ARTICLE{Yi9901:Extending, AUTHOR="Song-Yi Yi and M. Livny", TITLE="Extending the Condor Distributed Systems for Mobile Clients", JOURNAL="MC2R", VOLUME=3, NUMBER=1, PAGES="38-46", MONTH=jan, YEAR=1999, ABSTRACT="Condor is a distributed batch system for sharing the workload among the computers connected by a network. Condor distributed system was developed on the basis that every machine in a Condor pool is always connected by a network to run a Condor Job. Due to advances in wireless communication and mobile computing technology, conventional distributed computer systems can now include ``mobile'' clients as well as ``fixed'' clients. Moreover, mobile users want to be as low power as possible and benefit from offloading potentially power and resource consuming jobs. In this paper, we describe the design and implementation of extended Condor to support mobile clients. The main purpose of this work is to enable users on mobile computers to interact with Condor environment any time anywhere regardless of their connection to a Condor pool. The mobile Condor distributed system also aims to provide mobile users the same Condor services without making any significant changes to the existing Condor system.", URL="http://www.acm.org/sigmobile/MC2R/vol3\_toc.html#v3n1", } @ARTICLE{Kalo9901:Mobility, AUTHOR="A. Kaloxylos and Harri Hansin and L. Merakos", TITLE="Mobility Management for Large Private Wireless {ATM} Installations", JOURNAL="MC2R", VOLUME=3, NUMBER=1, PAGES=47, MONTH=jan, YEAR=1999, ABSTRACT="New mobility management protocols that aim to support terminal movement, in wireless ATM Customer Premises Networks (CPN) are presented. The functionality of these protocols consists of the procedures for handover (i.e., re-routing of active data connections to a new radio cell) and the procedures for location management (i.e., storing and retrieving the exact location of a mobile terminal). In the considered CPN environment, the ATM switches communicate using the PNNI protocol, the routing functionality of which is used by the mobility management protocols to perform their tasks more efficiently.", URL="http://www.acm.org/sigmobile/MC2R/vol3\_toc.html#v3n1", } @ARTICLE{Dana9901:Reflectance, AUTHOR="K. J. Dana and B. van Ginneken and Shree K. Nayar and J. J. Koenderink", TITLE="Reflectance and texture of real world surfaces", JOURNAL="Transactions of Graphics", VOLUME=18, NUMBER=1, PAGES="1-34", MONTH=jan, YEAR=1999, } @INPROCEEDINGS{Cher9901:Testing, AUTHOR="C. M. Chernick and Stefan Leigh and K. Mills and R. E. Toense", TITLE="Testing the Ability of Speech Recognizers to Measure the Effectiveness of Encoding Algorithms for Digital Speech Transmission", BOOKTITLE=milcom, MONTH=jan, YEAR=1999, KEYWORDS="speech recognition; speech quality; transmission impairment", ABSTRACT="Modern communication channels, such as digital cellular telephony, often convey human speech in a highly encoded form. Methods that rely on human subjects to evaluate the quality of such channels are too costly to deploy on a large scale; thus, automated methods are often used to model quality as perceived by humans. Traditional automated methods that use Signal to Noise Ratios (SNR) to judge the quality of channels do not model human perception well when applied to highly encoded speech. For this reason, researchers investigate alternative means to objectively measure the quality of such channels. In this paper we explore the feasibility and applicability of using automated speech recognition technology to model human perception of the quality of communication channels that carry highly encoded (compressed) human speech.", URL="http://www.argreenhouse.com/society/TacCom/papers99/47\_7.pdf", } @ARTICLE{Ande9901:Family, AUTHOR="B. Anderson and A McWilliam and H Lacohee and E Clucas and J Gershuny", TITLE="Family life in the digital home - domestic telecommunications at the end of the 20th century", JOURNAL=bttj, VOLUME=17, NUMBER=1, PAGES="85-97", MONTH=jan, YEAR=1999, REFERENCES=12, ABSTRACT="This paper describes results from the first stage of a long-term study of people’s use of ICT (information and communications technology) products and services in the domestic environment. It is part of BT’s ongoing commitment to understanding, modelling and meeting the needs of its residential customers. At one level the research has already generated significant knowledge that has led directly to commercial benefit; at a second it has validated a number of research methods needed to capture the data to build a rich picture of people’s actual as well as reported behaviour. At a third level it has also generated significant new scientific knowledge about the use of ICT products. The next step is to build on these successes using a 1000 strong UK household panel to build an unprecedented and unparalleled understanding of how and why people purchase, adapt and adapt to ICT as UK society moves into the 21st century.", URL="http://www.bt.com/bttj/archive.htm", } @ARTICLE{Trac9901:Developing, AUTHOR="Karen M. Tracey and C J H Fowler and C. Penn", TITLE="Developing an infrastructure to support communities of learning", JOURNAL=bttj, VOLUME=17, NUMBER=1, PAGES="98-110", MONTH=jan, YEAR=1999, REFERENCES=24, ABSTRACT="Through the National Grid for Learning (NGfL) the government is calling for new thinking about the potential of current educational institutions to support lifelong learning. One aspect of the reform is the creation and connection of a learning ‘community’. However, knowledge of best practice for implementing reform will only come about through understanding the processes that occur in communities of learning, and, from this, developing an infrastructure to support these processes. The BT Laboratories (BTL) research project, ‘HomeLearn’, examined the impact of an on-line educational service on a community of parents, children and teachers. The creation of a home/school network was the first step in involving the wider community in the learning process. The three-month trial demonstrated that children were enthusiastic and creative in their use of communications technologies in the home. They were extremely confident communicating with adults over a network; they learnt to organise meetings, to manage their own time and to resolve conflicts. Some of the families integrated the information communications technologies into their everyday lives. They gradually built up knowledge of the technology though experience and through learning from other members of the family. >From a service provider perspective we learnt that the critical concept in the development of a learning infrastructure is the support of ‘relationships’, a concept which entails more than simply providing a communications link or displaying static information. The widespread availability of new technologies means that people have an ever-increasing choice about how they want to communicate and with whom. An infrastructure to support learning must provide choice, be dynamic and be personalised. It is only by passing control of the system over to the users that a truly living system will exist.", URL="http://www.bt.com/bttj/archive.htm", } @ARTICLE{Warn9901:Exploring, AUTHOR="D Warne and C P Holland", TITLE="Exploring trust in flexible working using a new model", JOURNAL=bttj, VOLUME=17, NUMBER=1, PAGES="111-119", MONTH=jan, YEAR=1999, REFERENCES=17, ABSTRACT="Information technology (IT) facilitates novel forms of communication between individuals and organisations, thus supporting new flexible work patterns and making organisational boundaries more permeable. In general, this increases the physical and cultural distances both within and between organisations choosing to work together. In all of these situations, trust is a critical part of the process by which relationships develop. This paper presents a model of the trust development process called the ABC Trust Model. It is based on a synthesis of the management and information systems literature. The model is illustrated by applying it to a case example of remote working between individuals within an organisation. It is also demonstrated that the ABC Trust Model can be applied more generally to the fostering of co-operative relationships between both individuals and organisations that are supported by shared information systems. It is therefore of value to researchers investigating trust and also to managers involved in the design and implementation of IT-based co-operative relationships. The implications for new information systems design are discussed and opportunities for future research are outlined.", URL="http://www.bt.com/bttj/archive.htm", } @ARTICLE{Slat9901:Real, AUTHOR="M Slater", TITLE="Real people meeting virtually real people - a review of some experiments in shared virtual environments", JOURNAL=bttj, VOLUME=17, NUMBER=1, PAGES="120-127", MONTH=jan, YEAR=1999, REFERENCES=11, ABSTRACT="This paper reports on experimental studies looking into the experience of people who are collaborating in shared virtual environments. In these environments, people are represented as ‘avatars in virtual space. The studies reported here suggest that the way in which people are represented has a strong effect on others’perceptions. The effects on the feeling of closeness or ‘accord’of people who meet in this way are contrasted with more natural real-life meetings where all the normal social cues are available. The characteristics of the systems used to access the shared virtual environment are considered. Different systems offering differing degrees of perceived ‘immersion’in an environment are discussed, and their effects on social behaviours such as leadership are considered.", URL="http://www.bt.com/bttj/archive.htm", } @ARTICLE{Kala9901:Human, AUTHOR="R S Kalawsky and S T Bee and S P Nee", TITLE="Human factors evaluation techniques to aid understanding of virtual interfaces", JOURNAL=bttj, VOLUME=17, NUMBER=1, PAGES="128-141", MONTH=jan, YEAR=1999, REFERENCES=30, ABSTRACT="Advances in enabling technologies such as broadband wide area networks and the proliferation of the Internet has led to industry and home users looking beyond conventional communications media. Consequently, the telecommunications industry has been extending its application domain over recent years.Indeed, mediated communication has become a reasonably well established research area. Numerous modes of communication have been utilised successfully for various applications. >From e-mail and text chat to videoconferencing systems, the use of mediated communication has become a part of daily life. Virtual environments (VEs) are highly configurable media, ranging from relatively basic to extremely elaborate architectures. At their most complex, they promise a seamless interface between real and synthesised environments. The potential for media-rich environments is seeded in the technology’s capacity to faithfully represent the participants (both physically and dynamically) and for those participants to present and interact with (shared) data in an intuitive manner. It is the latter of these attributes which is highly relevant to communications and is discussed in this paper. The various configurations of virtual reality (VR) technology make matching the user to the technology an extremely complex task. Clearly, a basis for evaluating the effectiveness of these systems is required. Even though human factors (HF) evaluation and design techniques are well established in other human/computer interaction (HCI) fields, knowledge and understanding of virtual interfaces is limited. HF evaluation in VR is a complex subject and covers many aspects, such as basic human performance, cognition, and sensory capability. To address all these factors individually in an empirical fashion would demand a very long and expensive research programme. In addition, such studies may not predict the user’s overall performance in a multi-modal VE. This paper deals with an alternative approach to understanding the issues of human performance in virtual environments via a process of top-down systems engineering evaluation. This paper is designed to provide an introduction to the assessment of virtual environments, and a reference for interface designers and researchers engaged in the investigation of mediated communication.", URL="http://www.bt.com/bttj/archive.htm", } @ARTICLE{Sten9901:Dialogues, AUTHOR="F W Stentiford and P A Popay", TITLE="The design and evaluation of dialogues for interactive voice response services", JOURNAL=bttj, VOLUME=17, NUMBER=1, PAGES="142-148", MONTH=jan, YEAR=1999, REFERENCES=7, ABSTRACT="Good dialogue design is an essential component in the delivery of new interactive telephone services. It wins a competitive edge by improving the usability of services and reducing the risks of customer dissatisfaction. This paper outlines the steps taken to obtain consistent and effective dialogues across the company through the use of the Dialogues Style Guide, dialogue engineering courses and focus groups. Aspects of dialogue design will be illustrated with examples, trials and services developed within BT. Important results from dialogue studies under BT’s Strategic University Research Initiative at the Centre for Communication Interface Research (CCIR) at the University of Edinburgh are reported, together with a description of current activities. The achievements of the industry-funded Dialogues 2000 initiative is outlined in its pursuit of dialogue consistency. Currently this organisation has a membership of over 217 companies involved with interactive voice response systems.", URL="http://www.bt.com/bttj/archive.htm", } @ARTICLE{Attw9901:Large, AUTHOR="D J Attwater and S J Whittaker", TITLE="Large-vocabulary data-centric dialogues", JOURNAL=bttj, VOLUME=17, NUMBER=1, PAGES="149-159", MONTH=jan, YEAR=1999, REFERENCES=7, ABSTRACT="Data-centric speech dialogues using large-vocabulary speech have been investigated at BT Laboratories for some time now. The research to date has been focused on applications such as directory access, customer identification, auto-attendant and transaction completion. General lessons have been learned which are applicable to many goal-seeking dialogues where the vocabulary of the task is defined by the data sought. Several trials have been run which have provided evidence of good dialogue design principles. This paper presents a framework for the dialogue design of such services, discussing topics such as mixing spelling with spoken entry and the issues of confirmation and offering of information. In addition, the difficulties of designing for confusions due to homophones and synonyms have also been addressed.", URL="http://www.bt.com/bttj/archive.htm", } @ARTICLE{McIn9901:Effects, AUTHOR="F R McInnes and I A Nairn and D J Attwater and Mervyn A. Jack", TITLE="Effects of prompt style on user responses to an automated banking service using word-spotting", JOURNAL=bttj, VOLUME=17, NUMBER=1, PAGES="160-171", MONTH=jan, YEAR=1999, REFERENCES=7, ABSTRACT="Two experiments were performed to measure the effects of differing styles of prompt wording in a simulated telephone banking service incorporating a speech recogniser with word-spotting capabilities. It was found that users gave longer input utterances in response to an ‘open’style of prompt (‘How can I help you?’) than in response to a ‘closed’prompt which was more specific as to what input was expected, and that when a help facility was offered most users said ‘help’straight away. However, no significant difference was found in attitudes to the different versions of the service. Also no attitude difference was found with varying recognition accuracy. This may have been partly due to inadequate vocabulary coverage obscuring the effect of accuracy within the vocabulary, but the results suggest also that small numbers of recognition errors may have little impact on user attitude provided that the intended result of the call is achieved — this is a topic where further research could be valuable.", URL="http://www.bt.com/bttj/archive.htm", } @ARTICLE{Dutt9901:Please, AUTHOR="R T Dutton and J C Foster and Mervyn A. Jack", TITLE="Please mind the doors - do interface metaphors improve the usability of voice response services?", JOURNAL=bttj, VOLUME=17, NUMBER=1, PAGES="172-177", MONTH=jan, YEAR=1999, REFERENCES=3, ABSTRACT="Results are presented from an experiment to measure objective and subjective user responses towards three implementations of an automated voice response telephone service, two embodying rich implementations of metaphors in the service messages including appropriate sound effects to enhance realism, a third using a non-metaphorical presentation of standard menu prompts. It was found that task completion rates, navigation of the service and attitudes were all improved with the use of metaphors", URL="http://www.bt.com/bttj/archive.htm", } @ARTICLE{Attw9901:Fluency, AUTHOR="D J Attwater and Joseph Fisher and H R Greenhow", TITLE="Towards fluency-structured dialogues with natural speech input", JOURNAL=bttj, VOLUME=17, NUMBER=1, PAGES="178-186", MONTH=jan, YEAR=1999, REFERENCES=5, ABSTRACT="This paper presents the results of a study into how structured dialogue techniques in IVR systems can be extended to allow more natural speech interaction with the caller. A spoken language system was produced which allows callers to set reminder calls or bar outgoing or incoming telephone calls. In spite of the limits of speech recognition performance, the resulting system had a highly natural speech interface which allowed the caller to optionally offer one or more pieces of information at a time.", URL="http://www.bt.com/bttj/archive.htm", } @ARTICLE{Rana9901:Inter, AUTHOR="D W Ranasinghe and C C Smith and C B Hatch and S C Beaumont and P Kristiansen", TITLE="Inter-operator {OSS} interface for delivering pan-European {ATM} {VP} services", JOURNAL=bttj, VOLUME=17, NUMBER=1, PAGES="189-208", MONTH=jan, YEAR=1999, REFERENCES=21, ABSTRACT="The provision of ATM virtual paths across multiple network domains requires interaction between the operational support systems (OSS) used by the different network operators to manage those networks. This paper describes the interfaces needed between such OSS to support performance and accounting management. It also describes an apaproach to ensuring those interfaces are secure. The results may be suitable for operational deployment and applicable with further development for other ATM services such as virtual circuits and switched services.", URL="http://www.bt.com/bttj/archive.htm", } @INPROCEEDINGS{Li9901:Multi, AUTHOR="Xiao Li and Sunil Paul and Mahmoud Ammar", TITLE="Multi-Session Rate Control for Layered Video Multicast", BOOKTITLE="Multimedia Computing and Networking", ADDRESS="San Jose, California, USA", MONTH=jan, YEAR=1999, REFERENCES=17, ABSTRACT="In a video multicast session, the receivers may possess different capabilities or be connected to the network through a variety of different access speeds. Multicasting video traffic at any one rate to all of the receivers can be unfair as some receivers may experience high losses while others find that their full reception capacity is not fully utilized. Layered video multicast protocols have been developed to address this intra-session fairness problem. In such protocols (e.g., RLM and LVMR), video is multicast in multiple layers over separate multicast groups. Receivers join as many layers as they can handle. While protocols such as RLM and LVMR have been shown to successfully address the intra-session fairness issue in video multicast, they do not address the issue of inter-session fairness, i.e., fair sharing between multiple video sessions and TCP sessions. In this paper, we demonstrate and develop insight into the inter-session fairness problem through a set of simulation...", URL="http://www.cc.gatech.edu/Mostafa\_Ammar/papers/MMCN-full.ps.gz", } @ARTICLE{Valk9901:Cellular, AUTHOR="Andras Valko", TITLE="Cellular {IP:} A New Approach to {Internet} Host Mobility", JOURNAL="ACM SIGCOMM Computer Communication Review", VOLUME=29, NUMBER=1, PAGES="50-65", MONTH=jan, YEAR=1999, } @INPROCEEDINGS{Park9901:Anycast, AUTHOR="Vincent D. Park and Joe Macker", TITLE="Anycast Routing for Mobile Services", BOOKTITLE="Conference on Information Sciences and Systems, CISS '99", MONTH=jan, YEAR=1999, } @TECHREPORT{Bell9901:Nfaf, AUTHOR="Sarah Bell", TITLE="Nfaf - a Flexible, Modular Session Description Framework", TYPE="Technical Report", INSTITUTION="Distributed Systems Group, ART, BT Research Laboratories", ADDRESS="Ipswich, England", MONTH=jan, YEAR=1999, LANGUAGE="English", KEYWORDS="session description", ABSTRACT="We present a mechanism for describing the many types of real-time service expected to become widely available over the Internet as available bandwidth increases and multicast becomes prevalent. This mechanism, Nfaf, is designed to be as flexible and extensible as possible, allowing these varying services to be described. Its modular structure separates the various attributes required to describe a service into self-contained modules, also providing a separation between the user-oriented attributes of the service and the technical details which should be hidden from the user. It is this modularity that allows flexibility and extensibility, permitting services of simple or complex structure to be described, containing media or data streams of many formats, transported with many mechanisms. Key also is the ability to include policies within the modules to describe Quality of Service, security and charging. The framework is suitably generic to allow for the addition of new functionalities at a later date, such as the inclusion of complex metadata or emerging data formats and protocols. The self-contained modules allow for much flexibilty in the distribution of the session description, such that a very large description need not be transported complete. Nfaf allows a complete description of the technical requirements for a real-time service. As such, it could be used be an advanced middleware to construct a bespoke application for handling the service from a set of components [M3 ref]. Nfaf is to be implemented using XML and forms part of a larger body of work looking at all aspects of real-time service discovery for the Internet, including announcement distribution and advanced session directory tools.", URL="http://www.cs.columbia.edu/IRT/papers/others/isnpaper.pdf", } @ARTICLE{Li9902:Channel, AUTHOR="Jinyang Li and Ness Shroff and Edwin Chong", TITLE="Channel carrying: a novel handoff scheme for mobile cellular networks", JOURNAL=ieanep, VOLUME=7, NUMBER=1, PAGES="38-50", MONTH=feb, YEAR=1999, REFERENCES=14, ABSTRACT="We present a new scheme that addresses the call handoff problem in mobile cellular networks. Efficiently solving the handoff problem is important for guaranteeing quality of service to already admitted calls in the network. Our scheme is based on a new approach called channel carrying: when a mobile user moved form one cell to another, under certain mobility conditions, the user is allowed to carry its current channel into the new cell. We propose a new channel assignment scheme to ensure that this movement of channels will not lead to any extra co-channel interference or channel locking. In our scheme, the mobility of channels relies entirely on localized information, and no global coordination is required. Therefore, the scheme is simple and easy to implement. We further develop a hybrid channel carrying scheme that allows us to maximize performance under various constraints.", URL="http://www.acm.org/pubs/articles/journals/ton/1999-7-1/p38-li/p38-li.pdf", } @ARTICLE{Schu9902:Internet, AUTHOR="Henning Schulzrinne and J. Rosenberg", TITLE="{Internet} Telephony: Architecture and Protocols -- an {IETF} perspective", JOURNAL=cnis, VOLUME=31, NUMBER=3, PAGES="237-255", MONTH=feb, YEAR=1999, REFERENCES=38, KEYWORDS="Internet telephony; RTP; SIP; RTSP; signaling protocols; real-time transport; Internet", ABSTRACT="Internet telephony offers the opportunity to design a global multimedia communications systems that may eventually replace the existing telephony infrastructure, without being encumbered by the legacy of a century-old technology. We describe the upper-layer protocol components that are specific to Internet telephony services: the Real-Time Transport Protocol (RTP) to carry voice and video data, and the session initiation protocol (SIP) for signaling. We also mention some complementary protocols, including RTSP for control of streaming media, and WASRV for location of telephony gateways.", URL="http://www.cs.columbia.edu/~hgs/papers/Schu9902\_Internet.ps.gz", } @ARTICLE{Toga9902:ITU, AUTHOR="James Toga and Joerg Ott", TITLE="{ITU-T} standardization activities for interactive multimedia communications on packet-based networks: {H.323} and related recommendations", JOURNAL=cnis, VOLUME=31, NUMBER=3, PAGES="205-223", MONTH=feb, YEAR=1999, REFERENCES=24, KEYWORDS="Multimedia communications; teleconferencing; Internet telephony; CSCW; computer telephony integration (CTI); Mbone; multicast", ABSTRACT="The Telecommunications Sector of the International Telecommunications Union (ITU-T) has developed a series of recommendations together comprising the H.323 system that provides for multimedia communications in packet-based (inter)networks. This series of recommendations describe the types and functions of H.323 terminals and other H.323 devices as well as their interactions. The H.323 series of recommendations includes audio, video and data streams, but an H.323 system minimally requires only an audio stream to be supported. Motivated by straightforward interoperability with the ISDN and PSTN networks and a variety of other protocols, the recommendation H.323 has been accepted as being the standard for IP telephony, developed by the ITU-T and broadly backed by industry - which is also adopted by both the Voice over IP (VoIP) forum and the European Telecommunication Standards Institute (ETSI). This paper presents an overview of the H.323 architecture with all its functional components and protocols and points out all the related specifications.", } @MASTERSTHESIS{Fing9902:SIP, AUTHOR="Fredrik Fingal and Patrik Gustavsson", TITLE="A {SIP} of {IP-telephony}", SCHOOL="Department of Communication Systems, Lund Institute of Technology, Lund University", ADDRESS="Lund, Sweden", MONTH=feb, YEAR=1999, REFERENCES=31, KEYWORDS="SIP; Internet telephony; signaling; H.323", ABSTRACT="There are two different protocols competing in the Internet telephony world today, the Session Initiation Protocol (SIP) emerged from IETF and the H.323 emerged from ITU. The IP-telephony market is growing and will most likely affect the traditional circuit-switched telephony business in the future. We have studied the Session Initiation Protocol in the purpose of evaluating it and to make a small implementation of a client and a server. The tools Rational Rose and Java was used for the implementation. We have also compared it against the H.323 and tried to give a hint of what the future holds.", URL="http://www.cs.columbia.edu/~hgs/sip/drafts/Fing9902\_SIP.pdf", } @TECHREPORT{Schu9902:Forward, AUTHOR="Guido Schuster and Jerry Mahler and Ikhlaq Sidhu and Michael S. Borella", TITLE="Forward error correction system for packet based real time media", TYPE="U.S. Patent", INSTITUTION="3Com", ADDRESS="Chicago, Illinois", NUMBER="US5870412", MONTH=feb, YEAR=1999, KEYWORDS="FEC; packet audio; error correction; packet loss compensation", ABSTRACT="A computationally simple yet powerful forward error correction code scheme for transmission of real-time media signals, such as digitized voice, video or audio, in a packet switched network, such as the Internet. The invention appends to each of a series of payload packets a single forward error correction code that is defined by taking the XOR sum of a preceding specified number of payload packets. The invention thereby enables correction from the loss of multiple packets in a row, without significantly increasing the data rate or otherwise delaying transmission.", URL="http://www.patents.ibm.com/patlist?icnt=US\&patent\_number=5870412", } @TECHREPORT{Padh9902:Stochastic, AUTHOR="J. Padhye and V. Firoiu and Donald F. Towsley", TITLE="A Stochastic Model of {TCP} Reno Congestion Avoidance and Control", TYPE="Technical Report", INSTITUTION="Department of Computer Science, University of Massachusetts", ADDRESS="Amherst, MA", NUMBER="99-02", MONTH=feb, YEAR=1999, REFERENCES=12, KEYWORDS="TCP Performance; Stochastic Analysis", ABSTRACT={The steady state performance of a bulk transfer TCP flow (i.e. a flow with a large amount of data to send, such as FTP transfers) may be characterized by three quantities. The first is the {\em send rate}, which is the amount of data sent by the sender in unit time. The second is the $throughput$, which is the amount of data received by the receiver in unit time. Note that the throughput will always be less than or equal to the send rate due to losses. Finally, the number of non-duplicate packets received by the receiver in unit time give us the $goodput$ of the connection. The goodput is always less than or equal to the throughput, since the receiver may receiver two copies of the same packet due to retransmissions by the sender. In [1], we presented a simple model for predicting the steady state send rate of a bulk transfer TCP flow as a function of loss rate and round trip time. In this paper, we extend that work in two ways. First, we analyze the performance of bulk transfer TCP flows using more precise, stochastic analysis. We show that the predictions of the approximate model in [1] closely match the predictions of the more precise model, thus validating the approximate model. Second, we build upon the analysis in [1] to provide both an approximate formula as well as a more accurate stochastic model for the steady state throughput of a bulk transfer TCP flow. [1] J. Padhye, V. Firoiu, D. Towsley and J. Kurose, "Modeling TCP throughput: A simple model and its empirical validation", In Proceedings of SIGCOMM'98}, URL="ftp://gaia.cs.umass.edu/pub/Padhye99-markov.ps.gz", } @TECHREPORT{Song9902:NFR, AUTHOR="Dug Song and Matt Undy", TITLE="{NFR} Performance Testing", TYPE="Technical Report", INSTITUTION="Anzen Computing", ADDRESS="Ann Arbor, Michigan", MONTH=feb, YEAR=1999, KEYWORDS="packet sniffing; packet filter; tcpdump; Linux; BSD; Solaris; NT", ABSTRACT="In this paper, we attempt to loosely characterize NFR performance on various operating systems, comparing freely available and proprietary sniffing technology. Our results should be helpful in determining appropriate hardware/software configurations for successful NFR deployment.", URL="http://www.anzen.com/products/nfr/testing/", } @TECHREPORT{Ozde9902:Scalable, AUTHOR="Volkan Ozdemir and S. Muthukrishnan and I. Rhee", TITLE="Scalable, Low-Overhead Network Delay Estimation", TYPE="Technical Report", INSTITUTION="North Carolina State University, Computer Science Department", ADDRESS="Raleigh, North Carolina", NUMBER="TR-99-07", MONTH=feb, YEAR=1999, KEYWORDS="delay estimation; network measurements", ABSTRACT="Estimating the network delays between each pair of nodes in a multicast session is the key parameter in reliable multicast; it is used, among other things, in suppressing the implosion of request and repair packets, and in detecting congestion. Existing implementations use O(n) multicasts with O(n) message size each (total of O(n^2) bits); here, n is the session size. We present a new protocol that requires O(n) multicasts only with O(1) message size each. We also present another protocol that estimates delays from each receiver to the sender without causing feedback implosion. Because of reduced message complexity and feedback implosion, these protocols greatly enhance the scalability of reliable multicast. Furthermore, they do not require synchronized clocks, or any knowledge of network topology or the session size.", URL="http://www.csc.ncsu.edu/faculty/rhee/pub/delay.pdf", } @TECHREPORT{FCC9902:Trends, AUTHOR="Common Carrier Bureau", TITLE="Trends in Telephone Service", INSTITUTION="Federal Communications Commission", ADDRESS="Washington, D.C.", MONTH=feb, YEAR=1999, KEYWORDS="telephone system", URL="http://www.fcc.gov/Bureaus/Common\_Carrier/Reports/FCC-State\_Link/trends.html", } @TECHREPORT{Zyre9902:Brief, AUTHOR="Jim Zyren and Al Petrick", TITLE="Brief tutorial on {IEEE} 802.11 Wireless {LANs}", TYPE="Application Note", INSTITUTION="Intersil", NUMBER="AN9829", MONTH=feb, YEAR=1999, KEYWORDS="Wireless LAN; spread spectrum; WaveLAN; 802.11; multiple access", URL="http://www.intersil.com", } @TECHREPORT{Jean9902:Gilbert, AUTHOR="J.-P. W Ebert and Andreas Willig", TITLE="A Gilbert-Elliot Bit Error Model and the Efficient Use in Packet Level Simulation", TYPE="Technical report", INSTITUTION="Telecommunication Networks Group - Technical University Berlin", ADDRESS="Berlin, Germany", NUMBER="TKN-99-002", MONTH=feb, YEAR=1999, REFERENCES=13, KEYWORDS="Gilbert; Eliott; channel model; simulation; performance improvement", ABSTRACT="Simulation of communication protocols requires often an abstraction to packet or frame level. Discrete Event Simulation (DES) of such protocols can be very time consuming when considering the complexity of protocols (e.g. media access or transport protocols) and the necessary network simulation setup with a great number of network stations. Of great importance in investigating wireless communication protocols is the error prone wireless channel, since the errors have strong influence on the protocol performance. Therefore error models are needed. Unfortunately packet errors are ve!ry difficult to model, since they depend on channel and source characteristics and on the coding method used. Therefore, in order to model packet errors often a packet is simulated bit-by-bit, thus relying on bit bit error models. This can degrade the simulation performance significantly. Simulation at bit level means at least one simulation event for every bit instead of a few simulation events per packet. In this report we propose an approach to achieve packet level simulation performance while using bit level channel models which are based on the Gilbert-Elliot error modeling approach. In order to show that improved methods for bit error simulation have a significant impact on simulation durations for higher layer protocols, we simulated a relatively complex IEEE 802.11 MAC with our improved channel model.", URL="http://www-tkn.ee.tu-berlin.de/bibl/ours/tkn\_report02.ps.gz", } @ARTICLE{Gafs9902:Data, AUTHOR="Jamel Gafsi and Ernst Biersack", TITLE="Data Striping and Reliability Aspects in Distributed Video Servers", JOURNAL="Cluster Computing: Networks, Software Tools, and Applications", VOLUME=1, NUMBER=2, PAGES="75-91", MONTH=feb, YEAR=1999, KEYWORDS="Video server; data striping; server reliability", ABSTRACT="To provide the required amount of storage and bandwidth, a video server typically comprises a large number of disks. As the total number of disks increases, the influence of the striping algorithm that determines how video data are distributed across the disks becomes decisive in terms of overall server cost and performance. Also introducing fault-tolerance against disk failures becomes a must. In this paper, we first evaluate different striping algorithms in terms of throughput, buffer requirement, and start-up latency for a non-fault-tolerant server. We then examine the impact of data striping on a fault-tolerant server and show that the striping policy and the optimal technique to assure fault-tolerance are related: Depending on the technique used to assure fault-tolerance (mirroring or parity), different striping techniques perform best.", URL="http://www.eurecom.fr/~btroup/BPublished/", } @ARTICLE{Modi9902:Architectural, AUTHOR="E. Modiano and R. A. Barry", TITLE="Architectural considerations in the design of {WDM-based} optical access networks", JOURNAL=cn, VOLUME=31, NUMBER=4, PAGES="327-341", MONTH=feb, YEAR=1999, KEYWORDS="broadband; internet access; MAC protocols; DSL; local access network; HFC; ONU; protection; restoration; WDM; optical", ABSTRACT="We describe a WDM-based optical access network architecture for providing broadband Internet services. The architecture uses a passive collection and distribution network and a configurable Feeder network. Unlike earlier papers that concentrate on the physical layer design of the network, we focus on higher layer architectural considerations. In particular we discuss the joint design of the electronic and optical layers including: WDM Medium Access Control protocols; the choice of electronic multiplexing and switching between the IP and WDM layers; joint optical and electronic protection mechanisms; network reconfiguration algorithms that alter the logical topology of the network in response to changes in traffic; and traffic grooming algorithms to minimize the cost of electronic multiplexing. Finally we also discuss the impact of the optical topology on higher layer protocols such as IP routing, TCP flow control and multi-layer switching.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Garg9902:Services, AUTHOR="Frank Gargione and T. Iida and Francesco Valdoni and F. Vatalaro", TITLE="Services, Technologies, and Systems at Ka Band and {Beyond--A} Survey", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="133-144", MONTH=feb, YEAR=1999, REFERENCES=49, ABSTRACT="This paper discusses system and technology aspects crucial to the development of satellite communications at Ka band (20-30 GHz) and beyond. It surveys the evolution of Ka band geostationary Earth orbit (GEO) satellite communications until the present stage of development of systems for direct-to-user (DTU) provision of interactive multimedia services worldwide. Then it discusses the attenuation problem and main technical issues of this new technology. Finally, it provides a view on experiments and technological developments at extremely high-frequency (EHF) bands.", } @ARTICLE{Egam9902:Power, AUTHOR="Shunichiro Egami", TITLE="A Power-Sharing Multiple-Beam Mobile Satellite in Ka Band", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="145-152", MONTH=feb, YEAR=1999, REFERENCES=10, ABSTRACT="This paper presents a new power-sharing multiple-beam mobile satellite system concept in the Ka band. A wide allocated bandwidth and a large amount of frequency reuse based on hundreds to thousands of small spot beams will allow us to draw a drastically new mobile satellite systems concept in the Ka band. At first, requirements for beam size on the surface of the earth for various signal transmissions are considered. Based on these requirements, Ka-band geostationary systems with 3.5 and 10 m satellite antennas are shown. If the number of beams is hundreds to thousands, it is not appropriate to assume a fixed power transmitter for each beam because the traffic in each beam is not uniform or static. In order to cope with this multiple-beam-varying traffic problem, this paper proposes a new type offset reflector antenna fed through an equal phase-shift active array. The proposed active array consists of hundreds to thousands of equal phase-shift elements. Features and simulated performances of the proposed transmitting antenna are presented. Preliminary experimental results from a 2.1 m reflector fed through 332 hollow elements are also shown. Since each beam commonly utilizes all active array elements, power sharing among beams is possible, allowing traffic variation among beams without loss of power efficiency.", } @ARTICLE{Pind9902:Four, AUTHOR="Jennifer Pinder and Ippolito, Jr., Louis J. and Stephen Horan and Julie Feil", TITLE="Four Years of Experimental Results from the New Mexico {ACTS} Propagation Terminal at 20.185 and 27.505 {GHz}", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="153-163", MONTH=feb, YEAR=1999, REFERENCES=20, ABSTRACT="The Advanced Communications Technology Satellite (ACTS) propagation experiment has collected four years of propagation data at 20.185 and 27.505 GHz. The objective of the experiment is to develop long-term statistics and modeling techniques for predicting atmospheric propagation effects in the Ka band. The experiment includes seven identical earth stations at different locations in North America. Each location is meant to characterize a unique rain region. This paper presents the data collected in White Sands, NM. The data from this site provide an excellent resource for validating rain attenuation models due to its unique arid climate with occasional high rain-rate storms. The seasonal and cumulative four-year attenuation statistics for the 20.2 and 27.5 GHz beacons are presented. The Attenuation with respect to Clear Air (ACA) is compared to five different rain attenuation models and seven different frequency scaling models. The results illustrate how well each model predicts rain attenuation in a desert climate region.", } @ARTICLE{Nedo9902:Modeling, AUTHOR="N. Celandroni and Potorti Francesco", TITLE="Modeling Ka-Band Scintillation as a Fractal Process", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="164-172", MONTH=feb, YEAR=1999, REFERENCES=28, KEYWORDS="scintillation; rain fade; fractal model; signal degradation; fade countermeasures", ABSTRACT="We propose a model that describes the signal fading process due to scintillation in the presence of rain. We analyzed a data set of uplink (30 GHz) and downlink (20 GHz) attenuation values averaged over 1 s intervals. The data are samples relative to ten significant events, for a total of 180000 s recorded at the Spino d'Adda (North of Italy) station using the Olympus satellite. Our analysis is based on the fact that the plot of attenuation versus time recalls the behavior of a self-similar process. We then make various considerations, and propose a fractional Brownian motion model for the scintillation process. We describe the model in detail, with pictures showing the apparent self-similarity of the measured data. We then show that the Hurst parameter of the process is a simple function of the rain fade. We describe a method for producing random data that interpolate the measured samples, while preserving some of their interesting statistical properties. This method can be used for simulating fade countermeasure systems. As a possible application of the model, we show how to optimize fade measurement times for fade countermeasure systems.", URL="mailto:F.Potorti@cnuce.cnr.it", } @ARTICLE{Cox9902:Advanced, AUTHOR="Christina B. Cox and Thom A. Coney", TITLE="Advanced Communications Technology Satellite {(ACTS)} Fade Compensation Protocol Impact on Very Small-Aperture Terminal Bit Error Rate Performance", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="173-179", MONTH=feb, YEAR=1999, REFERENCES=5, ABSTRACT="The Advanced Communications Technology Satellite (ACTS) communications system operates at Ka band. ACTS uses an adaptive rain fade compensation protocol to reduce the impact of signal attenuation resulting from propagation effects. The purpose of this paper is to present the results of an analysis characterizing the improvement in VSAT performance provided by this protocol. The metric for performance is VSAT bit error rate (BER) availability. The acceptable availability defined by communication system design specifications is 99.5\% for a BER of 5E-7 or better. VSAT BER availabilities with and without rain fade compensation are presented. A comparison shows the improvement in BER availability realized with rain fade compensation. Results are presented for an eight-month period and for 24 months spread over a three-year period. The two time periods represent two different configurations of the fade compensation protocol.", } @ARTICLE{Grem9902:Comparative, AUTHOR="Boris Gremont and Miodrag Filip and Paul Gallois and Stephen Bate", TITLE="Comparative Analysis and Performance of Two Predictive Fade Detection Schemes for Ka-Band Fade Countermeasures", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="180-192", MONTH=feb, YEAR=1999, REFERENCES=38, ABSTRACT="The design of Ka-band satellite fade countermeasure (FCM) systems is conditioned by the detection/prediction algorithm to be included within practical DSP-based FCM controllers. It depends upon the ability of systems to efficiently integrate the dynamic and stochastic nature of the Ka-band fading process which is dominated by rain attenuation and amplitude scintillation. The paper analyzes the modeling and statistical performance of two predictive fade detection algorithms. Prediction is introduced as a way to minimize the impact of the finite response time on the BER/throughput of practical FCM systems. Both fixed (FDM) and variable (VDM) detection margin strategies are introduced and compared in terms of their margin requirements, FCM utilization factor, and channel capacity utilization. The VDM is shown to be more efficient than its fixed counterpart. The long-term BER availability and average user data throughput of a VDM/fixed-FEC/adaptive transmission rate FCM are then evaluated for a typical low-power low-rate Ka-band in-bound VSAT link.", } @ARTICLE{Acos9902:Advanced, AUTHOR="Roberto J. Acosta and R. K. Bauer and Richard J. Krawczyk and Richard C. Reinhart and Michael J. Zernic and Frank Gargione", TITLE="Advanced Communications Technology Satellite {(ACTS):} Four-Year System Performance", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="193-203", MONTH=feb, YEAR=1999, REFERENCES=21, ABSTRACT="The Advanced Communications Technology Satellite (ACTS) was conceived at the National Aeronautics and Space Administration (NASA) in the late 1970's as a follow-on program to ATS and CTS to continue NASA's long history of satellite communications projects. The ACTS project set the stage for the C-band satellites that started the industry, and later the ACTS project established the use of Ku-band for video distribution and direct-to-home broadcasting. ACTS, launched in September 1993 from the space shuttle, created a revolution in satellite system architecture by using digital communications techniques employing key technologies such as a fast hopping multibeam antenna, an on-board baseband processor, a wide-band microwave switch matrix, adaptive rain fade compensation, and the use of 900 MHz transponders operating at Ka-band frequencies. This paper describes the lessons learned in each of the key ACTS technology areas, as well as in the propagation investigations.", } @ARTICLE{Gaud9902:Capacity, AUTHOR="Riccardo De Gaudenzi and F. Giannetti and Marco Luise", TITLE="Capacity of a Multibeam, Multisatellite {CDMA} Mobile Radio Network with Interference-Mitigating Receivers", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="204-213", MONTH=feb, YEAR=1999, REFERENCES=13, ABSTRACT="More and more interference-mitigating algorithms are being investigated in an attempt to increase the capacity of code-division multiple-access radio networks. At the moment, the main question about interference-resilient receivers is: Do they really bring forth the capacity increase they promise on theoretical grounds? The aim of this study is to give a preliminary answer to such a question, through the capacity analysis of the forward link of a multisatellite, multibeam, radio communication network. Specifically, starting from simplified yet realistic assumptions on the beam layout, the antenna footprint shape, and the coding/multiplexing/modulation and power control strategies, it is shown that the blind, adaptive, interference-mitigation receiver, selected as an appealing representative of the lot, can indeed boost the system quality of service in terms of outage probability. The results are derived after a mix of theoretical analysis (as far as the detector performance evaluation is concerned) and simulation (to examine a number of different random system configurations) to circumvent the inherent complexity of the issue.", } @ARTICLE{Ioss9902:Differential, AUTHOR="Athanassios Iossifides and Fotini-Niovi Pavlidou", TITLE="Differential M-ary Orthogonal Signaling for {DS/CDMA} Land Mobile Satellite Communications", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="214-222", MONTH=feb, YEAR=1999, REFERENCES=15, ABSTRACT="In this paper, we derive an analytical framework for the performance evaluation of a recently proposed M-ary orthogonal scheme based on differential encoding/decoding of the Walsh/Hadamard chips prior/after spreading. This technique makes feasible nonpilot-assisted detection over fast fading environments such as the land mobile satellite (LMS) channel. Our results show that differential M-ary orthogonal signaling presents very good performance at Doppler frequency shifts much higher than the symbol rate. Amplitude statistics are considered to be Rayleigh, but may be easily extended to more general models based on the analytical derivation presented.", } @ARTICLE{Vala9902:Code, AUTHOR="Cyril G. F. Valadon and Greet A. Verelst and Payam Taaghol and R. Tafazolli and Brian Evans", TITLE="Code-Division Multiple Access for Provision of Mobile Multimedia Services with a Geostationary Regenerative Payload", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="223-237", MONTH=feb, YEAR=1999, REFERENCES=26, ABSTRACT="The design of a satellite mobile multimedia communication system operating at Ka band and using synchronous CDMA is presented. The air interface described in the paper was derived taking into account the requirements induced by the provision of multimedia services to compact portable and mobile terminals. In order to minimize the complexity of the satellite payload, the concept of partial frequency reuse is introduced. A novel algorithm based on evolutionary theory is derived in order to optimize the corresponding link dimensioning. The satellite payload is described, and techniques reducing the computational requirements are proposed. It is then shown that the on-board complexity associated with the given design is within acceptable technological limits.", } @ARTICLE{Bouc9902:Fast, AUTHOR="Marie-Laure Boucheret and Ivar Mortensen and Henri Favaro", TITLE="Fast Convolution Filter Banks for Satellite Payloads with On-Board Processing", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="238-248", MONTH=feb, YEAR=1999, REFERENCES=21, ABSTRACT="Filter banks able to demultiplex channels of different sizes are necessary on board the satellite when a single bit-rate channel is assigned to each user. In this paper, the method referred to as the fast convolution filter bank is analyzed for regenerative payloads. The size of the input fast Fourier transform (FFT) depends on the narrowest channel, while the inverse fast Fourier transform (IFFT) number of points is relative to the decimation ratio associated with each channel. In order to reduce the complexity, most of the frequency coefficients are forced to zero, leading to a violation of the overlap-and-save (OS) condition. It is shown that the resulting error can be modeled as a cyclostationary process, and an optimization method based on minimization of the associated mean-square error (MSE) is proposed. Fast convolution is then compared with multistage implementation in terms of flexibility, reconfigurability, and complexity.", } @ARTICLE{Pate9902:Simulation, AUTHOR="K. Patel and Joel Morris", TITLE="Simulation Study of an Adaptive Phase Alignment System for Optical Heterodyne Communications Under Misalignment Conditions", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="249-256", MONTH=feb, YEAR=1999, REFERENCES=9, ABSTRACT="A postphotodetection adaptive phase alignment system using an aperture array of photodetectors is presented to reduce the signal loss in an optical (free-space) heterodyne receiver resulting from wavefront misalignment (tilt) on a satellite platform. This paper compares two kinds of rectangular aperture configurations--full aperture and array aperture configurations--via a software simulation study of the error performance after DPSK demodulation for different angles of arrival (tilt) of the received signal wavefront. For the array configuration, an adaptive phase alignment system is used that phase aligns the signals from the different photodetector array elements, and constructively adds them to yield a higher signal magnitude as compared to that of signal of a single-element photodetector of the same total area. The optimum aperture length for a given wavefront misalignment is derived, and is verified via simulation.", } @ARTICLE{Birk9902:Judicious, AUTHOR="Y. Birk and Y. Keren", TITLE="Judicious Use of Redundant Transmissions in Multichannel {ALOHA} Networks with Deadlines", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="257-269", MONTH=feb, YEAR=1999, REFERENCES=19, ABSTRACT="This paper shows how to improve the classic multichannel slotted ALOHA protocols by judiciously using redundant transmissions. The focus is on user-oriented requirements: a deadline along with a permissible probability of failing to meet it. Subject to satisfying those, maximization of capacity is the optimization goal. When there is no success/failure feedback prior to the deadline, the use of information dispersal with some redundancy provided by error-correcting codes for the data in conjunction with a replicated, separately transmitted synchronization preamble, is proposed. It is shown to sharply reduce the overhead resulting from the use of shorter packets and to significantly increase capacity. When the deadline permits several transmission-feedback rounds, we propose a novel replication-based retransmission policy: all attempts except the final one entail the transmission of a single or very few copies, and a larger number of copies are transmitted in the final attempt. This sharply increases channel capacity, even with a single transmitter per station. The proposed approaches are particularly suitable for high-bandwidth satellites with on-board processing.", } @ARTICLE{Fars9902:Broadband, AUTHOR="and Ramjee - Prasad", TITLE="Broadband Wide-Area Networking via {IP/ATM} over {SATCOM}", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="270-285", MONTH=feb, YEAR=1999, REFERENCES=19, ABSTRACT="A concept for broadband wide-area networking based on the use of the Internet Protocol (IP) over asynchronous transfer mode (ATM) broadcast over extremely high-frequency (EHF) 30/20 GHz Ka-band satellite communication (SATCOM) is presented. It is primarily intended to support applications such as broadcast of data and video, fast Internet access, and teleconsultation with interactive white board. Operation from midsize terminals located at a corporate headquarters to small highly transportable terminals at remote facilities is envisioned.", } @ARTICLE{Gera9902:Throughput, AUTHOR="D. P. Gerakoulis and W. C. Chan and E. Geraniotis", TITLE="Throughput Evaluation of a Satellite-Switched {CDMA} {(SS/CDMA)} Demand Assignment System", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="286-302", MONTH=feb, YEAR=1999, REFERENCES=7, ABSTRACT="This paper presents throughput evaluation of a satellite-switched code-division multiple-access (SS/CDMA) system which operates under demand assignment control. SS/CDMA provides both multiple access and switching to a geostationary multibeam satellite. Multiple access is resolved by space, frequency, and code division. Space division is introduced by the multibeam antennas that provide frequency reuse in each beam. The spectrum is then channelized into frequency bands where each band is accessed by code division for both the uplink and downlink. The satellite on board performs the switching function, which is also based on compatible code-multiplexed switching. The switch may route both circuit calls and data packets which are assigned upon request. The on-board code-division switch operates under the control of a channel assignment algorithm. In this paper, we provide channel assignment algorithms for optimum, suboptimum, and random switch operation. The system throughput has been evaluated for each case and compared. Performance analysis has been carried out for the case of the optimum switch scheduling. The analysis is based on a discrete-time Markovian model, and provides the call-blocking probabilities and data packet delays. Computer simulations have been used to evaluate the performance of the optimum, suboptimum, and random cases. It is shown that the circuit call-blocking probabilities achieved for these cases are almost the same. The optimum algorithm achieves the minimum data packet delay, while the performance of the suboptimum algorithm is slightly better than the random one. Furthermore, data packets may be routed via the switch with limited delays, even with a heavy load of circuit calls.", } @ARTICLE{Baio9902:Definition, AUTHOR="A. Baiocchi and N. Blefari-Melazzi and M. Listanti and C. Soprano", TITLE="Definition and Performance Analysis of a Simple, {ABR-Like} Congestion Control Scheme for Satellite {ATM} Networks with Guaranteed Loss Performance", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="303-313", MONTH=feb, YEAR=1999, REFERENCES=9, ABSTRACT="In this paper, we describe an ATM system architecture for satellite communications. The proposed architecture includes on-board switching, and supports the ATM traffic categories defined in recent specifications. In this framework, a critical issue is the control of congestion phenomena. In particular, the application of feedback-based control strategies to a satellite network is critical due to the peculiarities of such an environment: very large propagation delay, expensive transfer capacity, and limited on-board processing capability. The available bit rate (ABR) is the ATM service category handled according to a reactive congestion control (RCC). The focus of this paper is the definition of an RCC that is fully compatible with the standard ABR protocols, and that takes into account the constraints of the satellite environment. We also derive an analytical model that allows us to evaluate the performance of the proposed scheme and to dimension the system. The analytical model is validated with simulations.", } @ARTICLE{Poch9902:Real, AUTHOR="Herve Le Pocher and Victor C. M. Leung and Duncan Gillies", TITLE="Real-Time Multimedia Scheduling Policies for End-to-End Delay Jitter and Loss Guarantees Across {ATM} Satellite Systems", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="314-325", MONTH=feb, YEAR=1999, REFERENCES=17, ABSTRACT="We propose a simple first-in first-out (FIFO)-based service protocol which is appropriate for a multimedia ATM satellite system. The main area of interest is to provide real-time traffic with upper bounds on the end-to-end delay, jitter, and loss experienced at various service queues within a satellite network. Various service protocols, each based on a common underlying strategy, are developed in light of the requirements and limitations imposed at each of the satellite's subsystems. These subsystems include the uplink (UL) earth station (ES) service queue, on-board processing (OBP) queues, and the downlink (DL) ES service queue feeding into a wireline ATM network or directly to an end-user application. Numerous network simulation results demonstrate the tractability, efficiency, and versatility of the underlying service discipline. Key features of our strategy are its algorithmic and architectural simplicity, its non-ad-hoc scheduling approach, and its unified treatment of all real-time streams at all service queues. In addition, the delay and jitter bounds are uncoupled. In this way, end-to-end jitter can be tightly controlled even if medium access requires long indeterminate waiting durations.", } @ARTICLE{Hend9902:Transport, AUTHOR="Thomas R. Henderson and Randy H. Katz", TITLE="Transport Protocols for Internet-Compatible Satellite Networks", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="326-344", MONTH=feb, YEAR=1999, REFERENCES=53, ABSTRACT="We address the question of how well end-to-end transport connections perform in a satellite environment composed of one or more satellites in geostationary orbit (GEO) or low-altitude earth orbit (LEO), in which the connection may traverse a portion of the wired Internet. We first summarize the various ways in which latency and asymmetry can impair the performance of the Internet's transmission control protocol (TCP), and discuss extensions to standard TCP that alleviate some of these performance problems. Through analysis, simulation, and experiments, we quantify the performance of state-of-the-art TCP implementations in a satellite environment. A key part of the experimental method is the use of traffic models empirically derived from Internet traffic traces. We identify those TCP implementations that can be expected to perform reasonably well, and those that can suffer serious performance degradation. An important result is that, even with the best satellite-optimized TCP implementations, moderate levels of congestion in the wide-area Internet can seriously degrade performance for satellite connections. For scenarios in which TCP performance is poor, we investigate the potential improvement of using a satellite gateway, proxy, or Web cache to ``split'' transport connections in a manner transparent to end users. Finally, we describe a new transport protocol for use internally within a satellite network or as part of a split connection. This protocol, which we call the satellite transport protocol (STP), is optimized for challenging network impairments such as high latency, asymmetry, and high error rates. Among its chief benefits are up to an order of magnitude reduction in the bandwidth used in the reverse path, as compared to standard TCP, when conducting large file transfers. This is a particularly important attribute for the kind of asymmetric connectivity likely to dominate satellite-based Internet access.", } @ARTICLE{Mine9902:High, AUTHOR="Ina Minei and Richard M. Cohen", TITLE="High-Speed {Internet} Access Through Unidirectional Geostationary Satellite Channels", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="345-359", MONTH=feb, YEAR=1999, REFERENCES=9, ABSTRACT="One of the proposed solutions for increasing the speed of Internet access is to connect the home user to a direct satellite channel, at a speed 20 times faster than that of an average telephone modem. Communication over satellite links is often characterized by sporadic high bit-error rates and burst losses. This is especially true when working in the Ka band, where weather conditions greatly affect link availability. Under such conditions, the TCP protocol that is predominantly used by data applications degrades dramatically in performance. Using simulations, this paper studies the performance of TCP under different network conditions. Several modifications, that take advantage of the special properties of the satellite channel, are proposed, and a new sender algorithm which can efficiently handle burst losses is presented. The main attractiveness of the proposed new sender algorithm is that it can be implemented only at the satellite ground station, rather than at every server in the world.", } @ARTICLE{Kora9902:Resource, AUTHOR="Heba Koraitim and Samir Tohme", TITLE="Resource Allocation and Connection Admission Control in Satellite Networks", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="360-372", MONTH=feb, YEAR=1999, REFERENCES=18, ABSTRACT="This work focuses on resource allocation and connection admission control (CAC) issues in broadband satellite networks. Broadband services can now be provided by satellite systems operating in the Ka band, due to the large bandwidth available at such frequencies. In this context, we propose a resource allocation algorithm which integrates three classes of services at the MAC layer: constant bit rate (CBR), bursty data, and best effort services. The double movable boundary strategy (DMBS) is proposed to establish a resource-sharing policy among these service classes over the satellite uplink channel. The DMBS is a dynamically controlled boundary policy which adapts the allocation decision to the variable network loading conditions. Connection-oriented and connectionless services can be supported by the system. The CAC and slot allocation decisions are taken at the beginning of each control period after monitoring the filling level of traffic request queues. A threshold level for the bursty data request queue is defined to regulate the CAC process. The impact of the queue threshold value on the performance of the DMBS allocation policy is particularly evaluated in this study. A dynamic variation of this value is also proposed to enhance the system response to interactive applications. We present a brief analytical formulation for the DMBS model, together with simulation study details and performance evaluation results. The obtained results indicate a good efficiency, in terms of overall channel throughput and CBR blocking probability, for both fixed and dynamic data queue threshold approaches. The dynamic approach, however, outperforms the fixed one in terms of overall encountered bursty data delay.", } @ARTICLE{ElBa9902:Optimization, AUTHOR="Tamer ElBatt and Anthony Ephremides", TITLE="Optimization of Connection-Oriented, Mobile, Hybrid Network Systems", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="373-384", MONTH=feb, YEAR=1999, REFERENCES=21, ABSTRACT="In this paper, we consider the extension of a cellular system by means of satellite channels. Specifically, we consider an area covered by a number of cells, that is also covered by a number of spot beams. We consider connection-oriented service, and call durations are assumed to be exponentially distributed. Also, users are mobile and, as such, they may cross cell and/or spot-beam boundaries, thus necessitating handoffs. We incorporate the possibility of call dropping due to unsuccessful hand-off attempts, in addition to satellite propagation delays along with the probability of new call blocking, and formulate a specific multifaceted cost function that must be ultimately minimized. The minimization is to be carried out by choosing: 1) the optimal partitioning of channels between the cellular and the satellite systems, and ii) the call admission and assignment policy, subject to the constraints of a demand vector that consists of an exogenous (new-call) generation process and an internal (handoff-based) process that results from the mobility model. Two subproblems of this complex optimization problem are solved by means of numerical techniques and by means of so-called standard clock simulation techniques. In this solution method, we employ the ordinal optimization approach which focuses on preserving the performance rank, rather than the performance prediction of the different control policies. We find that the ``double'' coverage, through both cellular and satellite resources, results in substantial improvement over pure terrestrial or pure satellite systems for parameter values that correspond to practical environments.", } @ARTICLE{Pris9902:Interworking, AUTHOR="F. D. Priscoli", TITLE="Interworking of a Satellite System for Mobile Multimedia Applications with the Terrestrial Networks", JOURNAL=ieeejsac, VOLUME=17, NUMBER=2, PAGES="385-394", MONTH=feb, YEAR=1999, REFERENCES=8, ABSTRACT="This paper deals with the interworking of a satellite system for mobile multimedia applications with the terrestrial environment. The concept of an ``overlying network'' is introduced with the aim of giving a common approach for the interworking of the considered satellite system with the various terrestrial networks (B-ISDN, N-ISDN, TCP/IP). The paper particularizes the introduced concept to the case in which the considered satellite system is interfaced with the broadband ISDN (B-ISDN).", } @ARTICLE{Guer9902:Quality, AUTHOR="R. Guérin and V. Peris", TITLE="Quality-of-Service in Packet Networks: Basic Mechanisms and Directions", JOURNAL=cn, VOLUME=31, NUMBER=3, PAGES="169-189", MONTH=feb, YEAR=1999, KEYWORDS="QoS Mechanisms; real-time traffic; scheduling; buffer management; aggregation", ABSTRACT="In this paper, we review the basic mechanisms used in packet networks to support Quality-of-Service (QoS) guarantees. We outline the various approaches that have been proposed, and discuss some of the trade-offs they involve. Specifically, the paper starts by introducing the different scheduling and buffer management mechanisms that can be used to provide service differentiation in packet networks. The aim is not to provide an exhaustive review of existing mechanisms, but instead to give the reader a perspective on the range of options available and the associated trade-off between performance, functionality, and complexity. This is then followed by a discussion on the use of such mechanisms to provide specific end-to-end performance guarantees. The emphasis of this second part is on the need for adapting mechanisms to the different environments where they are to be deployed. In particular, fine grain buffer management and scheduling mechanisms may be neither necessary nor cost effective in high speed backbones, where `aggregate' solutions are more appropriate. The paper discusses issues and possible approaches to allow coexistence of different mechanisms in delivering end-to-end guarantees.", URL="http://www.seas.upenn.edu/~guerin/publications/qos.ps.gz", } @TECHREPORT{Gerl9902:Generalized, AUTHOR="M. Gerla and Renato {Lo Cigno} and S. Mascolo and W. Weng", TITLE="Generalized Window Advertising for {TCP} Congestion Control", INSTITUTION="UCLA", ADDRESS="Los Angeles, California", NUMBER=990012, MONTH=feb, YEAR=1999, KEYWORDS="TCP; congestion control", ABSTRACT="Congestion in the Internet is becoming a major cause of network performance degradation. The Generalized Window Advertising (GWA) scheme proposed in this paper is a new approach for enhancing the congestion control properties of TCP. GWA requires only minor modifications to the existing protocol stack and is completely backward compatible, allowing GWA-hosts to interact with non-GWA hosts without modifications. GWA exploits the notion of congestion feedback from the network to end hosts. It is based on solid control theory results that guarantee performance and stable network operation. GWA is able to avoid window oscillations and the related uctuations in offered load and network performance. This makes it more robust to sustained network overload due to a large number of connections competing for the same bottleneck, a situation where traditional TCP implementations fail to provide satisfactory performance. GWA TCP is compared with traditional TCP, TCP with RED and also ECN using ns-2 simulation. Results show that in most cases GWA-TCP outperforms the traditional schemes. In particular, when compared with ECN, it provides smoother network operation and increased fairness. The coexistence of GWA TCP with RED and ECN is also tested. The test shows that, besides being backward compatible, GWA TCP is also friendly to older TCP versions.", URL="http://www.cs.ucla.edu/NRL/ipatm/publications/ebntcp.ps.gz", } @ARTICLE{Lett9902:Advances, AUTHOR="Paul Lettieri and Mani B. Srivastava", TITLE="Advances in Wireless Terminals", JOURNAL=ieeepcm, VOLUME=6, NUMBER=1, MONTH=feb, YEAR=1999, ABSTRACT="Current wireless terminals are limited to voice terminals such as cellular and PCS phones, and traditional laptop computers and PDAs configured with wireless modems and network interface cards. However, the current wireless networks, which are by and large wireless extensions of the circuit-switched voice networks, are being replaced by emerging wireless networking technologies that are intrinsically designed to support packet data and multimedia services. This will lead to novel networked applications and services, which in turn will require wireless terminals capable of exploiting these services. What shape will these next-generation wireless terminals take? The answer, based on the much talked about notion of", } @ARTICLE{Chan9902:Wireless, AUTHOR="Mun Choon Chan and Tai-Kuo Woo", TITLE="Next-Generation Wireless Data Services: Architecture and Experience", JOURNAL=ieeepcm, VOLUME=6, NUMBER=1, MONTH=feb, YEAR=1999, REFERENCES=30, KEYWORDS="mobile networks", ABSTRACT="Wireless data promises useful services and great convenience. The many technological and economical obstacles that have been hampering its growth are slowly being overcome. In this article we first explain our vision of what next-generation wireless data services may look like. Then we present the different elements of a base architecture designed to support the common requirements and features. As an example, we describe our initial experience in implementing a wireless data server prototype at Bell Laboratories.", URL="http://www.comsoc.org/pci/private/1999/feb/Chan.html", } @ARTICLE{Rein9902:Soft, AUTHOR="D. Reininger and R. Izmailov and Balasubramanian Rajagopalan and M. Ott and D. Raychaudhuri", TITLE="Soft {QoS} Control in the {WATMnet} Broadband Wireless System", JOURNAL=ieeepcm, VOLUME=6, NUMBER=1, MONTH=feb, YEAR=1999, REFERENCES=20, KEYWORDS="mobile networks", ABSTRACT="A framework for QoS control in broadband wireless networks is presented. The framework allows terminal and network-initiated bandwidth renegotiation to handle wide spatiotemporal traffic dynamics characteristic of mobile multimedia applications. The concept of", URL="http://www.comsoc.org/pci/private/1999/feb/Reininger.html", } @ARTICLE{Bhar9902:Fair, AUTHOR="V. Bharghavan and S. F. Lu and Thyaga Nandagopal", TITLE="Fair Queuing in Wireless Networks: Issues and Approaches", JOURNAL=ieeepcm, VOLUME=6, NUMBER=1, MONTH=feb, YEAR=1999, REFERENCES=11, KEYWORDS="mobile networks", ABSTRACT="Fair queuing has long been a popular paradigm for providing bounded delay channel access and separation between flows in wireline networks. However, adapting fair queuing to the wireless domain is not a trivial task because of the unique problems in wireless channels such as location-dependent and bursty channel error. In this article we identify the key issues in wireless fair queuing, define a wireless fair service model, present a generic framework for designing wireless fair queuing algorithms, and explore solutions within this framework. Using simple examples, we show that some of the wireless fair queuing algorithms currently proposed in literature can achieve wireless fair service.", URL="http://www.comsoc.org/pci/private/1999/feb/Bharghavan.html", } @ARTICLE{Nobe9902:Adaptive, AUTHOR="Robert van Nobelen and Nambirajan Seshadri and J. Whitehead and Shailender Timiri", TITLE="An Adaptive Radio Link Protocol with Enhanced Data Rates for {GSM} Evolution", JOURNAL=ieeepcm, VOLUME=6, NUMBER=1, MONTH=feb, YEAR=1999, REFERENCES=16, KEYWORDS="mobile networks", ABSTRACT="In this article we address the problem of link adaptation in a wireless data system. Link adaptation is necessary in order to match the data rate to time-varying channel and interference conditions. We present a robust radio link protocol based on the concept of incremental redundancy (IR). Here, redundant data, for the purpose of error correction, is transmitted only when previously transmitted packets of information are received and acknowledged to be in error. The redundant packet is combined with the previously received (errored) information packets in order to facilitate error correction decoding. If there is a decoding failure, more redundancy is transmitted. It is shown here that an RLP built using the IR concept is more robust and has better throughput than link adaptation schemes using explicit channel measurements such as instantaneous or average signal-to-noise or signal-to-interference ratio. We study the performance of an implementation of a IR-based RLP for EDGE data for and demonstrate its superior throughput and robustness properties. The penalty paid for increased robustness and higher throughput is additional receiver memory and higher delay. IR based RLP has already been standardized for IS-136+ packet data and is being actively considered for EDGE standardization.", URL="http://www.comsoc.org/pci/private/1999/feb/Seshadri.html", } @ARTICLE{Pan9902:Optical, AUTHOR="Yu-Chun Pan and C. Qiao and Yi Yang", TITLE="Optical Multistage Interconnection Networks: New Challenges and Approaches", JOURNAL=ieeecm, VOLUME=37, NUMBER=2, MONTH=feb, YEAR=1999, REFERENCES=12, ABSTRACT="Optical interconnections for communication networks and multiprocessor systems have been studied extensively. A basic element of optical switching networks is a directional coupler with two inputs and two outputs or switching elements. Depending on the control voltage applied to it, an input optical signal is coupled to either of the two outputs, setting the SE to either the straight or cross state. A class of topologies that can be used to construct optical networks is multistage interconnection networks, which interconnect their inputs and outputs via several stages of SEs. Although optical MINs hold great promise and have demonstrated advantages over their electronic counterparts, they also introduce new challenges such as how to deal with the unique problem of avoiding crosstalk in the SEs. In this article we survey the research carried out, including major challenges encountered and approaches taken, during the past few years on optical MINs.", URL="http://www.comsoc.org/ci/private/1999/feb/Pan.html", } @ARTICLE{Mars9902:WDM, AUTHOR="Marco {Ajmone Marsan} and A. Bianco and Emilio Leonardi and A. Morabito and F. Neri", TITLE="All-Optical {WDM} Multi-Rings with Differentiated {QoS}", JOURNAL=ieeecm, VOLUME=37, NUMBER=2, MONTH=feb, YEAR=1999, REFERENCES=10, ABSTRACT="This article considers all-optical WDM networks based on a slotted multichannel ring topology, where nodes are equipped with one fixed-wavelength receiver and one wavelength-tunable transmitter, and shows how to design very effective MAC protocols that provide packet-mode transport to multiple information flows with different QoS requirements. As an example, we describe SR3, a collision-free slotted MAC protocol which combines a packet scheduling strategy (called SRR), a fairness control algorithm (called MMR), and a reservation mechanism. SRR achieves an efficient exploitation of the available bandwidth, MMR guarantees fair throughput access to each node, and SR3, by permitting slot reservations, leads to tighter control on access delays, and can thus effectively support traffic classes with different QoS requirements.", URL="http://www.comsoc.org/ci/private/1999/feb/Marsan.html", } @ARTICLE{Saha9902:Light, AUTHOR="Laxman Sahasrabuddhe and B. Mukherjee", TITLE="Light-Trees: Optical Multicasting for Improved Performance in Wavelength-Routed Networks", JOURNAL=ieeecm, VOLUME=37, NUMBER=2, MONTH=feb, YEAR=1999, REFERENCES=10, ABSTRACT="We introduce the concept of a light-tree in a wavelength-routed optical network. A light-tree is a point-to-multipoint generalization of a lightpath. A lightpath is a point-to-point all-optical wavelength channel connecting a transmitter at a source node to a receiver at a destination node. Lightpath communication can significantly reduce the number of hops (or lightpaths) a packet has to traverse; and this reduction can, in turn, significantly improve the network's throughput. We extend the lightpath concept by incorporating an optical multicasting capability at the routing nodes in order to increase the logical connectivity of the network and further decrease its hop distance. We refer to such a point-to-multipoint extension as a light-tree. Light-trees can not only provide improved performance for unicast traffic, but they naturally can better support multicast traffic and broadcast traffic. In this study, we shall concentrate on the application and advantages of light-trees to unicast and broadcast traffic. We formulate the light-tree-based virtual topology design problem as an optimization problem with one of two possible objective functions: for a given traffic matrix, (i) minimize the network-wide average packet hop distance, or (ii) minimize the total number of transceivers in the network. We demonstrate that an optimum light-tree-based virtual topology has clear advantages over an optimum lightpath-based virtual topology with respect to the above two objectives.", URL="http://www.comsoc.org/ci/private/1999/feb/Mukherjee.html", } @ARTICLE{Yosh9902:Future, AUTHOR="Hiroshi Yoshimura and K. Sato and Noboru Takachio", TITLE="Future Photonic Transport Networks Based on {WDM} Technologies", JOURNAL=ieeecm, VOLUME=37, NUMBER=2, MONTH=feb, YEAR=1999, REFERENCES=11, ABSTRACT="It is expected that the recent explosion in Internet traffic implies a paradigm shift from a voice network to a data-centric network. The first and most important requirement of future transport networks is the large bandwidth transport capability which enables the paradigm shift. In addition, requirements for new service attributes are becoming more tangible. Furthermore, high reliability will be indispensable because the multimedia network will be the basis for the information society. To develop the robust and efficient networks that satisfy the requirements above, new network architectures and technologies should be developed. Photonic networks employing dense WDM technologies appear to be the solution. In this article, first the basic concept of the future photonic network is depicted. Next, the capability of large-capacity fiber transmission is shown. The critical degradation factor of fiber nonlinearity is analyzed, and the effectiveness of distributed amplification is quantitatively demonstrated. Furthermore, recent advances in fiber amplifiers which greatly widen the usable fiber window are shown. Other key technologies such as absolute frequency referencing and multiple channel frequency management techniques are also discussed.", URL="http://www.comsoc.org/ci/private/1999/feb/Sato.html", } @ARTICLE{III9902:Technical, AUTHOR="Joseph Mitola I. I. I", TITLE="Technical Challenges in the Globalization of Software Radio", JOURNAL=ieeecm, VOLUME=37, NUMBER=2, MONTH=feb, YEAR=1999, REFERENCES=13, ABSTRACT="During the past five years, the software radio has emerged from demonstrations in military research to become a cornerstone of the third-generation strategy for affordable, ubiquitous, global communications. This article reviews the concepts, architecture, technology challenges, and economics of the continuing productization and globalization of software radio. It provides a point of departure for subsequent articles in this feature topic.", URL="http://www.comsoc.org/ci/private/1999/feb/Mitola.html", } @ARTICLE{Tsur9902:Broadband, AUTHOR="Hiroshi Tsurumi and Yasunobu Suzuki", TITLE="Broadband {RF} Stage Architecture for Software-Defined Radio in Handheld Terminal Applications", JOURNAL=ieeecm, VOLUME=37, NUMBER=2, MONTH=feb, YEAR=1999, REFERENCES=10, ABSTRACT="Broadband RF is a general-purpose common RF stage for every standard within a set of RF bands. The RF stage architecture presented in this article is suitable for software-defined radios.", URL="http://www.comsoc.org/ci/private/1999/feb/Tsurumi.html", } @ARTICLE{Wald9902:Trends, AUTHOR="Robert H. Walden", TITLE="Performance Trends for Analog-to-Digital Converters", JOURNAL=ieeecm, VOLUME=37, NUMBER=2, MONTH=feb, YEAR=1999, REFERENCES=9, ABSTRACT="Analog-to-digital converters are key components of signal processing systems, and may even dictate system architectures due to their limitations on sampling rate and resolution. The state of the art for ADCs, including both experimental converters and commercially available parts, is reviewed herein. and the data imply that the performance measure, P = 2SNRbits ¸ fsamp, is mainly limited by uncertainty in the sampling process (aperture jitter) over a very wide range of sampling rates. For ADCs operating at multi-GSPS rates, the speed of the device technology is also a limiting factor (due to comparator ambiguity). Furthermore, technological progress as measured by P has been slow of late; the average improvement is only ~ 1.5 bits for any given sampling frequency over the last eight years.", URL="http://www.comsoc.org/ci/private/1999/feb/Walden.html", } @ARTICLE{Ches9902:Digital, AUTHOR="David Chester", TITLE="Digital {IF} Filter Technology for {3G} Systems: An Introduction", JOURNAL=ieeecm, VOLUME=37, NUMBER=2, MONTH=feb, YEAR=1999, REFERENCES=11, ABSTRACT="Contemporary digital communication systems such as those being developed for the deployment of third-generation cellular require ever increasing performance levels in their signal processing chains to extract higher data rates and to provide decreasing price/performance ratios. Additionally, communication systems like 3G that must support multimode flexibility, such as the software radio, must be able to reconfigure their signal processing chains while keeping circuit complexity to a minimum. Given these constraints, DSP is the only viable alternative for baseband processing and digital IF processing. DSP is in many cases the only viable alternative to analog IF processing. Digital IF affords greater flexibility and higher performance in terms of attenuation and selectivity. It also offers better time and environment stability and lower equipment production costs than traditional analog techniques.", URL="http://www.comsoc.org/ci/private/1999/feb/Chester.html", } @ARTICLE{Cumm9902:FPGA, AUTHOR="Mark Cummings and Shinichiro Haruyama", TITLE="{FPGA} in the Software Radio", JOURNAL=ieeecm, VOLUME=37, NUMBER=2, MONTH=feb, YEAR=1999, REFERENCES=12, ABSTRACT="As new radio standards are deployed without substantially supplanting existing ones, the need for multimode multiband handsets and infrastructure increases. This article describes how emerging FPGA technology's unique combination of size and power efficiency plus field programmability offers a transition of FPGAs from ASIC prototyping to embedded products. Software-defined receiver examples suggest an enlarged role for FPGAs in pragmatic paths toward the productization of software radio technology.", URL="http://www.comsoc.org/ci/private/1999/feb/Cummings.html", } @ARTICLE{Turl9902:Complexity, AUTHOR="T. Turletti and David Tennenhouse", TITLE="Complexity of a Software {GSM} Base Station", JOURNAL=ieeecm, VOLUME=37, NUMBER=2, MONTH=feb, YEAR=1999, REFERENCES=7, ABSTRACT="There is increasing interest in developing radio-based applications in software. The new architecture for implementing mobile telephony base stations has the potential of offering many benefits: great cost savings by using one transceiver per BTS instead of one per channel, tremendous flexibility by moving system-specific parameters to the digital part, and allowing the support of a wide range of modulation and coding schemes. A very important problem in designing software radio applications is the need to estimate the required complexity of processing to dimension systems. For example, with a software GSM BTS it is critical to estimate the number of channels that can be supported by a given processor configuration, and to predict the impact of future processor enhancements on its capacity. This article is a short version of one which appeared in the IEEE Journal on Selected Areas in Communications Special Issue on Software Radios [1]. It focuses on the design of a software implementation of a GSM BTS and proposes a platform-independent evaluation of its computational requirements based on SPEC benchmarks [2].", URL="http://www.comsoc.org/ci/private/1999/feb/Turletti.html", } @ARTICLE{Benj9902:Smart, AUTHOR="R. I. Benjamin and Ismail Kaya and A. Nix", TITLE="Smart Base Stations for ``Dumb'' Time-Division Duplex Terminals", JOURNAL=ieeecm, VOLUME=37, NUMBER=2, MONTH=feb, YEAR=1999, REFERENCES=13, ABSTRACT="Users of mobile IT systems are calling for ever higher data rates, but such mobile radios are subject to multipath fading and intersymbol interference, often calling for complex equalizers at both ends of each link. Where the links are of short range, they often use time-division duplex. This article demonstrates how this option permits much of the complexity of channel matching and equalization to be transferred from post-processing at the many sparsely used mobile terminals to a few intensively used preprocessors at the base station or central hub.", URL="http://www.comsoc.org/ci/private/1999/feb/Benjamin.html", } @ARTICLE{Chla9902:Scalable, AUTHOR="I. Chlamtac and V. Elek and A. Fumagalli and Csaba Szab", TITLE="Scalable {WDM} access network architecture based on photonic slot routing", JOURNAL=ieanep, VOLUME=7, NUMBER=1, PAGES="1-9", MONTH=feb, YEAR=1999, REFERENCES=17, ABSTRACT="This paper introduces an approach to solving the fundamental scalability problem of all-optical packet switching wavelength-division multiplexing (WDM) access networks. Current optical networks cannot be scaled by simply adding nodes to existing systems due to the accumulation of insertion losses and/or the limited number of wavelengths. Scalability through bridging requires, on the other hand, the capability to switch packets among adjacent subnetworks on a wavelength basis. Such a solution is, however, not possible due to the unavailability of fast-switching wavelength sensitive devices. In this paper, we propose a scalable WDM access network architecture based on a recently proposed optical switching approach, termed photonic slot routing. According to this approach, entire slots, each carrying multiple packets (one on each wavelength) are ``transparently'' routed through the network as single units so that wavelength sensitive data flows can be handled using a fast-switching wavelength nonsensitive devices based on proven technologies. The paper shows that the photonic slot routing technique can be successfully used to achieve statistical multiplexing of the optical bandwidth in the access network, thus providing a cost-effective solution to today's increasing bandwidth demand for data transmissions.", URL="http://www.acm.org/pubs/articles/journals/ton/1999-7-1/p1-chlamtac/p1-chlamtac.pdf", } @ARTICLE{Gree9902:Resource, AUTHOR="A. G. Greenberg and R. Srikant and W. Whitt", TITLE="Resource sharing for book-ahead and instantaneous-request calls", JOURNAL=ieanep, VOLUME=7, NUMBER=1, PAGES="10-22", MONTH=feb, YEAR=1999, REFERENCES=22, ABSTRACT="In order to provide an adequate quality of service to large-bandwidth calls, such as video conference calls, service providers of integrated services networks may want to allow some customers to book their calls ahead, i.e., make advance reservations. We propose a scheme for sharing resources among book-ahead (BA) calls (that announce their call holding times as well as their call initiation times upon arrival) and non-BA calls (that doe not announce their holding times). It is possible to share resources without allowing any calls in progress to be interrupted, but in order to achieve a more efficient use of resources, we think that it may be desirable to occasionally allow a call in progress to be interrupted. (In practice, it may be possible to substitute service degradation, such as bit dropping or coarser encoding of video, for interruption.) Thus, we propose an admission control algorithm in which a call is admitted if an approximate interrupt probability (compute in real time) is below a threshold. Simulation experiments show that the proposed admission control algorithm can be better (i.e., yield higher total utilization or higher revenue) than alternative schemes that do not allow interruption, such as a strict partitioning of resources.", URL="http://www.acm.org/pubs/articles/journals/ton/1999-7-1/p10-greenberg/p10-greenberg.pdf", } @ARTICLE{Hobs9902:Parallel, AUTHOR="Richard F. Hobson and P.-C. Wong", TITLE="A parallel embedded-processor architecture for {ATM} reassembly", JOURNAL=ieanep, VOLUME=7, NUMBER=1, PAGES="23-37", MONTH=feb, YEAR=1999, REFERENCES=29, ABSTRACT="The asynchronous transfer mode (ATM) reassembly algorithm for adaptation layer five is broken down into concurrent tasks for efficient VLSI implementation. VHDL and HSPICE simulations show that the proposed reassembly chip architecture will function with ATM line rates up to 700 Mb/s. The architecture is based upon three embedded lightweight processors, a variety of supporting circuitry, and a peripheral component interface (PCI) bus host interface. An important architectural feature is the use of a paged memory management system for the reconstruction of variable length messages.", URL="http://www.acm.org/pubs/articles/journals/ton/1999-7-1/p23-hobson/p23-hobson.pdf", } @ARTICLE{Chla9902:Energy, AUTHOR="I. Chlamtac and C. Petrioli and Jason Redi", TITLE="Energy-conserving access protocols for identification networks", JOURNAL=ieanep, VOLUME=7, NUMBER=1, PAGES="51-59", MONTH=feb, YEAR=1999, REFERENCES=10, ABSTRACT="A myriad of application are emerging, in which energy conservation is critical system parameter for communications. Radio frequency identification device (RFID) networks, smart cards, and even mobile computing devices, in general, need to conserve energy. In RFID systems, nodes are small battery-operated inexpensive devices with radio receiving/transmitting and processing capabilities, integrated into the size of an ID card or smaller. These identification devices are designed for extremely low-cost large-scale applications, such that the replacement of batteries is not feasible. This imposes a critical energy constraining on the communications (access) protocols used in these systems, so that the total time a node needs to be active for transmitting or receiving information should e minimized. Among existing protocols, classical random access protocols are not energy conserving, while deterministic protocols lead to unacceptable delays. This paper deals with designing communications protocols with energy constraint, in which the number of time slots in which tags need to be in the active state is minimized, while the access delay meets the applications constraints. We propose three classes of protocols which combine the fairness of random access protocols with low energy requirements.", URL="http://www.acm.org/pubs/articles/journals/ton/1999-7-1/p51-chlamtac/p51-chlamtac.pdf", } @ARTICLE{Nong9902:Nonblocking, AUTHOR="Ge Nong and Jogesh K. Muppala and Mounir Hamdi", TITLE="Analysis of nonblocking {ATM} switches with multiple input queues", JOURNAL=ieanep, VOLUME=7, NUMBER=1, PAGES="60-74", MONTH=feb, YEAR=1999, REFERENCES=16, ABSTRACT="An analytical model for the performance analysis of a multiple input queued asynchronous transfer mode (ATM) switch is presented in this paper. The interconnection network of the ATM switch is internally nonblocking and each input port maintains a separate queue of cells for each output port. The switch uses a parallel iterative matching (PIM) [7] to find the maximal matching between the input and output ports of the switch. A closed-form solution for the maximum throughput of the switch under saturated conditions is derived. It is found that the maximum throughput of the switch exceeds 99\% with just four iterations of the PIM algorithm. Using the tagged input queue approach, an analytical model for evaluating the switch performance under an independent identically distributed Bernoulli traffic with the cell destinations uniformly distributed over all output ports is developed. The switch throughput, mean cell delay, and cell loss probability are computed from the analytical model. The accuracy of the analytical model is verified using simulation.", URL="http://www.acm.org/pubs/articles/journals/ton/1999-7-1/p60-nong/p60-nong.pdf", } @ARTICLE{Capo9902:Delivering, AUTHOR="Jeffrey Capone and I. Stavrakakis", TITLE="Delivering {QoS} requirements to traffic with diverse delay tolerances in a {TDMA} environment", JOURNAL=ieanep, VOLUME=7, NUMBER=1, PAGES="75-87", MONTH=feb, YEAR=1999, REFERENCES=14, ABSTRACT="The focus of this paper is on determining the call admission region and scheduling policies for a time-division multiple-access (wireless) system supporting heterogeneous real-time variable bit rate applications with distinct quality of service (QoS) requirements and traffic characteristics. The QoS is defined in terms of a maximum tolerable packet delay and dropping probability. A packet is dropped if it experience excess delay. The call admission region is established for policies that are work-conserving (WC) and that satisfy the earliest due date (EDD) service criterion (WC-EDD policies). Such policies are known to optimized the overall system performance. In addition to the determination of the call admission region, this study leads also to the construction of scheduling policies that deliver any performance in the region established for WC-EDD policies. Finally, an upper bound on the call admission region that can be achieved under any policy (not limited to the WC-EDD policies) is determined.", URL="http://www.acm.org/pubs/articles/journals/ton/1999-7-1/p75-capone/p75-capone.pdf", } @ARTICLE{Tass9902:Cut, AUTHOR="L. Tassiulas", TITLE="Cut-through switching, pipelining, and scheduling for network evacuation", JOURNAL=ieanep, VOLUME=7, NUMBER=1, PAGES="88-97", MONTH=feb, YEAR=1999, REFERENCES=11, ABSTRACT="A general model of a virtual circuit network consisting of a number of servers and a number of traffic classes is considered. A traffic class is identified by the sequence of servers that should be visited and the corresponding service rates before a message (customer) of the class leaves the network. The following cases are distinguished: 1) the messages need nonpreemptive service; 2) the service of a message can be preempted at any time; 3) pipelining of the service in a sequence of servers is allowed; and 4) pipelining is not allowed. All of these cases arise in different transmission switching techniques and scheduling schemes. A fluid model that emerges when both preemption and pipelining are allowed is considered. Scheduling schemes in the fluid model are compared with corresponding one sin the network with nonpreemptive service and no pipelining. The problem of evacuating the network from an initial backlog without further arrival is identified in the fluid model. Based on that, a policy with nearly optimal evacuation time is identified for the store-and-forward case. Finally, scheduling with deadlines is considered and it is shown that in the fluid model, the evacuation problem is equivalent to a linear programming problem. The evacuation times under different work-conserving policies are considered in specific examples.", URL="http://www.acm.org/pubs/articles/journals/ton/1999-7-1/p88-tassiulas/p88-tassiulas.pdf", } @ARTICLE{Xion9902:Restoration, AUTHOR="Yongqiang Xiong and L. G. Mason", TITLE="Restoration strategies and spare capacity requirements in self-healing {ATM} networks", JOURNAL=ieanep, VOLUME=7, NUMBER=1, PAGES="98-110", MONTH=feb, YEAR=1999, REFERENCES=25, ABSTRACT="This paper studies the capacity and flow assignment problem arising in the design of self-healing asynchronous transfer mode (ATM) networks using the virtual path concept. The problem is formulated here as a linear programming problem which is solved using standard methods. The objective is to minimize the spare capacity cost for the given restoration requirement. The spare cost depends on the restoration strategies used in the network. In this paper, we compare several restoration strategies quantatatively in terms of spare cost, notably; global versus failure-oriented reconfiguration, path versus link restoration, and state-dependent versus state-independent restoration strategies are also highlighted. Such comparisons provide useful guidance for real network design. Further, a new heuristic algorithm based on the minimum cost route concept is developed for the design of large self-healing ATM networks using path restoration. Numerical results illustrate that the heuristic algorithm is efficient and gives near-optimal solutions for the spare capacity allocation and flow assignment for tested examples.", URL="http://www.acm.org/pubs/articles/journals/ton/1999-7-1/p98-xiong/p98-xiong.pdf", } @ARTICLE{Chen9902:QoS, AUTHOR="R.-G. Cheng and C. J. Chang and Lang Lin", TITLE="A QoS-Provisioning neural fuzzy connection admission controller for multimedia high-speed networks", JOURNAL=ieanep, VOLUME=7, NUMBER=1, PAGES="111-121", MONTH=feb, YEAR=1999, REFERENCES=22, ABSTRACT="This paper proposes a neural fuzzy approach for connection admission control (CAC) with QoS guarantee in multimedia high-speed networks. Fuzzy logic systems have been successfully applied to deal with traffic-control-related problems and have provided a robust mathematical framework for dealing with real-world imprecision. However, there is no clear and general technique to map domain knowledge on traffic control onto the parameters of a fuzzy logic system. Neural networks have learning and adaptive capabilities that can be used to construct intelligent computational algorithms for traffic control. However, the knowledge embodied in conventional methods is difficult to incorporate into the design of neural networks. The proposed neural fuzzy connection admission control (NFCAC) scheme is an integrated method that combines the linguistic control capabilities of a fuzzy logic controller and the learning abilities of a neural network. It is an intelligent implementation so that it can provide a robust framework to mimic experts' knowledge embodied in existing traffic control techniques and can construct efficient computational algorithms for traffic control. We properly choose input variables and design the rule structure for the NFCAC controller so that it can have robust operation even under dynamic environments. Simulation results show that compared with a conventional effective-bandwidth-based CAC, a fuzzy-logic-based CAC, and a neural-net-based CAC, the proposed NFCAC can achieve superior system utilization, high learning speed, and simple design procedure, while keeping the QoS contract.", URL="http://www.acm.org/pubs/articles/journals/ton/1999-7-1/p111-cheng/p111-cheng.pdf", } @ARTICLE{Lomb9902:Discrete, AUTHOR="A. Lombardo and G. Morabito and G. Schembra", TITLE="A discrete-time paradigm to evaluate skew performance in a multimedia {ATM} multiplexer", JOURNAL=ieanep, VOLUME=7, NUMBER=1, PAGES="122-139", MONTH=feb, YEAR=1999, REFERENCES=24, ABSTRACT="One of the most important quality-of-service parameters in a multimedia environment is skew, defined as the difference between the delays suffered by the monomedia flows belonging to the same multimedia stream. In this paper, an analytical paradigm is proposed to evaluate the skew affecting a multimedia traffic stream in an asynchronous transfer mode multiplexer. For this purpose, the emission process of each multimedia source loading the multiplexer is defined as the superposition of heterogeneous correlated emission processes, each of which models one monomedia source as a switched batch Bernoulli process (SBBP). In order to model the intermedia relationships, the transition probabilities in the Markov chain underlying each SBBP are functions of the state of the other monomedia sources. The model is applied to a case study and the dependence of skew performance on some of the source characteristics, such as intermedia correlation, and some of the environment characteristics, such as buffer size, output capacity, and buffer utilization is analyzed and discussed.", URL="http://www.acm.org/pubs/articles/journals/ton/1999-7-1/p122-lombardo/p122-lombardo.pdf", } @ARTICLE{Fici9902:Fuzzy, AUTHOR="G. Ficili and D. Panno", TITLE="A fuzzy algorithm for combined control of traffic parameters: assessment and key issues", JOURNAL=comcom, VOLUME=22, NUMBER=3, PAGES="199-210", MONTH=feb, YEAR=1999, ABSTRACT="One of the most critical functions in the management of high-speed networks using the ATM technique is that of", } @ARTICLE{Fisc9902:Automatic, AUTHOR="Stefan Fischer", TITLE="Towards the automatic generation of quality-of-service-preserving implementations from formal specifications", JOURNAL=comcom, VOLUME=22, NUMBER=3, PAGES="211-223", MONTH=feb, YEAR=1999, KEYWORDS="Formal description techniques (FDTs); FDT compilers; Automatic code generation; Multimedia systems; Quality of service", ABSTRACT="The possibility to automatically generate implementations from formal specifications of distributed systems and protocols is one of the major advantages of the use of formal methods. This process is well understood for standardized Formal Description Techniques (FDTs) such as Estelle, SDL and LOTOS applied to traditional communication protocols. In order to use these languages for the specification of modern telecommunication systems such as multimedia, which is addition, have certain real-time requirements, several real-time language enhancements have been proposed. In this article, we show how, based on a real-time extension of Estelle, implementations can be generated that are able to automatically guarantee specified real-time requirements during the system's runtime.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/19/18/article.pdf", } @ARTICLE{Lai9902:Virtual, AUTHOR="Wai-Sum Lai and R. F. Chang", TITLE="Virtual path layout in {ATM} networks based on the P-median problem", JOURNAL=comcom, VOLUME=22, NUMBER=3, PAGES="224-231", MONTH=feb, YEAR=1999, KEYWORDS="Virtual path layout; ATM; P-median problem", ABSTRACT="We study the problem of virtual path layout in Asynchronous Transfer Mode (ATM) networks. Virtual path (VP) and virtual channel are used by the ATM networks in realizing multiplexing, resource management and routing. The layout of virtual paths in ATM networks needs to consider some factors, such as link load, setup complexity, and utilization of routing tables. In addition, the choice of medians in networks in consideration of demand at a node and link cost has been studied extensively. The demand and the cost should also be treated as important factors in the layout of virtual paths on ATM networks. In this article, we consider those factors together and propose a method based on the P-median problem for virtual path layout in ATM networks. The method is shown to provide an asymptotically optimal solution for VP layout in terms of the link load.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/19/19/article.pdf", } @ARTICLE{Moha9902:Efficient, AUTHOR="G. Mohan and Chandra Murthy", TITLE="Efficient algorithms for wavelength rerouting in {WDM} multi-fiber unidirectional ring networks", JOURNAL=comcom, VOLUME=22, NUMBER=3, PAGES="232-243", MONTH=feb, YEAR=1999, KEYWORDS="Wavelength division multiplexing; Lightpath; Wavelength rerouting; Multi-fiber networks", ABSTRACT="In this article, we consider wavelength rerouting in wavelength-routed Wavelength-Division Multiplexed (WDM) multi-fiber unidirectional ring networks with circuit switching. The wavelength continuity constraint imposed by WDM networks leads to poor blocking performance. Wavelength rerouting is a viable and cost effective mechanism that can improve the blocking performance by rearranging certain existing lightpaths to accommodate a new request. Recently, in Ref. [1], a rerouting scheme called `Parallel Move-To-Vacant Wavelenth Retuning (MTV-WR)' with many attractive features such as shorter disruption period and simpler switching control has been proposed. A polynomial time rerouting algorithm has also been proposed in Ref. [1] to minimize the weighted number of rerouted lightpaths in WDM networks with the parallel MTV-WR rerouting scheme. However, this algorithm is not time optimal and works correctly when the fiber links, wavelength channels, and lightpaths are all bidirectional. We present here a time-optimal rerouting algorithm to minimize the number of rerouted lightpaths in wavelength-routed WDM multi-fiber unidirectional ring networks with parallel MTV-WR rerouting scheme. This algorithm requires only O(NFW) time units, where N is the number of nodes in the network, F is the number of fiber links between two consecutive nodes, and W is the number of wavelength channels available on a fibre link. We also present on O(NF2W) time rerouting algorithm to minimize the weighted number of rerouted lightpaths. The simulation results show that the rerouting algorithms improve the blocking performance considerably and only very few lightpaths are required to be rerouted per rerouting. The results also show that, for a given network load per wavelength per fiber, increasing the number of wavelengths or the number of fibers, leads to an improved performance by the networks with rerouting, without any rerouting and with full wavelength conversion capability at the routing nodes.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/19/20/article.pdf", } @ARTICLE{Venu9902:Impact, AUTHOR="K. R. Venugopal and E. Ezhil Rajan and Puneet Kumar", TITLE="Impact of wavelength converters in wavelength routed all-optical networks", JOURNAL=comcom, VOLUME=22, NUMBER=3, PAGES="244-257", MONTH=feb, YEAR=1999, KEYWORDS="Wavelength converters; Wavelength routed all-optical networks; Multihop virtual topology", ABSTRACT="This paper attempts to study the impact of wavelength converters in WDM wavelength routed all-optical networks. A new heuristic approach for placement of wavelength converters to reduce blocking probabilities is explored. Multihop virtual topology is designed to minimize the number and overall cost of the converters. Blocking probabilities for Static Lightpath Establishment (SLE) and Dynamic Lightpath Establishment (DLE) are analyzed. In the case of SLE, arranging lightpaths in ascending order of their path length reduces blocking probability. Wavelength converters placed at nodes with high nodal degree further reduces the blocking probabilities. Simulation studies performed on 28-node USA long haul network, 20-node arbitrary mesh network, and 19-node EON (European Optical Network) validate the observations made earlier.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/19/21/article.pdf", } @ARTICLE{Cata9902:Impact, AUTHOR="V. Catania and G. Ficili and D. Panno", TITLE="On the impact of traffic control algorithms on resource management in {ATM} networks", JOURNAL=comcom, VOLUME=22, NUMBER=3, PAGES="258-265", MONTH=feb, YEAR=1999, KEYWORDS="ATM; QoS; Management; Traffic management; Fuzzy logic", ABSTRACT="Resource allocation algorithms in ATM networks operate on the basis of the value of certain source traffic descriptors and the extent to which the network resources are occupied. The different types of algorithms exhibit varying degrees of efficiency in estimating the resource to be allocated. However, the values any of them estimate will only be reliable if the traffic descriptors values remain, throughout the lifetime of the connections, the same as those negotiated in the call set-up phase. This can be guaranteed by a source traffic policing function which forces the traffic of any violating sources to respect the values negotiated. Unfortunately, a certain amount of excess traffic escapes the control of real policing mechanisms. This overloads the ATM switch for access to the network and consequently may cause an increase in the cell loss ratio. The article estimates the correction required by the CAC algorithm to avoid this risk. We compare two different policing mechanisms, one based on conventional logic and another on fuzzy logic, assessing the influence of their degree of selectivity on the additional bandwidth the CAC algorithm needs to reserve in order to guarantee the QoS requirements of all connections.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/19/22/article.pdf", } @ARTICLE{Venk9902:Efficient, AUTHOR="D. Venkatesulu and Timothy A. Gonsalves", TITLE="Efficient fault-tolerant reliable broadcast in a multi-switch extended {LAN}", JOURNAL=comcom, VOLUME=22, NUMBER=3, PAGES="266-278", MONTH=feb, YEAR=1999, KEYWORDS="Extended LAN; Reliable broadcast; Fault tolerance; LAN switches; Deterministic performance model; Distributed computing; Distributed applications; Active networks", ABSTRACT="Several efficient reliable broadcast protocols were developed and implemented on broadcast LANs. To enhance the amount of bandwidth available per node on a shared media LAN, such as 10 Mb/s Ethernet, there is a rapidly growing use of LAN switches to interconnect independent LAN segments to form an extended LAN (E-LAN). The existing reliable broadcast protocols may be inefficient in E-LANs because the LAN switch in an E-LAN transmits both broadcast and multi-cast traffic on all the segments. However, in many group applications group members may be present only on few segments. In this article, we propose some reliable broadcast protocols (RBPs) that are designed to work efficiently in multi-switch E-LANs based on the class of programmable switches. This is achieved by judiciously adding functionality to the switches. Using simple deterministic models, we study the performance characteristics of our switched RBPs. We show that they are more efficient than the existing RBPs over a wide range of conditions.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/19/23/article.pdf", } @ARTICLE{Ku9902:Secure, AUTHOR="Wei-Chi Ku and Stephen Wang", TITLE="A secure and practical electronic voting scheme", JOURNAL=comcom, VOLUME=22, NUMBER=3, PAGES="279-286", MONTH=feb, YEAR=1999, KEYWORDS="Electronic voting schemes; Anonymous channel; Cryptographic techniques", ABSTRACT="Electronic voting schemes can be divided into homomorphism encryption and anonymous channel based schemes. The former type requires massive communications and computation, thereby, inappropriate for large-scale voting. However, the soundness of the latter type heavily relies on the cooperation of the voters. Under these schemes, voting is disrupted if some voter abstains in the intermediate stages. In this article, we present a secure electronic voting scheme of the latter type. The proposed scheme is practical in that its assumptions are quite appropriate for realistic environments. More specifically, the soundness of the proposed scheme does not rely on the cooperation of the voters.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/19/24/article.pdf", } @ARTICLE{Lee9902:Security, AUTHOR="N. Lee and Tzonelih Hwang", TITLE="On the security of fair blind signature scheme using oblivious transfer", JOURNAL=comcom, VOLUME=22, NUMBER=3, PAGES="287-290", MONTH=feb, YEAR=1999, KEYWORDS="Cryptography; Cryptanalysis; Digital signature; Fair blind signature", ABSTRACT="At EuroCrypt'95, Stadler et al. proposed the concept of fair blind signatures to prevent the misuse of blind signature schemes by the criminals. Two types of fair signature schemes were discussed and three schemes were developed in their paper. This article shall show that the second fair blind signature scheme is in fact unfair under some cases.", URL="http://www.elsevier.nl/gej-ng/10/15/19/30/19/25/article.pdf", } @ARTICLE{Puzm9902:Daniel, AUTHOR="Rita Puzmanova", TITLE="Daniel Minoli and Andrew Schmidt: Network Layer", JOURNAL=comcom, VOLUME=22, NUMBER=3, PAGES="291-292", MONTH=feb, YEAR=1999, URL="http://www.elsevier.nl/gej-ng/10/15/19/30/19/26/article.pdf", } @ARTICLE{Ciof9902:Digital, AUTHOR="John Cioffi and P. Silverman and T. Starr", TITLE="Digital subscriber lines", JOURNAL=cn, VOLUME=31, NUMBER=4, PAGES="283-311", MONTH=feb, YEAR=1999, KEYWORDS="broadband; internet access; ANSI T1E1; ADSL; VDSL; impulse noise; DMT; DSLAM; common carrier; specialized carrier; splitter", ABSTRACT="Digital Subscriber Lines (DSLs), transmission systems that allow high-speed digital transmission on ordinary phone lines, are overviewed in this article. This article focuses mainly on the transmission technologies and the challenges of high-speed transmission on twisted-pair phone lines, but also considers basic terms of reference and network/applications interfaces. Loop topology, transmission impairments, and transmission techniques are reviewed for the most popular DSLs, as are the basic connections necessary for a complete ADSL service through a service-provider's network. For a more complete discussion of DSLs, see the book by the same three authors [J. Cioffi, T. Starr, P. Silverman, Digital Subscriber Lines, Prentice-Hall, Upper Saddle River, NJ, 1998].", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Perk9902:Two, AUTHOR="S. J. Perkins and Alan Gatherer", TITLE="Two-way broadband {CATV-HFC} networks: state-of-the-art and future trends", JOURNAL=cn, VOLUME=31, NUMBER=4, PAGES="313-326", MONTH=feb, YEAR=1999, KEYWORDS="CATV data networks; cable modem; DOCSIS; HFC; hybrid fiber coax; MAC; MCNS; QAM", ABSTRACT="Cable modems allow two way digital data transmission between households and a central neighborhood server. In this overview we briefly describe some of the common characteristics of the Hybrid Fiber Coax (HFC) operation as presented by several standards bodies (both completed standards and works in progress). This includes a description and comparison of the media access control and physical layer operations of several competing proposals. Our desire is to give a concise but complete picture of the cable modem problem and the proposed solutions. References are provided for readers interested in further investigation.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Cota9902:Wireless, AUTHOR="Nicolae Cotanis and B. Jabbari", TITLE="Wireless local loop radio systems", JOURNAL=cn, VOLUME=31, NUMBER=4, PAGES="343-352", MONTH=feb, YEAR=1999, KEYWORDS="broadband; internet access; PCS; PCN; PWT; DECT; PACS; fading; high-tier mobility; low-tier mobility; WLL", ABSTRACT="Wireless local loop radio is expected to become a widely accepted technology for rapid access to network infrastructure by remote locations. Characteristics of a wireless local loop system are partially different from those in the mobile cellular system and therefore their design and planning require different considerations. This paper provides first an overview of the wireless local loop systems and then discusses the important design aspects such as the necessary fade margin to achieve a given availability, level crossing rate and average fade duration.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Hadj9902:Broadband, AUTHOR="M. H. Hadjitheodosiou and Anthony Ephremides and D. Friedman", TITLE="Broadband access via satellite", JOURNAL=cn, VOLUME=31, NUMBER=4, PAGES="353-378", MONTH=feb, YEAR=1999, KEYWORDS="satellite communications; broadband access; multiple access; internet access; hybrid networks; onboard processing; error control; ka-band; v-band", ABSTRACT="Satellites are well suited for broadband communications. In this paper we consider the special features of satellite systems, some of the broadband applications that are well-suited for satellites and some of the technologies which make possible broadband satellite communications, as well as the research programs that led to their development. We describe how such technologies, and other factors, have contributed to the evolution of broadband satellite systems, and discuss some of the challenges in establishing such systems. We finish by offering some concluding remarks on the role of satellites for broadband access.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Sari9902:Broadband, AUTHOR="Hikmet Sari", TITLE="Broadband radio access to homes and businesses: {MMDS} and {LMDS}", JOURNAL=cn, VOLUME=31, NUMBER=4, PAGES="379-393", MONTH=feb, YEAR=1999, KEYWORDS="broadband; internet access; DAVIC; DVB; MAC protocol; local access network; frequency planning; DAVIC; CDMA; OFDMA", ABSTRACT="This paper gives an overview of digital microwave multipoint distribution systems (MMDS) and local multipoint distribution systems (LMDS) originally developed for digital TV broadcasting and later extended to offer interactive services for homes and businesses. We first describe the specification work carried out by the Digital Video Broadcasting (DVB) project and the Digital Audio Visual Council (DAVIC) which forms the technical basis of these systems. Next, after presenting initial frequency allocations particularly in Europe and North America, we discuss the potential of MMDS and LMDS to offer broadband services to homes as well as to small- and medium-size businesses. We also discuss the major technical issues related to the design of these systems, frequency planning and reuse patterns, as well as future technical evolutions to make them more efficient in terms of performance, capacity, and the service offered. This discussion includes the use of higher-level modulations, multiple access techniques such as code-division multiple access (CDMA) and orthogonal frequency-division multiple access (OFDMA), and of adaptive arrays for electronic beamforming.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Ayan9902:Wireless, AUTHOR="Ender Ayanoglu", TITLE="Wireless broadband and {ATM} systems", JOURNAL=cn, VOLUME=31, NUMBER=4, PAGES="395-409", MONTH=feb, YEAR=1999, KEYWORDS="broadband; internet access; MAC protocols; wireless ATM; IP over ATM; TDMA; CDMA; OFDM; network layer switching", ABSTRACT="ATM (Asynchronous Transfer Mode) is a fixed-size packet switching technology, tailored to the integration of data, voice, and video communications. In this paper, we provide an update on the technical issues involved in implementing broadband wireless systems. This update covers the most recent developments on the subject. We briefly review physical, data link, and multiaccess layer issues; discuss networking and pertinent issues related to the networking protocol in terms of broadband wireless systems; summarize most recent prototyping efforts in the literature, and describe where the standardization efforts stand. We conclude with a summary on the state of broadband wireless networking.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Wari9902:Newly, AUTHOR="David L. Waring and Kenneth Kerpez and Steven Ungar", TITLE="A newly emerging customer premises paradigm for delivery of network-based services", JOURNAL=cn, VOLUME=31, NUMBER=4, PAGES="411-424", MONTH=feb, YEAR=1999, KEYWORDS="broadband; internet access; CEBus; residential gateway; plastic optical fiber; ethernet; IEEE 802.11; DECT; HIPERLAN", ABSTRACT={Low-speed home networks in some form are used for lighting, appliance control and security systems in over 20\% of U.S. households. The increasing penetration of personal computers (PCs) is leading to early deployment of twisted-pair Ethernet networks by information industry employees and early technology adopters. Digital video has matured to the point where the power of the MPEG compression algorithm is bearing fruit in new consumer electronics. The "jury is still out" on ultimate convergence of the entertainment center and the PC. However, it has definitely progressed with the advent of television Web appliances, and with the addition of video attributes being pulled down from Web sites and played on the PC. Rather than think of convergence in the context of a single-user device with full capability, increasing use of advanced digital networks in the home is the more likely evolution, with devices optimized for their particular task easily connecting to a whole-house network through attractive wall plates, by wireless, or through their commercial a.c. power cords. Several industries are formulating such concepts, examining advanced broadband digital networks with "plug-and-play" capabilities. For network service providers competing in an increasingly unregulated environment, success of service delivery will come to depend on a well-thought-out strategy for service termination. The old paradigm of "customer premises equipment" which was relatively well defined, specified and controlled by the network operator will give way to home networks which are extremely sophisticated in their own right. Service providers will be forced to think in terms of delivering services into this local environment, with an interface which is more driven by the customer's local deployment decisions, somewhat analogous to the business environment today in which carriers provide trunks and private lines to PBXs and gateways. This paper will examine the trends in home networking, and propose architectures which service providers can use to deliver services to, and across, home networks, to end-user devices. We will discuss recent industry activity focused on the concept of a residential gateway (RG), an electronic device which mediates between different service-provider access networks and different devices and networks within the home. We will discuss how the RG can facilitate intelligent testing capabilities to reduce maintenance costs, and intelligent provisioning which can support flexible service capabilities.}, URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Rind9902:Telephony, AUTHOR="J. Rinde", TITLE="Telephony in the year 2005", JOURNAL=cn, VOLUME=31, NUMBER=3, PAGES="157-168", MONTH=feb, YEAR=1999, KEYWORDS="IP telephony; internet", ABSTRACT="The growth of packet-based voice services is leading to integration of voice and other services over packet switched data networks. This paper explores a possible path that the telephone service industry may follow as this integration is accelerated by technological advances that improve the capabilities of packet-based services while reducing their costs.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Reid9902:Multimedia, AUTHOR="Mark Reid", TITLE="Multimedia conferencing over {ISDN} and {IP} networks using {ITU-T} H-series recommendations: architecture, control and coordination", JOURNAL=cn, VOLUME=31, NUMBER=3, PAGES="225-235", MONTH=feb, YEAR=1999, KEYWORDS="multimedia; conferencing", ABSTRACT="This article discusses the architecture, control protocols, and coordination mechanisms used in today's multimedia conferencing standards for ISDN (Integrated Services Data Network) and IP (Internet Protocol) networks. Specifically, the ITU-T's (International Telecommunication Union - Telecommunication Standardization Sector) H.320 and H.323 multimedia conferencing standards are discussed and compared with respect to their architecture and position in the market.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Huba9902:Impact, AUTHOR="J.-P. Hubaux and Constant Gbaguidi and Shawn Koppenhoefer and Jean-Yves Le Boudec", TITLE="The impact of the {Internet} on telecommunication architectures", JOURNAL=cn, VOLUME=31, NUMBER=3, PAGES="257-273", MONTH=feb, YEAR=1999, KEYWORDS="intelligent network; telecommunications management network; telecommunications information networking architecture; PSTN/internet interworking; internet telephony; virtual private network", ABSTRACT="The ever-growing popularity of the Internet is dramatically changing the landscape of the communications marketplace. The two separate worlds of the Internet and Telecommunications are converging. The respective advantages of the two environments are being integrated to fulfill the promise of the information super-highways. In this paper, we examine the impact of the Internet on the main telecommunication architectures, namely the IN, the TMN and TINA. There are two new tendencies for implementing telephony services in combination with the Internet: running part of the control system over the Internet, or conveying both the user data and the control information over the Internet. We examine these two tendencies, and elaborate on possible ways of salvaging the best parts of the work achieved by the TINA-Consortium in the Internet context.", URL="http://www.elsevier.com/locate/comnet", } @ARTICLE{Reed9902:Modeling, AUTHOR="Michael K. Reed and P. K. Allen", TITLE="{3-D} Modeling from range imagery", JOURNAL=image, VOLUME=17, NUMBER=1, PAGES="99-111", MONTH=feb, YEAR=1999, } @INPROCEEDINGS{Hunt9902:Coign, AUTHOR="Guerney Hunt and M. Scott", TITLE="The Coign Automatic Distributed Partitioning System", BOOKTITLE="3rd Symposium on Operating System Design and Implementation", MONTH=feb, YEAR=1999, } @INPROCEEDINGS{Perk9902:Ad, AUTHOR="Charles E. Perkins and Elizabeth M. Royer", TITLE="Ad-hoc On-Demand Distance Vector Routing", BOOKTITLE="Second IEEE Workshop on Mobile Computing Systems and Applications", ADDRESS="New Orleans, LA", PAGES="90-100", MONTH=feb, YEAR=1999, } @INPROCEEDINGS{Elli9902:Architecture, AUTHOR="Georgios Ellinas and George K. Chang and R. A. Wagner and William H. Anderson", TITLE="Architecture Considerations in Merging Multi-vendor {WDM} Rings for the {MONET} Washington {D.C.} Network", BOOKTITLE="Optical Fiber Communications (OFC) Conference", ORGANIZATION="OSA", MONTH=feb, YEAR=1999, LANGUAGE="English", } @INPROCEEDINGS{Elli9902:Protection, AUTHOR="Georgios Ellinas and Aklilu Hailemariam and Thomas Stern", TITLE="Protection of a Priority Connection from an Optical Switch Failure in Mesh Networks with Planar Topologies", BOOKTITLE="Optical Fiber Communications (OFC) Conference", ORGANIZATION="OSA", MONTH=feb, YEAR=1999, LANGUAGE="English", } @TECHREPORT{Lass9902:Resource, AUTHOR="Ora Lassila and Ralph R. Swick", TITLE="Resource Description Framework {(RDF)} Model and Syntax Specification", TYPE="W3C Recommendation", INSTITUTION="World Wide Web Consortium", MONTH=feb, YEAR=1999, LANGUAGE="English", } @INPROCEEDINGS{Kell9902:Pricing, AUTHOR="Tim Kelly", TITLE="Pricing international services towards cost-orientation", BOOKTITLE="Seminar on cost-based tariffing", INSTITUTION="ITU", ADDRESS="Delhi, India", DAYS=16, MONTH=feb, YEAR=1999, KEYWORDS="Supply and demand; approaches to pricing; approaches to costing; TRAI tariff study; tariff rebalancing; tariff comparisons; price regulation; economics; pricing; settlements; international telephone calls", ABSTRACT="Understanding international market structures; Competitive versus monopoly markets; Call origination versus call termination; Retail pricing versus wholesale pricing; Cost drivers for international services; Retail price trends; Wholesale price trends; Pressure for reform of accounting rate system; Development of interconnect regimes; Trading of telecom minutes", URL="http://www.itu.int/ti/papers/India/PowerPoint\%20-Intl2.pdf", } @INPROCEEDINGS{Kell9902:Impact, AUTHOR="Tim Kelly", TITLE="The impact of the {Internet} on the pricing of telecommunication services", BOOKTITLE="Seminar on cost-based tariffing", INSTITUTION="ITU", ADDRESS="Delhi, India", DAYS=16, MONTH=feb, YEAR=1999, KEYWORDS="Internet economics; pricing; charging; Internet telephony", ABSTRACT="The phenomenal growth of the Internet; Internet economics; Internet telephony; Pricing the Internet: What makes it different?; Vulnerability of telephone companies to competition from the Internet; Corporate positioning by telephone companies", URL="http://www.itu.int/ti/papers/India/PowerPoint\%20-Internet4.pdf", } @INPROCEEDINGS{Ngin9903:Generalised, AUTHOR="Hoon Tong Ngin and Chen Khong Tham and Wee-Seng Soh", TITLE="Generalised Minimum Queuing Delay: An Adaptive Multi-rate Service Discipline for {ATM} Networks", BOOKTITLE=infocom, ADDRESS="New York", MONTH=mar, YEAR=1999, LANGUAGE="English", KEYWORDS="Traffic management; scheduling", ABSTRACT="In this paper, we propose a generalised minimum queuing delay (GMQD) service discipline for high speed networks, mainly asynchronous transfer mode (ATM) networks. This proposed scheme is similar to service disciplines based on fair queuing, but instead of using only a single service rate for each session for its entire connection lifetime, multiple service rates are used. The service rate of any session at any point in time is computed efficiently based on the number of bits backlogged in the queues of the session and another imaginary reference session at that point in time. The main advantage of this scheme is that the queuing delays suffered by all the sessions connected to a single output node are minimised, leading to a smaller cell delay variation. In addition, this smaller cell delay variation also implies a smaller variance in the maximum queue length, thereby, reducing the possibility of buffer overflow. Keywords: ATM, scheduling, multi-rate service disciplines", URL="http://www.ieee-infocom.org/1999/papers/03b\_03.pdf", } @INPROCEEDINGS{Chiu9903:High, AUTHOR="Tzi-cker Chiueh and Prashant Pradhan", TITLE="High Performance {IP} Routing Table Lookup using {CPU} Caching", BOOKTITLE=infocom, ADDRESS="New York", MONTH=mar, YEAR=1999, LANGUAGE="English", KEYWORDS="Routing \& Multicasting", ABSTRACT="Wire-speed IP (Internet Protocol) routers require very fast routing table lookup for incoming IP packets. The routing table lookup operation is time consuming because the part of an IP address used in the lookup, i.e., the network address portion, is variable in length. This paper describes the routing table lookup algorithm used in a cluster-based parallel IP router project called Suez. The innovative aspect of this algorithm is its ability to use CPU caching hardware to perform routing table caching and lookup directly by carefully mapping IP addresses to virtual addresses. By running a detailed simulation model that incorporates the performance effects of the CPU memory hierarchy against a packet trace collected from a major network router, we show that the overall performance of the proposed algorithm can reach 87.87 million lookups per second for a 500-MHz Alpha processor with a 16-KByte L1 cache and a 1-MByte L2 cache. This result is one to two orders of magnitude faster than previously reported results on software-based routing table lookup implementations. This paper also reports the performance impacts of various architectural parameters in the proposed scheme and its storage costs, together with the measurements of an implementation of the proposed scheme on a Pentium-II machine running Linux.", URL="http://www.ieee-infocom.org/1999/papers/10c\_02.pdf", } @TECHREPORT{Rose9903:Programming, AUTHOR="J. Rosenberg and J. Lennox and Henning Schulzrinne", TITLE="Programming {Internet} Telephony Services", TYPE="Technical Report", INSTITUTION="Columbia University", ADDRESS="New York, New York", NUMBER="CUCS-010-99", MONTH=mar, YEAR=1999, REFERENCES=31, KEYWORDS="Internet telephony; signaling; programming", ABSTRACT="Internet telephony enables a wealth of new service possibilities. Traditional telephony services, such as call forwarding, transfer, and 800 number services, can be enhanced by interaction with email, web, and directory services. Additional media types, like video and interactive chat, can be added as well. One of the challenges in providing these services is how to effectively program them. Programming these services requires decisions regarding where the code executes, how it interfaces with the protocols that deliver the services, and what level of control the code has. In this paper, we consider this problem in detail. We develop requirements for programming Internet telephony services, and we show that at least two solutions are required --- one geared for service creation by trusted users (such as administrators), and one geared for service creation by untrusted users (such as consumers). We review existing techniques for service programmability in the Internet and in the telephone network, and extract the best components of both. The result is a Common Gateway Interface (CGI) that allows trusted users to develop services, and the Call Processing Language (CPL) that allows untrusted users to develop services.", URL="ftp://ftp.cs.columbia.edu/reports/reports-1999/cucs-010-99.ps.gz", } @ARTICLE{Alou9903:Application, AUTHOR="M. S. Alouini and Marvin K. Simon", TITLE="Application of the Dirichlet Transformation to the Performance Evaluation of Generalized Selection Combining over Nakagami-m Fading Channels", JOURNAL=jcn, VOLUME=1, NUMBER=1, PAGES="5-13", MONTH=mar, YEAR=1999, KEYWORDS="Nakagami-m fading; Maximal ratio combining diversity; Selection Combining; Generalized Selection Combining; Hybrid SC/MRC", ABSTRACT="The Dirichlet transformation may be used to simplify certain multiple integrals which occur in the distribution theory of ordered gamma random variables. The evaluation of the average error rate performance of generalized selection combining receivers for digital signals transmitted over Nakagami-$m$ channels involves just such a multiple integral and thus is a perfect application for the transformation. A well-structured procedure for obtaining the average error rate in a simple form suitable for numerical evaluation is presented for the generic problem of selection combining $L\_c ({\le L})$ out of $L$ received paths and specific results are presented for a number of examples both numerically and as simple closed form expressions. As a byproduct of the general results, some interesting closed form expressions are presented for certain single and multiple definite integrals which heretofore appear not to have been tabulated.", URL="http://jcn.or.kr/library\_abstract/frame\_library2.html", } @ARTICLE{Kim9903:Existence, AUTHOR="Jaehyung Kim and Haiyan Song", TITLE="Existence of Cyclic Hadamard Difference Sets and its Relation to Binary Sequences with Ideal Autocorrelation", JOURNAL=jcn, VOLUME=1, NUMBER=1, PAGES="14-18", MONTH=mar, YEAR=1999, REFERENCES=18, KEYWORDS="Pseudorandom Binary Sequences; Ideal Autocorrelation; Cyclic Hadamard Difference Sets", ABSTRACT="Balanced binary sequences with ideal autocorrelation are equivalent to ($v, k, \lambda$)-cyclic Hadamard difference sets with $v = 4n-1, ~k=2n-1,~\lambda=n-1$ for some positive integer $n$. Every known cyclic Hadamard difference set has one of the following three types of $v$ : (1) $v = 4n-1$ is a prime. (2) $v$ is a product of twin primes. (3) $v=2^n-1$ for $n=2,~3,\cdots$. It is conjectured that all cyclic Hadamard difference sets have parameter $v$ which falls into one of the three types. The conjecture has been previously confirmed for $n<10000$ except for 17 cases not fully investigated. In this paper, four smallest cases among these 17 cases are examined and the conjecture is confirmed for all $v\le 3435$. In addition, all the inequivalent cyclic Hadamard difference sets with $v = 2^n-1$ for $n \le 10$ are listed and classified according to known construction methods.", URL="http://jcn.or.kr/library\_abstract/frame\_library2.html", } @ARTICLE{Choi9903:Unsupervised, AUTHOR="S. Choi and Andrzej Cichocki", TITLE="An Unsupervised Hybrid Network for Blind Separation of Independent Non-Gaussian Source Signals in Multipath Environment", JOURNAL=jcn, VOLUME=1, NUMBER=1, PAGES="19-25", MONTH=mar, YEAR=1999, KEYWORDS="blind signal separation; Hebbian/anti-Hebbian learning; independent component analysis; multichannel blind deconvolution/equalization; neural networks; spatio-temporal decorrelation; unsupervised learning", ABSTRACT="This paper is concerned with the problem of recovering multiple source signals that are transmitted through a linear Multiple Input Multiple Output (MIMO) system, without resorting to any prior knowledge. Source signals are assumed to be spatially independent and temporally i.i.d. non-Gaussian sequences. We present an unsupervised hybrid network (a linear feedback network with FIR synapses followed by a linear memoryless feedforward network) which is able to recover multiple source signals blindly. A simple criterion for multichannel blind deconvolution and an associated learning algorithm are presented. Extensive computer simulation results confirm the validity and high performance of the proposed method.", URL="http://jcn.or.kr/library/frame\_library.html", } @ARTICLE{Kara9903:Outage, AUTHOR="George K. Karagiannidis and S. Kotsopoulos and Chris Georgopoulos", TITLE="Outage Probability Analysis for a Rician Signal in L Nakagami Interferers with Arbitrary Parameters", JOURNAL=jcn, VOLUME=1, NUMBER=1, PAGES="26-30", MONTH=mar, YEAR=1999, REFERENCES=9, KEYWORDS="Rician Fading; Nakagami Fading; Outage Probability; Co-Channel Interference; Mobile Radio; Micro-cellular; Pico-Cellular", ABSTRACT="Effective techniques have been developed to determine outage probability in a Nakagami interference environment. However, there is no solution in the literature to the outage problem of a Rician desi