"From ATM to IP and back again: the label switched path to the converged Internet, or another blind alley?"
Chair: Leonidas Georgiadis, Aristotelian Univ. of Thessaloniki.
Abstract: The drafting of the ATM standards for a multiservice packet switched network some 15 years ago marked the start of an intense research effort into the issue of QoS: how to meet the different requirements of a range of real time and data applications? The author has participated actively and enthusiastically in this research while growing increasingly sceptical and disillusioned about the solutions proposed in the various standards. The talk will offer a personal retrospective on QoS, discussing the merits and demerits of ATM transfer capabilities, Intserv service classes, Diffserv per-hop behaviours and MPLS traffic trunks. Our perspective is somewhat unusual in that we evaluate these architectures in the light of what we know about the statistical nature of network traffic. We are also concerned that the converged Internet should constitute a viable business platform for the network provider. These considerations lead us to propose an alternative QoS solution based on a relatively simple enhancement of the current best effort network.
Biography: Jim Roberts has a BSc in mathematics from the University of Surrey, UK and a PhD from the University of Paris . He has been with the France Telecom research labs since 1978. His research has been mainly in the field of performance evaluation and design of traffic controls for multiservice networks. He was chairman of three successive European COST projects on the performance of multiservice networks, this activity culminating in the publication of the book "Broadband Network Teletraffic" (Springer 1996). He has published extensively and is or has been a member of a several journal editorial boards including Computer Networks and IEEE/ACM Transactions on Networking. He was a guest editor for the IEEE JSAC issue on Internet QoS in 2000. He is member of many conference programme committees in the networking field including Infocom and SIGCOMM. He was TPC co-chair for Infocom 2003.
"Cross-layer design issues for quality of service provisioning in wireless networks "
Chair: Michael Paterakis, Technical Univ. of Crete.
Abstract: Next generation wireless networks are envisioned to provide integrated services via inexpensive low-powered mobile computing devices. End users often expect seamless transition from wire-line to wireless networks. That requires quality of service provisioning that is compatible in the wireless and the wire-line parts of the network. Wireless networks though exhibit peculiarities due to which meeting stringent quality of service requirements becomes a rather challenging task. The volatile, error-prone mobile channel on one hand and the interference limited radio medium on the other, necessitate a cross-layer approach in the design of higher layers. We will present various approaches for network control at the access layer where the controller should rely on channel state information passed from the physical layer, while making resource allocation decisions. Furthermore, several considerations belonging typically to the physical layer, like channel coding rate, signal constellation selection as well as power level adjustments, frequency selection and beam steering in multiple antenna systems are to the disposal of the access controller in several current schemes for broadband wireless access. We will present approaches for dealing with these design choices and discuss related state-of-the art broadband access technologies. The impact of these techniques on the efficiency in terms of bandwidth, spectrum utilization and energy consumption will be discussed.
He is Associate Editor for Communication Networks for IEEE Transactions on Information Theory and has been an editor for IEEE/ACM Transactions on Networking. His research activity received several recognitions including a National Science Foundation (NSF) Research Initiation Award in 1992, an NSF Faculty Early Career Development Award in 1995 and the Office of Naval Research Young Investigator Award in 1997. He coauthored the paper that got the INFOCOM `94 best paper award. In 1999, he was awarded the "Bodossaki Foundation Academic Prize" in the field: Applied Science: Theories, Technologies and Applications of Parallel and Distributed Computing Systems, that is awarded to scientists of Greek origin under the age of 40 for excellence in their field. He is National Expert representing Greece in the 6th framework program of the European Union, in the field Information Society Technologies.
"Research challenges in wireless sensor and actuator networks"
Chair: George Stassinopoulos, National Technical Univ. of Athens.
Abstract: Wireless Sensor and Actuator Networks (WSANs) refer to a group of sensors and actuators linked by wireless medium to perform distributed sensing and actuation tasks. The aim of this talk is to give an overview about research challenges in WSANs. First, the sensing and actuation tasks are explained and general differences between classical sensor and WSANs are pointed out. Further, the physical architecture of WSANs is presented and research challenges and requirements due to the presence of actuators are explored. In particular, the challenges for the design and development of sensor/actuator network communication protocols are presented.
Biography: IAN F. AKYILDIZ is Ken Byers Distinguished Chair Professor with the School of Electrical and Computer Engineering, Georgia Institute of Technology and Director of Broadband and Wireless Networking Laboratory. He has published over two-hundred technical papers in journals and conference proceedings. He is the Editor-in-Chief of Computer Networks (Elsevier Science) and for the newly launched AdHoc Networks Journal (Elsevier Science). Dr. Akyildiz is an IEEE FELLOW (1995), an ACM FELLOW (1996). He served as a National Lecturer for ACM from 1989 until 1998 and received the ACM Outstanding Distinguished Lecturer Award for 1994. Dr. Akyildiz received the 1997 IEEE Leonard G. Abraham Prize award (IEEE Communications Society) for his paper entitled "Multimedia Group Synchronization Protocols for Integrated Services Architectures" published in the IEEE Journal of Selected Areas in Communications (JSAC) in January 1996. Dr. Akyildiz received the 2002 IEEE Harry M. Goode Memorial award (IEEE Computer Society) with the citation "for significant and pioneering contributions to advanced architectures and protocols for wireless and satellite networking". He also received the 2002 IEEE Best Tutorial Paper award (IEEE Communications Society) for his paper entitled "A Survey on Wireless Sensor Networks" published in the IEEE Communications Magazine in July 2002. Dr. Akyildiz further received the 2003 ACM SIGMOBILE award for his outstanding research contributions to the wireless networking field. His current research interests are in Sensor Networks, Wireless Networks, InterPlaNetary Internet.