[παλιό] 12/4/06 Talk by Leandros Tassiulas

[Ethel]

ΔΙΑΛΕΞΗ ΤΕΤΑΡΤΗ 12 ΑΠΡΙΛΙΟΥ
ΩΡΑ 12:00
ΑΙΘΟΥΣΑ ΤΗΛΕΚΠΑΙΔΕΥΣΗΣ ΚΕΝΤΡΟΥ ΔΙΚΤΥΩΝ
Τμήμα Πληροφορικής και Τηλεπικοινωνιών ΕΚΠΑ

Information flow issues in cross-layer models of wireless communication networks

by Leandros Tassiulas

Computer Engineering and Telecommunications University of Thessaly Volos, Greece

Advances in communication technology over the last several years made possible the deployment of broadband wireless networks that provide integrated services via inexpensive low-powered mobile terminals. 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 and network 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.



Biography: Leandros Tassiulas is Professor in the Dept of Computer Engineering and Telecommunications at the University of Thessaly Greece since 2002. His research activity over the last fifteen years is towards the development of communication and information processing networks that facilitate access and exchange of information among multiple entities. Current research and teaching topics include wireless mobile communications, ad-hoc networks, smart antennas, sensor networks, high speed networked environments. He was Assistant Professor. at Polytechnic University, NY, 1991-1995, Associate Prof. at the University of Maryland, College Park until 2002 (on leave 2000-2002) and Professor of Computer Science at the University of Ioannina Greece 1999-2002. He obtained the Diploma in Electrical Engineering from the University of Thessaloniki, Greece in 1987, and the M.S. and Ph.D. degrees in Electrical Engineering from the University of Maryland, College Park in 1989 and 1991 respectively. He has been Associate Editor for Communication Networks for IEEE Transactions on Information Theory and 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 CAREER Award in 1995, the Office of Naval Research Young Investigator Award in 1997 and 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