The keynote speaker for the seminar is Professor Paul Kuhn from the University of Stuttgart
Speaker: Professor Paul Kuhn (Institute of Communication Networks and Computer Engineering at the University of Stuttgart)
Title: Performance Modelling of GGG and WLAN Performance Modelling
Abstract: The talk will feature actual issues on Performance Modelling of GGG and WLAN Performance Modelling.
Paul J. Kühn received the Dipl.-Ing. and Dr.-Ing. degrees in Electrical Engineering from the University of Stuttgart, Germany, in 1967 and 1972, respectively. From 1973 to 1977, he was head of a research group for traffic research in computer and communications systems at the University of Stuttgart. In 1977, he joined Bell Laboratories, Holmdel, NJ., where he worked in the field of computer communications. In 1978, he was appointed professor for Communications Switching and Transmission at the University of Siegen, Germany. Since 1982, he is holding the chair of Communication Networks and Computer Engineering at the University of Stuttgart, Germany. His areas of interest are communication network architectures and protocols, computer engineering, performance modelling and evaluation, wherein he authored more than 100 technical publications.
Professor Kühn is a member of IEEE, ACM, ITG (German Information Technology Society), and GI (German Informatics Society). He has been appointed member of Communications Switching Committee of the ITG, IFIP Working Groups 6.2, 6.3 and 7.3 and International Advisory Council (IAC) of the International Teletraffic Congress (ITC). He was appointed Vice President of the ITC in 1985, and Governor of the ICCC in 1987. 1989 Professor Kühn has been elected Fellow IEEE. He was Program Chairman of ICCC 1986, Conference Chairman and Co-Chair of the IFIP Conferences "Broadband Communications" in 1998 and 1999, respectively, of various national conferences on Computer Communication and Performance Modelling, Editor and Guest Editor in the areas of Communication Networks for ETT and IEEE-JSAC. In 1991, Professor Kühn was appointed Professeur Associé at the Télécom Paris/ENST. 1991 Professor Kühn has been elected Chairman of the International Advisory Council IAC of the International Teletraffic Congress (ITC). In 1993, he was appointed Member of the Academy of Sciences of Heidelberg, Germany, and in 1995, Member of the Academy Leopoldina, Halle. In 1996, Professor Kühn has been awarded Dr. h.c. for Technology by the Lund Institute of Technology, Sweden, and in 1998 Dr.-Ing. E. h. by the University of Technology of Dresden, Germany. 1998 he was appointed Honorary Member of the Senat of the University of Mannheim, Germany, for his support of the new department of Computer Engineering. Also in 1998, he received the Christopher Columbus Gold Medal from the Council of the City of Genova, Italy, for his contributions in the field of telecommunications.
There are to be three invited speakers for the seminar. More details will be included here when final acceptances have been received.
Speaker: Professor Rudolf Mathar (Institute of Theoretical Information Technology, RWTH Aachen University)
Title: Elements of Cellular Radio Network Planning
In order to achieve high capacity, careful planning of cellular radio
networks is important. In this talk, we introduce the channel allocation problem
for FD/TDMA technology as is used in GSM networks. The basic formulation as a
mathematical optimization program is presented, and corresponding solution
heuristics, which have proved extremely successful in practice. Furthermore, the
planning process for CDMA networks is outlined. Interference minimization is the
central objective here. A corresponding branch-and-bound algorithm is introduced
for coping with this problem.
The main objective of this talk is to summarize some of the basic approaches in radio network planning. Most of the material is supported by graphics and pictures.
Professor Rudolf Mathar received his Dipl.-Math. and his Dr. Rer. Nat. degree in mathematics from the Aachen University of Technology, Germany, in 1978 and 1981, respectively. From 1986 to 1988, he worked as a lecturer in computer science at the European Business School and in an optimization research group at the University of Augsburg. He is currently Head of the Institute of Theoretical Information Technology, Dept. of Electrical Engineering, RWTH Aachen University. He is a cofounder of the Center of Network Optimization (CNO), and a cofounder and manager of Telecommunications Network Consulting ltd. His research interests include applications to mobile communication systems through performance analysis and optimization of stochastic networks.
Speaker: Dr Taka Sakurai (Honorary Fellow of Melbourne University)
Title: MAC access delay in IEEE 802.11e EDCA wireless LANs
In recent years, demand for wireless Internet connectivity has led to a proliferation of wireless local area networks (WLANs). Products based on the IEEE 802.11 family of standards have captured the lion's share of this burgeoning market. As in the wider Internet, the majority of network traffic carried on a typical IEEE 802.11 WLAN today consists of non-realtime applications such as web browsing and email that are carried over the TCP transport protocol. However, in the near future, it is expected that a significant proportion of the traffic on WLANs will consist of new realtime services such as voice over IP and video. To address the more stringent QoS requirements of these services, a new MAC layer standard, IEEE 802.11e, has recently been ratified. This specifies a random access scheme to support differentiated services called Enhanced Distributed Coordination Access (EDCA). In this talk, an analytical model of an EDCA WLAN operating under saturation will be presented. The model yields explicit expressions for the mean and standard deviation of the packet access delay, as well as permitting computation of the entire distribution. Numerical results will be presented which show that the model is highly accurate.
Dr Taka Sakurai received a PhD in electronic engineering from the University of Melbourne in 2004. He is currently a Senior Technical Specialist with the Chief Technology Office of Telstra, as well as an Honorary Fellow of the University of Melbourne. He previously held positions at Telstra Research Laboratories and the R&D departments of Lucent Technologies and NEC Australia. His research interests are in the performance modelling of emerging and future broadband wireless networks, the analysis and optimization of MAC protocols for wireless LANs and sensor networks, and computational probability.
Speaker: John Papandriopoulos (University of Melbourne)
Title: Getting the most out of MANETs: Distributed Algorithms for Cross-Layer Optimization
Congestion control algorithms such as TCP have recently been shown to approximately solve an underlying network utility maximization (NUM) problem, as a distributed computation for the globally optimum rate allocation. In a mobile ad-hoc network (MANET), we can optimize source rates as in TCP, but also link capacities through power control. In the non-linear NUM framework, the transport (TCP) and physical (power control) layers neatly decouple through Lagrangian dual prices. The resulting algorithm relies on message-passing between nodes for power control, involving congestion state and link noise measurements. In this talk, we focus on MANETs subject to fading, where link capacities fluctuate with channel variations. Tracking the dynamic fading state across the network induces an excessive message-passing overhead. We will show an alternative to avoid such fast-update problems by considering the statistical variations of the channel. Interestingly, the resulting problem is a difficult non-convex optimization. We will outline a novel method that solves for the global optimum, inducing a distributed algorithm that makes use of limited message passing. A practical ideal is for zero message passing, and so we will also outline a sub-optimal scheme having this desirable property.
John Papandriopoulos is currently with the ARC Centre for Ultra-Broadband Information Networks (CUBIN), at the University of Melbourne, Australia. He was awarded a Victoria Fellowship for his PhD research in 2005 that brought him to many prestigious universities, including Stanford and Princeton. John graduated from RMIT University with combined engineering and computer science degrees in 2001, and was subsequently awarded the university medal (J.N. McNicol prize) in 2002. He is the co-inventor of one patent and has enjoyed time with NEC Australia (3G Mobile R&D Division), Agilent Technologies (Advanced Networks Division) and Telstra Ltd. From 2003, John served two years as the IEEE Student Branch chairperson at the University of Melbourne. His research interests include nonlinear (non)convex optimization techniques and applications, particularly in the cross-layer design of wireless networks and resource allocation applied to OFDM and CDMA-based networks.