Although the wireless access networks have been extensively studied for many years, there is currently no clear answer to the fundamental question: what is the flow-level capacity of a wireless access network under a network-layer quality of service (QoS) constraint. In this talk, a cross-layer analytical framework will be presented, which integrates network-layer queueing analysis with a novel non-saturated medium access control (MAC) analysis model. Specifically, we consider a wireless local area network with distributed coordination function (DCF) based MAC, and compute the maximum number of on/off voice flows that can be supported over the WLAN, under the constraint of a network-layer stochastic delay bound. Moreover, the cross-layer framework is further exploited for statistical multiplexing gain analysis, contention window optimization, and voice traffic rate design. We will also discuss the possible approaches to extend the proposed framework for multi-hop wireless network analysis.

Yu Cheng received the B.E. and M.E. degrees in Electrical Engineering from Tsinghua University, Beijing, China, in 1995 and 1998, respectively, and the Ph.D. degree in Electrical and Computer Engineering from the University of Waterloo, Waterloo, Ontario, Canada, in 2003. From September 2004 to July 2006, he was a postdoctoral research fellow in the Department of Electrical and Computer Engineering, University of Toronto, Ontario, Canada. Since August 2006, he has been with the Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, Illinois, USA, as an Assistant Professor. His research interests include service and application oriented networking, autonomic network management, Internet measurement and performance analysis, wireless networks, and wireless/wireline interworking. He received a Postdoctoral Fellowship Award from the Natural Sciences and Engineering Research Council of Canada (NSERC) in 2004, and a Best Paper Award from the International Conference on Heterogeneous Networking for Quality, Reliability, Security and Robustness (QShine'07), Vancouver, British Columbia, August, 2007. He is an Associated Editor for IEEE Transactions on Vehicular Technology, and he serves as the TPC co-chair for ICC09 Wireless Networking Symposium.