Toronto Networking Seminar

Interaction of Rate and Medium Access Control in Wireless Networks

Peter Marbach
Dept. of Computer Science
University of Toronto

Date:  Friday, November 10,  3pm
Location: BA 1170 (Bahen Center)


It has been observed that the combination of TCP rate control with the IEEE 802.11 MAC protocol can lead to very poor performance in terms of fairness. However, a systematic approach to overcome this problem is still elusive as proposed solutions  are either too complex, or do not provide clear design guidelines for obtaining good system performance. In the talk, we take a fresh look at this problem. We start out by asking the following questions: (a) what properties should a MAC protocol have in order to provide fair bandwidth allocation among TCP connections and  (b) how can this properties be implemented in a fully distributed manner?  An interesting aspect of our analysis is that the resulting protocols are conceptually very similar to well-known protocols for wireline networks (such as active queue management and scheduling), but their implementation take into account the unique features of wireless networks (such as interference and the distributed nature of congestion). There is also a connection between the presented work and maximal weight matching schedulers.


Peter Marbach was born in Lucerne, Switzerland. He received the Eidg. Dipl. El.-Ing. (1993) from the ETH Zurich, Switzerland, the M.S. (1994) in electrical engineering from the Columbia University, NY, U.S.A, and the Ph.D. (1998) in electrical engineering from the Massachusetts Institute of Technology, Cambridge, Massachusetts, U.S.A. He was appointed as assistant professor in 2000, and associate professor in 2005, at the Department of Computer Science of the University of Toronto. He has also been a Post-Doctoral Research Fellow at the Center for Communication Systems Research, University of Cambridge, UK, and a visiting scientist at the Siemens Corporate Research Center in Munich. Peter Marbach has received the IEEE INFOCOM 2002 Best Paper Award for his paper "Priority Service and Max-Min Fairness". His research interests are in the fields of communication networks.