Real-time Guarantee of Aperiodic Packets in

Wireless Ad-hoc Networks

Chang-Gun Lee: Department of Electrical and Computer Engineering, Ohio State University, Columbus, OH 43210. (TEL) +1-614-292-7290 (FAX) +1-614-292-7596 (E-Mail) cglee@ece.osu.edu (URL) http://www.ece.osu.edu/~cglee

Abstract

Building real-time applications on 802.11 wireless networks is challenging because the medium access protocol is distributed and nodes contend for the channel non-deterministically. So far all attempts at providing real-time services in 802.11 require restrictive traffic assumptions such as periodicity. In this talk we describe the first modification to 802.11 that offers real-time guarantees for aperiodic packets using "distributed prioritization" and "distributed admission control". We show that barring external errors such as interference on the channel or incorrect scheduling this protocol guarantees deadlines will be met in single-hop networks. Then, we will discuss how the protocol can accompany a routing protocol to meet the end-to-end deadlines in multi-hop networks.

Short Biography

Chang-Gun Lee: Chang-Gun Lee is an Assistant Professor in the Department of Electrical and Computer Engineering, Ohio State University, Columbus OH. His current research interests include real-time systems, complex hybrid embedded systems, QoS management, and mobile wireless communications.

Before he joined the faculty of Ohio State University in 2002, he was a Research Scientist in
the Department of Computer Science, University of Illinois at Urbana-Champaign from 2000 to 2002 and a Research Engineer in the Advanced Telecomm. Research Lab., LG Information Communications, Ltd. from 1998 to 2000. He received the BS, MS and Ph.D. degrees in computer engineering from Seoul National University, Korea, in 1991, 1993 and 1998, respectively.