Events Calendar

Network Scheduling with a Mix of Heavy-tailed and Light-tailed Traffic

Speaker: Eytan Modiano, Massachusetts Institute of Technology

Talk Title: Network Scheduling with a Mix of Heavy-tailed and Light-tailed Traffic

Abstract: We describe recent results on scheduling and routing in the presence of a mix of heavy-tailed and light-tailed traffic. In particular, we show that when some of the traffic in the network is heavy-tailed, under max-weight scheduling the expected delay is unbounded even for the light-tailed traffic. This surprising result shows that max-weight scheduling is delay unstable when some of the traffic is heavy-tailed. Further, we provide examples where max-weight scheduling can lead to delay propagation throughout the network.

We then study the class of throughput optimal max-weight-α scheduling policies, and show that with an appropriate choice of the α parameters, the light queue can achieve bounded expected delay. Moreover, we derive an exact asymptotic characterization of the steady-state queue length distributions. We extend our results to the case where the links have intermittent on-off connectivity and show that the behavior of the queue occupancy distribution strongly depends on the connectivity parameters and the arrival rates to the queues. Finally, we consider backpressure routing in the presence of heavy tailed traffic, and describe settings where backpressure routing also leads to delay propagation throughout the network.

This talk is based on joint work with Krishna Jagannathan, Mihalis Markakis, and John Tsitsiklis


Biography: Eytan Modiano received his B.S. degree in Electrical Engineering and Computer Science from the University of Connecticut at Storrs in 1986 and his M.S. and PhD degrees, both in Electrical Engineering, from the University of Maryland, College Park, MD, in 1989 and 1992 respectively. He was a Naval Research Laboratory Fellow between 1987 and 1992 and a National Research Council Post Doctoral Fellow during 1992-1993. Between 1993 and 1999 he was with MIT Lincoln Laboratory where he was a project leader for MIT Lincoln Laboratory's Next Generation Internet (NGI) project. Since 1999 he has been on the faculty at MIT, where he is a Professor in the Department of Aeronautics and Astronautics and the Laboratory for Information and Decision Systems (LIDS). His research is on communication networks and protocols with emphasis on satellite, wireless, and optical networks. He is an Editor-at-Large for IEEE/ACM Transactions on Networking, and served as Associate Editor for IEEE Transactions on Information Theory, the IEEE/ACM Transactions on Networking, and the AIAA Journal of Aerospace Information Systems. He was the Technical Program co-chair for IEEE Wiopt 2006, IEEE Infocom 2007, and ACM MobiHoc 2007. He is a Fellow of the IEEE and an Associate Fellow of the AIAA.

Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248

Audiences: Everyone Is Invited

Contact: Gerrielyn Ramos