February 6, 2004, 2pm, Douglas Auditorium
"Unified Framework for Optimal Video Streaming"
Keith Ross, Polytechnic University

We study the problem of how to stream layered video (live and stored) over a lossy packet network in order to optimize the video quality that is rendered at the receiver. We present a unified framework that combines scheduling, FEC error protection, and decoder error concealment. In the context of the unified framework, we study both the case of a channel with perfect state information and the case of a channel with imperfect state information (delayed or lost feedback). We adapt the theory of infinite-horizon, average-reward Markov decision processes (MDPs) with average-cost constraints to the problem. Based on simulations with MPEG-4 FGS video, we show that (1) optimizing together scheduling, FEC error correction and error concealment improves performance significantly and (2) policies with static error protection give near-optimal performance. We also find that degradations in quality for a channel with imperfect state information are small; thus our MDP approach is suitable for networks with long end-to-end delays.

Professor Ross joined Polytechnic University as the Leonard Shustek Professor in Computer Science in January 2003. Before joining Polytechnic University, he was a professor for five years in the Multimedia Communications Department at Eurecom Institute in Sophia Antipolis, France. From 1985 through 1997, he was a professor in the Department of Systems Engineering at the University of Pennsylvania. From July 1999 to July 2001, Professor Ross found and lead Wimba, an Internet voice messaging startup.

Professor Ross is currently working in the areas of P2P systems and video streaming. He is an associate editor for IEEE/ACM Transactions on Networking. Professor Ross is co-author of the best-selling textbook, Computer Networking: A Top-Down Approach Featuring the Internet, published by Addison-Wesley. Professor Ross is also the author of the research monograph, Multiservice Loss Models for Broadband Communication Networks, published by Springer in 1995.