Statistical Multiplexing of Self-Similar Video Streams: Simulation Study and Performance Results

B. Bashforth and C. L. Williamson. Proceedings of the Sixth International Symposium on the Modeling, Analysis, and Simulation of Computer and Telecommunication Systems (MASCOTS'98), Montreal, PQ, pp. 119-126, July 1998.

Abstract: Achieving statistical gains when multiplexing video streams, as in a video-on-demand (VOD) scenario, is difficult because of the stringent QOS demands and the self-similar nature of the traffic. This paper explores, through empirical simulation, the QOS, network utilization, and statistical characteristics of the aggregate traffic resulting from multiple independent MPEG video streams. In addition, the simulation results are compared against several recently-derived theoretical results for self-similar network traffic.

There are three main results that are evident from our experiments. First, there is a moderate amount of statistical multiplexing gain to be had, even when aggregating multiple self-similar traffic streams. Second, video multiplexing is extremely sensitive to traffic phasing effects, and to heavy-tailed frame size distributions, as has been noted by other researchers. Finally, the theoretical approaches that we consider (namely, the Norros effective bandwidth formulation) seem promising, but still require some fine tuning if they are to be practical for call admission and network dimensioning.