Abstract— We compare the performance of two real-time systems for communication of distortion-tolerant content such as audio and video over rate-varying channels. The basic difference between the systems is the placement of a buffer either before or after the rate-controlled encoder. For our evaluation we target signal quality versus end-to-end delay. We develop an analytical framework for their comparison, when the systems use a deterministic rate-varying channel. Furthermore, for stochastic rate-varying channels we use the Gilbert-Elliott channel model and suggest some heuristic rate-control strategies for the two systems when communicating over such a channel. Contrary to intuition it is shown that one of the systems performs better than the other system. As the analysis uses approximations, performance is also validated through simulations.

Index Terms— Buffers, Interactive systems, Source coding, Rate-varying channel.

Cite: Muhammad Ajmal, Peter Johansson, and Robert Forchheimer, "Performance Evaluation of Rate-Control Strategies for real-time Systems Over a Rate-Varying Channel," Journal of Communications, vol. 5, no. 5, pp.390-399, 2010. Doi: 10.4304/jcm.5.5.390-399