Window-Based Rate Control Approach for Video Streaming Over Wireless Networks

Abstract

Source-rate control is an important issue in video streaming applications, particularly for wireless networks where channel resources are often shared among a variable number of stations using a contention-based access mechanism. In this context, the resulting throughput available for the video server has been demonstrated to be bursty, which is a feature that makes high-quality video streaming quite difficult. On the basis of this observation, we propose a rate control algorithm that works adjusting the rate on a per-window basis to compensate low-throughput periods with high-throughput periods so as to avoid the "saw" effect that is typically observed in frame-based rate control. The time axis is divided into windows of fixed size and rate changes are introduced only at the beginning of each window with the aim of keeping the probability of playback buffer starvation lower than a desired threshold during the entire current window. To achieve this objective, the algorithm makes use of a short-term prediction of the network delay using historical data. Simulations proved the efficiency of algorithm when controlling the starvation probability while avoiding the introduction of sudden changes in the source rate.

Performance Evaluation of Rate-Control Strategies for real-time Systems Over a Rate-Varying Channel

“…The idea behind the Engineer's algorithm scheme resemble the rate-control scheme described in [20], where the encoding rate is adjust for every T seconds, on the basis of channel information and play back buffer occupancy. The essence of the strategy is to make a general algorithm, that adjusts the coding rate on short time instant basis, so as to allow for a broader class of channels (more than two states).…”