Fixing Multi-Client Oscillations In HTTP-based Adaptive Streaming: A Control Theoretic Approach

In recent years, the technology for video delivery over the Internet is shifting towards a new paradigm: HTTP-based adaptive streaming (HAS). An HAS client receives video contents on a segment by segment basis via standard HTTP GET requests. It can dynamically change the rate and quality of the video in the presence of time-varying bandwidth changes. When multiple clients compete over a common bottleneck link, however, they often fail to converge to their respecitive fair share of bandwidth. This leads to constant oscillations in the received video quality. In this paper, we uncover the cause of such oscillations based on observations from large-scale test bed experiments. We then propose a novel client rate adaptation algorithm, which strives to stabilize the playout buffer at a reference level via a proportional-integral controller (PIC). Test bed evaluation results confirm the effectiveness of the proposed PIC scheme and its superior performance over Microsoft Smooth Streaming.