Dynamic rate adaptation for adaptive video streaming in wireless networks

• Rate adaptation for scalable video in wireless networks is modeled as an MDP process.
• Offline optimal solution and online sub-optimal solution are given.
• Experiments using testbed show the feasibility and advantage of the online solution.

In this paper, we investigate the streaming strategy for dynamic adaptive streaming over HTTP (DASH). Specifically, we focus on the rate adaptation algorithm for streaming scalable video (H.264/SVC) in wireless networks. We model the rate adaptation problem as a Markov Decision Process (MDP), aiming to find an optimal streaming strategy in terms of user-perceived quality of services (QoS) such as playback interruption, average playback quality and playback smoothness. We then obtain the optimal MDP solution using dynamic programming. However, the optimal solution requires the knowledge of the available bandwidth statistics and has a large number of states, which makes it difficult to obtain the optimal solution in real time. Therefore, we further propose an online algorithm which integrates the learning and planning process. The proposed online algorithm collects bandwidth statistics and makes streaming decisions in real time. A reward parameter has been defined in our proposed streaming strategy, which can be adjusted to make a good trade-off between the average playback quality and playback smoothness. We also use a simple testbed to validate our proposed algorithm. Experimental results show the feasibility of the proposed algorithm and its advantage over the existing work.