Delay-Optimized Network Coding for Video Streaming over Wireless Networks

In this paper, we study delay-optimized network coding for video streaming over wireless networks with network coding capabilities. It has been demonstrated that network coding can increase throughput in wireless networks, by mixing packets from different flows into a single packet, thus increasing the information content per transmission. However, network coding potential is not always fully exploited in this setting, because there may not be enough packets at intermediate nodes to do network coding due to bursty nature of transport protocols, packet losses, and difference in path delays. One way to deal with this problem is to delay packets at intermediate nodes in order to create more network coding opportunities. However, introducing large or varying delays eventually hurts video traffic, which requires low delay and delay jitter. In this paper, we study this tradeoff in coded wireless networks, and we propose a packet delaying scheme at intermediate nodes to maximize video quality.