Proactive Prioritized Mixing of Scalable Video Packets in Push-Based Network Coding Overlays
Network coding applied to end-system multicast is a viable solution for a multitude of issues related to on-demand video streaming. End-system multicast on network overlays is a desirable option for relieving the content server from bandwidth bottlenecks and computational load as well as allowing decentralized allocation of resources for terminals with different computational and display capabilities. Network coding has proven to be able to solve many issues related to content distribution and rate allocation on end-system overlays, one of them being the coupon-collection problems typical of P2P networks. In this paper we present a scalable video streaming system based on end-system multicast, where the network coding technique with push-based content distribution is extended to perform prioritized streaming with error and congestion control. We identify a problem of layer and rate selection due to the difficulty in estimating the max-flow in end-system overlays, which, with many previously proposed techniques, yields to bandwidth inefficiencies. We present a mechanism for selecting and encoding chunks of scalable video prior to forwarding, and a peer-selection technique, targeting increased efficiency with the available bandwidth, that also improves quality and continuity of service with better use of network rate. Simulated tests results are presented to prove the performance of our system.