Video multicast over wireless mesh networks with scalable video coding (SVC)

We address the problem of rate allocation for video multicast over wireless mesh networks. An optimization framework is established to incorporate the effects of heterogeneity in wireless link capacities, traffic contention among neighboring links and different video distortion-rate (DR) characteristics. We present a distributed rate allocation scheme with the goal of minimizing total video distortion of all peers, without excessive network utilization. The scheme relies on cross-layer information exchange between the MAC and application layers. It adopts the scalable video coding (SVC) extensions of H.264/AVC for video rate adaptation, so that graceful quality reduction can be achieved at intermediate nodes within each multicast tree. The performance of the proposed scheme is compared with a heuristic scheme based on TCP-Friendly Rate Control (TFRC) for individual peers. Network simulation results show that the proposed scheme tends to allocate higher rates for peers experiencing higher link speeds, leading to higher overall video quality than the TFRC-based heuristic scheme.