Synchronization of Multiple Descriptions Coding for Streaming Media

At present, many application layer multicast protocols (ALM) based on multiple description coding (MDC) have been proved to be more scalable and robust than traditional multicast protocols in practical environment. In this paper, we propose an ALM system called SMD for streaming media based on MDC to address the problem of synchronization of available descriptions among maximum hosts. SMD concentrates on the video quality and robustness, hosts can join the different overlay trees in different layers simultaneously, then the maximum covering set (MCS) based on acquired descriptions information is figured out to achieve the best video quality. To mine the potential of hosts and lower link stress, we propose efficient caching strategies to make tradeoff between them with low overhead. Simulations implemented on Internet-like topology indicate that SMD achieves higher video quality, lower control traffic than traditional ALM protocols while comparable latency, link stress and robustness are achieved as well.