A Scalable Multicast Scheme for High Definition Streaming Media

IP multicast has been proposed for over a decade, but deployment in heterogeneous Internet is still limited within small area for lack of network management and congestion control. Many application layer multicast (ALM) protocols have been proved to be more scalable and feasible than IP multicast in practical environment. In this paper, we propose an ALM protocol called scalable hierarchical multicast for high definition streaming media (SHMHD) that makes best of end to end bandwidth to achieve HD media transmission without increasing much protocol and control overhead. The hosts in overlay tree only forward some blocks of piece which is the basic unit during transmission according to the available bandwidth between each other in heterogeneous environment. With the novel many-many transmission style in hierarchical architecture, HD data delivery is conducted by multiple parents collaboratively in most circumstances. Simulations implemented on Internet-like topology indicate that SHMHD achieves lower link stress and end to end latency than traditional ALM protocols, and comparable latency and stability are achieved at same time.