HHMSM: a hierarchical hybrid multicast stream merging scheme for large-scale video-on-demand systems

The key performance bottleneck for large-scale video-on-demand (VoD) systems is the server bandwidth, which controls the number of clients a video server can support. Two existing stream scheduling schemes can save server bandwidth significantly by using multicast method to transmit video data: the batching scheme and the patching scheme. However, the batching scheme results in long start-up latency and high reneging probability. The patching scheme does not work well at high client request rates due to mass retransmission for same video data. In this paper, we propose a hierarchical hybrid multicast stream merging scheme, called HHMSM, which can save server bandwidth significantly over a wide range of client request rates. Furthermore, the start-up latency raised by the HHMSM scheme is far less than that of the batching scheme.