A hierarchical video-on-demand system with double-rate batching

In this paper, a two-tier hierarchical network architecture is exploited to provide true video-on-demand (VoD) services using double-rate (DR) batching in multicast environment. In the proposed system, new customers will be grouped together by the local server with the DR batching scheme and then be served by the multicast backbone network. Two scheduling policies are developed to serve customers at the local batching servers. The results show that the hierarchical VoD system can greatly reduce the resources requirement compared with the centralized approach. In addition, in order to secure the multicast channels for the new multicast groups, the backbone channel reservation algorithm that is similar to the look-ahead scheme [Multimedia Systems 3 (1995) 137] is proposed. If there are 100 videos and 500 backbone multicast channels, the system is able to support 0.2 requests/s with less than 7% admission blocking probability.