Hybrid Broadcast for the Video-on-Demand Service

Multicast offers an efficient means of distributing videocontents/programs to multiple clients by batching their requests andthen having them share a server's video stream. Batching customers'requests is either client-initiated or server-initiated. Most advancedclient-initiated video multicasts are implemented by patching. Periodicbroadcast, a typical server-initiated approach, can be entirety-based orsegment-based. This paper focuses on the performance of the VoD service forpopular videos. First, we analyze the limitation of conventionalpatching when the customer request rate is high. Then, by combining theadvantages of each of the two broadcast schemes, we propose a hybridbroadcast scheme for popular videos, which not only lowers the servicelatency but also improves clients' interactivity by using an activebuffering technique. This is shown to be a good compromise for bothlowering service latency and improving the VCR-like interactivity.