Random Access Support for Large Scale VoD

The implementation of an interactive Video on Demand service is conventionally expensive because each viewer must be allocated a video stream. On the other hand, video streams can be multicast to a number viewers, reducing the system resources. This paper proposes a scheme, called Random Access PMC (RAPMC) which reduces the requirements for supporting an interactive VOD service. It is shown that the number of video streams needed can be greatly reduced, compared to the conventional method. However, RAPMC requires a very large buuer at the cus-tomers' video terminals which can be provided by a fast local magnetic disk.