A cost comparison of distributed and centralized approaches to video-on-demand

With video-on-demand (VoD) regarded as one of the drivers for the deployment of broadband integrated service digital networks (B-ISDNs), an important issue is how to provide wide area VoD services most efficiently. A large contributor to the cost of a VoD system is storage. The nature of the service requires massive amounts of storage and bandwidth to be supplied from a video server located within the network. We examine the costs of storage in such servers and develop an efficient allocation scheme designed to minimize this cost. Using this scheme, centralized and distributed approaches to VoD are compared. We conclude that a distributed approach to storage costs no more than a centralized approach and offers considerable advantages in terms of bandwidth requirements and service quality.