Networking Requirements for Interactive Video on Demand

A signiicant driver for the consumer use of high bandwidth in the near future will be interactive video on demand (IVOD). A range of service types can be deployed, based on a diiering sophistication, which must be traded against the network costs (bandwidth) and component costs (switch complexity and memory). The potential aggregate bandwidth required is huge (O(1Pbps)), and thus it is essential to properly engineer the network to reduce the bandwidth required. This paper describes a variety of IVOD scenarios, and introduces a cost function that captures the combined bandwidth and storage requirements of the network. This cost function is used to compare diierent network engineering alternatives, particularly VOD program caching and stream sharing. The eeects of nonlinear pricing and diiering weights of bandwidth and storage are also reeected by the cost function. In addition, a simulation model is used to evaluate caching of programs or windows within programs. The overall intent of this work is to evaluate the eeects of various server, cache, and sharing strategies on the bandwidth and storage requirements of the network and their proper placement within the network.