Distributed video presentation

In this paper, we consider a distributed video server environment where video movies need not be stored entirely in one server. Blocks of a video movie are allowed to be distributed and replicated over multi-ple video servers. Customers are served by one video server. This video server, termed originating server, might have to interact with other servers for down-loading missing blocks of the requested movie. We present three types of presentation plans that an orig-inating server can possibly construct for satisfying a customer's request. A presentation plan can be consid-ered as a detailed (temporally synchronized) sequence of steps carried out by the originating server for pre-senting the requested movie to the customer. Cre-ation of presentation plans involves obtaining commit-ments from other video servers and the network service provider, as well as making commitments of local re-sources, within the limitations of available bandwidth, available buer, and customer consumption rates. For evaluating the goodness of a presentation plan, we introduce two measures of optimality for presenta-tion plans: minimizing wait time for a customer, and minimizing access bandwidth. We present algorithms for computing optimal presentation plans, and com-pare experimentally their performance. We have also mathematically proved certain results for the presen-tation plans.