Scheduling and optimization of the delivery of multimedia streams using query scripts

New techniques are necessary to satisfy the high bandwidth requirement and temporal relationships of multimedia data streams in a network environment. Clients can experience gaps between the multimedia data streams during presentations as the multimedia server services multiple clients. This variable delay occurs between the end of one multimedia stream and the beginning of the next multimedia stream because client requests are queued awaiting service. This leads to interruptions and discontinuities of the client's presentation. Special techniques are necessary to manage the temporal relationships between multimedia streams in distributed environments. In this paper we propose two scheduling algorithms for delivering multimedia streams by using the query script, which is a multimedia database interface for clients. A client can specify all the multimedia objects that make up the presentation and their temporal relationships in a query script. Once submitted, the information in the query script is used by the multimedia database system to schedule and optimize the delivery. Using simulations we analyzed the performance of the proposed delivery scheduling algorithms and the predelivery optimization method. The simulation results show that delivery scheduling algorithms satisfy the specified temporal relationships between multimedia streams while maintaining better use of system resources.