RETRIEVAL SCHEDULES BASED ON RESOURCE AVAILABILITY AND FLEXIBLE PRESENTATION SPECIFICATIONS

A distributed multimedia document presentation involves retrieval of o bjects from one or more document servers and their presentation at the client system. The presentation of the multimedia objects has to be c arried out in accordance with the specification of temporal relationsh ips between the objects. The retrieval of multimedia objects from the document server(s) is influenced by factors such as temporal specifica tion of objects presentations, throughput offered by the network servi ce provider, and the buffer resources on the client system. Flexibilit y in the temporal specification of the multimedia document may help in deriving an object retrieval schedule that can handle variations in n etwork throughput and buffer resource availability. In this paper, we develop techniques for deriving a flexible object retrieval schedule f or a distributed multimedia document presentation. The schedule is bas ed on flexible temporal specification of the multimedia document using the difference constraints approach. We show how the derived retrieva l schedule can be validated and modified to ensure that it can work wi th the offered network throughput and the available buffer resources.