Timed Petri net representation of the Synchronized Multimedia Integration Language (SMIL) of XML

Abstract

A multimedia server needs to satisfy the temporal ordering of multimedia data streams when servicing a client. Multimedia data has high bandwidth requirements, and within a network a server may need to service many clients at the same time. During a presentation a client may have to wait indefinitely before receiving the next multimedia data stream. This happens because client requests are queued by a server before they can be serviced. This results in a loss of synchronization between the different multimedia objects required by a client for its presentation. In this paper we propose a technique by which clients in advance can submit to the server information of all the required multimedia objects and their temporal relationships for presentation. The technique uses an enhanced timed Petri net (TPN) to capture information of multimedia objects along with their timing and synchronization specified in the Synchronized Multimedia Integration Language (SMIL). We display a graphical representation of the temporal and synchronization information captured by the data structure representing the timed Petri net. This information can be used by a multimedia server to schedule and optimize the delivery of multimedia data streams.