In: Telecommunication Systems, Vol. 11, No. 1-2, pages 161-185. 1999.
Abstract: This paper presents a formally defined architecture allowing the design and the corresponding implementation of a set of modules that fulfill the quality of service requirements of PNSVS (Petri Net Synchronized Video-conference System), an application designed to run on top of an asynchronous environment. It describes the mechanisms and architecture allowing the system to enforce the temporal synchronization between the audio and video streams, the presentation quality, and the end to end delay. This synchronization method relies on a formal model extending time Petri nets: the Time Stream Petri Net (TSPN) model, that will be used to completely specify the time constraints of the application streams. From this, the communication architecture is improved by introducing a new partial order transport service that maximizes the PNSVS quality of service. The partial order transport principle is presented together with the pre-synchronization sub-layer, which makes the partial order transport service match the applicative synchronization requirements. Moreover, it will be shown that each layer of this synchronization architecture can be formally modeled by a well defined set of TSPN models.
Keywords: kernel support, multimedia synchronization, time Petri nets, video-conferencing applications.