An integrated communication architecture for distributed multimedia applications.

摘要

Distributed multimedia applications require that the underlying system provide timing, throughput and synchronization support. These performance requirements necessitate the development of a new type of distributed multimedia system architecture. The goal of this research is to design an integrated communication architecture to support these applications and to bridge the gap between an application's communication specification and real-time network support.; The architecture is called the Distributed InterProcess Communication System (DIPCS). DIPCS is organized around providing applications known levels of Quality of Service (QoS). A QoS parameter represents the applications requirements for system resources. This architecture is targeted to run over an Integrated Services Network (ISN), the next generation of network architecture. Communication management is done in the context of a novel distributed process group model, which allows the expression of the applications end-to-end delay and synchronization requirements. These groups are designed to effectively support the wide range of equipment and media types and connection control requirements which characterize distributed and collaborative multimedia systems.; The DIPCS architecture uses a general-purpose multi service-class ISN as the base of support. We develop an integrated set of network level scheduling and routing algorithms to efficiently support the performance requirements for each group. Communication establishment is performed using a source-based procedure. We derive a schedulability result for guaranteeing real-time multimedia traffic. Routing within this architecture uses a new ISN-based path production algorithm, coupled with an analytical model that predicts the probability of a route or set of routes being able to support the group specification. Three algorithms for route selection are considered. The first is a least-loaded approach. The second is a stochastic hillclimbing approach, while the third is a hybrid algorithm drawing on evolutionary computing principles. Simulation results show that the new path production algorithm coupled with the latter two approaches for routing selection can significantly increase the ability of the network to support multimedia communication.; This thesis demonstrates that combining multimedia call management and communication control with real-time network support can substantially simplify the development of distributed multimedia applications and can be achieved with a general-purpose real-time network.