RESOURCE MANAGEMENT FOR DISTRIBUTED MULTIMEDIA STREAMS WITH CRITICALITY
Zhang Zhan · Chinese Journal of Computers · 1998
The guarantees of steady rate of multimedia streams is key issue in resource management of distributed multimedia systems. Many multimedia applications possess character of the criticality that describes the critical extent about media streams. The multimedia stream and its sequentially accessing resources, such as CPU, buffers, I/O and network bandwidth, have been defined. A session with criticality has four states i. e. waiting, running, preempted and closed. This paper presents a prototype of resource management based on the session with criticality including the mechanism of resource management, the strategy of resource management, the algorithm of QoS negotiation and adaptation, and the algorithm of session preemption with high criticality. The prototype can meet steady rate of multimedia streams with criticality. It can maximize not only the total number of concurrent multimedia streams, but also the number of high-criticality multimedia streams scheduled and the QoS of all multimedia streams. System resource manager (SRM)manages a waiting queue of sessions with criticality order. In the prototype, the resource manager will adjust QoS including QoS shrink and QoS extension of all sessions and preempts other sessions when a new session requires resource to schedule high criticality session as possible. Finally, this paper compares performance overhead and effect of session preemption algorithms in client/server model and Windows95/Windows NT environment and shows that the algorithm B is a available algorithm for real-time multimedia systems.