Connection admission control methods for multimedia communication systems.

In this thesis, Quality of Service (QoS) and resource management in multimedia communication systems are briefly reviewed. Then, two Connection Admission Control (CAC) methods, one for a media server with multiple disks supporting the simultaneous retrieval of continuous media streams and the other for Asynchronous Transfer Mode (ATM) networks supporting multimedia traffic under varying traffic conditions and different QoS requirements, are proposed, simulated and evaluated in order to improve system performance with respect to the delivery of multimedia services in multimedia communication systems. The proposed CAC method for the media server with multiple disks can be applied to the different media stream storage patterns on the disks, which is also well-suited to support retrieval service for Redundant Arrays of Inexpensive Disks (RAID). This CAC method can distribute the workload of applications evenly across the disks in order to maximize the system processing capabilities. The proposed CAC method for ATM networks can be applied to not only an ATM multiplexer but also an output buffer type switching node. Since cell loss rate and average queuing delay are two main important performance objectives provided by the networks to connections, which is closely related to the buffer sizes in the ATM switching node or the multiplexer, our proposed CAC method with buffer model can improve statistical multiplexing gains due to the effects of different buffer sizes. Also, a two-level CAC method is proposed so that our proposed algorithm could be guaranteed to compute in real-time. Computer simulations are used to help the performance evaluation for two CAC methods. The simulation results show that the proposed CAC methods can provide very high efficient admission control, guarantee the real-time continuous retrieval of delay sensitive media streams or achieve high utilization efficiency by taking account of statistical multiplexing effects based on different buffer sizes