Dynamic allocation of buffer and link capacity for vp-based multimedia communications

摘要

A new algorithm, for dynamic resource allocation at nodes of a Virtual Path (VP) used for multimedia communication over an ATM-based network, is presented and evaluated. This algorithm allocates buffer space and link capacity that guarantee a prescribed end-to-end QoS (Mean Cell Transfer Delay (MCTD) and Cell Loss Ratio (CLR)) simultaneously over the VP for dynamically varying input loads. Previous works have guaranteed a CLR alone and not both MCTD and CLR simultaneously. The principle of operation of the algorithm is presented in detail. The algorithm consists of two parts: the first part deals with allocation of MCTD's and CLR's at the various nodes of the VP. The second part deals with allocation of buffer space and capacity of the outgoing channel at individual nodes. M/D/1/K and MMPP/D/1/K queueing models are used to develop analytical expressions for the QoS at the nodes in terms of number of input sources, the probability that a source is On, the generation rate of the sources, the capacity of the outgoing link and the buffer size at the node. These analytical expressions are then used to develop the algorithm for allocating required link capacity and buffer size. An example has been worked out to illustrate the application of the algorith. This algorithm can also be used to allocate resources in wireless networks.