Rate adaptive multimedia streams: optimization and admission control

This work investigates support of rate adaptive multimedia streams on communication networks. Optimal and practical mechanisms to maximize the customer average quality of service (QoS), defined in terms of a normalized time average received rate, are established. By scaling the arrival rate and link capacity, we obtain asymptotic expressions for customer average QoS in the case of networks with single bottleneck links. The optimal adaptation policy is identified as the solution to an integer program which has an intuitive "sort by volume" interpretation for the case of single bottleneck links, where stream volume is the total number of bits associated with a stream at its maximum resolution. Our asymptotic analysis shows the optimal adaptation policy may yield performance improvements of up to 42% over baseline policies. We demonstrate that a static multi-class admission control policy can achieve the same asymptotic QoS as that of the optimal adaptation policy. This implies that dynamic adaptation may be unnecessary for large capacity networks with appropriate call admission.