Throughputs in processor sharing models for integrated stream and elastic traffic

We present an analytical study of throughput measures in processor sharing queuing systems with randomly varying service rates, modelling e.g. a communication link in an integrated services network carrying prioritised fixed rate stream traffic and rate-adaptive elastic traffic. A number of distinct throughput measures for the elastic traffic are defined, analysed and compared under various system conditions, both by analytical means and simulation. It is concluded that the call-average throughput, which is most relevant from the user point of view but typically hard to analyse, is very well approximated by the newly proposed so-called expected instantaneous throughput, which is readily obtained from the system’s steady state distribution.