Queueing analysis of an ATM multimedia multiplexer with non-pre-emptive priority

Abstract

A queueing-theoretic analysis of an ATM multiplexer handling two-class multimedia traffic is described. Specifically, it assigns class-1 cells, constituting real-time traffic, high service priority, and class-2 cells, constituting non-real time traffic, low service priority. The priority discipline used is non-pre-emptive. For the purpose of the analysis, the multiplexer is modelled as a priority, discrete time, single-arrival, single-server queueing system with an infinite buffer and geometric service time. The model dynamics are extracted by a rather complex difference equation whose solution is sought using a generating function technique. This difference equation approach is a major contribution of the paper. Unlike the prevalent stochastic equation approach, it makes the physical details of the system present and visible during the analysis. Results are obtained for the multiplexer occupancy and cell waiting time. These results are verified analytically by producing from them some previously published results as special cases. They are also verified by applying them to numerical examples and obtaining intuitively acceptable values.