A Discrete-Time HOL Priority Queue with Multiple Traffic Classes

Priority scheduling for packets is a hot topic, as interactive (voice,video) services are being integrated in existing data networks. In this paper, we consider a discrete-time queueing system with nonpreemptive (or Head-Of-the-Line) priority scheduling and a general number of priority classes. Packets of variable length arrive in the queueing system. We derive expressions for the probability generating functions of the packet delays. From these functions, some performance measures (such as moments and approximate tail probabilities) are calculated. We apply the theoretical results to a queue that handles arriving multimedia traffic.