Mixed Finite-/Infinite-Capacity Priority Queue with Interclass Correlation

We consider a discrete-time queueing system with two priority classes and absolute priority scheduling. In our model, we capture potential correlation between the arrivals of the two priority classes. For practical use, it is required that the high-priority queue is of (relatively) small size and we hence use a model with finite high-priority queue capacity. We obtain expressions for the probability mass functions of the steady-state system content and delay of the high-priority class as well as for the probability generating functions and moments of the steady-state system content and delay of the low-priority class. The results are compared to those of a similar system, but with an infinite capacity for high priority packets, and it is shown that the latter can be inaccurate. We also investigate the effect of correlation between the arrivals of both priority classes on the performance of the system.