Delay characteristics of a tagged cell stream in a discrete-time single-server queue, in the presence of background traffic

We present the delay analysis of a tagged cell stream (TCS) in a discrete-time queueing system with one output link. The transmission of the tagged cells is sometimes prohibited due to the presence of background traffic, which represents a superposition of cell streams generated by various other sources, independently of the TCS arrivals. We first derive an expression for the probability generating function of the TCS delay. From this result, closed-form expressions for the mean TCS delay and the tail distribution of the TCS delay are obtained. In addition, lower and upper bounds that allow accurate estimates for these quantities and that are easily evaluated, are also given.