Throughput optimality of single queue priority schemes

The throughput optimality of priority management strategies in a single buffer has been studied for a general aggregate arrival law. The tight upper bounds found are useful to understand optimality in utilization of specific priority schemes such as push-out buffer (POB) and partial buffer sharing (PBS). This paper further focuses on the maximum allowable load ρ_max versus the priority mix α for a PBS and a random push-out buffer (R POB) of size K for a wide variety of arrival processes. The role of priorities in a special type of bursty arrivals, the compound Poisson process with constant burst length and random priority assignment within the burst, is found to be less pronounced than that of `pure´ Poisson arrivals. On the other hand, the results for on-off cell arrivals modeled by a MMPP(2), MMPP(3), and higher order Markov modulated processes closely follow the behaviour of the maximum allowable load in the R POB with Poisson arrivals, however scaled to lower loads. The results indicate that the priority mix distribution within the aggregate arrival flow influences the shape of ρ_max(α)-curve more than the aggregate arrival distribution itself