A delay-throughput performance analysis of the pi -persistent protocol for unidirectional broadcast bus networks

The authors investigate the delay-throughput performance of this protocol operating under either equal or nonuniform load conditions based on the fairness criterion of equal average packet delay. Because of the complexity of the system, an approximate analytical model for selecting the p_i for this fairness criterion is developed. The p_i that satisfy the fairness criterion are determined from a Markov chain model for the protocol. The authors begin by considering the finite-buffer case and then proceed to the infinite-buffer one. They find that the performance of the protocol is insensitive to bus length, data rate, and the number of stations on the network. Hence, the network is suitable for long-distance, high-bandwidth applications as in fiber-optic local and metropolitan area systems. Simulation studies which serve to establish the range of validity of the analytical model are presented