Reliability and performance analyses of balanced gamma network for use in broadband communication switch fabrics

Balanced gamma network, a multipath, multistage interconnection network, which features 4x4 switching elements may be considered as a potential candidate for use in broadband communication switch fabrics. This paper studies the fault tolerance and reliability of the balanced gamma network. The three main reliability measures -- terminal reliability, broadcast reliability, and network reliability -- are computed for the balanced gamma network in this paper. The input-output and network mean times to failure of the balanced gamma network are also calculated. The performance of a multistage interconnection network in the presence of faults gives a better understanding of the dependability of the network than the reliability measures normally used. The performance analysis of the balanced gamma network with faults, under the uniform traffic type is presented. It is shown that the balanced gamma network is single fault-tolerant and robust under multiple faults. Simulation results of the throughput performance of the balanced gamma network with and without faults, under uniform traffic patterns, are also compared in this paper.