Reliability Evaluation of Modified Gamma Network with Reduced number of Stages

Abstract

Reliability of multiprocessing systems greatly depends upon performance of Interconnection Network (IN) employed in it. Multistage Interconnection Networks (MIN) provide cost effective communication between multiple processors and memory modules, connected in parallel. Hence to improve the performance of multiprocessing systems, reliability and fault tolerance enhancement of MIN is of paramount importance. Some of the major papers on gamma networks have been reviewed in this paper. It has been found that these networks still lack in achieving fault tolerance at input and output node, cost is high, regularity of the network has been compromised etc. In this paper a new framework of Gamma Network has been proposed, which is considerably more reliable and fault tolerant. This has been named as Modified Gamma Network (MGN). MGN demonstrates improved reliability as compared to existing MGN topologies. It has been shown that the proposed topology possesses less number of stages as compared to GIN. Additionally, it possesses more number of parallel paths with at least two totally disjoint paths between each Source Destination (S-D) node pair, hence increased reliability and fault tolerance has been achieved as compared to GIN and its variants. The proposed MGN possesses less cost with minimum latency for a packet to be transmitted from a source to required destination as it has to pass through minimum number of nodes. In this paper ST-Reliability (Source-Terminal Reliability) of proposed network has been evaluated and the results achieved are compared with most of the existing Gamma Networks in literature. MGN demonstrates 23 % improved reliability and reduction in cost with fault tolerance feature.