Throughput analysis of buffered CSMA/CD based single channel Fast Ethernet optical LAN

Abstract

This paper provides the throughput performance of a buffered CSMA/CD based single channel Fast Ethernet optical LAN. The conventional CSMA/CD does not provide good throughput due to its inherent unfairness caused by collisions and binary exponential backoff algorithm. Packet loss and Ethernet capture effect make CSMA/CD LANs unsuitable for heavy load conditions and degrade the throughput. Aim of this paper is to improve the throughput of CSMA/CD based LAN by reducing collisions and eliminating packet loss. In the enhanced CSMA/CD system, each node has a finite buffer capacity which helps to reduce the number of collisions and Ethernet capture effect. At the same time, to ensure that no packet is lost or discarded, a new special-jamming signal is used. The network throughput performance based on the proposed CSMA/CD is evaluated against several design parameters i.e. number of nodes, bus length and offered load. Throughput performance of the system is also compared to the conventional CSMA/CD system which shows significant improvement. Throughput against number of nodes and offered load are increased more than 10% and 13% respectively compared to the conventional system.