A Realistic Approach to Analyzing Performance of the Ethernet based on the Space-Time Model

A very popular access control method for local area networks having the bus topology is the carrier sense multiple access with collision detection (CSMA/CD) protocol because of its simplicity. This protocol can provide high throughput if the signal propagation time plus carrier detection delay is much smaller than the packet transmission time. Therefore, it is very crutial for performance analysis to consider both the exact timing of a sequence of the events at individual stations and their positions on the network. A study of the CSMA/CD protocol on the basis of space-time model which describes not only times of events but also spatial location is analyzed. A simulation study of the Ethernet operation is presented. First, the throughput of the protocol are monitored at the several different observation points on the bus. Second, the effect of packet length is examined. Then these realistic simulation results based on the space-time model are compared to previous time domain results. These results show that the throughput is much higher than time domain results.