An analysis of a time window multiaccess protocol with collision size feedback (WCSF)
M. Y. Elsanadidi, Wesley W. Chu · ACM SIGMETRICS Performance Evaluation Review · 1982
We analyze the performance of a window multiaccess protocol with collision size feedback. We obtain bounds on the throughput and the expected packet delay, and assess the sensitivity of the performance to collision recognition time and packet transmission time. An approximate optimal window reduction factor to minimize packet isolation time is {equation}, where n is the collision size and R the collision recognition time (in units of packet propagation delay). The WCSF protocol, which requires more information than CSMA-CD, is shown to have at least 30% more capacity than CSMA-CD for high bandwidth channels; that is, when packet transmission time is comparable to propagation delay. The capacity gain of the WCSF protocol decreases as the propagation delay decreases and the collision recognition time increases. Our study also reveals the inherent stability of WCSF. When the input load increases beyond saturation. The throughput remains at its maximum value.