Improving Carrier-Sense Multiple Access Using Cues of Channel Utilization

A simple variation of Carrier Sense Multiple Access (CSMA), CUE-CSMA (for Channel Utilization Estimation), is introduced in which the transmission-persistence probability is a function of the perceived average length of idle periods, which is used as a cue of channel utilization. Nodes need not know or estimate the number of nodes in the network. A simple analytical model is used to derive the throughput of CUE-CSMA and compare it with non-persistent and 1-persistent CSMA without having to assume saturation mode as several prior studies have done. The model considers the effect of acknowledgments (ACK) and receive-to-transmit turnaround times. The results clearly show that using estimates of average idle periods as simple cues of channel utilization can provide the benefits of 1-persistent CSMA at light loads and match or outperform non-persistent CSMA at higher loads.