Optimized Physical Carrier Sensing Threshold in High Density CSMA/CA Networks

We address the PCS (physical carrier sensing) threshold selection problem for dense wireless local area networks (WLANs). This important network parameter determines the spatial reuse permitted by the CSMA/CA protocol, which consequently determines the interference level. Using Poisson Point Processes (PPP) from stochastic geometry, we obtain a closedform expression for PCS threshold selection. Our primary aim is to find the PCS threshold value that improves the spatial density of throughput (SDT). Assuming a Rayleigh fading channel, we derive the PCS threshold as a function of node density and path loss exponent, parameters that are global and easily measured. That is, we determine the optimal PCS threshold based on the fundamental parameters of the network without requiring channel knowledge of each link. To assess the impact of the proposed method, simulation results reveal gains in throughput density over the conventional and the random selection methods.