Optimized Carrier Sensing Thresholds for Dense mmWave Wireless Networks Coexistence

Densification is an essential paradigm for future wireless networks in the unlicensed millimeter-wave (mmWave) band. Despite the promises of multi-gigabit data rates in mmWave due to wide spectrum availability, high node density could lead to severe interference and channel contention that reduce spatial reuse and overall throughput performance. To that effect, this paper investigates an approach to improve spatial average of throughput by optimizing the carrier sensing thresholds that govern the effectiveness of the channel access protocols. We consider a network with two radio access technologies (RATs) coexisting in the unlicensed mmWave spectrum. Using stochastic geometry tools to model network density, channel access protocols and spatial statistical average of throughput, closed-form expressions are proposed for selecting the carrier sensing thresholds without requiring frequent channel sounding to obtain network information. Numerical results obtained through simulation demonstrate the effectiveness of optimizing the carrier sensing thresholds to account for node density, transmit power and the mmWave propagation characteristics.