A Novel Load Estimation Based Dynamic CBAP Allocation Policy for mmWave WLANs

The new millimeter-wave (mmWave) wireless local area network (WLAN) standards such as IEEE 802.11ad and IEEE 802.11ay utilize the spectrum from 57 to 71 GHz to offer high data rates. However, at such high frequencies, the channel conditions are adverse, thus reducing the communication range. Hence, both the access point (AP) and stations (STAs) use high-gain directional beamforming with the entire coverage area around the AP divided into virtual antenna sectors. The STAs communicate with the AP by contending for the channel during the allocated contention-based access periods (CBAPs) to the sector in which it is residing. However, the AP uniformly allocates the CBAPs for every sector, reducing channel utilization if the traffic generation across the sectors is non-uniform. In this paper, we exploit the drawbacks of uniform CBAP allocation and propose a new load estimation-based dynamic CBAP allocation policy to improve channel utilization under non-uniform traffic regimes across the sectors. Also, we develop a novel and accurate analytical model for analyzing the performance of different CBAP allocation policies. The analysis shows that the proposed allocation policy improves the overall network throughput by 17% and reduces the packet overflow ratio by 54% on average compared to the uniform allocation policy.