Characterization of the Beamforming Training Interruption in IEEE 802.11ay Networks

The IEEE 802.11ad and IEEE 802.11ay standards define the medium access control (MAC) operation for millimeter-wave communications. During the beamforming training (BFT) period, the stations compete for the channel adopting a modified version of slotted aloha, where stations mandatorily transmit and can retry in a finite number of slots. This change makes the probability of a station accessing a given slot dependent on the previous ones. Additionally, stations halt the competition for BFT, if the number of consecutive collisions reaches a predefined collision threshold (CT) value. In this paper, we characterize the probability of a station interrupting the competition for BFT due to consecutive collisions. To address the characterization of the interruption for the BFT competition, we model the individual collision distribution and the distribution of a station reaching the CT over multiple BFT periods. The proposed model is validated through simulation and its performance is compared to other approximated IEEE 802.11ad models, confirming the accuracy of the proposed approach.