The incoming IEEE 802.11ax standard designed for HEW (High Efficiency WLANs : Wireless Local Area Networks) networks aims at improving spectral efficiency and area throughput in real world densely deployed Wi-Fi (Wireless-Fidelity) environments. To meet these needs, several innovative techniques and methods have been incorporated at both Physical (PHY) and Medium Access Control (MAC) layer of the IEEE 802.11ax standard. Among these new amendments, we focus on Full Duplex (FD) radio communications, which double the throughput of the Half Duplex (HD) radio without any effort. In this paper, our main goal is studying and comparing the two main MAC protocols existing for enabling the innovative Full Duplex radio communications in the future standard IEEE 802.11ax, namely: OFDMA Two-symbol Coordination MAC (O2-MAC) and In-Frame-Querying. These protocols allow to solve the same problem, which is maximizing the radio capacity of full duplex transmissions. The simulation results obtained show for the first time that, the In-Frame-Querying protocol is efficient in case where the down-link (DL) and up-link (UL) data streams have variable lengths. In contrary, when the length of down-link and up-link data streams are the same, the O2-MAC protocol is the best. The performance metrics considered in the analysis are throughput and overhead.
High Efficiency WLANs, IEEE 802.11ax Standard, Full Duplex Radio Communications, Medium Access Protocols, Study and Comparison