Solving Hidden Station Problem using Self-Localization Asymmetric Full-Duplex MAC Protocol in WLANs

Abstract

In recent years, Full-Duplex (FD) communication has become a potential technology for the future wireless local area network (WLAN). The FD Medium Access Control (MAC) enables both asymmetric and symmetric transmission behaviors. Asymmetric full-duplex transmission is used when only Access Point (AP) possesses the full duplex functionality, whereas mobile stations remain conventional half duplex devices. Symmetric full-duplex transmission is used when both AP and mobile stations have full duplex functionality. As a result, asymmetric full-duplex transmission is considered a useful fast solution to improve channel throughput by upgrading mobile devices. Asymmetric fullduplex transmission allows the up-link and down-link communications to take place simultaneously at an AP where the AP send a packet to one mobile station, while receiving a packet from another mobile station, in which both stations are hidden from each other. In order to achieve such an asymmetric fullduplex transmission, the AP must be able to control or guide the transmission of each station to avoid unnecessary collisions without substantial modification to the existing four-way handshake (RTS/CTS) as used in IEEE 802.11 Distributed Coordination Function. In this work, we aim to utilize the mobile station locations to assist the AP to perform proper asymmetric full-duplex transmissions as often to enhance the system throughput.