AUB: A Full-Duplex MAC Protocol for the Efficient Utilization of the Idle Uplink Period in WLAN

Recently, full-duplex radio has attracted attention as a solution for wireless local area networks (WLANs) where traffic is exploding but available frequency bands are insufficient. Full-duplex radio exploits various self-interference cancellation technologies to transmit and receive signals concurrently in the same frequency band. Thus, the efficiency of the frequency band is doubled compared with that of conventional half-duplex radios. However, to effectively exploit full-duplex radio, new problems that do not exist in conventional half-duplex radio, such as fullduplex link setup, inter-node interference avoidance, and idle uplink period (IUP), must be addressed. We propose a full-duplex medium access control (MAC) protocol to effectively exploit fullduplex radio by addressing these problems. In particular, our MAC protocol uses an IUP to transmit an acknowledgment (ACK) frame and report the buffer information of nodes. Accordingly, an access point can gather the node's buffer information during the IUP and schedule the transmission of nodes without competition. In addition, because the uplink ACK frame is transmitted during the IUP, additional channel usage time for the uplink ACK frame transmission is not required. Therefore, the proposed MAC protocol improves the WLAN throughput by reducing the number of control frame transmissions and the IUP. The results of our performance analysis and simulation show that the MAC protocol achieves throughput improvements compared with those of previous studies.