Provisioning QoS in Wi-Fi Systems with Asymmetric Full-Duplex Communications

The traffic volume carried by wireless local area networks (WLANs) continues to increase at a rapid pace. Full-duplex communication is a key solution for satisfying the growing traffic demand, enhancing spectrum efficiency, and reducing latency for WLAN users. In this paper, we consider the application of asymmetric full-duplex (AFD) communications in WLANs, exemplified by a Wi-Fi system. Our system model relies on a full-duplex-enabled Wi-Fi access point to simultaneously transmit uplink and downlink to a pair of half-duplex Wi-Fi stations. Providing QoS guarantees in WLANs with AFD communication capabilities is challenging due to inter-node as well as residual self-interference. The heterogeneity of the QoS requirements between paired uplink and downlink stations further complicates the problem. To tackle these challenges, we introduce a framework called AFD-QoS, which incorporates AFD communications in WLANs and supports QoS. AFD-QoS consists of three components: 1) AFD-enabled uplink/downlink station-pair selection algorithm; 2) AFD-enabled block-acknowledgment session initiation/termination protocol; and 3) joint transmission rate/AFD communication mode adaptation scheme. Our adaptation scheme relies on intelligent and cognitive approaches to improve Wi-Fi networks awareness about channel dynamics as well as inter-node and self-interference. We introduce new intelligent MAC-layer procedures for supporting QoS services in AFD communications, and cast light on many challenges and their solutions. Our simulation results indicate that AFD-QoS outperforms classical half-duplex frameworks and achieves up to 90% of the optimal AFD performance.