A-Duplex: Medium Access Control for Efficient Coexistence Between Full-Duplex and Half-Duplex Communications

• Published in: IEEE transactions on wireless communications Vol. 14; no. 10; pp. 5871 - 5885
• Main Authors: Tang, Aimin, Wang, Xudong
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2015; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Access control; Asymmetry; Clients; coexistence between full duplex and half duplex communications; Communication; Computer simulation; Delay; Delays; Design of experiments; Ethernet; full duplex communication; Interference; Legacy; Media Access Protocol; Medium access control; Receivers; Throughput; Wireless communication; Wireless LAN; full-duplex communication; Medium access control; wireless LAN; coexistence between full-duplex and half-duplex communications
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2015.2443792

As full-duplex wireless communication evolves into a practical technique, it will be built into communication nodes in many application scenarios. However, it is difficult to do so for legacy communication nodes. Thus, full-duplex communication nodes will coexist with half-duplex communication nodes in the same application environment. In this paper, a wireless local area network with a full-duplex access point (AP) and half-duplex clients is studied, and a media access control (MAC) protocol called asymmetrical duplex (A-Duplex) is developed to support efficient coexistence between half-duplex clients and the full-duplex AP. A-Duplex explores packet-alignment-based capture effect to establish dual links between the AP and two different clients. In this way, the capability of a full-duplex AP can be utilized by half-duplex clients, which leads to much improved network throughput. Moreover, to ensure fairness of the MAC protocol, a virtual deficit round-robin algorithm is proposed for the AP to select appropriate half-duplex clients for dual-link setup. A-Duplex does not require any change in the physical layer of half-duplex clients; only an update of MAC driver is necessary. Thus, it is well suited for coexistence between half-duplex clients and a full-duplex AP. Both analysis and simulations are conducted to evaluate performance of A-Duplex. Results show that it improves the throughput by 48% and 188% and reduces the average packet delay by 26% and 22%, as compared to the IEEE 802.11 Distributed Coordination Function with and without RTS/CTS, respectively. Moreover, the throughput remains steady as the number of clients grows. A-Duplex also maintains a high level of fairness.