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

Abstract

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 (LAN) 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 (DCF) 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.Index Terms-Medium access control, full duplex communication, wireless LAN, coexistence between full duplex and half duplex communications

In-band full-duplex medium access control design for heterogeneous wireless LAN

“…An FD-MAC was proposed for a WLAN by [18], where AP is FD capable and all the clients are traditionally HD capable. In this method, AP and all the clients need to calculate and update the signal-to-interference ratio map continuously, which may increase the computational load as well as the complexity.…”

Interference Aware Full-Duplex MAC Protocols Design and Evaluation for the Next WLANs

“…Both AP and STAs should have full-duplex capability in symmetric full-duplex link, but only AP supports full-duplex capability and STAs may be half duplex nodes. So far some full-duplex MAC protocols are proposed on the assumption that all nodes have full-duplex capability [15][16][17][18][19][20]. However, there are a few full-duplex MAC protocols considering the scenario that AP supports full-duplex capability but STAs do not support full-duplex capability [21][22][23].…”

“…So far, there are a lot of works focus on the full-duplex MAC design [15][16][17][18][19][20][21][22]. However, in most researchers assume that all the node in the network have full-duplex capability [15][16][17][18][19], and only a few researchers pay attention to study the full-duplex MAC protocols in which only AP has full-duplex capability and STAs have no full-duplex capability for WLANs [20][21][22].…”

“…However, in most researchers assume that all the node in the network have full-duplex capability [15][16][17][18][19], and only a few researchers pay attention to study the full-duplex MAC protocols in which only AP has full-duplex capability and STAs have no full-duplex capability for WLANs [20][21][22]. In this paper, it is assumed that AP is a full-duplex node but STAs are all half-duplex nodes, and the co-existence between a full-duplex AP and half-duplex STAs should be considered.…”

“…In [20] a full-duplex MAC protocol named as asymmetrical duplex (A-Duplex) is proposed. A-Duplex adopts capture effect to establish the full-duplex link, and the fullduplex link is established only if a STA accesses channel.…”