Adaptive Range-Based Efficient Spatial Reuse MAC Mechanism in Wireless Full-Duplex Ad Hoc Networks

Abstract

Full-duplex (FD) technologies enable wireless nodes to simultaneously transmit and receive signals using the same frequency band. FD communications among the nodes could improve their physical-layer throughputs. However, in wireless ad hoc networks, such communications may produce new interference patterns, as the extra signals transmitted from the receivers interfere with the receptions of other nodes or prevent them from accessing the channel. Unlike half-duplex (HD) communications, FD communications can cause potential hidden terminal problems to appear around the senders. After analyzing the relationships among the transmission ranges (TRs), carrier sensing ranges (CSRs), and interference ranges (IRs) of the nodes in the case that power control is adopted, we propose an adaptive range- based efficient spatial reuse media access control (MAC) mechanism in wireless FD ad hoc networks. For both HD and FD communications, we reduce the transmit power of each sender as much as possible to increase the opportunities for channel access by other senders and to avoid hidden terminal problems. In particular, for FD communications, we avoid the interference risk caused by the size difference in the data frames of each FD pair. Moreover, to balance the throughput gain of FD communications and the potential expansion of the spatial occupation, we determine the communication mode of the current link by comparing the ratios of the link's throughputs and the sizes of the spatial occupations in both HD and FD modes. We conduct the numerical simulations to validate and evaluate our proposed mechanism, and show that it could effectively improve the throughput per unit area of wireless ad hoc networks.