Hybrid Scheduling in Heterogeneous Half-and Full-Duplex Wireless Networks

Abstract

Full-duplex (FD) wireless is an attractive communication paradigm with high potential for improving network capacity and reducing delay in wireless networks. Despite significant progress on the physical layer development, the challenges associated with developing medium access control (MAC) protocols for heterogeneous networks composed of both legacy half-duplex (UD) and emerging FD devices have not been fully addressed. Therefore, we focus on the design and performance evaluation of scheduling algorithms for infrastructure-based heterogeneous networks (composed of UD and FD users). We develop the hybrid Greedy Maximal Scheduling (U-GMS) algorithm, which is tailored to the special characteristics of such heterogeneous networks and combines both centralized GMS and decentralized Q-CSMA mechanisms. Moreover, we prove that H-GMS is throughput-optimal. We then demonstrate by simple examples the benefits of adding FD nodes to a network. Finally, we evaluate the performance of U-GMS and its variants in terms of throughput, delay, and fairness between FD and UD users via extensive simulations. We show that in heterogeneous UD-FD networks, U-GMS achieves 5-10x better delay performance and improves fairness between HD and FD users by up to 50% compared with the fully decentralized Q-CSMA algorithm.