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

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 (HD) and emerging FD devices have not been fully addressed. Therefore, we focus on the design and performance evaluation of scheduling algorithms for infrastructurebased heterogeneous networks (composed of HD and FD users). We develop the hybrid Greedy Maximal Scheduling (H-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 H-GMS and its variants in terms of throughput, delay, and fairness between FD and HD users via extensive simulations. We show that in heterogeneous HDFD networks, H-GMS achieves 5–10× better delay performance and improves fairness between HD and FD users by up to 50% compared with the fully decentralized Q-CSMA algorithm.