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 (HD) 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 HD-FD networks (composed of HD and FD users). We first show that centralized Greedy Maximal Scheduling (GMS) is throughput-optimal in heterogeneous HD-FD networks. We propose the Hybrid-GMS (H-GMS) algorithm, a distributed implementation of GMS that combines GMS and a queue-based random-access mechanism. We prove that H-GMS is throughputoptimal. Moreover, we analyze the delay performance of H-GMS by deriving lower bounds on the average queue length. We further demonstrate the benefits of upgrading HD nodes to FD nodes in terms of throughput gains for individual nodes and the whole 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 HD-FD networks, H-GMS achieves 16-30× better delay performance and improves fairness between HD and FD users by up to 50% compared with the fully decentralized Q-CSMA algorithm.

Wideband Full-Duplex Wireless via Frequency-Domain Equalization

“…Similar problems are considered in FD multi-antenna/MIMO systems [26,38,46]. Medium access control (MAC) algorithms are studied in networks with all HD users [16,21] or with heterogeneous HD and FD users [18]. Moreover, network-level FD gain is analyzed in [39,42,43,45] and experimentally evaluated in [31,33] where all the users are HD or FD.…”

Open-access full-duplex wireless in the ORBIT and COSMOS testbeds

“…Similar problems are considered in FD multi-antenna/MIMO systems [35], [48]- [51]. Medium access control (MAC) algorithms are studied in networks with all HD users [52], with all FD users [53], or with heterogeneous HD and FD users [54]. Moreover, network-level FD gain is analyzed in [25], [55]- [57] and experimentally evaluated in [26], [58] where all the users are HD or FD.…”

“…These trends and results show that in a realworld environment, the total network throughput increases as more users become FD-capable, and the improvement is more significant with higher user SNR values. Note that we only apply a TDMA scheme and a more advanced MAC layer (e.g., [54], [58]) has the potential to improve the FD gain and fairness performance. As with the 3-node experiment, a similar version is run on the COSMOS testbed in Section VI-B3.…”

Uplink and Downlink Performance Bounds for Full Duplex Cellular Networks

“…Recent studies of FD in the context of cellular communication systems show the performance improvements of FD over HD, [1]- [3]. The performance of FD system in heterogenous networks is studied in [4], [5]. However, these works model BSs and UE locations as independent Poisson point processes, without considering the spatial dependencies of the users and the BSs.…”