A Polling-Based Traffic-Aware MAC Protocol for Centralized Full-Duplex Wireless Networks

Recent advances in self-interference cancellation techniques have enabled in-band full-duplex (IBFD) transmission, which can double ergodic capacity and reduce end-to-end delay. However, how to solve the channel contention problem in IBFD radios with inter-node interference and asymmetric traffic is still a challenge. This paper presents pFD-MAC, a novel polling-based traffic-aware medium access control (MAC) protocol for centralized full-duplex wireless networks. To solve the channel contention problem and fully utilize the channel resources under full-duplex mode, we first design a novel polling-based transmission mechanism and make comprehensive investigations on the effect of polling profile in full-duplex communication. By characterizing the inter-node interference into a directed non-conflict graph, we study the polling profile generation problem in which our objective is to minimize the packet transmission time. The problem is then theoretically formulated and proved to be NP-hard, which means it cannot be solved in polynomial time. Thus, we develop a heuristic traffic-aware algorithm and apply it to work with the packet transmission procedure in parallel. Full-duplex communication opportunities are highly exploited by parallelly organizing per-node upstream/downstream traffic according to the generated polling profile. Moreover, to achieve fairness without sacrificing throughput, deficit round robin algorithm has been applied with respect to the access time considering concurrent transmission time. Simulation results reveal that our proposed protocol can achieve improved performance in terms of throughput and transmission delay while maintaining fairness, compared with two state-of-the-art centralized MAC protocols.