An efficient and fair MAC scheme for Wireless Mesh Networks using beamforming antennas

Using beamforming antennas significantly improves bandwidth utilization in Wireless Mesh Networks (WMNs); however, it introduces unprecedented MAC problems (e.g., deafness). Indeed, when using directional transmissions in contention-based MAC schemes (e.g., IEEE 802.11), a node is usually unaware of all ongoing neighboring transmissions; thus, it may initiate inappropriate transmissions resulting in unfair use and waste of bandwidth. Note that most of existing beamforming MAC schemes are contention-based without consideration of fairness. In this paper, we propose EF-DMAC, a synchronized-based MAC scheme that aims at realizing efficient and fair bandwidth utilization in WMNs. EF-DMAC (1) guarantees that each node is aware of all ongoing neighboring transmissions, and thus avoids beamforming-related problems making efficient bandwidth utilization; and (2) provides per-link fairness. Compared to existing schemes, EF-DMAC reduces control overhead, maximizes bandwidth utilization, and provides fairness and scalability. The ability of EF-DMAC to provide fairness and efficiency is shown using extensive simulations.