SpotMAC: A Pencil-Beam MAC for Wireless Mesh Networks

Deafness is a key problem. It erodes the performance gains provided by directional antennas, and introduces a new hidden terminal problem. To address deafness, and hence the hidden terminal problem, we propose SpotMAC. By exploiting narrow or pencil beams, SpotMAC achieves high spatial reuse, throughput and fairness. In addition, pencil beams simplify the collision avoidance process and constrain the hidden terminal problem to a linear topology which can be solved using an inverse RTS/CTS exchange. From extensive simulation studies, we confirm nodes using SpotMAC have several orders of magnitude higher throughput than those using the IEEE 802.11 MAC with omni-directional antenna.