A novel MAC protocol for wireless Ad hoc networks with directional antennas

MAC (Media Access Control) protocols for wireless Ad hoc networks with directional antennas have been studied to increase network capacity for years, since directional antennas can offer long-range communications and enhance the possibility of spatial multiplexing. This paper proposes a TDMA (Time Division Multiple Access)-based MAC algorithm with directional antennas, which is named SDVCS (Slotted Directional Virtual Carrier Sensing). The algorithm in this paper is similar to the method in DTRA [1], [2] while performing neighbor discovery, but defers quite a lot when allocating slots for transmission. SDVCS can dynamically allocate slots upon demand of each node. Although directional antennas are used, interference in the space can still occur due to a relatively wide main lobe of the antennas. And SDVCS tries to reduce this kind of interference when allocating slots for transmission. A simulation using OPNET is conducted to evaluate the performance of SDVCS. This paper ran both SDVCS and DTRA in scenarios with random topology and random mobility. And the results show that SDVCS outperforms the latter.