A deafness free MAC protocol for ad hoc networks using directional antennas

Using directional antennas in mobile ad-hoc networks can greatly improve the spatial reuse and the transmission range. However, it also introduces new kinds of problems arising from directivity. One major problem is deafness. In this paper, we propose a new directional MAC protocol with advance notice strategy, called AN-DMAC (Advance Notice Directional MAC). Each node in AN-DMAC maintains a LIT (Local Information Table), in which the potential senders are recorded according to the advance notice strategy. Additional control packets are sent to prevent such potential transmitters from encountering deafness. Meanwhile, a new cooperation mechanism is presented to enhance the reliability of the advance notice strategy. Performance analysis and simulation results indicate that AN-DMAC can alleviate deafness, and outperform existing directional MAC protocols, such as DMAC and CDR-MAC (Circular Directional RTS MAC), in terms of throughput and overhead.