An auxiliary tone based MAC scheme for high density ad hoc networks with directional antennas

Using directional antennas in wireless ad hoc networks offers many benefits. However, utilizing this antennas with IEEE 802.11 MAC protocol which is introduced for omni-directional antennas can cause new problems like hidden node, exposed node and deafness problems. In this paper we propose an auxiliary tone-based DMAC (ATB-DMAC) scheme to tackle all of these problems and give an analytical model for the performance of new scheme. In spite of the majority of last approaches, ours does not need any prior information about neighbors´ locations. We compare the analytical results for two directional MAC schemes. The evaluation results show that ATB-DMAC outperforms the RTS/CTS based directional MAC in high density networks. Also the new scheme performs better than the latter in networks with high probability of transmission.