Using directional antennas for power controlled multiple access protocol in ad hoc networks

The main advantage of using directional antennas in ad hoc networks is due to the higher gain from its directivity, which can be utilized to reduce interference and thereby improve the network capacity. However, the negative problems such as side lobe interference and hidden terminals which exist in the directional networks may offset this advantage. In order to maximally save the average power consumption in the network, we propose a Busy tone and Directional antenna multiple access protocol with power control (BT-DMACP). Based on an adaptive interference estimation algorithm, our protocol maintains a minimum transmission power level for effective transmission of packets under the case of side lobe and multiple access interference. Meanwhile, the hidden terminal problems are resolved by transmission of the directional busy tone signals from the communication nodes. Simulation results show that our proposed protocol can effectively support the application of directional antennas and provide higher channel utilization and lower energy consumption.