A Power-Efficient MAC Protocol with Two-Level Transmit Power Control in Ad Hoc Network Using Directional Antenna

摘要

The use of directional antenna in wireless ad hoc networks largely reduces radio interference, thereby improving the utilization of wireless medium and consequently the network throughput, as compared to omni-directional antenna, where nodes in the vicinity of communication are kept silent. In this context, researchers usually assume that the gain of directional antennas is equal to the gain of corresponding omni-directional antenna. However, for a given amount of input power, the range R with directional antenna will be much larger than that using omni-directional antenna. In this paper, we propose a two-level transmit power control mechanism in order to approximately equalize the transmission range R of an antenna operating at omnidirectional and directional mode. This will not only improve medium utilization but also help to conserve the power of the transmitting node during directional transmission. The performance evaluation on Qual-Net network simulator clearly indicates the efficiency of our protocol.