Abstract

Abstract: Using directional antennas in wireless ad hoc networks (WANETs) offers great potential for reducing the radio interference, and improve the communication throughput. Directional antennas, however, introduces new problems in the wireless media access control (MAC), deafness and new hidden terminals, which may cause severe perfor-mance degradation. To solve the deafness problem and the new hidden terminal problems, in this paper, we propose an effective Circular RTR Directional MAC (CRDMAC) protocol for WANETs by using a sub-transmission channel and RTR (Ready To Receive) packets, which modifies the IEEE 802.11 distributed coordinated function (DCF). The sub-channel avoids collisions to other ongoing transmission, and the RTR packets notify the neighbor nodes that the mutual transmission has been finished. We evaluate the CRDMAC protocol through simulations. Simulation results show that the proposed protocol outperforms the existing DMAC (Directional MAC) protocol and the CRCM (Circular RTS and CTS MAC) protocol in terms of throughput and packet drop rate.