A MAC protocol for deafness avoidance in wireless multi-hop
networks with directional antennas <Abstract> In wireless multi-hop networks, communications using a beam-forming by directional antennas have been discussed because the spatial reuse of the wireless channel is improved. The throughput is limited due to the hidden terminal or the deafness problem in these networks. This paper proposes a medium access control (MAC) protocol using two narrow-band signals for wireless multi-hop networks with directional antennas. In the proposed protocol, transmitters exchange two narrow-band signals (Pulse/Tone) prior to starting the communication. Because Pulse/Tone is very short-time signal, the collisions hardly occur. Therefore, transmitters can understand whether the state of the receivers is busy without additional overhead. Thus, the proposed protocol increases the throughput because collisions of the packets and the transmission delay caused by deafness problem decrease. Network simulations show that the proposed protocol improves the network performance by reducing the effect of the hidden terminal and the deafness problem. |