A Directional MAC Protocol for Mitigating Frame Collision and Deafness Problem in Wireless Multi-Hop Networks <Abstract> This paper proposes a Medium Access Control(MAC) protocol for wireless ad hoc networks with smart antennas for avoiding the frame collision and the deafness problem. The basic idea is that Pulse/Tone exchange is applied to the OPportunistic Directional MAC protocol(OPDMAC). By applying the Pulse/Tone exchange prior to Request To Send/Clear To Send (RTS/CTS) handshake, the hidden-node and directional hidden-node collisions disappear in the proposed protocol. Additionally, directional hidden-node collisions are changed to deafness problem by using the Pulse/Tone exchange. Therefore, the proposed protocol find the cause of the Pulse/Tone exchange failure, which is the concurrent transmission collision or deafness problem. As a result, the transmitter can avoid the deafness problem by sending another frame instead of transmission-failure frame. Simulation results show the validity and effectiveness of the proposed protocol. |