Using directional antenna to realize multi-relay MAC for wireless Ad Hoc networks

IEEE 802.11 PHY layer protocol supports multiple data transmission rates which is a tradeoff between channel capacity and bit error rate. Several MAC layer protocols have been proposed to accommodate this multi-rate feature. However, those protocols either just considered how to exploit channel condition of the direct link from the sender to the receiver, or just studied how to using a single relay node to realize MAC layer relay. In this paper, we propose a multi-relay enabled MAC protocol by introducing directional antenna to further enhance the performance of MAC relay. With the aid of directional antenna, the proposed protocol can realize pipelined data transmission throughout the relay process. The simulation results show that the proposed protocol significantly improves the performance in terms of both throughput and packet delay.