摘要

A novel multichannel MAC protocol, namely distributed channel reservation multiple access protocol, is presented for efficient channel sharing in multihop mobile ad hoc networks. It flexibly employs request-to-send and clear-to-send (RTS/CTS) dialogue on a common channel and selects conflict-free traffic channel to accomplish the transmission of data packet based on a novel channel selection scheme. The acknowledgment (ACK) packet for the data packet transmission is replied to the sender over another common channel, which effectively eliminates the influence of exposed terminal problem. The influence of hidden terminal problem is also greatly reduced because most of possible packet collisions on a single channel are avoided due to traffic load balance on multiple channels. In addition, any communication pairs within locality can take full advantage of multiple traffic channels without collisions and the spatial reuse of same channel are extended to neighboring communication pairs even within 2 hops from them. Finally, performance comparison of the proposed protocol with the CAM-MAC protocol is provided, and simulation results show that it outperforms the CAM-MAC protocol on total channel utilization, average channel utilization and average packet delay.