An Asynchronous Multi-channel MAC Protocol with Pulse/Tone Exchange for RTS Collision Avoidance

In multi-channel wireless ad-hoc network, the nodes need to negotiate the channel reservation. Preparing the control channel is one of the strategies for the channel reservation. When the control channel congests due to frame collisions, the control channel is bottleneck for obtaining high throughput. This paper proposes a MAC protocol for multi-channel wireless ad-hoc network for frame collision avoidance on the control channel. The proposed protocol requires only one transceiver in each node, no time-synchronization mechanism among nodes, and few overheads. In the protocol, the node negotiates the channel using the RTS/CTS handshake. The Pulse/Tone exchanges are applied prior to the RTS/CTS handshake for RTS-frame collision avoidance. Additionally, the exposed node problem due to Pulse/Tone exchange is also mitigated, because of the good compatibility between multi-channels and the Pulse/Tone exchanges. It is shown from simulation results that the proposed protocol achieves higher throughput than the previous protocols, especially for heavy offered load condition.