A receiver-centric multi-channel MAC protocol for wireless networks

Abstract

We consider the issues of mitigating interference and improving network capacity in wireless networks from the viewpoint of channel diversity. Multi-channel diversity allows multiple pairs to concurrently use the wireless medium, thus increasing the achievable capacity; this multi-channel diversity can then be fully utilized by enabling wireless nodes to dynamically switch their channels. However, the process of switching channels in a wireless transceiver incurs switching overhead, resulting in the degradation of the throughput performance. We propose a receiver-centric multi-channel MAC protocol (RcMAC) that allows nodes to efficiently utilize multiple channels by reducing unnecessary channel switching. Receiver-centric channel switching enables each sender node to asynchronously and independently switch channels to one where its intended receiver resides, without requiring explicit channel negotiation. Thus, the wait time at the control channel is reduced, in addition to the number of channel switchings, thereby improving channel utilization. As this scheme requires prior knowledge of which channel a node is switched to, each node cooperatively shares its channel usage information in order to recognize the channels that its neighboring nodes are using. Through extensive simulations, we show that the proposed MAC protocol significantly improves network throughput and reduces end-to-end delay compared with other multi-channel MAC protocols.