Multi-Channel Multi-Interface MAC Protocol in Wireless Ad Hoc Networks

In wireless ad hoc networks, utilizing multiple interfaces as well as multiple channels at MAC layer is known as one of key techniques to improve network capacity. Since the existing multi-channel MAC protocols like MMAC and SSCH assume that a single interface is used, a protocol such as HMCP was proposed in order to make the best use of multiple interfaces. However, a fixed specific channel is assigned to an interface in HMCP. In addition, HMCP requires one interface to accomplish an exclusive purpose of either transmission or reception. To address these shortcomings, we propose a multi-channel multi-interface MAC (MM-MAC) protocol, which dynamically assigns channels to each interface of the nodes and reserves the transmission times of nodes on these selected channels. The scheduled transmission of packets also enables our MM-MAC protocol to reduce the number of channel collisions and the overhead of exchanging control messages. Through extensive study using the ns-2 simulator, we observe that our MM-MAC protocol performs better than the existing protocols such as MMAC and HMCP.