Channel allocation evaluation for a multi-channel MAC protocol

In recent years, the use of multi-channel MAC protocols in the Wireless Sensor Networks has attracted the attention of many researchers. In this paper, we analyze the different techniques that are used in multi-channel MAC protocols proposed for WSNs. These protocols often use either a centralized or a distributed manner to select and allocate channels. We present HMC-MAC, a Hybrid Multi-Channel MAC protocol that takes advantage of the synchronous activity of TDMA to achieve collision free communications, of the flexibility offered by CSMA/CA to offer a scalable network, and of the parallel transmissions over different channels provided by FDMA to enhance the overall throughput. It is based on a decentralized method for channel allocation that enables nodes to choose the most convenient channel in its 3-hop neighborhood. The method used to evaluate this channel allocation scheme is based on the number of conflicts generated by the use of the same channel in a three-hop neighborhood. We present simulation results using NS-2 that show the efficiency of the proposed channel allocation method.