Co-MAC: Energy Efficient MAC Protocol for Large-Scale Sensor Networks

Sensor nodes in large-scale sensor networks autonomously and proactively report diverse information obtained from extensive target area to a base station, which is energy unconstrained node. To efficiently handle the variable traffic, we present Co-MAC, an energy efficient medium access control protocol for large-scale sensor networks. In Co-MAC, an overall network is divided into independent subnets, and each subnet orthogonally operates on time line in a temporal fashion. The novelty in this protocol is to evenly distribute sensor nodes in a certain geographic area to subnets at the association process with probability p. In our simulation, it was observed that energy efficiency of Co-MAC outperforms S-MAC by 6 times and T-MAC by 2 times under identical conditions. The reason for this phenomenon is that the overhearing frequency between sensor nodes is relatively lower in Co-MAC. The results of these analyses demonstrate that Co-MAC obtains significant energy savings.