A Cooperative Lifetime Extension MAC Protocol in Duty Cycle Enabled Wireless Sensor Networks

To reduce energy consumption in wireless sensor networks, the concept of duty cycle is used in many MAC protocols. Although these protocols provide efficient energy-conservation solutions, they cannot resolve the energy hole problem in a multi-hop network, where a few nodes near the sink must relay the packets from the rest of the network, and consequently exhaust their batteries earlier. The previously proposed REACT forwarding protocol triggers the cooperation of several nodes to extend transmission range and hop over the highly burdened node, thereby allowing it to save its energy and extend the lifetime of the network. However, the previous work lacked a MAC protocol with a duty cycle. In this paper, we propose a novel cooperative duty cycle MAC (CDC-MAC) protocol, by employing a wake-up rendezvous selection scheme for multiple sensor nodes to exchange messages and a cooperator recruiting mechanism that favors nodes with more residual energy than the highly burdened node. Simulation results demonstrate that CDC-MAC can prolong the entire network longevity efficiently in comparison with another duty cycle MAC protocol, OC-MAC.