A Utility-Optimal Backoff Algorithm for Clustered Sensor Networks

This paper presents a novel backoff algorithm in CSMA/CA-based Medium Access Control (MAC) protocols for clustered sensor networks. We first show that every node should have the same value of Contention Window (CW) in a cluster by formulating resource allocation as a utility maximization optimal problem, then assume all nodes have the same CW and gain the relation between the optimal value of CW and the number of nodes by maximizing the total network utility with constrains of minimizing collision probability. The result is a new retransmission algorithm that uses an optimal shared CW that is easy to implement and results in fewer collisions than binary exponential backoff algorithm. The proposed scheme can decrease delay and improve throughput, moreover, it is also energy-efficiency for clustered sensor networks, simulation results validate our conclusion.