Efficient contention resolution in MAC protocol for periodic data collection in WSNs

Abstract

Due to the infrequent medium access in Wireless Sensor Networks (WSN), their MAC protocols are mostly based on CSMA. In this paper we present an efficient contention resolution scheme for CSMA based MAC protocols which is suitable for periodic data collection in WSNs. Taking into account that the number of nodes in a single cluster is fixed, this protocol uses successively decreasing contention window. It is characterized by non-overlapping contention window, that maintains a constant successful transmission rate. It significantly decreases data collection time by minimizing the time wastage due to collisions. At the same time, by using adaptive CW, it reduces the time wastage in empty slots. Experimental results demonstrate that in periodic data collection within a single hop cluster this scheme has performance superior to the recently proposed Synchronous Shared Contention Window (SSCW) based scheme in terms of time wastage and throughput.