Adaptive Contention Window based Wireless Medium Access Mechanism for Periodic Sensor Data Collection Applications

Contention window based medium access protocols are of practical interest in low data rate wireless communication scenarios. In periodic data collection applications, nodes mostly produce small data packets that are collected by the cluster heads and routed to the base station. In this paper, a new mechanism for adaptively selecting the size of the contention window based on the number of contending nodes has been presented. The proposed scheme effectively reduces the number of collisions in periodic collection scenarios with fixed number of nodes. Theoretical analysis and simulation results demonstrate that, in periodic data collection processes, the new protocol reduces the data collection time significantly as compared to IEEE 802.11 and the recently proposed Synchronized Shared Contention Window (SSCW) based scheme.