An Adaptive Back-Off Mechanism for Wireless Sensor Networks

Wireless sensor networks (WSNs) have been extensively applied in many domains such as smart homes and Internet of Things (IoT). As part of WSNs’ communication protocols, back-off mechanisms play an essential role in the deployment of wireless channels for network nodes and have been at the core of ensuring effective communication. The performance of many back-off algorithms is excellent in light or middle load networks. However, it degrades dramatically in heavy load networks. In this paper, we propose an adaptive contention window medium access control (MAC) protocol to improve the throughput performance under heavy load. By using the number of historical collisions as the parameter in the back-off mechanism to reflect the channel status, the size of the contention window is adjusted automatically, and the throughput of network is then improved. Simulation results show that our optimized MAC protocol has higher throughput and energy efficiency.