Impact of Power Control in Wireless Sensor Networks Powered by Ambient Energy Harvesting (WSN-HEAP) for Railroad Health Monitoring

The use of wireless sensor networks (WSNs) for structural health monitoring is gaining popularity since it allows for a low-cost, rapid and robust assessment of structural integrity. Meanwhile, recent advances in ambient energy harvesting technology have made it a viable alternative source of energy for powering WSNs. WSNs powered by ambient energy harvesting (WSN-HEAP) are potentially moreuseful and economical in the long term than traditionalbattery-powered WSNs as they can operate for very long periods of time without the need for human involvement, thus paving the way towards alleviating energy constraints that continue to challenge WSNs. In this paper, we evaluate the impact of transmit power control on the usefulness of a multi-sink WSN-HEAP, deployed in uniform string topology for railway track monitoring. Based on current achievable energy harvesting rates from track deflections, and commercially available sensor mote parameters, our analysis reveals that availability can be maximised while maintaining good data delivery ratio and throughput-fairness by appropriate setting of the transmit power over a wide range of deployment density, Signal-to-Noise Ratio requirements and energy harvesting characteristics.