LAUSR

Wireless sensor networks (WSNs) are widely used in a variety of fields including environmental and industrial monitoring. However, the battery-powered sensor devices in WSNs can suffer from a lack of energy resources problem because of their limited battery capacity. Although the energy harvesting (EH) sensor devices recently have become an attractive alternative to address the limited battery capacity problem, a small number of EH sensor devices can be deployed because of their high cost. To address this problem, we propose an energy-efficient data reporting scheme based on spectrum sensing. In the proposed scheme, each sensor device senses the spectrum over the air and then determines the transmission time of the access signal and the number of repetitions of access signal transmission. Also, the sink node resolves the collisions by detecting the variation of the received signal power. The simulation results show that the proposed scheme increases the total energy efficiency of the sensor devices and moreover it decreases the access failure probability of the sensor devices.