VARSA: An Efficient VAriable Radius Sensor Activation Scheme for Target Tracking using Wireless Sensor Networks

Energy efficiency advancement is vital in target tracking Wireless Sensor Networks (WSNs) due to resource constraints of tiny detectors. On the other side, Tracking quality must also be assured while minimizing energy consumption. The main aim of target tracking algorithms is to depict the trajectory of the target at a sink node using the aggregated data from all sensor nodes. Monitoring an Area of Interest (AoI) while other sensors are in sleep mode has been shown to effectively improve energy efficiency in WSNs. In this paper, we propose a VAriable Radius Sensor Activation (VARSA) algorithm to decrease the sensing energy consumption of tracking applications using WSNs. VARSA uses a dynamic sensing radius adjustment and sends the appropriate sensing radius to the next predicted sensor to wake up with. In addition to sending sensors into sleep mode when they are not in the AoI, we propose to decrease the sensing radius of the sensors in the AoI in real time to further decrease the consumed energy of sensing. Simulation results demonstrate that the proposed algorithm significantly decreases the sensing energy consumption, while providing better tracking quality over time.