An Adaptive Energy Efficient Low Latency Sleep Schedule for Target Tracking Sensor Networks

Energy management in sensor networks is a critical issue to prolong the network lifetime. However, the end-to-end latency increases due to energy saving algorithms. We propose a new protocol, ELS (Energy efficient low Latency Sleep Schedule for Target Tracking Sensor networks), that provides a dynamic sleep schedule for the radios to increase the network lifetime as well as transmit the target’s information to the sink with low end-to-end latency. In the surveillance state, the radios of interior nodes are put into sleep using a static schedule. If a target arrives, radio schedule of the nodes nearby the target is dynamically changed to wake up the neighbors and start sensing before the target reaches their location. The intermediate nodes in the target to sink path is activated in order to transmit the information to the sink with low latency. We show theoretically how the energy consumption of the interior and border nodes is balanced using our schedule. Our approach is to (1) increase the network lifetime (2) transmit the target location to the sink with low latency. Simulation results show that ELS provides low latency when compared to S-MAC and increases the network lifetime by 25% more than S-MAC at low load.