TARS: An Energy-Efficient Routing Scheme for Wireless Sensor Networks with Mobile Sinks and Targets

Wireless sensor networks (WSNs), which are operated with strict resources, offer promise for surveillance technology including target tracking and environmental monitoring. In some sensor network applications, aggregating and delivering sensing data from mobile targets to mobile sinks is necessary. Nevertheless, such mobility can cause the established routes non-optimal and even broken, and require repeated route recovery procedures. To address this issue, previous TRENS routing protocol presented a tracking-assisted routing scheme to avoid the need for frequent rerouting. In this paper, we propose an enhancement of TRENS, called TARS, that also deals with the routing issue for WSNs consisting of multiple mobile targets and sinks. Compared with TRENS, TARS proposes an enhanced tracking technology and a lightweight shortcutting approach to decrease redundant messages, so as to increase the efficiency of routing procedures and to optimize the routing paths in the context of dynamic topology. Besides, TARS introduces a time-scheduling method to control the radio channels of idle nodes to save more energy. Comparing TARS with previously proposed grid-based schemes through extensive simulations, we unveil that our scheme conserves more energy and achieves better performance in aspect of specified evaluation metrics.