Energy-preserving node scheduling scheme for chain oriented wireless sensor networks

Due to energy constraints and limited lifetime, sensor nodes are usually deployed densely in the target fields. Moreover, some applications do not require 100% coverage all the time. In view of these two concepts we may turn off some of the sensor nodes exploiting the redundancy of deployed sensor nodes. On the other side, the underlying communication logical topology is an important issue regarding energy consumption by the network. To mitigate the constraints of sensor nodes researchers employ a variety of logical topologies among which chain oriented topology is one of the significant contenders. In this paper we combine all these concepts to present a novel node scheduling scheme by which we schedule the on-duty nodes in large sensor networks. The selected nodes then create multiple chains to communicate each other. Chain oriented topology saves more energy compare to other topologies like cluster based or flat topology. Moreover, choosing only a selected number of sensors, instead of choosing all of them saves more energy and lengthens lifetime of the network. The main criterion to select a sensor node we propose in this paper is the use of shared sensing region of a sensor node with its neighbours. Simulation results show that our protocol saves a large number of sensor nodes while maintaining significant amount of coverage.