An Energy Efficient Node Scheduling Protocol for Target Coverage in Wireless Sensor Networks

The technological advancement in the field of wireless communication and electronic systems have provided the opportunity for the wireless sensor network to achieve the development of low-cost, low power and multi-functional sensor nodes which can be placed on a single chip and can communicate over a short distance. The critical issue faced by wireless sensor networks is the efficient energy utilization and is to keep the network alive as long as possible. The coverage problem is basically defined as how well and for how long the sensor nodes are able to monitor the given targets. The most efficient and effective way to ensure coverage, while preserving the energy is scheduling the nodes to remain in active or sleep modes. Trust metrics are incorporated in the networks to tackle the uncertainties present in the environment. In this paper, we propose an energy efficient target coverage preserving protocol, which determine a set of nodes to keep in active state such that every target region is being monitored by at least one sensor node and the data sensed by these nodes satisfies the predefined confidence level. In the proposed protocol, observer nodes monitor the neighborhood nodes to calculate the trust level. The nodes having the lower coverage probability are termed as observer nodes and are used to determine the trust value of the nodes, which is a convenient option as it reduces the communication overhead. The performance of the network is improved by incorporating the aggregation mechanism based on the link stability/availability and the residual energy of the nodes.