Optimal Node Scheduling Based on Randomized Sleep Assignment and Active Node Failure for Energy-Efficient Coverage of WSNs

The applications of Wireless Sensor Networks (WSNs) have been gaining an important place as they possess the ability to bridge the gap between the physical and virtual world. The sensor nodes are usually deployed in hostile and remote areas for applications like earthquake monitoring, seismic activity monitoring, and the military surveillance over a region of several acres which may either a land or an ocean, and disaster relief operations. In these applications, the deployment of nodes in a sensor field takes place by their aerial dispersion. An unmanned plane (UAV) deploys motes in a sensor field after which their network is established. The probability of falling of nodes is uniform, though there may be more nodes at a particular place while very less nodes at other places. There will be an overlapping coverage amongst adjacent nodes if nodes being deployed are very large. Thus, when one node is active, there is a possibility of multiple nodes being active within its range which is not desirable as it leads to the wasteful power consumption. One of the effective methods to avoid this situation is the optimal sleep scheduling of sensor nodes. In this paper, the results of the software and hardware implementation of Optimal Node Scheduling Protocol (ONSP) based on a new algorithm that optimizes the node schedule based on the randomized sleep assignment and the probability of failure of active nodes within the range of a probing node. The evaluation based on the simulation carried out in MATLAB and the runtime assessment of the protocol for the performance enhancement of randomly deployed WSNs is presented in the paper.