Redundancy reduction protocol with sensing coverage assurance in distributed wireless sensor networks

In large scale applications like military surveillance, sensing coverage is essential for target detection and optimization of power consumption is important for lifetime extension of the network. In battle field, nodes are deployed randomly which results some places empty and some places dense. To assure the sensing coverage for the whole area of interest, sensors are deployed several times which represents random distribution with dense node deployment. This dense sensor deployment shows redundancy. These redundant traffics result collisions, packet losses and retransmissions. Consequently it consumes more energy and decreases the lifetime of the network. In order to use this dense sensor network efficiently to increase the lifetime of the network, it is necessary to find out a set of small number of working nodes that can cover the region of interest and reduce redundancy. In this paper, we propose a new energy efficient protocol where each node in the network takes decision to turn on or turn off in a distributed manner that results a set of small number of active nodes throughout lifetime of the network and covers sensing area of interest for target detection. It reduces redundancy, power consumption and increase the lifetime of a network. In this protocol, nodes balance their energy by going to working state based on their residual energy to keep the nodes alive to assure the coverage throughout the lifetime. The simulation results of this protocol shows that throughout network lifetime the coverage is preserved in a range from 84% to 100% and about a constant number of nodes are working.