Energy Efficient Extended Coverage in Wireless Sensor Networks

Wireless sensor network(WSN) has been widely implemented on a large scale that deals with monitoring and controlling the real environment. Coverage and connectivity are the two most active areas of concerned and also these functionalities are desired in WSN. Connectivity in WSN is generally defined as how well the nodes are connected so that the sink node must receive every bit of information sent by any other node. In the mean while, any event occurred at any point in the specified area should be detected, and it is referred as coverage in WSN. In order to fulfill both these requirements, in this paper, we proposed a coverage algorithm, in which a hierarchical structure is first constructed to satisfy the connectivity and the same structure is further extended to achieve full coverage in WSN. In this proposed approach, a tree is constructed by using a routing mechanism with sleep scheduling, such that all intermediate nodes which are participating in routing are in active mode, and the rest of the nodes are likely to be in sleep mode. Further, to fulfill the coverage requirement, we divide the leaf nodes again into two parts, i.e., the leaf nodes that are active, but not participating in routing, and the leaf nodes that are completely in sleep mode. The tree is re-constructed periodically to ensure balanced consumption of energy among all the nodes in WSN. The performance of the proposed protocol is carried out using the Castalia simulator.