Coverage and Clustering guarded for Wireless sensor network

In wireless sensor networks that consist of a large number of low power, short-lived, unreliable sensors, one of the main design challenges is to obtain long system lifetime, as well as maintain sufficient sensing coverage and reliability. Sensor networks also pose a number of new conceptual and optimization problems.Some, such as location, deployment, and tracking, are fundamental issues, in that many applications rely on them for needed information. Coverage preservation is one of the ba sic QoS requirements of wireless sensor networks, yet this problem has not been sufficiently explored in the context of cluster-based sensor networks. Specifically, it is not known how to select the best candidates for the cluster head roles in applications that require complete coverage of the monitored area over long periods of time. In this paper, we take a unique look at the clustering problem, specifically concentrating on applications where the maintenance of full network coverage is the main requirement