—In a wireless sensor network, the network lifetime is an important issue when the size of the network is large. In order to make the network scalable, it is divided into a number of clusters. In each cluster, a set of nodes is grouped and coordinated by a cluster-head. Due to high computations and data forwarding tasks at the cluster-heads, cluster-heads get drained out sooner. Hence, high power nodes are used as clusterheads. Cluster-heads that are far away from the sink transmit their data packets via intermediate cluster-heads in a multi-hop fashion to the sink. Thus the cluster-heads that are near to the sink get overloaded and drained out sooner due to which the network lifetime decreases. In order to balance the lifetime of the cluster-heads, the existing works try to find either the optimum density or the optimum transmission range for the cluster-heads. The cluster-head placement algorithms should consider the fact that the node density and their transmission ranges are rel...
Marudachalam Dhanaraj, C. Siva Ram Murthy