Non-uniform deployment of nodes in clustered wireless sensor networks

In this paper, we consider the problem of placing, with course-grained control, a large number of wireless networked sensor nodes employing a clustering network architecture. The goal of the deployment strategy is to maximize the lifetime while ensuring connectivity between cluster-heads so that samples from the monitored area may be forwarded to a fusion center. A model is derived to approximate the lifetime of a differentially deployed random network using both the density of cluster-heads and non-clusterheads as variables. Through optimization of the lifetime expression over both variables and through simulation results, it is shown that 1) a differential node deployment with a uniform cluster-head density increases the lifetime of the network over a uniform deployment and 2) the addition of a suitable differential cluster-head density further increases lifetime over the differential node deployment with uniform cluster-head density.