Weight based clustering in wireless sensor networks

We study the impact of heterogeneity of energy in hierarchically clustered wireless sensor networks. Heterogeneity in energy of the sensor nodes can be because of (i) differences in transmission levels of sensor nodes, (ii) differences in initial energies, or (iii) due to introduction of high energy sensor nodes within the sensor network to revitalize it [11]. Clustering protocols divide sensor nodes into groups of member nodes called clusters. Each cluster contains a cluster head. Cluster heads form an independent dominating set. We identify a potential drawback of such a scheme in heterogeneous sensor networks. In a heterogeneous sensor network, electing sensor nodes with high energy (called advanced nodes) which lie within the same transmission radius may be better than electing a single advanced node as cluster head. Cluster heads expend more energy than member nodes during each round. Therefore, election of advanced nodes as cluster heads becomes imperative for the performance of the sensor network. We propose a weighted cluster head election scheme, called Weight Based Clustering for Heterogeneous sensor Networks (WBCHN). WBCHN prolongs the stability period (time before the first node dies) through the election of high percentage of advanced sensor nodes as cluster heads.