Evaluation of optimal cluster size in heterogenous energy wireless sensor networks

The use of cluster-based networks is a well known technique to prolong the lifetime of wireless sensor networks (WSNs). In a cluster-based network, a node can be partitioned into a number of small groups called clusters. Each cluster has a cluster-head (CH) node which transmits data collected by each member to the sink node. One of the important issues in cluster-based networks are determining the optimal number of clusters (k). Without identifying the optimal number of clusters, the energy consumption of the network becomes inefficient and degrades the network quickly. A majority of previous studies has focused on the k values for homogeneous WSNs. Few studies have measured the k values for heterogeneous WSNs. Therefore, in this paper we derived the k value by considering the energy consumption for each iteration. The analytical simulation shows the relationship of energy consumption per iteration, the k value and distance of CH to the sink node. The analytical simulation was verified by the Three Level Heterogeneous Energy (TLHE) protocol simulations. The simulations indicate that the k value for a three-level heterogeneous network is 4.