Energy efficient multilevel network model for heterogeneous WSNs

In this paper, we propose a multilevel heterogeneous network model that is characterized by two types of parameters: primary and secondary parameters. The primary parameter decides the level of heterogeneity and the secondary parameters are decided according to the level of heterogeneity. This model can describe a network in which the nodes can have up to nth level of energy (n is a finite number) depending upon the parameter values. We evaluate the performance of the HEED, a clustering protocol, using this model and name the resultant protocol as MLHEED (Multi Level HEED) protocol. For n level of heterogeneity, this protocol is denoted by MLHEED-n. The numbers of nodes of each type in any level of heterogeneity are determined by the secondary model parameter. The MLHEED protocol (for all level heterogeneity) considers two parameters for deciding the cluster heads, i.e., residual energy and node density. In this work, we illustrate the network model up to six levels. Experimentally, as the level of heterogeneity increases, the rate of energy dissipation decreases and hence the nodes stay alive for longer time. The MLHEED-1, MLHEED-2, MLHEED-3, MLHEED-4, MLHEED-5, and MLHEED-6 increase the network lifetime by 73.05%, 143.40%, 213.17%, 267.90%, 348.60%, respectively, by increasing the network energy as 40%, 57%, 68.5%, 78%, 84%, with respect to the original HEED protocol.