A Horizontal Multi-Level Heterogeneous Routing (HMHR) Protocol with TDOA Localization for Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are generally set out in a remote workplace, since sensor nodes are tiny in size, cost-proficient, low-power gadgets, and have restricted battery supply. Due to the constrained availability of power sources, energy utilization has been considered as the most crucial factor for proposing network routing protocols. The fundamental concern is to improve the lifetime of the network based on the energy constraints. But, in areas like geophysical and environmental monitoring, localization of nodes is also critical for proper data processing. Several homogenous cluster based routing protocols have been proposed in literature for lifetime improvement of the sensor network but many of them fail to function effectively in heterogeneous environment and moreover, these protocols have not considered a proper localization technique for evaluating the location estimates of nodes in the network. In this paper, a Horizontal Multi-Level Heterogeneous Routing (HMHR) protocol that mainly focuses on lifetime improvement of nodes, and also incorporates a TDOA localization technique, for accurate estimation of node locations, is proposed. Performance parameters of the proposed scheme are compared with other three already existing prominent protocols named LEACH, SEP and Z-SEP and a significant improvement in lifetime of the network is obtained. The accuracy of the localization technique used is evaluated by plotting the corresponding Mean Square Error (MSE) curve.