Unequal Rotating Energy Efficient Clustering for Heterogeneous Devices (UREECHD).

Heterogeneous Wireless Sensor Networks (HWSNs) are composed of battery powered devices that can have different initial energy, different transmission rate and different hardware. Nodes consume energy to exchange data they sense from their surroundings. In this context, clustering is an approach to reduce devices energy consumption, increasing WSNs lifetime. Clustering partitions the WSN nodes into a set of clusters with a coordinator. Coordinators are called cluster heads (CHs) and gathers data from their member nodes, forwarding it to a centralised Base Station (BS). Most of the existing clustering protocols consider the nodes residual energy when electing a CH. Rotating Energy Efficient Clustering for Heterogeneous Devices (REECHD) is a novel clustering algorithm where the leader election, not only considers the node residual energy, but also the node rate. In this paper we introduce a novel unequal variation of REECHD (i.e., UREECHD) where clusters that are closer to the base station are smaller when compared to clusters that are farther away from the Base Station. Our experiments show that UREECHD outperforms REECHD of 20% when first node die lifetime measure is considered.