On Lifetime Maximisation of Heterogeneous Wireless Sensor Networks with Multi-Layer Realisation

Lifetime maximisation is a key challenge in the design of resource constrained wireless sensor networks (WSNs). This leads the research communities to investigate energy conservation techniques for WSNs while maintaining the required quality of service. Dynamic clustering is considered as one of the most well established energy conservation techniques in the literature. However, uneven distribution of cluster heads within the network and variable number of sensor nodes in the clusters results inefficient energy consumption; hence minimise the network lifetime. The conventional dynamic clustering become more energy in-efficient, when there exists heterogeneity of sensing devices within a network. In other words, obtaining optimal solution with conventional single layer realisation become more computationally complex. In this paper, a dynamic clustering scheme is proposed for heterogeneous WSNs with multi-layer realisation where each layer comprise of homogeneous sensing devices. To attain energy efficiency, we are proposing intra-layer (horizontal) and inter-layer (vertical) optimisation in the search of global minima, which requires reduced number of iterations in comparison to the conventional single-layer realisation of a heterogeneous WSN. Moreover, cooperation among sensor nodes is considered to relay data to fusion centre receiver to enhance transmission reliability in variable channel conditions. The proposed scheme is expected to provide energy efficient solutions for future generation WSNs. Simulation results demonstrate that for a heterogenous WSN with 50% activity factor, proposed scheme outperforms the existing scheme by saving 11% residual energy of the network.