Energy Hole Minimization Techniques in Wireless Sensor Networks

Abstract

Energy Hole Minimization Techniques in Wireless Sensor Networks (Terrestrial, Underwater, Body Area Networks) Revolutionary development in integrated circuit miniaturisation facilitates the in- volvement of electronic sensors in every aspect of our life. This involvement results in a wide range of Wireless Sensor Network (WSN) applications in terrestrial, un- derwater and health care. However, small size poses power limitation on these sensors. In order to conserve their energy, energy efficient strategies are needed at all layers of network model. However, this dissertation focuses on energy hole anal- ysis and proposition of energy efficient solutions in WSNs (terrestrial, underwater, and body area) at the network layer only. In terrestrial WSNs, we identify that uneven number of Cluster Heads (CHs) se- lection is the major cause of uneven cluster size. This uneven cluster size leads to imbalanced energy consumption of sensors (nodes) in the network, which ul- timately leads to creation of energy hole. In order to cope with this issue, we propose two energy efficient routing techniques; Density Controlled Divide-and- Rule (DDR) and Divide-and-Rule (DR). These techniques logically divide the network area into static clusters (regions) and nodes are randomly distributed in these regions. The two techniques differ in terms of regions’ formation and nodes’ association with CH(s). In Wireless Body Area Networks (WBANs), limited num- ber of nodes are placed on the human body, and typically, three communication modes are used; direct, intermediate node based, and cluster based. In this regard, our contribution factors in a detailed energy consumption analysis. Analytical and experimental analysis reveals important results regarding energy consumption of these techniques. In UWSNs, we propose two techniques; Delay Intolerant Energy Efficient Routing (DIEER) with sink mobility and Spherical Hole Repair Tech- nique (SHORT). In DIEER, we analyze energy consumption of nodes in Depth Based Routing (DBR) techniques and devise an optimised way of forwarder node x selection. On the other hand, SHORT’s energy hole analysis reveals that knowl- edge acquisition phase of DBR, and static transmission power level are the major contributors in nodes’ energy consumption. We devise a solution to repair the coverage holes which are created due to regular death of nodes. The simulation results show that our newly proposed techniques perform better than the selected existing ones in terms of the selected performance metrics.