Optimized Positioning of Relay Nodes using Bat Algorithm in Heterogeneous Wireless Sensor Networks

In heterogeneous wireless sensor network (HWSNs), relay nodes are deployed to improve the network lifetime, connectivity and/or coverage of the network. The deployed relay nodes (RNs) can also perform data aggregation and disseminate the data to sink node, hence acting as cluster head. Therefore it is vital and challenging to identify optimal positions for placement of RNs. In this paper, we have studied four different metaheuristic algorithms for relay node placement problem. Also, in order to maintain the data latency, we have employed mobile sink for data collection purpose. Employing mobile sink(s) provide considerable benefits to the deployed Wireless Sensor Network(s) (WSNs) in terms of increased network lifetime, decreased energy consumption, decreased data latency and evenly distributed load on the sensors in the network. Three mobile sink traversal techniques are simulated for data collection purpose. The results obtained through extensive simulations demonstrate the superiority of bat algorithm for relay node placement.