Coverage Maximization in Wireless Sensor Networks Using Minimal Exposure Path and Particle Swarm Optimization

Abstract

The fundamental objective of deploying wireless sensors is to monitor a physical condition(s) within the desired region and relay the measured data to the interested parties through a gateway. However, achieving maximum coverage over the desired area after the initial random deployment of nodes is likely impossible. Arbitrary paths become exposed, uncovered by any of the sensor nodes questioning the quality of service of the network. In our proposed coverage maximization scheme, exposure profiles of sensor nodes were used by the sink node to compute the minimal exposure path. A combination of the computed minimal exposed path and the ratio of covered to uncovered grids were used as the function fitness in our particle swarm optimization algorithm. Bearing in mind the energy constraints of sensor nodes, randomly deployed nodes were only repositioned in the optimization process when their energy levels are above the predefined threshold. The accuracy and efficiency of our scheme are established via simulations. We compared the results of our scheme with a similar optimization scheme. The results showed our scheme achieved a higher coverage degree with the same number of deployed nodes over a region of interest of the same size.