Minimum Sensor Relocation for k-Coverage in Wireless Sensor Networks

Sensor deployment is a critical task in the implementation of wireless sensor networks. Given a deployment scheme, either at the initial stage or during the sensing process, the network may not meet the desired coverage performance for sustained and reliable operations even in the presence of redundant sensors. The coverage performance could be improved by either deploying more sensors or relocating some existing sensors, the latter of which is generally considered as a more cost-effective approach. We formulate and investigate a Minimum Movement-assisted k-Coverage deployment problem in a two-dimensional continuous space where a minimum set of sensors are selected and relocated to appropriate positions such that each point in the entire region is covered by at least k sensors. We analytically determine a maximum subset of candidate sensors for possible relocations and then find a minimum number of appropriate relocation positions. We propose a heuristic approach to this sensor relocation problem and evaluate its performance through extensive simulations in sensor networks of various scales.