Redundant Node Management in Wireless Sensor Networks with Multiple Sensor Types

One of the major challenges in Wireless Sensor Networks (WSNs) is saving energy to prolonging sensor motes' lifetime, as battery capacities are limited and often difficult to replace or re-charge. In dense sensor a mote deployment, which is often the case, energy consumption could be reduced by activating only a subset of the sensors at a time based on the spatial and temporal correlations among the sensors. However, identifying such subsets is nontrivial as the associated set-cover problem is NP-complete. Therefore, we propose a heuristic-based algorithm called the Correlated Set Calculation Algorithm (CSCA) to determine the subset of motes to be activated at a given time. CSCA considers both the spatial correlation among sensors and multiple sensor types in determining the subset of sensor motes to activate. Therefore, CSCA could enhance the coverage of the area of interest while minimizing the overall energy expenditure and maximizing the lifetime of the WSN. Experimental and simulation results show that a significant number of motes can be turned off based on the schedule calculated by CSCA. Thus, the proposed algorithm could save significant energy and prolong the lifetime of sensors extensively.