Power-Efficient Clustering in Wireless Sensor Networks under Coverage Constraint

Maximizing network lifetime and minimizing energy consumption and are two central issues in the design wireless sensor networks (WSN) protocols. In this paper, we address energy-efficient state assignment to sensors in cluster-based WSN, under the constraint of full coverage of the area the sensors are deployed in and connectivity of cluster heads. We consider that any sensor can be turned on, turned off or promoted cluster head, each of these states having a predefined power consumption level.We propose a sensor state assignment heuristic that processes an energy-efficient sensor configuration where every sensor is connected to a cluster head. Besides, we constraint any admissible configuration to have all its cluster heads forming a spanning tree used as a logical routing topology. First, we formulate this global problem as an Integer Linear Programming model that we prove NP-Complete. Then, we implement a greedy heuristic and we show that, compared to its lower bound, this heuristic provides quite good network lifetime values while performing low computation times, practically suitable for large-sized sensor networks.