Energy-efficient models for coverage problem in sensor networks with adjustable ranges

In wireless sensor networks, coverage problem is a fundamental issue that has attracted considerable attention in recent years. To prolong the network lifetime, sensor nodes are scheduled to work in rounds so that a set of active nodes in each round is selected under the constraints of two conflicting objectives: minimizing the energy consumption, while maintaining a high degree of coverage. In this paper, we introduce a set of coverage models that is used as a guideline to select active nodes in each round of a node scheduling mechanism. Each coverage model is formed by the regular placement of sensor nodes with adjustable sensing and communication ranges. However, as opposed to the existing techniques, we design a universal pattern that can generate a set of new coverage models in a systematic manner. Mathematical analysis and simulation show that our proposed models outperform existing ones in terms of various performance metrics.