Coverage Control Methods For Mobile Wireless Sensor Networks

Proposed in late 1990s, Wireless Sensor Networks (WSNs) technology is one of the hot spots in IT domain and predicted to be an important new technology to change the world. Due to its characteristics of self-organizing, dynamic, reliability and data-center, WSNs is widely used in national defense, industrial, medical, household and other fields, and will gradually penetrate into all areas of human life.Coverage is the foundational problem for WSNs influences the performance of whole network. The three dimensional coverage for WSNs is a difficulty for can not carry out through expanding dimension of existing two-dimensional coverage methods. The existing three-dimensional coverage methods at home and abroad in wireless sensor network are summarized, analyzed and compared. On this basis, the characteristic of mobile nodes and requirement of coverage algorithm are studied, three new three-dimensional coverage control methods are presented suitable for mobile nodes. The three algorithms are as follows:1,For the energy consumption imbancing by randomly selecting head nodes, a energy efficient coverage method in 3D WSNs is proposed. Compare the combination of weights of the available energy, the average distance with adjacent nodes and the connectivity to determine the head node of cluster, calculate the energy efficient depth of each node. The coverage of 3D WSNs is maintained and suitable for the networks formed of mobile nodes.2,For the existing of coverage blind area and redundancy of sensor nodes, a coverage algorithm based on regional segmentation in 3D Wireless Sensor is proposed in this paper. According to the density of nodes, inscribed cube or circumscribed cube is used to segment monitoring area. Then coverage of 3D WSNs is maintained and suitable for the networks formed of mobile nodes.3,For coverage algorithms'difficulty to converge to the most optimal solution, a coverage method based on modified PSO/GA algorithm in 3D wireless sensor networks is proposed. Paralled particle swarm algorithm is combined with the traditional genetic algorithm, 3D coordinates model is used to maintain coverage control. This method is suitable for the networks formed of mobile nodes. Finally, the three algorithms are simulated on the plateform of Matlab 7.1 and VC. The simulation results show that the coverage based on combined weighted clustering reduces energy consumption, balances network energy and extends lifetime of sensor networks, guarantees the coverage ratio and connectivity premise; the coverage algorithm based on regional segmentation in 3D Wireless Sensor reduces the number of working nodes and achieves total coverage; the coverage method based on modified PSO/GA algorithm in 3D wireless sensor networks converges to the most optimal solution faster, improves operation efficiency and coverage ratio, reduces the number of iterations.