Research On Connectivity And Coverage Problems In Wireless Sensor Networks

Since 1990s, along with technique development of wireless communication, embedded computation, sensor and MEMS (Micro-ElectroMechanical Systems) et al, people have paid more attention to micro sensor with the capability of sensing, computing and wireless network communication, and WSN(Wireless Sensor Networks) that is made up of such sensors. This thesis researches on the problems of connectivity, coverage and sensor deployment in the WSN.In wireless sensor networks, the number of sensor nodes has direct relation to WSN's cost and performance, such as robustness, fault-tolerance. And furthermore, it is considered at first as WSN is designed. Analyzing the coverage problem of WSN, the thesis proposes the concepts of efficient coverage area and efficient coverage area ratio. It is theoretically proved through math modeling, theoretical analysis and formula deducting that how much the maximum of efficient coverage area, the maximum of efficient coverage area ratio, the maximum of net efficient coverage area and the maximum of net efficient coverage area ratio of sensor node is if full and seamless coverage is met in WSN. At last, the analysis formula is given that minimum number of sensor nodes is demanded in a given sensor field if the field is covered fully and seamlessly.In order to conveniently manage a network by different levels, save energy and implement scalability, WSN forms into clusters in wireless sensor networks and it is proved that clustering WSN is an effective method. The thesis simplifies complex connectivity problem step by step. By means of theoretical analysis, math modeling and geometry proving, and making use of geometry and the method of mathematics induction, the method of grid partition of sensor field is proposed from the viewpoints of topology. In the end, the analysis formula of minimum number of cluster heads is theoretically educed under circumstances of full and seamless connectivity in wireless sensor networks. Still further, the thesis synthetically considers the problem of connectivity and coverage in wireless...