Research On Virtual Force-Based Optimal Deployment For WSN

As a distributed network, the wireless sensor network(WSN) is a multi-hop and self-organizing network, the sensors in which can sense and monitor the external world. WSN can not only be set flexibly, the location of the device in which can be changed at any time, but also connect with the Internet in a wired or wireless manner. In the past ten years, the academe and industries pay much attention to WSN, which has been widely used in civil and military fields. The node deployment is a fundamental area in the research of WSN. A reasonable node deployment is helpful to reduce the node redundancy, improve the network coverage and equalize the energy consumption of nodes.Node deployment means to arrange nodes in a certain monitoring area according to the specific requirements. However, the monitoring area may be located at severe environment, making it impossible to replace or charge the nodes, which brings great technical challenge to the node deployment.This thesis has done some researches on node deployment in WSN. The structure of this thesis is the following: Chapter 1 introduces the research background significance of the research, and summaries the research status at home and abroad; Chapter 2 introduces the basic concept in WSN, including its architecture, network characteristics, network application; Chapter 3 analyzes characteristics and application environment of the virtual force algorithm, and then proposes an improved virtual force algorithm for network deployment to overcome the shortcomings and application limitations in virtual force. Chapter 4 presents the performance simulation and analysis of the improved virtual force algorithm. Finally, it sums up the discoveries, shortcomings and prospects of the research.Chapter 3 and chapter 4 are the key parts of this thesis. In the third chapter, in order to achieve seamless coverage, a node deployment algorithm based virtual force is proposed, which not only studies the optimal coverage of the region, but also considers the energy consumption of the mobile nodes. For regional coverage, firstly, the scope of virtual force between nodes is reduced to the range of the communication, and then, the threshold of virtual force is determined from the perspective of seamless coverage. For the boundary coverage problem, the appropriate distance from the node to the boundary is determined when the nodes' coverage redundant at the boundary reaches its minimum. In this way, the number of action forces which nodes are applied is reduced, helping all nodes reach equilibrium of forces. In addition, the average of nodes' moving distance reflects the overall energy consumption of the network, and the standard deviation of nodes' moving distance reflects the differences in energy consumption of nodes. In order to reduce the average and the standard deviation, a weight, which is associated with the magnitude of the forces each nodes is applied. Finally the maximum coverage and the minimize energy consumption can be achieved. Chapter 4 carries performance simulation the WVFA, and the simulation results show that: the WVFA can be better than VFA, CBS and HLVFA in improving the network coverage and reducing the energy consumption of network, and it can extend the network lifetime, and realize the optimal deployment of WSN.