Under The Emergency Environmental Construction Of Wireless Sensor Network And Node Localization Research

The rapid development of various advanced technologies results in the invention and application of wireless sensor network (WSN), which has brought a revolution in sensing technology with its unique network architecture and great value. As a new kind of information acquisition and processing technology, WSN builds network automatically and has lots of features like cheap and rapid deployment. It has shown its great prospects for applications such as military affairs, environmental monitoring, and agricultural sensing.When disaster strikes, the rapid deployment of WSNs in the disaster area is helpful to real-time monitoring of environmental indicators and improving the efficiency and quality of emergency rescue. In the meanwhile, some factors like the unpredictability of disaster, harsh environment and the urgency of network system put forward lots of special needs in network architecture, sensor nodes designing, and technical realization. Therefore, it is very important and necessary to carry out some research on building WSNs in emergency circumstances.This dissertation focuses on building WSNs in emergency circumstances and contains the following research. Firstly, requirements of network system have been analyzed detailedly and an overall design scheme has been proposed. Secondly, research has been done on the realization of some main technologies in the proposed scheme, including the MAC protocol, mobile access, routing protocols, and node localization. A mobile access mechanism based on the X-MAC protocol has been designed. A "decision rule for effective path of interest propagation", using nodes’position for clear direction on interest spread, has been proposed to reduce network traffic and energy consumption in Directed Diffusion. An improved node localization algorithm(ADV-Hop) based on the DV-Hop has been proposed to reduce network traffic and improve positioning accuracy in a variety of network by limiting times of packets forwarding, discarding remote anchors’info, estimating distance with two different average distance per hop according to the hops between nodes. Finally, some related simulation of the improved routing and node localization algorithm has been done. Experimental results show that using the proposed decision rule can significantly reduce network traffic and energy consumption during interest forwarding; the ADV-Hop achieves more stable performance and better positioning accuracy than the other two reference algorithm in different scenarios.