Research On Energy-Efficient Transmission And Node Localization In Wireless Sensor Network

Wireless sensor network attracts more attention by academia and industry for its bright prospects. Based on advanced information and communication technologies to improve health care services, improve health care for ordinary people is one of hot issues of the information communication field.To solve this problem, this thesis focuses on the key issues in wireless sensor networks, taking mobile e-health applications as the main application background, to carry out researches on energy-efficient transmission and positioning technologies in ubiquitous pan-health care wireless sensor network systems. Main research contents are as follows:First of all, this thesis summarizes key technologies of wireless sensor networks and researches several typical scenarios in e-health applications, focusing on the latest development, importance and solutions of disaster scenarios. The analysis of basic functions and typical data in e-health applications scenarios is given from a technical perspective, and energy efficiency has been discussed.Next, this thesis uses the probability method to analyze nodes positioning problem in wireless sensor network. This thesis pays attention on the DV-Hop localization algorithm, and presents proposals that can improve the performance of conventional DV-Hop by statistical analysis methods. Proposed schemes which can optimize distance estimation by adjusting every single node's estimation according to its certain circumstance in order to improve the positioning accuracy of the whole network. In addition, the deployment, communication cost and computing complexity of the novel algorithms are discussed. Finally, this article researches the building method of wireless sensor network simulation platform with energy management functions in OMNet++ simulation environment. Energy management, network connection management and node energy statistics method and related key mechanisms are described in detail.In the end of this thesis, a summarization is made and the future direction of the study is also pointed out.