Research Of Data Management And Index Technology In Wireless Sensor Networks

Wireless Sensor Networks (WSNs) is a self-organized distributed intelligent system which consists of sensing, data processing and communicating components. WSNs, which integrates the technologies of sensor, micro electro mechanical system, wireless communications and distributed computation, is a novel mode of computing and a hotspot of information technology after internet. Any application system based on WSNs can not live without management of sensor data. With this background, we research on the data management in WSNs. The major contribution of this thesis is stated as follows:⑴According to the requirement of the application of WSNs, we design a data management system of WSNs, which is called NHSensor. NHSensor provides a simple, SQL-like interface to specify the data you want to extract. Given a query specifying your data interests, NHSensor collects that data from motes in the environment, filters it, aggregates it together, and routes it out to the basestation. NHSensor dose this via power-efficent in-network processing algorithms.⑵R-tree, as an efficient data structure, is used to index spatial object. This thesis proposes a management method of sensor node based on R-tree. This allows WSNs to manage the spatial information of sensor node, greatly increasing their ability to process spatial information.⑶Spatial query is used frequently in WSNs. Most of the researches suppose that the query region is a rectangle, and the complex region has not been considered. This thesis proposes"three-tier presentations, two-stage mapping", a method of spatial region processing. We have three ways to map from coordinate tire to mote tire, and they fit different situations respectively accoding our analysis,⑷Data secure, the prerequisite of application of WSNs, is an important problem which data management system has to handle. In this thesis, we propose a method to manage the spatial authority. Different users of the WSNs have different authorities. All the queries have to be checked according to the authorization information before being sended to the network.