Design Of Topology Discovery And Node Localization Algorithm Based On Wireless Sensor Network

In the engineering application of wireless sensor network, Getting network topology structure and node localization is the basis of engineering monitor, and providing a certain support to the network life cycle and network robustness. A remote monitoring system is a net structure monitoring system, which formed by wireless senors and applied in Tibet railway’s BeiLuHe area, by adapting a multi ad-hoc network structure can get physic information data in monitoring area effectively. In wireless sensor network, the nodes in sensor network interacts data with each other by using Z-Stack protocol stack, and on one hand, Android gatway interacts with coordinator node using bluetooth, on the other hand, Android gatway stores data information and uploads to remote service. Due to the nodes are placed random in monitoring area, and the nodes have no function of localization, the inoperation node can’t be signed with the other nodes, which have impact on the network life cycle. Aiming at this problem, the paper designed an algorithm of three-dimension node localization and network topology algorithm, and using Android gatway to display network structure and unknown node localization information.Using network topology algorithm to get WSN network, which aim to getting the nodes connecting path and transfer relation, then getting the unknow node relative position coordinates by using beacon nodes localization. Aiming at topology structure is a mesh wireless network, adapting Z-Stack protocol stack and graph theory to get the lopology relation in mesh network successfully. At the same time, by integrated RSSI probability density function, three dimensional spherical cover and centroid algorithm, the unkown nodes localization in three dimensional is realized. At last, an interactive interface is designed to display the network topology structure and unknown node localization in Android intelligent terminal.The paper completely designed a function of network topology and node localization, and making a research in process of localization error and node density, making a corresponding test of related algorithm, which includes connect relation between nodes, unknown nodes localization and so on, and recording the test results.Practical results indicates that the designed topology discovery method and ihree-dimension node location are satisfied with practical works requirements, having a good capable of network structure and node localization, reached a certain research goal.