Research On APIT Localization Algorithm In Wireless Sensor Networks

With the advancement of technology,wireless sensor networks have been widely used in various fields.Among the many core technologies of wireless sensor networks,node localization is one of the most basic and key technologies,which plays a supporting role for the entire network platform.However,the classical node localization technology is not ideal enough to meet the growing positioning requirements,especially when the node is attacked by network security.Therefore,it is important to study how to improve the accuracy of node localization and implement secure localization under network attack.This thesis focuses on the range-free based node localization technology and improved methods.The main contents include:First,starting from the theory,the basic concept of wireless sensor network is briefly introduced,and the related theoretical knowledge of node location technology is elaborated.On the basis of reading a large number of documents,the existing classic algorithms are sorted and analyzed,and then the inadequacies of the APIT algorithm are analyzed.Second,aiming at the boundary effect caused by the decision rule of neighbor nodes in the APIT localization algorithm,a virtual node-based APIT localization algorithm with low computational complexity is proposed.The effective location of the target node is determined by introducing a small number of virtual nodes.A certain number of virtual nodes are estimated according to the position of the target node on the triangle edge formed by the anchor node,and the signal strength received from the anchor node by the virtual node is compared with the signal strength of the target node to determine whether the target node is inside the triangle.Finally,a plurality of triangular regions are stacked to obtain position information of the target node.The simulation results show that the algorithm effectively improves the localization accuracy of the APIT algorithm.Third,aiming at the node security problem in wireless sensor networks,a secure APIT localization algorithm against sybil attacks is proposed.The nodes in the network are detected by the relationship between the number of neighbor nodes and the strength relationship of the received signals.Combining the sybil node detection method with the APIT localization method,the node security detection is performed on the triangle composed of the anchor nodes in the network,and firstly,according to the broadcast information,whether the anchor node in the triangle has a suspicious anchor node pair,and then the above suspicious node of the detection result performs the detection of the received signal strength difference,thereby determining whether the anchor node pair is a sybil node.The method has high stability and correct rate,and can effectively improve the reliability of target node location and network security.