Research On Node Localization Algorithm Based On A Mobile Beacon For Wireless Sensor Networks

As the core technology in the field of Internet of Things,wireless sensor networks(WSNs)have developed rapidly in recent years.WSNs are composed of a large number of sensor nodes,which are used to monitor events in the environment and need to have the ability of location-aware.In some existing localization methods,mobile beacon node is often used to provide location data packets,assisting sensor nodes in completing localization.And how to plan the path of the mobile beacon in complex environment and realize efficient and precise localization is an important issue for the research on WSNs.In the real environment,the random deployment of sensor nodes or node's failure would form holes in the network,and sending data packets in such regions is meaningless.For solving the problem,this paper proposes a dynamic path scheme DPDC(Dynamic Path combined with Deterministic Curves)of the mobile beacon for node localization.The algorithm design of DPDC includes the design of communication process of nodes in the network and the design of dynamic path of the mobile beacon.In the design of communication process,according to the different positioning states,the life cycle of sensor nodes is divided into three stages,which improves the communication efficiency between them.And the proposed path scheme uses the local topology information and the perspective of area exploration,which could make the beacon flexibly avoid the holes and ensure the complete positioning for a connected network.In addition,as an extension of terrestrial WSNs,underwater WSNs have a more complex node deployment environment.The node mobility caused by ocean currents and other factors would lead to a bigger ranging error and make some nodes cannot receive enough data packets.To solve the problem,this paper proposes a SCAN trajectory based localization algorithm called LSMB(Localization algorithm based on SCAN trajectory and Mobile Beacon).The algorithm makes use of the attenuation law of signal strength and the geometric relationship between a sensor node and the trajectory of the mobile beacon,reducing the impact of random errors on distance measurement.On this basis,by analyzing the overall moving trends of sensor nodes,this paper analyzes and studies the countercurrent movement and downstream movement of the mobile beacon respectively,so as to make LSMB suitable for dynamic environment.This paper uses MATLAB to simulate the above two algorithms.Simulation results show that DPDC reduces the path length of the mobile beacon while keeping a high localization ratio and that LSMB reduces the impact of node mobility on localization.The communication loads of the two algorithms are low and the localization accuracy is less dependent on the placement density of data packets,showing good adaptability and stability.