摘要
In many applications of Wireless Sensor Networks(WSNs),event detection is the main purpose of users.Moreover,determining where and when that event occurs is crucial;thus,the positions of nodes must be identified.Subsequently,in a range-free case,the Distance Vector-Hop(DV-Hop)heuristic is the commonly used localization algorithm because of its simplicity and low cost.The DV-Hop algorithm consists of a set of reference nodes,namely,anchors,to periodically broadcast their current positions and assist nearby unknown nodes during localization.Another potential solution includes the use of only one mobile anchor instead of these sets of anchors.This solution presents a new challenge in the localization of rang-free WSNs because of its favorable results and reduced cost.In this paper,we propose an analytical probabilistic model for multi-hop distance estimation between mobile anchor nodes and unknown nodes.We derive a non-linear analytic function that provides the relation between the hop counts and distance estimation.Moreover,based on the recursive least square algorithm,we present a new formulation of the original DV-Hop localization algorithm,namely,online DV-Hop localization,in WSNs.Finally,different scenarios of path planning and simulation results are conducted.
