Abstract: When anchor nodes form collinearity， which means that the anchor nodes locate in almost the same straight line， negative effect will be caused upon positioning accuracy， and therefore the precision will be declined. Considering the collinearity features， a DVHop strategy was proposed for the largescale rangefree localization in wireless sensor network. Voronoi diagram was used to divide the network into several regions. Then anchor nodes were selected and purified by collinearity. According to the hop limit threshold， the information of anchor nodes in each region and conform collinearity condition were utilized to localize the unknown node. Simulation results showed that the proposed strategy， compared with the traditional DVHop and collinearity algorithm， could effectively decrease the computational complexity， improve the node positioning accuracy and reduce the localization error. For the asymmetrical networks， the strategy could achieve higher precision node positioning and be suitable for complex environment.

Key words: wireless sensor network, node localization, DVHop algorithm, collinearity, anchor node term