Mobility Strategy For Anchor Node In Wireless Sensor Networks Based On Virtual Forces

With the rapid development of information technology, wireless sensor networks(WSNs)has become a hot spot in the field of IT. The localization scheme for WSN based on mobile anchor node is widely used because of its low cost and high flexibility. As the foundation technology of the above scheme, the mobility scheme for anchor node in WSNs also attracts many scholars to research. However, some of the existing schemes are not very effective to avoid traversing the empty area of network. Some schemes usually do not consider the distribution shape of virtual anchor nodes. And some of them have long paths which make the anchor node consume too much energy.Considering the advantages and disadvantages of current methods, two mobility strategies for anchor node in WSNs are proposed in this paper: mobility strategy for anchor node based on virtual forces (VFMS) and mobility strategy for anchor node based on optimal node selection (ONSMS). Both of these two strategies are based on the study of virtual forces.The virtual force between an unknown node and the anchor node is calculated mainly with three elements, namely the intensive weight attribute of the unknown node which is related with the number of its neighbors and the distance to the neighbors, the virtual beacons the unknown node has received and the distance between the unknown node and the anchor node.In VFMS, the anchor node divides its communication area into six zones and chooses the best direction according to the virtual forces. Simulation experiments show that the strategy can help the anchor node avoid entering the cavity area in the network. It reduces the number of the collinear virtual anchor nodes and has relatively high positioning accuracy and adaptability. ONSMS chooses some optimal nodes according to the intensive weight attribute mentioned above. The anchor node will traverse along the optimal nodes. Simulation experiments show that this strategy can help the anchor node move with the specific circumstances of unknown nodes distributed, and effectively shortening the moving path of the anchor node.