Mobile anchor assisted distributed localization for wireless sensor networks with holes

Location information of sensor node is very significant in wireless sensor networks (WSNs). Currently, localization approaches can be divided into two categories: distributed and centralized. Due to the requirement of the flexibility and real-time performance, distributed algorithms reveal huge advantage. DV-Hop is a classical distributed one which works by transforming the distances to all anchors from hops to units of length measurement (e.g., meters, feet) using the average size of a hop. In anisotropic networks with holes, the performance of DV-Hop degrades because of the imprecise estimation of the hop count and average size of a hop. In this work, a mobile anchor assisted distributed localization method (MAA-DL) is proposed which can decrease the impact of holes in sensor networks. The proposed method uses some mobile anchors to mark some nodes on the boundary of the holes to refine the distances to the anchors. Simulation results show that the proposed algorithm is adapted to anisotropic networks in different situations when varying the node scale and anchor scale. The localization error can be largely decreased using MAA-DL in networks with convex or concave holes.