Real-time path planning of mobile anchor node in localization for wireless sensor networks

Localization is a fundamental problem in wireless sensor networks (WSN). Many applications of WSN and middleware such as router require the sensor nodes to obtain their locations. Most existing localization algorithms use some mobile anchor nodes (e.g., equipped with GPS) to transmit beacons with their own coordinates for localizing other nodes. These algorithms do not need too much cost but obtain higher localization precision according to the mobile path. In the case path planning of the mobile anchor is the fundamental problem to be solved. In this paper we first study the path planning of the mobile anchor in localization for wireless sensor networks using graph theory. We regard wireless sensor networks as a connected undirected graph and then the path planning problem is translated into having a Spanning Tree and traversing graph. The paper proposes Breadth-First (BRF) and Backtracking Greedy (BTG) algorithms for Spanning Tree. The BRF and BTG algorithms provide robust localization for WSN under the random distribution and obtain higher localization precision in the simulations and real experiments.