A Two-Level Range-Free Localization Algorithm for Wireless Sensor Networks

Localization of mobile nodes has been a fundamental issue for wireless sensor networks. The existing localization algorithms can be classified into two categories: range-based and range-free. Range-free scheme is more cost-effective than range-based scheme. This paper proposes a two-level range-free localization algorithm (2RaLA), which consists of two methods. Mid-Perpendicular method is proposed for normal nodes which have at least three neighbor anchors, while Checkout DV-hop method is proposed for normal nodes which have less than three neighbor anchors. Simulation results show that the proposed algorithm has higher precision than the existing ones such as Centroid, CPE and DV-hop, while calculation cost only increases a little.