Issues and Challenges of Wireless Sensor Networks Localization in Emerging Applications

Wireless sensor networks (WSNs) are widely being used in many environments (e.g., disaster relief and target tracking), and WSNs localization is still a crucial research area because of the new localization requirements for emerging application domains such as cyber-physical systems and cyber-transportation systems (CTS). In this article, we review different node localization approaches, and point out the issues and challenges of WSNs localization in emerging applications. First, the measurement-based techniques are introduced, and the range-free localization that is further classified into proximity-based localization, one-hop localization and multi-hop localization, is deeply analyzed. Then, the method of nonline-of-sight error mitigation is also reviewed. In addition, we give two representative applications (unmanned vehicle with WSNs navigation and CTS) to state the new obstacles for WSNs localization. Finally, the main issues and challenges for improving WSNs localization are outlined in brief.