Advances and Future Directions in Range-Free Localization Techniques for Self-Organizing Networks

The demand for self-organizing network node localization technology is increasingly prominent in various fields, including the Internet of Things (IoT), mobile communications, and smart cities, making it a key focus of current research. As an important subfield, Range-Free Localization achieves node localization by leveraging relative information between nodes, without requiring precise distance measurements. This approach significantly simplifies the localization process and reduces hardware costs. This paper analyzes the two core technologies of Range-Free Localization: distance estimation and location estimation. For distance estimation, which is entirely independent of hardware, we review the latest advancements in model-based and node-based techniques. In the location estimation section, we focus on algorithmic frameworks, analyzing the principles and improvements of DV-Hop algorithms and metaheuristic algorithms. Finally, the paper summarizes the current research status and challenges associated with Range-Free Localization technology and explores potential directions for future development.