A Survey on Localization in Wireless Sensor networks

Recent technological advances have enabled the development of low-cost, low-power, and multifunctional sensor devices. These nodes are autonomous devices with integrated sensing, processing, and communication capabilities. In general, wireless sensor networks intend to provide information on spatio-temporal characteristics of the observed physical world. Hence, it is necessary to associate sensed data with locations, making data geographically meaningful. A number of applications, such as object tracking, environment monitoring, inherently rely on location information. Besides, location information also supports fundamental network layer services, such as topology control, routing, clustering, and so on. Hence, Localization, a mechanism for autonomously discovering and establishing spatial relationships among sensor nodes, is of great importance in the development of wireless sensor networks. This survey reviews diverse physical measuring abilities of sensor nodes, discusses issues in localization algorithm design, presents the state-of-the-art localization techniques, and finally suggests future directions in localization studies. Many localization approaches are proposed based on diverse positioning principles, environmental constrains, accuracy requirements, etc., making them suitable/unsuitable for different applications. This survey in depth elaborates and compares existing approaches from two aspects: physical measurement and network-wide localization. The design tradeoffs of localization algorithms, as well as their advantages and disadvantages, are emphasized for comparison. Among these localization techniques, no specific algorithm is a clear favorite across the spectrum. In conclusion, localization is a new and exciting field, with new algorithms, hardware, and applications being developed at a feverish pace. A lot of work still needs to be done to realize practical applications for wireless sensor networks.