Performance analysis of range free localization methods for wireless sensor networks

Wireless Sensor Networks (WSNs) consist of a huge number of resource constrained Sensor Nodes (SNs). These networks are frequently deployed in remote and hostile environments to sense and report location based events. In wireless networks, this location information is obtained by attaching Global Positioning System (GPS). However, obtaining location data using GPS is a costly procedure in WSNs due to resource constrained nature of SNs. To this end, researchers proposed several localization methods that works without the help of GPS. These methods are broadly classified into two categories: range-based and range-free. Range-free localization methods are more flexible and easily computable as compared to range-based methods. In this paper, authors present a study on various range-free localization methods for WSNs. After presenting the study of range-free localization methods, the performance of these methods are analyzed using simulations. With the extensive simulations, it is noted that each method has its own advantages and limitations in accurately computing the location data. Finally, by analyzing the simulation results, the authors suggest extensions to these methods to improve the accuracy of computing the location data.