Location systems with sensors - Overview and new approach

A traditional approach to indoor tracking uses non-RF techniques, such as infrared and ultrasound. A disadvantage of these methods is that they do not work unless the sensors have direct connection with the nodes, to which the reference made the estimations of the distance. Another approach for inside buildings location systems uses only RF sensors, a similar principle to the one used by the Global Position System (GPS). The goal of the paper is to highlight the main differences between these systems and to propose a new method for inside buildings location systems.