Pervasive and ubiquity computing are expected to expand the devel- opment of new business oriented mobile applications. Knowing the exact phys- ical location of the wireless devices is crucial for providing awareness of these applications. Many algorithms have been proposed for wireless localization, but most of them are designed for outdoor localization by using Global Positioning System (GPS) signals. In indoor environments, the GPS is not available, which makes localizations not trivial. This paper surveys state-of-the-art attempts to- ward efficient indoor localization for smartphones. We define a taxonomy used for better classification of the algorithms. Furthermore, we describe the charac- teristics of modern indoor positioning systems, as well as the challenges associ- ated with the localization techniques. Finally, we provide real experiments us- ing different smartphone models in order to discover typical problems that oc- cur when signal strength is used as a range measurement technique in indoor lo- calization systems.
indoor localization · taxonomy · smartphone · RSSI