A Survey of Recent Indoor Positioning Systems using Wireless Networks

Global navigation satellite systems (GNSS), which are widely used today by positioning and navigations systems, are becoming increasingly important in daily life. GNSS, however, do not work well in indoor environments due to the satellite signal outages that occur in closed structures. Yet the demand for indoor positioning systems is growing as handheld devices become cheaper. Consequently, position estimation is a problem that has been addressed using a variety of technologies. This study classifies indoor positioning technologies into four types, radio frequency (RF), proximity detection, triangulation, and scene analysis, of which the final two are the most common for wireless sensor networks. RF systems are widely used owing to the properties of radio signals. Recent research shows that radio signal strength (RSS) methods have several advantages over time based methods. Lastly, a review is provided of recent studies on wireless positioning for an indoor environment using a wireless sensor networks.