The Development of Two Systems for Indoor Wireless Sensors Self-location
In the last few years, there have appeared many studies to self-locate sensors in indoor environments. Many of them can only be used in a single room (usually when they use infrared or bluetooth technologies), others do not take care of the walls inside the buildings so they use to have tags, and even, in some of them, there is an access point in each room of the floor to locate the sensor. This paper describes two approaches where wireless sensors could find their position using WLAN technology inside a floor of a building. The scenario is an indoor environment with walls, interferences, multipath effect, humidity, temperature variations, etc., and both approaches are based on the Received Signal Strength Indicator (RSSI). The first approach uses a training session and the position is based on a heuristic system using the training measurements. The second approach uses triangulation model with some fixed access points, but taking into account wall losses and signal variations. Finally we will compare real measurements of our proposals with the measurements taken by the Ekahau system.
wlans indoor location system positioning system