3-Dimensional Approach to WiFi Indoor Positioning

This paper proposes an algorithm which can be applied for a 3D-environment, providing the height information such as the floor on which the mobile device is located. At the same time this algorithm aims at providing better accuracy than the signal propagation model but not as computationally intensive as the fingerprinting techniques. The algorithm uses a combination of both the statistical methods and the signal propagation model technique for positioning the mobile device. The technique presented in this paper assumes that the location of the APs in a building can be obtained from the network maintenance; using this information and the floor plans of the building, the coordinates of each AP are evaluated. The AP's MAC address and the location co-ordinates of the AP are saved to database which will be later on used in the positioning of the mobile device. The second step is to collect data in the test area, which is divided into blocks. The data collection is done using a WiFi network scanner tool (such as NetStumbler or inSSIDer). RSSIs and MAC addresses at each scan point, and the location of scan point are recorded. This information is then processed to calculate an equation which would describe signal propagation in each block and this data is stored to database. During the positioning phase, the algorithm uses the database to provide 3-dimensional co-ordinates of the mobile device.