Implementation of Smartphone-based Indoor Positioning Application Using Trilateration

Positioning applications using GPS, A-GPS, and other technologies are now commonly found in most held hand smart devices. The advents in applications/tools such as Google Maps have made outdoor positioning and guidance much easier. Compared to outdoor positioning, Indoor positioning has always been more challenging. Indoor positioning faces an uphill task of proper Position fixing due to an array of issues that are otherwise absent in the outdoor environment. In this chapter, through trilateration, we have devised an application that takes the help of Wi-Fi signals and does Position fixing in an indoor environment. Indoor localization and positioning is still a challenging topic in Wireless Sensor Networks, and also it is vital because of its effects on monitoring, power consumption, etc., for our work distance calculation of an object using the proposed path loss model, and Trilateration method is implemented to calculate the unknown Position of a device under the environment. It collects all the Wi-Fi signals and finds the exact matches with the database to calculate the user's actual Position on the map. It reduces the complexity of computing the distance of different access points from the user and reduces error. The tool was found to be quite promising in detecting the Position of the host device. Future work that can be extended from this work can include work with a path loss model, Multi-Sensor Fusion, to the inclusion of pattern recognition.

Keywords: A-GPS, Indoor positioning, Position-fixing, Trilateration, Wi-Fi.