Calculating distance within a building

Question

I started doing some thinking about creating an Android application that can be used within a corporate building to determine what room you are in. Obviously I\'m thinking GPS a

Answer 1

Perhaps it is not too much help but the papers I have found on this subject are these:

RSSI-Based Indoor Localization and Tracking Using Sigma-Point Kalman Smoothers

Pedestrian Tracking with Shoe-Mounted Inertial Sensors

Enhancing the Performance of Pedometers Using a Single Accelerometer

I have no idea how these methods would perform in real-life applications or how to turn them into a nice Android app.

I am curious what other answers you will get.