Localize Yourself in Malls: An Anatomy of a Commercial Localization System with One-million Users

The past two decades have witnessed the surge of smartphones and mobile applications. When going out, people will naturally open the map application (such as Google Maps) to find their current location (i.e., localization) and the way to their destination (i.e., navigation). At the same time, many people rely on their smartphones for localization when they walk into shopping malls, especially in large shopping centers. In outdoor environments, we usually leverage GPS to estimate our location. However, satellite signals are oftentimes weak inside buildings, resulting in large positioning errors and thus a poor navigation experience for users.