Demo Abstract Alps - The Acoustic Location Processing System

We demonstrate ALPS [1], a platform that augments BLE proximity beacons with ultrasonic transmitters in a manner that allows for precise and robust indoor localization. ALPS uses Time-Difference-Of-Arrival (TDOA) and TimeOf-Flight (TOF) ranging to accurately localize mobile devices such as off-the-shelf smartphones and tablets in 2D space. Users inside the demo area will be able to determine their location and can directly plot it relatively to a map of the area using our app on a smartphone. Once a receiving device has determined its initial position, it can synchronize its audio clock with the transmission infrastructure to perform TOF-based localization, which provides similar position accuracy to TDOA-based localization with fewer beacons. Multilateration and trilateration processing for each device's location is offloaded onto a cloud-based solver that can provide localization as a service to ALPS and similar TOF/TDOA-based systems.