HABLO: Inaudible acoustic beacons for micro-localization

We present HABLO, an acoustic beacon system for low-range (<; 0.5 m) indoor localization, which remains a difficult task for existing indoor localization technologies. The beacons utilize an audio band which is inaudible to humans but can be received by the microphones on consumer devices such as laptops, tablets and smartphones. HABLO is designed to be low-cost, easy to integrate with existing infrastructure using USB connectors and to be usable with unmodified end-user devices. We present a technical description of the software and hardware implementation of our prototype and show the results of an initial feasibility study of our system for a localization application within an office environment.