Leveraging Physical Locality to Integrate Smart Appliances in Non-Residential Buildings with Ultrasound and Bluetooth Low Energy

Smart appliances and sensors have become widely available. We are deploying them in our homes to manage the level of comfort, energy consumption or security. While such smart appliances are becoming an integral part of modern home automation systems, their integration into non-residential buildings is problematic. Indeed, smart appliance vendors rely on the assumption that the Local Area Network (LAN) guarantees locality and a single unit of use/administration. This assumption is not met in non-residential buildings, where the LAN infrastructure might cover one or several buildings, and where several organizations or functional units are co-located. Worse, directly coupling smart appliances to the Internet opens up a range of security issues as device owners have very little control over the way their smart appliances interact with external services. In order to address these problems, we propose a solution that couples the use and management of smart appliances with physical locality. Put differently, we propose that smart appliances can be accessed via smartphones, but only from the room they are located in. Our solution combines opportunistic connectivity through local Bluetooth Low Energy (BLE) with an ultrasound-based method for room level isolation. We describe and evaluate a prototype system, deployed in 25 offices and 2 common spaces of an office building. This work opens up intriguing avenues for new research focused on the representation and utilization of physical locality for decentralized building management.