VibroComm: Using Commodity Gyroscopes for Vibroacoustic Data Reception
With the rise of the Internet of Things (IoT), pairing and transmission schemes that gracefully scale to dense ecosystems of “smart” devices are going to be more important than ever. Unfortunately, wireless schemes (e.g., Bluetooth, NFC, and ultrasound) are ill-suited for this task, as their long range makes interactions less explicit. Mere proximity to a device should not be interpreted as an interaction request. For this reason, most systems often rely on physical buttons to trigger time-limited open connection windows (inherently unsafe), or temporary PINs to make sure others nearby do not connect (needlessly cumbersome).
Our transmission approach takes advantage of the unique characteristics of gyroscopic sensors to show that these ubiquitous sensors can be co-opted as vibroacoustic data receivers. This allows a smartphone (or, in principle, any IMU-equipped device) to be pressed to a surface and receive data encoded as structured vibrations induced by a low-cost transducer (e.g., piezo, and voice coil), which can be embedded in an object. Unlike wireless transmission approaches, which cannot distinguish between devices that are near vs. touching, our approach requires direct physical contact (i.e., acoustic coupling). This unique property makes our approach targeted and explicit in nature, requiring intent to interact. Our approach also requires physical presence, offering a useful security dimension that wireless methods cannot. This gives our technique a substantially different feel than e.g., opening a camera app on a phone and aiming it towards an object or marker. Additionally, it excels in situations with many dense targets, and also apps wanting higher guarantees of physical presence (e.g., not capturing a QR code through a window or over someone’s shoulder).
Our best performing transmission scheme achieved 2028 bits/sec when applying error correction for the 95th percentile of bit error rate. This performance is an order of magnitude faster than prior IMU-based approaches. Our technique is also robust to ambient noise and vibrations – in addition to collecting study data on a static table, we also captured data in two extreme vibration conditions: an airplane in flight and when the receiving smartphone is playing music. We show that VibroComm can be used to improve security, but also rapidly transmit small payloads, like a device ID or URL (e.g., for convenient paring). Overall, VibroComm has a unique set of properties that make it a valuable addition to the toolbox of data transmission techniques researchers and practitioners can draw upon in the creation of future interactive systems.
Xiao, R., Mayer, S. and Harrison, C. 2020. VibroComm: Using Commodity Gyroscopes for Vibroacoustic Data Reception. In Proceedings of the 22nd International Conference on Human-Computer Interaction with Mobile Devices and Services (October 5 - 8, 2020). MobileHCI ’20. ACM, New York, NY.