LLAP:Device-Free Gesture Tracking Using Acoustic Signals

LLAP(Low-Latency Acoustic Phase) is a device-free gesture tracking scheme based on ultrasound signals, that can be deployed on existing mobile devices as a software (such as an APP) without any hardware modification.

This is an IOS implementation of the LLAP paper in Mobicom 2016.

LLAP enables you to track the distance of the movement by only use the microphones and speaker.LLAP emits 17500~20300 Hz ultrasound signals, measures the phase changes of the sound signals caused by hand/finger movements and then converts the phase changes into the distance of the movement. LLAP achieves a tracking accuracy of 3.5 mm and a latency of 15 ms on COTS mobile phones with limited computing power.

For more details, please check our paper and our video in Mobicom 2016.

Our work is reported by MIT TECH REVIEW: "This App Lets You Control Your Phone Using Sonar".

llapfly