NeTS: Small: Networking and Sensing Using Visible Light Communications

Dartmouth College, Hanover NH

Investigators

Abstract

Mobile computing is accelerating beyond the smartphone era. Today, people wear smart glasses, smart watches, and fitness devices and carry smartphones, tablets and laptops. In a decade, the very same people are likely to wear or carry tens of wireless devices and interact with the Internet and computing infrastructure in markedly different ways. Two fundamental challenges emerge in a post-smartphone era: dealing with the impending spectrum crunch before it becomes a full-fledged crisis, and, advancing human-computer interaction (HCI) before people buckle under the demands of dealing with an ever increasing number of personal devices. This project seeks to address these two challenges by proposing a first of its kind integrated networking and sensing environment based on visible light communication (VLC). The proposed research advances VLC research in two new directions: VLC networking and VLC sensing. The project designs integrated VLC networking and sensing for smart spaces (iVLC) and a set of robust VLC networking and sensing algorithms. The VLC networking algorithms address the following challenges: 1) frequent connection disruptions caused by user mobility and the limited coverage of individual VLC links, 2) link interference from diffusive lights, and 3) determining the optimal placement and density of LED lights. Addressing these challenges requires efficient handoff schemes between adjacent LEDs, interference handling schemes for VLC networks, and optimization algorithms to determine the LED light deployment in smart spaces. The VLC sensing requires accurate inference of user gestures using shadows rendered on the floor. The combination of light from multiple light sources on the ceiling obfuscates and distorts these shadows. To tackle this challenge, the iVLC system separates shadow components by embedding identifiers into light signals from LEDs allowing light sensors on the floor to measure the light illuminance of individual light sources. Finally, a novel proof-of-concept iVLC testbed will be designed, built, and deployed, which comprises LEDs and light sensors. Results from the Bits in the Light Project will help accelerate the deployment of VLC as a new mobile networking and sensing technology.