Researchers at Disney Research and ETH Zurich have demonstrated that consumer-grade light-emitting diode (LED) bulbs can, with some modifications, do double duty — both illuminating a room and providing a communications link for devices in that room.
This visible light communication (VLC) system would be suitable for connecting the many devices, such as appliances, wearable devices, sensors, toys and utilities, that could comprise the Internet of Things, or IoT, said Stefan Schmid, a Ph.D. student at Disney Research and ETH Zurich.
LEDs can both produce light and serve as light sensors. By having individual LEDs alternate between sending modulated light signals and serving as receivers of signals, it is possible to create a network of bulbs that can send messages to each other and connect to devices, while having no discernible effect on room lighting.
Schmid and his colleagues designed and implemented such a VLC system, demonstrating that it is a viable way to interconnect devices within a room. They will share details of the system, called EnLighting, on June 26, 2016 at the IEEE International Conference on Sensing, Communication and Networking (SECON) 2016 in London.
“Interconnecting appliances, sensors and a wide variety of devices into the Internet of Things has many potential benefits, but using radio links to do so threatens to make the radio spectrum an even scarcer resource,” said Markus Gross, vice president at Disney Research. “Visible light communication networks conserve the radio spectrum, while also making it difficult to eavesdrop for anyone out of line of sight of the network.”
LEDs are an attractive option for interconnecting devices because they are low-cost, non-intrusive and ubiquitous. No special wiring is needed and the bulbs can be positioned anywhere.