CEA-Leti has demonstrated its new prototype for wireless high data rate Li-Fi (light fidelity) transmission at Light + Building 2014 in Frankfurt, Germany.
The technology employs the high-frequency modulation capabilities of light-emitting diode (LED) engines used in commercial lighting. It achieves throughputs of up to 10Mb/s at a range of three meters, suitable for HD video streaming or Internet browsing, using light power of less than 1,000 lumens and with direct or even indirect lighting.
With this first proof of concept and its expertise in RF communications, Leti forecasts data transmission rates in excess of 100Mb/s with traditional lighting based on LED lamps using this technology approach and without altering the high-performance lighting characteristics.
Visible light communications (VLC), or Li-Fi, have gained significant momentum in recent years, primarily because of expectations that LEDs will become predominant in the lighting market. Indeed, as part of its Ecodesign process, the European Union established a schedule for LED lighting penetration (regulation No. 1194/2012). Halogen lamps will be phased out and replaced by LED lighting by Sept. 1, 2016, in 30 European countries.
Moreover, because LEDs can be modulated at very high frequencies and their oscillations are invisible to humans, they permit information transmission at very high data rates.
Other technical and market factors also are increasing interest in data transmission through lighting. These include crowding of the conventional radiofrequency (RF) spectrum, the mobile data-traffic explosion in cellular networks, and the need for wireless data transmission without electromagnetic field (EMF) interference.
The demonstration is part of a Leti project begun in 2013 to achieve a high data rate Li-Fi prototype by applying Leti’s expertise in digital communications, hardware prototyping and solid-state lighting.
The optical system consists of an A19 lamp based on LEDs at the transmitter and an avalanche photodiode at the receiver. The digital communication component is implemented on a proprietary and reconfigurable platform that carries out a flexible multi-carrier modulation.
Leti, which is demonstrating the Li-Fi capability to show a promising alternative to conventional RF wireless communications, is also focusing on component optimization to offer a bidirectional link.