Scientists have managed to turn plain LED light bulbs into functioning wireless internet networks, armed with only a few extra components.
Thanks to what they call visible light communication (VLC), researchers at Fraunhofer Institute for Telecommunications in Berlin have constructed 800 mbps WLAN networks that are able to send HD quality films to phones or laptops.
The optical networks are used as the information transfer method, using LEDs in the ceiling that light up ten square metres.
The receiver can be placed anywhere within this range to pick up the signal without any loss in quality.
“This means that we transferred four videos in HD quality to four different laptops at the same time,“ said Dr. Anagnostis Paraskevopoulos, one of the researchers.
“The fundamentals of visible light communication (VLC) were developed together with the industry partners Siemens and France Telecom Orange Labs. For VLC the sources of light – in this case, white-light LEDs – provide lighting for the room at the same time they transfer information.”
“With the aid of a special component, the modulator, we turn the LEDs off and on in very rapid succession and transfer the information as ones and zeros.”
The modulation of the light is imperceptible to the eye, so there’s no danger of turning your sitting room into an acid warehouse rave.
A simple photo diode then sits on a laptop or phone as a reciever. This means that there are actually very few additional parts involved in setting up such a wireless system.
Of course the major downside here is that the signal strength is going to be totally reliant on the light being uninterrupted – so anyone walking around in the background will mean trouble. However, the scientists are not trying to persuade anyone that this will take over standard wireless networks.
There are many other applications though. For example the technology could be beneficial in places where radio transmissions might not be allowed, such as hospitals. Or the tech might make it possible to control wireless surgical robots or transmit x-ray images.
Another example is on an airplane, films could be streamed from the overhead lights, saving on cabling required otherwise.