Telecommunications

LED lightbulbs create wireless networks wherever they are installed

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Engineers have devised a method of allowing almost any device fitted with standard LEDs to communicate with other equipment with similar lights
Engineering professor Maite Brandt-Pearce
Dan Addison/U.Va
Engineers have devised a method of allowing almost any device fitted with standard LEDs to communicate with other equipment with similar lights

Various researchers have created ways to transmit wireless information from LED light fittings, to act as a form of enhancement to Wi-Fi based networks known as "Li-Fi." But now engineers at the University of Virginia (U.Va) have come up with a new twist on this theme – they claim to have created an algorithm that makes almost any device fitted with standard visible-light LEDs able to communicate with other equipment with similar LEDs. So, for example, the LED headlights in your car could communicate to the car in front of you through its LED taillights, or the LED display in your clock radio could tell the coffee maker to turn on via its indicator light.

Prof. Maite Brandt-Pearce and Mohammad Noshad, the latter formerly of U.Va but now a postdoctoral fellow at Harvard University, came up with a way for light from LED fixtures to transmit signals to wireless devices. Streaming data at around 300 Mbps from each light, any and all LED lights in the vicinity could be used as wireless access points without the limiting bandwidth problems of radio frequency (RF) wireless networks.

"We developed a modulation algorithm that increases the throughput of data in [visible light communications]," says Brandt-Pearce. "We can transmit more data without using any additional energy. As more light fixtures get replaced with LED lights, you can have different access points to the same network."

Unlike conventional RF Wi-Fi, the system could also be used in places where radio waves create problems or are not permitted, such as around medical equipment in hospitals, inelectromagnetically-sensitive manufacturing environments, and in passenger aircraft cabins.

"The idea in this technology is to transmit the data using the lighting systems that are already used for the illumination of indoor environments. [Visible light communications] offer a compact, dual-use, energy-saving solution and can provide a high-speed secure network connection for a large number of users," says Noshad.

"You can use it any place that has lighting," adds Professor Brandt-Pearce. "In a stadium, in a parking lot, or from vehicle to vehicle if using LED headlights and taillights." This is the point of difference of the U.Va system.

Sure, it doesn't boast the claimed speeds of a system like the SiSoft Li-Fi (though it is three times faster than a similar "Wi-Fo" set up from Oregon State), but the possibility of transmitting data from anything that has LEDs to anything with LEDs turns things on their head. The Internet of Things (IoT), for example, could be enabled much more easily and cheaply than ever thought of before.

"[Visible light communications] has the potential to significantly increase the speed of internet connection in multiuser indoor environments due to the broad bandwidth of the visible light," says Noshad. "It will offer a huge energy saving for the nation since energy is already used for lighting, and thus does not need to be expended for communications."

The researchers have already been granted several patents in relation to their work and are now working on a Li-Fi enabled desk lamp to show to investors, along with investigating ways to increase the number of concurrent users on their devices.

Source: University of Virginia

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10 comments
KyleKlein
It's great to know the amazing path LED lights are taking!
Τριαντάφυλλος Καραγιάννης
ok, we got that the transmitting part will be the LED. Do they plan to make this a transmit-only solution? Or does it mean that the LEDs are able to receive data as well, somehow? (which would simply amaze me, to say the least)
Douglas Bennett Rogers
Doesn't say how LED acts as photo detector (or how signal is detected). Also, some kind of modulator is needed in lamp.
witipete
"ok, we got that the transmitting part will be the LED. Do they plan to make this a transmit-only solution? Or does it mean that the LEDs are able to receive data as well, somehow? (which would simply amaze me, to say the least)"

It is possible to use an LED as a photoreceptor.
John Banister
Here's an article about a li-fi receiver that might pick up these sorts of transmissions: http://electronicdesign.com/power/li-fi-receiver-optimization-program-comes-light Interestingly, even as the transmitters discussed here talk about using no more energy that the lighting does without transmitting data, so also, the receivers are described as using the energy received both for data reception and also charging. I immediately think of this tech in combination with UV LEDs for allowing members of a swarm of small drones to communicate with one another.
Fred Borman
Wow, this will make things easier for Skynet.
phantastron
I think that this could be extremely dangerous without shielding.
Consider that light consists of packets and that those packets travel extraordinary distances than the next step would be to design a very low-noise receiver that could pickup these transmission from across the road or from space.
sagebrush6
Hello Hal ---------
BernhardHnida
we doing a lot of automation and wifi audio nowadays developing multi room audio, video and all such stuff. Fast data everywhere is a standard dream we have ! we developed since years home-automation systems at www.sclan.de and wonder all time how nice and good this light data transport could be and discussing it also in team.
in sight ore not is not a problem I feel think about how hard it is to get the out of sight from light in a lit up room ? so this is no real problem i suppose as light is every were in the room. at least in my room if the light is on. but i would prefer a not visible light transmission instead a visible light. Data and light simply dose not belong together and makes no sense to combine ! And this we had already with Infrared (IRDA Transmitters low transport rates to low emitting power) better would be of course much faster brighter invisible Ultra Violet Light Transmitters as they much higher frequency range hence more data possible then IR and visible light. Of course the speed is not the big issue at least not for the private home. Having 1GB in each room not being restricted by the usage ore downloads in another rooms would be already so brilliant sounding like a 20 Minute trip to Mars ;-)…. except for mars it is not possible but for ultraviolet data Transport 1-10G its simple and easy to make … sounds like a really new breaking idea?? as it solves real problems compared to visible light transport
UV Light Transmission is real future technology.
who really wants to kill data transport just because visible light is dimmed ore off ? i love to surf in dark were no visible light is available! i see no sense making data transport in visible lights.
UV light is the solution !!!!!
If there is someone wanting to support develop a better more use and powerful system with UV light faster to market and better on performance pls contact me. ;-) via www.sclan.de ore bhnida@medianet-home.de ;-)
best regards Bernhard
FoxTiako
So cool. I think one day trees will be able to trasmit Wifi signals