We use the term "Wi-Fi" to mean wireless Internet connectivity the same way we say "Google" to mean Internet search, despite the fact that Wi-Fi doesn't work particularly well a lot of the time.
Now, researchers have found a faster way to wirelessly connect to the Web using LED lightbulbs.
Standard Wi-Fi uses radio waves to connect from an Internet router to a wireless router in your computer or mobile device. Researchers at the University of Virginia have found a way to transmit wireless data in light waves from LED lights, which is much faster and more reliable than radio wave Wi-Fi.
The light waves can carry data at speeds 300 megabits per second from LED fixtures to wireless devices. The system was developed by University of Virginia engineering professor Maite Brandt-Pearce and her former student Mohammad Noshad, who is now a postdoctoral fellow at Harvard.
"Researchers have called it 'Li-Fi,'" Brandt-Pearce told Phys.org. "Our modulation can be used in any optical device so this has the potential for widespread use and much better access than present Wi-Fi based on radio waves."
Using the "Li-Fi," the data can be transmitted faster with light waves using no more energy than is already required to run the lights. Obviously, it will only work with devices that have some sort of optical receiver, but it could vastly improve connectivity speeds with the possibility to use every light in the home, office or coffee shop as an Internet transmitter. LED headlights in a car could even be used to connect to your vehicle.
Brandt-Pearce, Noshad and the University of Virginia have filed a patent for the technology. Noshad's company, VLNComm (Visible Light Network Communications), for which his former professor consults, is developing a prototype desk lamp that provides Internet connectivity.
"We can make different products, such as a large LED panel for shopping centers, airports and conference rooms," said Noshad. "And we can build LED bulbs for use in the home."
Brandt-Pearce also said that there could be security advantages to using light wave-powered networks over radio wave Wi-Fi.
"It can't be detected outside the room because the light waves stop when they hit something opaque, such as a wall," she said. "That can keep communications secure from room to room."
Of course, this could also be seen as a drawback. Using light waves would mean that you would need a clear line of sight from the LED to the wireless device at all times.
Noshad says the system has potential to significantly increase the speed of Internet connection in multi-user indoor environments due to the broad bandwidth of the visible light. Devices with LED circuits in them can also communicate with each other creating a network of devices.
"Anything with an LED can talk to anything else with an LED. You don't need a separate transmitter because you are not using radio waves."
For example, vehicles in a car park could transmit to each other, or multiple devices in a home could transmit to one another.
The problem is that the system would require far more infrastructure than radio Wi-Fi. Right now, you can plug in a Wi-Fi router in your living and you have connectivity of some sort throughout the house. The LEDs may be able to submit data very quickly to devices, but the lights themselves need to be connected to the Internet first. There's also the problem that most current devices wouldn't have any optical receiver with which to connect.
Still, there are certain areas where this technology could be used, particularly in environments where radio waves can interfere with existing technology like hospitals and airplane cabins.
