Researchers at University of Virginia use LEDs to create wireless networks

University of Virginia (UVA) researchers have come up with a new way of using light as a form of enhancement to Wi-Fi-based networks, creating a method of using light waves from light-emitting diode fixtures to carry signals to wireless devices at 300 megabits per second from each light.

Maite Brand-Pearce, a professor in the Charles L. Brown Department of Electrical and Computer Engineering, and Mohammad Noshad, now a postdoctoral fellow in the Electrical Engineering Department at Harvard University, have filed a patent, along with the university, on their idea. Noshad also created a company called VLNComm, for Visible Light Network Communications, a firm that is developing a desk lamp prototype to provide an Internet connection through light.

"We developed a modulation algorithm that increases the throughput of data in [visible light communications]," Brandt-Pearce told UVA Today. "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 also could be used in places where radio waves create problems or are not permitted, such as around medical equipment in hospitals, in electromagnetically-sensitive manufacturing environments, and in passenger aircraft cabins, according to Gizmag.

"This is not a replacement for Wi-Fi; it's an augmentation," Brandt-Pearce told UVA Today. "Researchers have called it 'Li-Fi.' 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."

The researchers say part of the value lies in its versatility. It can be used any place that has lighting, which could be a stadium, parking lot or even vehicle-to-vehicle if using LED headlights and taillights.

Noshad told UVA Today that some experts have forecast the LED communications market at $6 billion by 2020, and he noted that people working in Asia and Europe are working on it as well.

Li-Fi supporters contend that using the vast amounts of readily available free and unlicensed visible light could solve issues of limited and congested RF spectrum and deliver much faster wireless speeds. In a Li-Fi-like system, researchers at Oxford University back in February revealed how they used light to deliver data to a computer at more than 100 gigabits per second, with the potential for data rates of 3 terabits per second and up. That indoor optical wireless technology also isn't likely to replace Wi-Fi, but it could wind up being part of how people link devices to the Internet.

For more:
- see this UVA Today article
- see this Gizmag article

Related articles:
Oxford researchers use Li-Fi-like system to deliver 100 Gbps
Germany's Fraunhofer Institute prepares to show off Li-Fi hotspot at Electronica
Li-Fi successfully tested in China