Riverside Researcher Working to Build Wi-Fi System with LED Lights

Tuesday, July 9th, 2013

Product will be of particular benefit to hospitals and ‘smart traffic’ solutions

(Includes excerpts from the article written by Mark Muckenfuss and published by the Press-Enterprise)

Gang Chen, an associate adjunct professor, at right, and students Qian Gao, Feng Bo, Zening Li, Dongfang Zheng and Linchao Liao,left to right, are shown with their LED-guided "car" at their UCR lab. The team is installing a pilot project at Loma Linda University Medical Center to transmit wifi signals with light. Photo by Kurt Miller, PE Staff Photographer.

Albert Wang, a professor of electrical engineering at UC Riverside, is developing LED lights that transmit wireless signals and mapping information. He envisions a time when traffic lights will talk to cars and your computer will connect to the Web through a light.

Wang and his colleagues are getting ready to install a pilot project at Loma Linda University that would allow the medical computers to work off of the LEDs lighting a training clinic. The lights are produced by Gallium LED Lighting Systems, a Yucaipa-based company.

The effort is part of a larger project called Ubiquitous Communication by Light, or UC-Light, a cooperative effort involving 12 researchers at five UC campuses — including Berkeley, Davis, Merced and Santa Barbara — and the Lawrence Berkeley National Laboratory. Wang is the lead researcher on the project.

Information is transmitted by making the lights flash on and off. The modulation takes place so rapidly that the human eye can’t detect it.

Wang said the visible light spectrum offers a capacity that is as much as 100 times greater than radio frequencies, the current method for transmitting wifi signals. Limited bandwidth is a challenge with radio signals. As more and more information is being funneled through wireless systems, those systems are reaching capacity.

“Every hospital has asset problems,” he said. “This is what we’re trying to demonstrate at Loma Linda.”

Larry Feenstra, director of clinical engineering for Loma Linda University, said the medical center sometimes struggles with too much wireless traffic.

“The hospital environment is fairly saturated,” Feenstra said. “Wifi is used not only for the portable computer systems within the hospital, but also for communication with some of the medical equipment (including patient monitors). What we run into is poor connectivity and competition for that bandwidth. “

Private devices such as cellphones and tablets also cloud the picture.

“We have dropouts with those systems that are sometime difficult to explain,” he said.

Although research in using light to transmit digital information has been going on for more than a decade, this will be a unique project, said Jeff Baxter, Gallium’s head of business and technology development.

“The LED industry is well aware of this (technology), as is the communications industry,” Baxter said. “In our experience, we are the only ones trying to take it to the next step. A lot of institutions have developed this type of technology, but we’re the only ones we know of who are actively trying to commercialize it.”

Researchers are also working with utilizing LED signals to locate something or someone, as well as developing a network of the lights and a light detector that is mounted on a small robotic car to tell the car where to go. In the latter scenario, a prescribed path can be fed into the car’s computer; it uses the LED lights as references for navigating that path. In one simulation, the robotic car traced a precise square around the main floor of the lab at UCR.

Wang isn’t planning on putting any self-driving cars on the road anytime soon, but with the number of LED lights that are already out in the environment, he sees potential for lots of shared information.

“I’m more interested in the smart traffic,” he said. “Imagine I have a car and the headlights and taillights are already LED.”

If two vehicles with those lights got too close to one another and were communicating via their LEDs, they could automatically be told to slow down. The cars could also communicate with traffic signals, he said, most of which are now LEDs. If you pull up at a signal, the light could automatically give you location information and, perhaps, some commercial data as well.

To read the full article as published on PE.com, click here.

For more information on the LED research project, UC Light, click here.