Wireless13.07.2015

Using LED lights to move data at 300Mbps

By Staff Writer

University of Virginia engineering professor Maite Brandt-Pearce and Harvard professor Mohammad Noshad have devised a way of using light waves from LEDs to carry signals to wireless devices at 300 megabits per second.

“We developed a modulation algorithm that increases the throughput of data in visible light communications,” said 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.”

Their breakthrough means that data can be transmitted faster with light waves using no more energy than is already required to run the lights.

Noshad and Brandt-Pearce have filed a patent for their idea and Noshad has created a company – VLNComm (Visible Light Network Communications) – to which Brandt-Pearce is a consultant.

The firm is developing a prototype for potential investors – a desk lamp that provides an Internet connection through light.

“We can make different products, such as a large LED panel for shopping centres, airports, and conference rooms. And we can build LED bulbs for use in the home,” said Noshad.

He said computers would require the addition of software to connect to the LED transmitters.

“This is not a replacement for Wi-Fi – it’s an augmentation,” said Brandt-Pearce. “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.”

“You can use it any place that has lighting.”

Like current wireless communications, encryption is necessary to keep data secure, but Brandt-Pearce noted that a secure network could be created in a room with no windows.

“It can’t be detected outside the room because the light waves stop when they hit something opaque, such as a wall.”

And two networks in different rooms would not interfere with each other the way they do with present Wi-Fi networks.

She said devices with LED circuits can also communicate with each other. “Your alarm clock can communicate with your coffee maker that it is time to start making the coffee.”

Because the system does not use radio waves, it can be used in places where radio waves could create problems, such as in hospitals, in manufacturing facilities, and in aeroplane cabins.