As LEDs become the dominant lighting technology worldwide, researchers are exploring how they could double as a foundation for radio-free data communication.
By 2035, white LEDs are expected to provide approximately 95% of indoor lighting around the world, but because they can be rapidly controlled, they could be integrated into a wireless data transmission system that offers a number of benefits over wifi.
A team from the University of Oulu in Finland is now investigating how light-based data transfer could one day become one of the dominant forms of wireless data transmission.
The transmitter could be a standard LED lamp – for example, a desk lamp that also functions as a wifi router, sending information to a receiving device in a manner akin to hyperspeed Morse code.
Light offers advantages that radio-based communication cannot match – it’s fast and secure, and doesn’t interfere with equipment that relies on radio signals. Another advantage is energy efficiency, because the energy consumed for lighting can double up as an information transmission medium.
“Developing light-based communication is rooted in sustainability. We’re studying how existing infrastructure, like lighting, can be used in new ways,” said professor Marcos Katz, a 6G research expert.
“The LED lamp is modulated to flicker, and the receiver interprets the flicker. When the light is on, the receiver reads a one; when it’s off, a zero.”
The flicker would be much faster than the human eye is able to perceive, so it would not have a noticeable impact on room lighting. Data transmission can also occur in the reverse direction through invisible light, for instance infrared, enabling everyday tasks such as sending an email.
“It would be distracting if visible white light were emitted from a phone or computer. Infrared light allows data to be sent discreetly,” Katz explained.
The team is developing light-based communication for environments where radio signals might interfere with sensitive equipment, such as hospitals, factories and aircraft. Hospitals restrict phone use in some areas, as radio signals can disturb medical equipment. For the same reason, phones must be set to flight mode on aircraft.
“With light, there’s no such problem. Our goal is that in the future devices could switch flexibly between light and radio, depending on the environment,” he added.
Security is another major advantage as light-based data streams can only be received by someone physically present in the same space as the source.
The researchers believe that light won’t replace radio technology but complement it, as it also has limitations, especially in more rural areas and efficient communication requires a clear line of sight between the transmitter and receiver.
“If a finger happens to block the smartphone’s light sensor,” Katz said, “the connection weakens or cuts out entirely, prompting the device to fall back on radio waves.”
E&T
