PureLiFi announced Monday it has raised an additional £1.5 million ($2.3 million dollars) from investors to develop its wireless communication system that uses visible light, instead of radio signals, to send data.
Visible light communication (VLC), which the company has dubbed “LiFi”, takes advantage of the digital nature of LED lightbulbs. LEDs can vary the intensity of their output incredibly quickly, so that what appears to be steady illumination may in fact carry a hidden signal — dim-bright-dim-dim-bright — that human eyes can’t detect.
A LiFi access point is created by attaching an ethernet-connected controller to an LED light fixture, allowing it to convert data from the Internet into those subtle light fluctuations. Computers and other devices receive the signal through a light-sensitive dongle, and send back their own data using an infrared emitter. PureLiFi’s products claim up to 10Mbps transmission rates in both directions.
The technology is similar to WiFi in many ways, but differences arise from the fact that visible light doesn’t penetrate walls and other objects. That’s bad for range, since each room will need its own access point (or even multiple access points) to ensure coverage. But it’s good for security, because it becomes harder for an outside snoop to pick up on the signals. It also adds to the total “data density” of the system — whereas a couple of WiFi access points can blanket a building but each carry their own transmission limits and potential for interference, dozens of LiFi nodes can be packed into the same space to allow more people to send more data more quickly. PureLiFi describes its tech as “complimentary” to radio signals, which retain advantages in outdoor settings or where longer range is needed.
Lighting infrastructure is ubiquitous and many Internet of Things technologies are taking advantage of that fact to piggyback other functions, like audio speakers, into LED lights. With the IoT’s similar demand for a ubiquitous communications infrastructure, LiFi could allow many devices that already include a light source to talk not only to the Internet, but also directly to one another. One example is cars with head- and tail-lights that can pass information to vehicles ahead and behind.
PureLiFi began shipping its Li-Flame product at the end of last year, and plans to us the angel funding to expand its efforts to capture this merging market. The company also expects to close a proper VC funding round in late 2015.