• Mobile operators are set to use millimetre wave (mmWave) spectrum to deliver services such as 5G fixed wireless access (FWA)
• But mmWave signals struggle to penetrate windows and walls
• A Scottish company developing Li-Fi technology believes it has found a new way to ‘get outside signals in’

BARCELONA – MWC24 – Li-Fi, the optical version of Wi-Fi that uses light instead of radio to transmit data, has been around for the past decade or so, and now its most prominent  pioneer, Scottish company pureLiFi, has shown off a game-changing Li-Fi product here in Barcelona.

When the Li-Fi concept was unveiled about 10 years ago, some observers thought it was destined for success, especially given the problems associated with Wi-Fi at the time.  But the Gartner curve soon set in and Li-Fi remained waiting in the wings, a position not helped by Wi-Fi’s remarkable progress over the past decade as it was assigned more public spectrum and the technology improved as new standards were released.  

Despite this, there may still be a healthy niche for a complementary, optical version of the technology, especially when it comes to serving radio sensitive applications.

This week, pureLiFi announced the LINXC Bridge, a self-installable double limpet that attaches itself to both sides of a window (see picture, above). 

“The idea is to help the signal get through glass,” explained pureLiFi CEO, Alistair Banham. The device transmits an optical version of the incoming radio signal through the glass window so the data can then be distributed to a router or other device once inside the room.

According to Banham, “getting outside signals in” has become ever more difficult as radio technologies have climbed the frequency range and adopted complex encodings, such as orthogonal frequency division multiplexing (OFDM), while the materials used to construct buildings have become less  permeable to radio signals. This is a looming problem, he says, because telcos will increasingly rely on millimetre wave (mmWave) fixed 5G radio links to extend broadband services, especially to those hard-to-reach homes and businesses in remote locations, and mmWave doesn’t like walls or windows.

The pureLiFi LINXC Bridge, developed in partnership with Canadian company Solace Power, is designed to overcome some of those problems. “A top priority is the avoidance of truck roll, so a key attraction for our telco customers is the system’s ease of installation – there’s no requirement to for an outside antenna or hole-boring through the side of the customer’s building, as the LINXC is designed to be self-installed, which eliminates installation costs and shortens the time to market for telco-delivered wireless broadband,” said Banham.

But the real Li-Fi breakthrough came about halfway through 2023 when the IEEE (Institute of Electrical and Electronics Engineers) took the wraps off 802.11bb, the optical variant of the Wi-Fi standard and, as a result, Li-Fi and Wi-Fi should be able to interwork within a customer’s premises. 

“Last year,” Banham explained, “we developed the light antenna so a Wi-Fi network can see it as just another antenna, so now we have full interoperability and that means we can demonstrate a complete ecosystem so that customers can see, touch, feel and understand its benefits.”

Perhaps the biggest benefit, and most attractive niche for Li-Fi, is within so-called radio sensitive environments which, thanks to the interoperability with Wi-Fi,  will enable it to selectively reach and connect things like critical medical equipment, for instance (a large and growing application area).

The new mmWave bridge product isn’t pureLiFi’s only offering –  there’s SkyLite, a “whole-room Li-Fi access point” and the Cube, described as a simple, secure working from home, gaming, streaming and on-the-move connectivity device.  

Banham says the ambition doesn’t stop there, as the company has plans to have Li-Fi “augment and extend other wireless and wireless technologies, ushering in a new era of bandwidth, speed and reliable communications."

- Ian Scales, Managing Editor, TelecomTV