O2 has used beams of light to transmit data through light bulbs in a trial of LiFi, a technology that could prove a rival to Wi-Fi.
LiFi was spun out of a University of Edinburgh project in 2012 and uses LED lights to transmit data, which appears to humans as conventional white light.
The UK operator installed the LiFi-XC system at the "Explore Room" of its headquarters just outside of London.
Data was transmitted from an LED light bulb and back by adjusting the bulb's brightness. O2 said a network of bulbs could create a web of wireless data.
It added that the technology could become a rival to Wi-Fi, arguing its light-based transmission could be safer, more reliable and more secure. It also said its deployment has the potential to reduce infrastructure complexity and energy consumption.
Despite its criticisms of Wi-Fi, O2 runs a network of 15,000 hotspots across the United Kingdom.
Derek McManus, O2’s Chief Operations Officer, said: “At O2 we're committed to building the best network possible for our customers, and a huge part of that is making sure we're ahead of the pack in testing the latest technology.
“Our LiFi trial shows how you can deliver high-speed connectivity to customers in new ways and is another example of how we're future-proofing our network as we pave the way for 5G in the UK.”
Alistair Banham, CEO of pureLiFi, said: “With the proliferation of Internet-of-Things devices and continued growth in mobile users, the demand for spectrum is under increasing pressure.
"LiFi is capable of unlocking unprecedented and much-needed data and bandwidth, and we are delighted that O2 has chosen to partner with pureLiFi to explore this tremendous potential
"O2 is at the forefront of championing technologies to provide real solutions for 5G and beyond, and we look forward to working with them towards our common goal.”