The joint test by British Telecom (BT) and French networking equipment company Alcatel-Lucent achieved the high speeds of 1.4 terabits per second on the existing fibre network in London.
The breakthrough is being seen as highly important for Internet service providers (ISPs), as it means a greater amount of information can be sent through existing broadband infrastructure, reducing the need for costly upgrades.
There are faster methods of transmitting data - such as the use of complex laser technology - but this is the first test to achieve such high speeds in "real world" conditions, outside testing labs, 'BBC News' reported.
The test was conducted in October and November last year, on a line from BT Tower in central London and the company's research campus near Ipswich.
Kevin Drury, optical marketing leader at Alcatel-Lucent, likened the development to reducing space between lanes on a busy motorway, enabling more lanes of traffic to flow through the same area.
He said flexibility meant some could be adapted to specific needs - like opening an extra lane during the morning rush hour.
In Internet terms, this would mean, for example, streaming video would get a large, wide lane, while accessing standard web pages would need only a small part of the fibre's capacity.Catch the latest from the Consumer Electronics Show on Gadgets 360, at our CES 2026 hub.