Three UK has switched on carrier aggregation on almost 3,000 sites across the country, potentially increasing speeds by as much as a third.
Sites across the cities of London, Birmingham, Cardiff, Edinburgh and Glasgow can now take advantage of the technology.
Three UK estimates around half of the devices on its network supports carrier aggregation. The operator said these customers will receive the biggest improvement in network quality although it noted its entire base will benefit from the freeing up of capacity.
It has been estimated that Britons could consume 18GB of data per month by 2021. Three's customers consume 3.5 times more data than that of the average UK consumer.
Dave Dyson, Chief Executive at Three UK, said: “Three customers are the highest consumers of data, with this trend expected to continue for several years.
"As we ready our network for 5G, we’re moving quickly to put the right technology in place to deliver the most reliable mobile experience for our customers.
"This latest innovation plays a critical role in ensuring our customers will be able to make the most of their mobile devices, both now and in the future.”
In total, 2,700 sites will be upgraded to use carrier aggregation
It follows the operator signing an agreement with O2 and SSE Enterprise Telecoms in September that will allow it to access a fibre network in London.
Three said the move would pave the way for it to improve its LTE network and build the foundations for 5G.