Vodafone is introducing advanced LTE, or 4.5G, for customers in London, Birmingham and Manchester thanks to spectrum acquired in an Ofcom auction last year.
The company is boasting that customers will get greatly increased speeds, especially indoors, where 70 per cent of customers use their mobile device most.
Vodafone refers to the technology variously as Carrier Aggregation, LTE Advanced and 4.5G.
Fergal Kelly, Vodafone UK technology director, said: "This clever technology is the next big step to deliver faster speeds per user and to increase the capacity so more customers can enjoy a great 4G experience when and where they want it."
The rollout will commence in the three cities mentioned, and in other unnamed locations, by the end of 2015.
Carrier aggregation uses a mix of the low frequency 800MHz spectrum and the 2.6Ghz spectrum.
Vodafone said that the former travels further and makes its way through walls with ease, and that the latter is good for smaller, high-density locations. The mobile operator claims that Carrier Aggregation delivers theoretical peak speeds of up to three times faster than existing 4G speeds based on the 800MHz band.
Rival EE launched a similar carrier aggregation service in east London last year, claiming that the pairing of its 20MHz spectrum at 1800MHz and 20MHz at 2.6GHz would provide speeds of up to 300Mbps.
Earlier this month, EE began testing networks with 400Mbps speeds. Vodafone said that its new service offers theoretical 225Mbps connections.
Cotton seedling freezes to death as Chang'e-4 shuts down for the Moon's 14-day lunar night
Fortnite easily out-earns PUBG, Assassin's Creed Odyssey and Red Dead Redemption 2 in 2018
Meteor showers as a service will be visible for about 100 kilometres in all directions
Saturn's rings only formed in the past 100 million years, suggests analysis of Cassini space probe data
New findings contradict conventional belief that Saturn's rings were formed along with the planet about 4.5 billion years ago