Three has become the first UK operator to roll out VoLTE, after rolling out its 800MHz spectrum to tackle indoor coverage blackspots.
It was dubbed the technology 4G Super Voice and said it is available to half of the UK's population. In London, Edinburgh, Exeter and Birmingham it covers 75 percent of their residents.
Three bought 2x5MHz of 800MHz frequency during the 2013 spectrum auction. Lower frequency spectrum has a great ability to punch through into buildings, increasing an operator's indoor coverage.
The operator said work was under way to roll out VoLTE in Cardiff, Manchester, Liverpool and Bristol. It predicted that by the end of this year, 65 percent of the population would be covered.
Devices such as the forthcoming iPhones are VoLTE compatible. Three said as many as 5.5 million of its customers could be using VoLTE by 2017.
Bryn Jones, Chief Technology Officer at Three, added: “By the end of the year, one million of our customers will have access to better indoor coverage and be able to use their phones in more places than ever before. We are proud to be the first network to roll this out across the country.”
Director of Customer Strategy Danny Dixon, added: “Not being able to use your phone as and when you want, no matter where you are, is one of the biggest pain points for customers. Today’s announcement is the latest step in our efforts to offer customers a quality experience on what is already the UK’s most reliable network.”
Three already offers a Wi-Fi calling service, although it is in-app rather than native. Vodafone is turning its attention to VoLTE, after it said it would begin rolling out its Wi-Fi calling service last week.