Three has switched on Voice over LTE (VoLTE) calling technology on its network in a move that should bring faster and clearer phone calls to its customers.
Three is calling the technology 4G Super-Voice, and it will run on the firm's 800MHz spectrum band acquired during the 2013 spectrum auctions.
The 800MHz spectrum can travel further and penetrate buildings far more effectively than Three's 3G 1800MHz network, which should boost signal quality and strength.
VoLTE works by using the 4G data network to place and host calls, rather than 2G or 3G networks. This means that calls are placed instantly, rather than having to wait five seconds or so to connect, and call quality is much higher.
However, only certain phones have the necessary technology at present. Three confirmed that the Samsung Galaxy S5, LG G4 and some Xperia handsets can use Super-Voice at the moment.
It did say, though, that the newly unveiled iPhone 6S and iPhone 6S Plus will support the technology and more Android handsets should join the list in the future.
Three said that around one million customers will be able to use the service by the end of the year as it extends coverage across London, Edinburgh, Exeter and Birmingham.
Cardiff, Manchester, Liverpool and Bristol should also be added by the end of the year, taking the total coverage to 65 percent.
Three’s chief technology officer, Bryn Jones, said that the company is proud to be the first to offer VoLTE in the UK.
“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,” he added.
Rival EE is also soon expected to unveil VoLTE calling, but has said that it will go live with the service only when it is convinced that the quality is high enough.
Vodafone announced last week that it is bringing WiFi calling to its network, as all the operators rush to introduce new features to entice, or retain, customers.
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