The Three UK wireless network has started rolling out VoLTE technology to its customers. Three is the first UK carrier to support VoLTE, which it calls "4G Super-Voice".

Three says:

"Based on a roll-out of low frequency 800 MHz spectrum it allows a mobile signal to travel much further into buildings and extends its reach to more rural areas, removing many of the current coverage 'blackspots' across the country. Customers will be able to make calls, send texts and get online in places that previously had poor or no signal. 4G Super-Voice is made possible by the addition of the low frequency spectrum to the Three network, that will enable its 4G network to carry voice calls using VoLTE technology as well as texts and data.

VoLTE "4G Super-Voice" already covers 50% of the UK population for indoor coverage and will be available to 5.5 million Three customers by 2017.

Source: Three UK