The UK's first 4G mobile network has been turned on by Everything Everywhere, with plans to extend it to 16 cities by Christmas.
4G signal can already be found in large areas of London, Bristol, Cardiff and Birmingham. It is currently not for public use, but can be tested by engineers.
Everything Everywhere, owner of Orange and T-Mobile and yesterday rebranded 'EE', says 4G will deliver speeds around five times faster than 3G networks.
The firm's coverage will initially reach 20 million people, expanding to reach 98% of the population by 2014. The roll-out is costing £1.5bn over three years.
"We look forward to connecting the country with superfast mobile speeds in the coming weeks, months and years" said EE chief executive Olaf Swantee.
"And it starts today, with the announcement of our new business, our new brand and a new digital infrastructure that our company, our customers and the country can be proud of."
Sony Music UK CEO and chairman Nick Gatfield recently told Music Week that 4G will result in telecoms companies becoming "a huger partner for us".
Devices confirmed to be compatible with EE's 4G yesterday included a specially created version of Samsung's SIII, the latest Nokia Lumia handsets, HTC and Huawei devices, plus a laptop dongle and a personal Wi-Fi hotspot device.
The iPhone 5, which is due to be unveiled on later today (September 12) in California, is also expected to be compatible.