The new network will launch as 'EE', and will run alongside Orange and T-Mobile. London, Birmingham, Cardiff, and Bristol will be the first four cities with 4G capability, with testing starting in those areas today. Before the end of the year, that list will include Belfast, Derby, Edinburgh, Glasgow, Hull, Leeds, Liverpool, Manchester, Nottingham, Newcastle, Sheffield, and Southampton.
Three Android devices - the Huawei Ascend P1 LTE, the HTC One XL, and Samsung's Galaxy S III LTE - will be launched with the network in the coming weeks, but the company says that more devices will be added in the future.
At the launch this morning, London Mayor Boris Johnson said, "I barely understand it, but information will spout unstoppably from these gizmos. It will bring huge advantages to anyone living or working in London."