For details about what 4G is, how it works and why it is only now being launched in the UK see our guide to what you need to know about 4G.
When the first 4G network launched last month, Consumer Editor Chris Choi looked at the considerable cost of joining this new generation.
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The PM faces a countdown to settle a deal before her minority government tries to get its Queen's Speech plans approved by the Commons.
More details will come today on proposals to offer EU residents the right to a new "settled status" in Britain after it leaves the bloc.
Scotland and Northern Ireland could see rain later but for the rest of the UK it should be a fine day.