EE has launched the UK's first next-generation 5G mobile network, with a concert by rapper Stormzy live-streamed from a boat on the River Thames.
5G mobile networks offer faster downloads, but customers will need a new handset to take advantage.
At first, the service will only be available in limited areas of Belfast, Birmingham, Cardiff, Edinburgh, London and Manchester.
Rival Vodafone plans to switch on its 5G service in the coming weeks.
EE's lowest-priced deal is £54 a month plus a one-off £170 fee for a compatible handset. But this only includes 10GB of data a month, which can be used up quickly if you download lots of movies or games.
On Thursday morning, BBC Breakfast had the UK's first live news broadcast over 5G.
Many news channels currently link several 4G connections together in order to stream video over mobile networks.
But using the 5G network, the BBC's technology correspondent Rory Cellan-Jones was able to broadcast in high definition using just one Sim card.
5G is not just about faster internet speeds. It also offers lower latency than 4G connections: that means less of a delay between sending a request and getting a response.
For Rory, that meant a shorter delay between hearing a question in his earpiece and answering live on TV.
One technical hitch delayed Rory's broadcast. The test transmission had ploughed through the data allowance on the Sim card, so it needed a top-up before Rory could go live on BBC Breakfast.
That makes EE's 10GB data cap on its cheapest price plan seem a little bit limiting.