EE has expanded its 4G network to cover more towns, airports and train routes in the UK.

The telecoms company claims to have twice as much 4G coverage as any other provider. It said it wants to ensure that people have the best possible mobile data access where people might use it most, that is, at transport hubs.

Eighteen of the UK's largest airports have now been switched on for 4G, from London airports Heathrow, Gatwick, Stansted, Luton and City, to Birmingham, Manchester, Edinburgh, Newcastle and George Best Belfast City. Other airports benefiting from the EE 4G network include Glasgow, Liverpool John Lennon, Bristol, Nottingham East Midlands, Leeds-Bradford, Belfast International, Robin Hood and Blackpool.

Later this year, EE plans to connect up rail commuters to the 4G network. In the first stage, travellers on the London Euston to Birmingham New Street route will be connected, with an extension to Manchester and Liverpool, and London Victoria to Brighton, in the second stage.

In the third stage, the superfast network will reach Glasgow by the end of the year.

This is in addition to the 4G network that EE is building for Eurotunnel passengers to France, which is set to be completed by late summer.

Meanwhile, EE said it had added 14 places to the list of those connected to 4G, totalling 174 towns. The additions include Cannock, Ellesmere Port, Grangemouth, Harrogate, Hartlepool, Keighley, Motherwell, Paignton, Richmond in North Yorkshire, Skelmersdale, Torquay and Widnes.

Despite the 4G expansion, EE was keen to emphasise that it was still focusing on improving mobile phone call quality for customers. It has pledged to spend £275 million on call quality and innovation this year, and is making enhancements around the UK's motorways, such as the M25, M1, M4 and M6, by the summer.

Olaf Swantee, CEO at EE, said: "We are leading the way with 4G, with twice as much coverage as any other provider, connecting more customers in more places.

"But our network investment in 2014 is not just about giving people faster mobile data - phone calls are still an incredibly important part of the mobile experience, and we're investing to ensure that people travelling all over the UK can make phone calls in more places and with better quality than ever before."

Separately, EE said it plans to grow the size of its apprenticeship programme to more than 1,300 young people by the end of 2015. It has hired 80 percent (368 staff) of the 460 apprentices who have completed the programme so far. The apprenticeship scheme was first announced in March 2013.