Southampton is to be one of the first cities in the UK to get 4G mobile internet.

By the end of the year, the city will be one of 16 targeted by Everything Everywhere (EE), the countries largest network operator.

It is expected the services, which are five times faster than current 3G technology, will be available by Christmas.

Unveiled at the Science Museum in London, the 4G network, which offers speeds up to five times faster than 3G, will be available on HTC, Samsung, Nokia and Huawei devices, as well as "one more to come", which is widely expected to be Apple's iPhone 5.

The announcement is likely to enrage EE's competitors, including Vodafone, 3 and O2, who have threatened legal action over telecoms regulator Ofcom's decision last month to allow EE to launch 4G on its existing network.

EE owns the T-Mobile and Orange networks.

The 4G services will allow uninterrupted access to the web on the go, high definition movies to be downloaded in minutes and TV to be streamed without buffering, it is promised.

Four cities - London, Bristol, Cardiff and Birmingham - are switched on today for the company's engineers to begin live testing and systems integration in readiness for the customer launch.

EE gave no specific date but said 4G will be available to its customers by Christmas in London, Edinburgh, Cardiff, Belfast, Birmingham, Bristol, Derby, Glasgow, Hull, Leeds, Liverpool, Manchester, Newcastle, Nottingham, Sheffield and Southampton.

The group plans to roll out the service to further towns, cities and rural areas next year, with population coverage of 70% and rising to 98% in 2014.

EE chief executive Olaf Swantee said the launch of 4G will become another "great moment for the country in 2012" and will make Britain, which is lagging behind countries such as the US and Germany with its 4G roll-out, a "more modern country".

The company and network will be re-branded EE but the Orange and T-Mobile brands will continue to exist alongside.

The EE brand will cover the 4G service as well as a fibre broadband product, set to reach 11 million households and businesses by the end of the year.

The company announced it is to open EE-branded stores, with more than 700 being unveiled across Britain's high streets in line with its customer brand launch.

The new EE stores - formerly Orange and T-Mobile shops - will serve customers of all three brands.

Orange and T-Mobile customers will continue to use the 3G and 2G mobile networks and must upgrade to EE if they wish to access 4G services.