While 3G is still a dream for some areas of the UK, the networks are pushing ahead with trialing the next big thing in London – a 4G network.We've already heard about the Everything Everywhere and BT trial in Cornwall, but this exercise tests the high-speed data technology in a busy, built-up area. And it doesn't get much busier than the capital. The trial will run for the next nine months, with O2 offering hundreds of consumers, businesses and venue owners access to the 4G network, which covers a combined area of 40 square kilometres. Specifically, the network will stretch from Hyde Park to (surprise, surprise) The O2 in Greenwich, taking in Canary Wharf, Soho, Westminster, South Bank and Kings Cross.It promises a mobile internet experience comparable to the fastest landline fibre home broadband connections. A 500MB file could be downloaded as fast as under one minute, compared to over five minutes on 3G. Good news if you need to download a high definition movie in the go, not great if your monthly data allowance is 500MB. The temptation could be too much.O2 will provide trialists with Samsung B3730 mobile broadband dongles, supporting speeds of up to 100Mbps, and well as 4G personal wireless hotspots and handsets from a number of other vendors. Over 1,000 individuals are expected to take part, as well as businesses, organisations and venues such as the previously-mentioned O2 arena. Both performance data and feedback will be collected throughout the trial, shaping the final service offered by O2, likely to be offered anytime between the end of 2012 up to 2014.'O2 has been at the heart of the mobile data explosion over the last three years and our priority has always been to build ahead of the curve,' said Ronan Dunne, CEO of Telefónica UK (O2). 'Our work in London will give us a better understanding of the capabilities of 4G technology and will allow us to explore the superfast benefits it will bring to people and industry across the UK. This 4G trial is the next step on our journey to a smarter network - a network that offers a seamless, connected experience across multiple devices, locations and services.''The forthcoming spectrum auction is a watershed moment for the UK mobile industry, which will see the release of the airwaves capable of powering a whole range of exciting next generation mobile services. We are actively engaged in the auction and are supportive of a fair process that meets the Government’s and Ofcom’s planned timeline.'