Three has adopted the term "Ultrafast" to describe the DC-HSDPA network that it has been rolling out in the UK. Deployment was announced in February 2012.

The company has also revealed that it will be rolling out LTE in 2013, but hasn't specified whether this is going to be from the 1800MHz spectrum Three bought from EE, or from the future 4G auction. 

Talking to Pocket-lint.com and posting to its blog, Three has revealed that nearly 40 per cent of the UK can now access its DC-HSDPA network, which will give you theoretical speeds up to 42Mbps. 

This figure should increase to 50 per cent in the next month and it covers most metropolitan areas. The existing Three HSPA+ network is now reported to cover 90 per cent of the UK population. 

Speeds you can theoretically get and what you actually get are two very different things. But sitting in a Pimlico café with Three, we witnessed speeds of 21Mbps down and 3Mbps up on the iPhone 5, which is pretty impressive.

Of course, you'll need a device that has the hardware to support DC-HSDPA and Three details the iPhone 5, Sony Xperia T and HTC 8X as devices offered with Ultrafast compatibility. The great thing is that you'll get faster speeds on these devices as soon as you enter a DC-HSDPA area.

READ: Sony Xperia T review

The iPhone 5 would also be compatible with Three's 1800MHz LTE network if and when deployed - although presumably, Three will have a different pricing structure for LTE. 

The DC-HSDPA trump card being pushed by Three, of course, is on price. With EE's 4G prices attracting criticism, Three's all-you-can-eat data plans look mightily attractive.