Three Mobile Broadband – 3G Premium Dongle

So-called ‘mobile broadband' modems use the mobile phone networks to transmit the computer data that allows laptops to access the internet.

This one is sold by mobile network Three and plugs into a USB port on the computer. It's a little smaller and thinner than ones we've seen before, but it's still over 3in (85mm) long.

The USB connector swivels for a good fit, but there's also an extension cable supplied for if space is tight or if you don't get good reception at the computer. It's made by Chinese manufacturer Huawei (model number E367) which in fact makes most of these adapters for mobile networks, regardless of how they're branded.

The software to make it work is supplied on the device itself, so you have the choice to install it when you plug it in. It worked simply and without fuss, though Windows 7 includes its own software to get online with such devices, so you can use that to avoid adding extra software if you wish. It's important to note that connection speeds will vary depending on the quality of 3's signal in your area.

We tried it in south-west London and got no signal at all, but in central London it was much better with an download speed of over 2mbits/sec - a far cry from the claimed maximum of 21mbits/sec but still impressive. A cheaper ‘Everyday' modem has slower transfer rates.

Those speeds are over the 3G network but it also works when there's no 3G signal. The network has recently changed how it offers non-3G coverage (through an agreement with T-Mobile) but it told us that when you buy the device you can check coverage against your postcode. There's also a 14-day money-back returns policy if you find that real-world coverage doesn't match the claims.

Costs vary depending on the price plan you choose – for £10 a month you get a not-very-generous 1GB of data on an 18-month contract, while for £18 a month you can have 15GB a month with a 24-month contract. If you can get Three coverage where you're likely to be using it, this is a good mobile broadband product.