While 3G struggles to take off, operators are looking to the next wave of technology to power our mobile phones.

T-Mobile is the latest mobile operator in the UK to complete live trails of a HSDPA (High-Speed Downlink Packet Access) calls in the UK, Netherlands, and Germany.

While the commercial launch of HSDPA isn't scheduled until next year the company along with competitors O2 and Vodafone are keen to show the industry that successful tests are being carried out.

HSDPA is a software upgrade to 3G that delivers download speeds over four times faster than currently possible with a theoretical maximum of 1.8Mbps in the first phase, compared to today's theoretical maximum of 384Kbps on standard 3G networks.

T-Mobile follows hot on the heels of operator O2 who earlier in the month started trailing the service on the Isle of Man with its subsidiary Manx Telecom and Lucent Technologies.

It said that its service would offer 1.3 Megabits per second (Mbps) - limited only by the capability of current-generation handsets - and will provide theoretical maximum peak data speeds of up to 14.4Mbps.

At launch a customer will be able to send a 5Mb video clip in under 30 seconds.

Vodafone is hoping to run trials of its service in the new year.