Vodafone has announced that, after trials in April, it will begin High Speed Downlink Packet Access (HSDPA) transmission across the country in the middle of this year.

The first area to receive the transmissions, which can double or quadruple 3G speeds, will be the M25 area, and the service will be rolled out to cities across the country over the coming year.

HSDPA also has three times the capacity of 3G, allowing more users to share the same transmission cell.

"HSDPA offers a win-win opportunity for both customers and Vodafone, delivering on the promise of 3G to provide broadband-like services while on the move," said Michael Ransom, research director for wireless at Current Analysis.

"With higher HSDPA-driven wireless performance, Vodafone will enable business customers to move beyond mobile email and become mobile enterprises."

Following trials near the company's headquarters in Newbury, a second trial in London with 100 businesses will begin in April.

"We have seen high demand for 3G since its launch two years ago and our customers are hungry for the improvements that HSDPA will deliver," said Tim Miles, chief executive of Vodafone UK.

"These important trials are part of a continuing drive to lead the UK through superior network performance and a customer experience that is second to none."

A recent survey by the Global Mobile Suppliers Association identified 70 network operators with an interest in deploying HSDPA systems, reflecting an increase of 40 per cent in the past four months.

The survey also confirmed that the majority of the 102 operators which have commercially launched 3G/WCDMA services have also committed to deploying HSDPA in their networks.