The upgrade of Vodafone's 3G mobile network to the high-speed downlink packet access (HSDPA) protocol will increase download speeds from 384Kbps to a peak of 1.8Mbps.

Vodafone spokesperson, Greg Spears, would not reveal the official launch date of the service, but said it would be before the end of the year.

The chosen few were hand-picked by Vodafone account managers to trial and provide feedback on the telco's new HSDPA network which will be marketed as "mobile broadband" to spare consumers from the cumbersome acronym.

The 40 participants, all from the lower North Shore, are existing Vodafone Mobile Connect customers using 3G data cards.

"The purpose of this trial is to test every element of the customer experience," Spears said. "From the moment they open the box and read the instructions, to the performance of the network's speed and coverage."