Mobile operator O2 is going to roll out HSDPA, the enhanced 3G standard known as 3.5G. It will appear this year in O2's traditional testing ground, the Isle of Man, and reach the mainland maybe next year - although other operators will probably adopt at the same time, since HSDPA is essentially a software upgrade to the 3G network.

"No one else is doing HSDPA in Europe," said Mike Short, vice-president for research and development at O2. So far Japanese operator DoCoMo has the most advanced plans to deliver the technology (which stands for high speed downlink packet access) offering broadband speeds - around 4 Mbit/s - to mobiles.

"We need a wider range of devices before we launch in the UK," said Short, commenting that the Isle of Man trial will be of datacards. "The trial makes sense because [O2's Manx Telecom subsidiary] provides fixed and mobile communications and we can deploy quickly," he said. "We need to learn how stable the customer equipment is." He expects HSDPA handsets in 2006, but these will be PDAs and communicators with voice.

"Speed alone does not sell," said Short, promising multimedia content, which will be delivered by a Siemens-built IP multimedia subsystem. IMS - a SIP-based standard defined by the 3G Partnership Project (3GPP) will allow presence, chat and the ability to share multimedia.

Short echoed the industry's general rejection of EDGE, the 2.5G technology that adds high speed to GPRS networks. "It was deployed in countries where they have spectrum difficulties, or weren't worried about roaming," said Short. "We didn't see it as cost-effective - we will transition to 3G instead."

Short was proud to say that O2 will market 3G at the same price per megabyte as it sells GPRS, instead of charging a further premium - although given the per-megabyte charges for mobile, we'd have thought those prices were quite rapacious enough, thanks.

Although O2 is a member of the UMA consortium which has made the specifications that make BT's project Bluephone possible, O2 has no plans to launch anything like it, said Short. The project has been revealed as a mobile-centric system, that uses Bluetooth or Wi-Fi to extend mobile coverage indoors, but he does not expect good enough voice quality. "We have done voice on Bluetooth tests. Bluetooth is not geared to be a PSTN replacement," said Short. "I can see voice over Wi-Fi, but only after some time."