Two multimedia broadcast technologies are competing for scarce bandwidth following the launch of a pilot Digital Video Broadcasting (DVB-H) service for handhelds in Oxford.

Digital Audio Broadcasting (DAB) trials have also taken place, with cable giant NTL having a foot in both camps.

Imagination Technologies and Radioscape, Britain's two world-leading DAB developers, have each celebrated sales of a million devices - although Imagination's Dave Harold was scornful of his rival's claim.

'Products using our technology have far greater sales,' he said. 'I think they are counting chips, not whole products. There is more than one chip per product.'

Imagination is offering DVB-H technology for use in products and Radioscape partner Texas Instruments is developing a chip for the purpose.

Harold believes DVB-H and Dab will develop quite separately. Much depends on how much bandwidth (if any) is made available to each.

Nigel Oakley, his opposite number at Radioscape, did not rule out developing a DVB-H product but said its power efficiency and ability to deliver mobile data had yet to be tested for real.

Some DVB-H backers had been shocked to find that it needs twice as much terrestrial transmit power than they had thought, he said.