Japanese mobile company and pioneer of multimedia mobile systems, NTT DoCoMo, lashed out at last week at suggestions that the 3G (third generation) mobile service the company plans to launch on 30 May was anything but the world's first commercial 3G service.

DoCoMo president Keiji Tachikawa maintained the service is not a 'fake' and blamed software bugs for the delay to 1 October of a full service launch.

NTT DoCoMo's failure to kickstart the world's first 3G system made many commentators and much of the IT press across the world jittery as to the truth of rumours, some of which emanated from DoCoMo itself, that the service would not live up to expectations.

Speaking at a Tokyo news conference, Tachikawa responded to criticism that the plans amount to little more than a trial and is not the commercial service the company has long been promising and hyping. "History will prove it, 30 May is the launch date," he said. "This is a commercial service and we will receive money from users. This is not a fake."

He said delays arose from a combination of bugs in the network - some of which are still present today - and lessons learned both last year, when the company's I-mode system collapsed several times after it failed to keep up with subscriber growth, and earlier this year when bugs were found in four models of mobile phones after they had begun shipping.

"I did not have this idea a year ago," he said of the introductory service period, "but in the Iridium project an introductory service was used and I suppose the idea came up recently that this could be used in Foma as well." Foma is the brand name DoCoMo is using for its 3G service.

Iridium was not a perfect model for Tachikawa to use - the satellite telephone company launched with great fanfare and after much hype in 1998 went bankrupt in 2000 after falling $4.4bn into debt. It was only this month that the service was saved by a backer that paid a fraction of the hundreds of millions the service has cost.

The packet data service, which offers downstream speeds of up to 384Kbps (kilobits per second), will cost just over a tenth of DoCoMo's current charges for each 128KB packet. The price reduction reflects the much greater amount of data that will be sent for services such as video on demand - services that would be prohibitively expensive if charged at the current rate.