With more of a whimper than a bang Japan's NTT DoCoMo began the world's first commercial third-generation (3G) mobile phone service this morning in Tokyo.

The low-profile launch, which came with no ceremonies or events, reflects DoCoMo's caution regarding the service until it feels confident about the range of content and terminals that it can offer.

By December, DoCoMo plans to launch the service in the heavily populated Osaka-Kyoto-Kobe region of western Japan and the central Japanese city of Nagoya.

For now the service, known as Foma, is available in the Tokyo metropolis and nearby city of Yokohama. Service will spread to the rest of the nation, beginning in major cities, from the second quarter of 2002, according to DoCoMo's schedule.

Based on the WCDMA (wideband code-division multiple access) system, the new service has a theoretical maximum data transfer speed of 384Kbps (kilobits per second) — 26 times faster than the highest-speed mobile service DoCoMo offers today and six times that of the fastest service offered by DoCoMo's competitors.

But most telcos and 3G purveyors aren't telling the whole truth about bandwidth — most users won't see that level supplied all the time.

The high-speed service is packet- rather than circuit-switched, which means users pay according to the amount of data sent and received. It also enables the system to support many more data users than GSM.

Foma will form the basis of a faster version of the i-Mode wireless internet service. The service will also be available for people with PC Card data modems.

A second data service, circuit-switched 64Kbps, is also available and will be used by the much-hyped mobile videoconferencing service. DoCoMo opted to put this service on a circuit-switched service because it will offer a time-based charge, which is similar, though more expensive, than regular telephone calls.

DoCoMo has signed up 10 companies to make handsets, although only two had products ready for today's launch.

Products available include a standard terminal, the N2001 manufactured by NEC, similar to current handsets, a videophone handset, the P2101V manufactured by Panasonic (aka Matsushita), and a PC Card data modem terminal, the P2401, again from Panasonic.

Compared to current handsets, the new telephones command a price premium. But despite the hefty price tag the company says can meet its subscriber goal.

Telecommunications operators around the world are expected to closely watch the service to see if it lives up to expectations and whether they have a chance of making back the vast sums of money many shelled out for 3G licenses in early 2000.