Foma is based on wideband code division multiple access (W-CDMA) and is superior to Japan's existing 2G format. The differences can be found in the two data transmission services offered with the system. A packet-based service provides transmission at speeds up to 384Kbps (bits per second); while the videophone's circuit-switched service runs at 64Kbps. DoCoMo's 2G service is capable of packet transmission at speeds of 14.4Kbps.
Users can choose between three devices: NEC's N2001, which is a 3G version of a current second-generation (2G) handset; and Panasonic's P2101V videophone and P2401 PC Card data modem.
The phones are more expensive than non-3G handsets. When they first went on sale the N2001 sold for £246 and the P2101 was priced at £360. The most expensive 2G handset costs between £115 and £172.
Foma has been plagued by delays and technical hitches, however. One early adopter complained of a short battery life, saying the handset required recharging every day. "I had a full battery and I sent four e-mail messages, but after that the phone already started running out of power," he said.
The videophones have proved to be a hit, possibly because they offered the promise of a genuinely new application. However, there is a supply problem. DoCoMo managed to deliver 20,000 N2001 units to stores, but only a few thousand P2101V videophones were made available.
Some of the videophones' worst connectivity problems have been cleared up, but complaints persist.
One user criticised the handset's size and weight - at 150g the device is at least 50g heavier than most Japanese 2G handsets and is also a centimetre thicker. "It's now just another i-Mode [service] which can be browsed on a bigger handset," said the user.
One of the few truly new services to take advantage of 3G technology - a video-clip-on-demand system called i-Motion - was not available when Foma was launched, because of technical problems with the handsets.
I-Motion will now be launched sometime before the end of the year, leaving DoCoMo with a commercial service that has fewer features than the trial service.
DoCoMo claims that Foma attracted 10,300 users in its first month of service. The company has so far been careful with its predictions for Foma and has only issued one firm target: that 150,000 users will be signed up the service by the end of March 2002.