FOMA, officially short for Freedom of Mobile Multimedia Access, is the brand name for the 3G services being offered by Japanese mobile phone operator NTT DoCoMo.
FOMA was the world's first W-CDMA 3G service when launched in 2001. FOMA is compatible with standard UMTS, both via the radio link as well as via USIM card exchange, and hence provides several alternative options for global roaming: either with or without change of handset.
The world's first commercial W-CDMA service, FOMA, was launched by NTT DoCoMo in Japan in 2001.
Elsewhere, W-CDMA deployments have been exclusively UMTS based.
NTT DoCoMo's 3G network, FOMA, was the first commercial network using W-CDMA since 2002. The first W-CDMA version used by NTT DoCoMo was incompatible with the UMTS standard at the radio level, however USIM cards used by FOMA phones are compatible with GSM phones, so that USIM card based roaming is possible from Japan to GSM areas without any problem. Today the NTT DoCoMo network — as well as all the W-CDMA networks in the world — use the standard version of UMTS, allowing potential global roaming. Whether and under which conditions roaming can actually be used by subscribers depends on the commercial agreements between operators.
