The NFC Forum, responsible for the Near Field Communications standard, has released specifications for the four different kinds of tag making up the NFC standard, and three of them might seem strangely familiar.
Tags of Type 1 and 2 are based on ISO14443A, so Londoners are already using NFC under the Oyster brand.
ISO14443C was stalled in development before Sony and NTT DoCoMo took the standard out of the ISO and called it FeliCa. FeliCa is now widely deployed in Japan for ticketing, and forms the basis of the EDY payment system - the NFC Type 3 is basically a FeliCa chip, so the Japanese are already using NFC too.
Type 4 tags are what's most likely to turn up in modern devices - compatible with Types 1 and 2, but with 32KB of memory per application and a communication speed of up to 424Kb/sec. A Type 4 tag could contain an Oyster application (should London Transport decide to release one), and perhaps a Mastercard PayPass application too.
The concept is that punters could install and remove applications as they wish, perhaps using their mobile phone interface to manage the installed applications on the embedded NFC chip in their handset.
Backwards compatibility with existing standards makes sense, though it seems compatibility with FeliCa would have been technically too complicated. This means Type 3 NFC tags are unlikely to get used outside Japan, and unlikely to be called anything other than FeliCa, while the rest of the world skips past to Type 4 while maintaining compatibility with the basic systems already deployed.
Having Type 3 does mean the NFC Forum can claim its billion tags though, and take credit for all those FeliCa applications the Japanese have been enjoying for years. ®