Hallo Shekhar, NDEF is a data exchange format for NFC (NDEF = NFC Data Exchange Format). It can be used with NFC tags (reader-writer mode) and in peer- to-peer mode.
The NFC Forum Type tag formats specify a standardized way to store NDEF data (and possibly other data) onto certain tags. So these specifications define the tags' data structures and commands to access the data. The four tag types are based on previously existing vendor specific RFID tag types: NFC Forum Tag Type 1 is based on Innovision Topaz/Jewel NFC Forum Tag Type 2 is based on NXP MIFARE Ultralight NFC Forum Tag Type 3 is based on Sony FeliCa NFC Forum Tag Type 4 is based on APDU-based smart cards Besides these standard tag types NXP released application notes that define ways to store NDEF formatted data onto other RFID tag types (application notes are available for MIFARE Classic and for ICODE). As the tag types are based on existing RFID tag technologies, they also correspond to certain RFID/smartcard standards: NFC Forum Tag Type 1 sits on top of ISO/IEC 14443-3 Type A (but without anti-collision!) NFC Forum Tag Type 2 sits on top of ISO/IEC 14443-3 Type A NFC Forum Tag Type 3 sits on top of JIS X 6319-4 NFC Forum Tag Type 4 sits on top of ISO/IEC 14443-4 and ISO/IEC 7816-4 Corresponding to the ISO NFC standards (ISO/IEC 18092, ...), the NFC Forum combined certain RFID standards to the NFC Digital Protocol. The digital protocol has three RFID technologies named NFC-A, NFC-B and NFC-F: NFC-A matches the RFID standard ISO/IEC 14443-3 Type A NFC-B matches the RFID standard ISO/IEC 14443-3 Type B NFC-F matches the RFID standard FeliCa JIS X 6319-4 (or rather those parts of that standard that were incorporated by ISO/IEC 18092) Additionally, the Nexus S (or the NXP chip thats inside it) understands a forth RFID technology that uses the same frequency as NFC but is that not really related to NFC: ISO/IEC 15693 (called NFC-V in the Android API, where V stands for Vicinity as the ISO standard refers to this technology as vicinity cards). ISO-DEP is the data exchange protocol on top of ISO/IEC 14443-4. It is based on the same command exchange protocol that is used with contact smartcards: ISO/IEC 7816-4. ISO/IEC 14443-4 joins the two low-level protocols defined in ISO/IEC 14443-3 into one common high-level protocol. br, Michael -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
