ISO/IEC 21481 (NFCIP-2)

ISO/IEC 21481 (NFCIP-2) defines the mode switching mechanism that allows an NFC device to dynamically select between three operating modes: reader/writer mode (ISO 14443/15693), card emulation mode (ISO 14443), and peer-to-peer mode (ISO 18092). This standard enables a single NFC controller to support all NFC use cases — reading tags, emulating cards for payments, and exchanging data with other NFC devices — by detecting the communication context automatically.