Near Field Communications is a set of standards for portable devices enables peer-to-peer radio communications establishment, for passing data from one device to another by touching them or putting them very close together of 10 cm or less. Simply sending data over radio waves, NFC uses magnetic induction between two loop antennas located within each other’s field forming an air-core transformer; operating within the globally available and unlicensed RF (Radio Frequency) ISM band of 13.56 MHz with data rates of 106, 212 or 424 kbit/s.
NFC standards are defined by the NFC Forum group, which includes Nokia, Sony and Philips. NFC always involves an active initiator who generates an RF field that can power a passive target (e.g tags, stickers or cards). NFC targets’ data are read-only (and can be writeable) can securely store personal data such as credit card information and networking contacts. Also both initiator and target device can actively communicate by alternately generating their own fields where both devices typically have power supplies.
NFC devices are full-duplex to enable both sending and receiving data at the same time. Thus, they can check for potential collisions if the received signal frequency does not match the transmitted signal’s frequency. However, NFC offers no protection against eavesdropping and can be vulnerable to data modifications. Thus applications may use higher-layer cryptographic protocols to establish a secure channel.
Although NFC and Bluetooth are both short-range communication technologies available on mobile phones, however NFC operates at slower transfer rates consuming far less power with no pairing requirements like in bluetooth. At the same time, NFC is compatible with existing passive RFID (radio-frequency identification) infrastructures that also uses electromagnetic induction to send information over shorter distances. But NFC is standardized for smartphones and personal entities.