NFC, or Near Field Communication, is a short-range wireless technology which enables the communication between devices over a short distance. It is also called "contactless" because there need not be a real contact between the communicating devices, though the distance between them should be very short (about 10cm).

The most common contactless protocols are the following:

  • ISO 14443 Type A

  • Mifare – Is based on ISO 14443 Type A but includes NXP proprietary encryption & authentication

  • ISO 14443 Type B – This protocol uses the same Block Transmission Protocol as Type A (ISO 14443-4) but the physical layer and initialization procedure (anticollision and selection) are different from Type A

  • ISO 14443 Type B’ or Innovatron – This protocol use the same physical layer as Type B but the layers above are proprietary

  • Felica from Sony (Proprietary) also called type C   

  • ISO 15693 – This protocol is used for RFID Tags

The above protocols share some common behaviour depending on the device role:

Contactless Reader/validator

  • When switched-on, the contactless reader generates a Radio Frequency (RF) field

  • It starts polling for a contactless device by sending requests (REQA,REQB,…) periodically

  • If a correct answer is received, it executes an anticollision loop in order to detect all devices in the field. Then it selects one of them and starts data communication

Contactless cards

  • The power is provided by the RF field

  • An RF antenna is connected to the card to retrieve this power

Contactless mobile phones

  • Specifications of the NFC Forum to address use cases related to a contactless mobile phone environment

  • Antenna in on the mobile connected to a NFC chip, this NFC chip forwards contactless data to the SIM card