NFC, Near Field Communication, is short-range wireless commun ication. The standard NFC communication frequency is 13.56MHz, the data transmission distance is generally within 10cm, and the protocols to be followed are ISO14443A, ISO14443B and ISO15693. In the application, the NFC reader sends a specific electromagnetic wave to the carrier carrying the NFC chip (such as a bus card), and the series resonant circuit in the carrier body has the same frequency as that transmitted by the reader, and after receiving the electromagnetic wave of the reader/writer, The resonant circuit generates resonance, generates power and provides operating voltage for other circuits, and the NFC reader can complete data transmission and interaction with the carrier.
Since March 29, 2004, mainland China officially began to renew the second generation of resident ID cards with built-in contactless IC smart chips (NFC chips). The second-generation ID card adopts the high-frequency 14443B protocol, which is very confidential and is a special chip of the Ministry of Public Security.
2. Traffic card
The M1 card used for the traffic card, the built-in NFC chip mostly follows the ISO14443A protocol. At the same time, the bus card is also an application of the NFC e-wallet function. Traffic cards are widely used, and traffic travel belongs to the field of competition for mobile payment parties, and competition is fierce. With the increasing intelligence of the traffic travel field, the form of the future traffic card will change greatly. For example, the use of mobile phone NFC function to simulate the traffic card has changed the form of the traffic card, and Alipay and WeChat The introduction of the electronic traffic card, the ride code and the face-lifting station, etc., directly changed the original nature of the traffic card.
3. Access card
Access cards are also one of the important applications of NFC, such as access cards, parking cards, etc., for access control systems. The access card is set by the system administrator before the end user is used to determine the usable area and user rights. The user uses the access card to swipe the card into the management area. If there is no access card or permission, the user cannot enter the management area.