As the English abbreviation of Near Field Communication, NFC can exchange data when they are close to each other. It is evolved from the integration of non-contact radio frequency identification (RFID) and interconnection technology. The chip integrates the functions of inductive card reader, inductive card and point-to-point communication, and uses mobile terminals to realize applications such as mobile payment, electronic ticketing, access control, mobile identification, and anti-counterfeiting.

The "near field" in the Chinese name of NFC range refers to radio waves that are close to the electromagnetic field. Because radio waves are actually electromagnetic waves, it obeys Maxwell's equations. The electric field and magnetic field will alternately perform energy conversion and mutually enhance each other during the process of propagating from the transmitting antenna to the receiving antenna, such as the radio used by our mobile phones. Signals are propagated using this principle, a method known as far-field communication. Within 10 wavelengths of electromagnetic waves, the electric field and magnetic field are independent of each other. At this time, the electric field is meaningless, but the magnetic field can be used for short-distance communication, which we call near-field communication.

The application of NFC technology has received widespread attention around the world. Different roles such as domestic and foreign telecom operators and mobile phone manufacturers have carried out application trials, and some international associations have also actively carried out standardization work. According to the forecast of relevant organizations in the industry, mobile phone applications based on near-field communication technology will become the next killer application of mobile value-added services.

In order to be compatible with contactless smart cards, the NFC standard stipulates a flexible gateway system, which is divided into three working modes: point-to-point communication mode, reader mode and NFC card simulation mode.

1. Point-to-point form

点对点模式,两个NFC设备可以交货change data. For example, multiple digital cameras and mobile phones with NFC function can use NFC technology for wireless interconnection to realize data exchange such as virtual business cards or digital photos.

For the point-to-point form, the key point is to connect two devices with NFC function, so that the data transmission between points can be realized. By taking the point-to-point mode as the premise, the NFC-enabled mobile phones and computers and other related devices can truly achieve point-to-point wireless connection and data transmission, and in subsequent related applications, it can be used not only for local applications, but also for network applications. Therefore, the application of the point-to-point form plays a very important role in the rapid Bluetooth connection between different devices and the transmission of communication data.

2. Card reader mode

Read/write mode, in this mode the NFC device is used as a non-contact reader. For example, a mobile phone that supports NFC plays the role of a reader when interacting with tags, and a mobile phone with NFC enabled can read and write tags that support the NFC data format standard.

The NFC communication in the card reader mode is used as a non-contact card reader, which can read relevant information from electronic tags for exhibition information, movie posters, advertising pages, etc. The NFC mobile phone in the card reader mode can collect data resources from the TAG, and complete information processing functions according to certain application requirements. Some application functions can be directly completed locally, and some need to be combined with mobile communication networks such as TD-LTE. NFC application fields based on the card reader mode include advertisement reading, ticket reading, movie theater ticket sales, etc. For example, there is a TAG label on the back of a movie poster. Connect to buy movie tickets. The NFC mode of the card reader can also support the acquisition of bus station information and tourist attraction map information, improving the convenience of people's travel and transportation.

3. Card simulation form

Simulated card mode, this mode is to simulate a device with NFC function as a tag or a contactless card, for example, a mobile phone supporting NFC can be read as an access control card, bank card, etc.

The key of the card simulation form is to simulate the device with NFC function to make it into a contactless card mode, such as bank card and access control card. This form is mainly used in non-contact mobile payments such as shopping malls or transportation. In the specific application process, users only need to put their mobile phones or other related electronic devices close to the card reader, and at the same time enter the corresponding password to complete the transaction. . For cards in card emulation mode, the key is to power through the RF domain of the contactless card reader, so that the NFC device can continue to work even if it has no power. In addition, for the application of card simulation form, it is also possible to collect data in related devices with NFC functions, and then transmit the data to the corresponding processing system for relevant processing, and this form can also be applied to barring systems and local payments and other aspects.

Comparison of NFC and RFID

首先,工作模式是不同的。NFC施暴者es point-to-point communication functions, reader functions and contactless card functions into one chip, while RFID consists of two parts: a reader and a tag. NFC technology can both read and write, while RFID can only read and judge information.

Second, the transmission distance is different. The transmission distance of NFC is much smaller than that of RFID. The transmission distance of NFC is only 10 centimeters, and the transmission distance of RFID can reach several meters or even tens of meters. NFC is a short-distance private communication method. Compared with RFID, NFC has the characteristics of short distance, high bandwidth, low energy consumption, and high security.

Third, the application fields are different. NFC is more used in the field of consumer electronics, and plays a huge role in access control, public transportation, mobile payment and other fields; RFID is better at long-distance identification, and is more used in production, logistics, tracking, and asset management. superior.