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1. How does NFC works?

Carlos Alatorre edited this page Dec 19, 2023 · 1 revision

NFC is a technology that enables two-way communication.

In order to exchange data, NFC technology creates a short-range network using electromagnetic radio signals. NFC tags have a storage capacity of between 96 and 4,096 bytes and may be read as well as written too. This calls for at least two signal-receiving and sending devices.

There are two main NFC specifications: ISO/IEC 14443 and ISO/IEC 18000-3. The first defines the card's ID, which is used to store data like that found in NFC tags, while the second describes the RFID communication that NFC devices employ.

NFC, a type of RFID, can only communicate within a 10 cm range; in contrast, other types of RFID may be read from a considerably greater distance. Within the family of RFID technology, NFC particularly refers to a branch of high-frequency (HF) wavelengths.

Active NFC

Active NFC devices, such as smartphones, have the ability to read and write data from NFC tags, communicate data with other compatible devices, and modify data on the NFC tag (if authorized).

Passive NFC

On the other hand, passive NFC can only convey data; it does not read any data itself, but instead includes information that other devices may read. Since passive NFC may operate without electricity, it can be implemented in a variety of devices that require communication with one another.

Some examples of passive NFC devices are:

  • NFC Tags.
  • NFC bank cards.
  • Tickets.
  • Identifications.
  • Physical access badges or cards.

NFC Tags types

The NFC Forum has established four different categories of NFC tags. The NFC Forum specifications have recently been updated to incorporate the fifth kind with associated NFC-V technology. Blocks are the fundamental data units utilized in memory management. The size of each block is set at 16 bytes. The circuitry of the chip determines how many memory blocks are accessible. Memory blocks are not directly addressed, but rather in relation to the service to which they belong.

  • Type 1 NFC Type 1 tags provide data collision prevention and can be read-only or rewritable. Their memory sizes range from 93 bytes to 2 KB, which is sufficient for a URL or other modest amount of data, and they have a 106 kbit/s transfer rate. Type 1 tags do not support the anti-collision feature and have a lower market price.

  • Type 2 Similar to Type 1 tags, Type 2 NFC tags adhere to ISO/IEC 14443A, can be read-only or rewritable, and have a 106 kbit/s communication speed. However, these tags do support the anti-collision feature and have memory sizes ranging from 48 bytes to 2 KB.

  • Type 3 Compared to Type 1 and Type 2 tags, Type 3 NFC tags are speedier and have greater memory. With the exception of the fact that encryption and authentication are not supported, they are consistent with ISO/IEC 18092 and JIS X 6319-4 requirements. Type 3 tags support the anti-collision feature, have 2 KB of memory, and may be set to read-only or rewritable mode. 212 kbit/s or 424 kbit/s is the data rate.

  • Type 4 The ISO/IEC 14443 standard is complied with by Type 4 NFC tags. They are read-only by default and need specialized servicing tools to get their data updated. They can handle data speeds of 106 kbit/s, 212 kbit/s, and 424 kbit/s and the anti-collision system, and they can store up to 32 KB of memory.

  • Type 5 NFC Forum specifications recently accepted Type 5 NFC tags, which adhere to the ISO/IEC 15693 standard, support a data rate of 26.48 kbit/s, have greater capacity than 64 KB, and incorporate an anti-collision mechanism.