Overviews of NFC ISO standards

Interoperability with available NFC readers and NFC software is an important base for the success of the NFC technology. Therefore, several specifications were developed in order standardize the usage of the NFC. In the following, the most important specifications are summarized. NFC Tag specification can be divided into two different levels:

1. The hardware level which specifies the technical requirements for the usage of NFC
2. The software level which specifies how data are stored on NFC tags

ISO/IEC 14443

The international norm series ISO/IEC 14443 addresses the structure of contactless chip cards. The norm series differentiates between reader (PCD = Proximity Coupling Device) and chip card (PICC = Proximity Integrated Circuit Card). The norm includes four parts:

• 14443-1: Defines physical properties / measurements of contactless cards.
• 14443-2: Specifies a frequency of 13.56 MHz and defines the available modulation procedures.
• 14443-3: Describes the technical communication process, in particular the initialisation of communication and the collision handling (several cards in reach).
• 14443-4: Specifies the transmission protocol for advanced functions such as authentification or encryption.

Summarized: For NFC Tags only section 1443-2 and 14443-3 of the norm series are relevant because in part 2 the frequency and modulation are defined and in part 3 the communication process is described. Part 1 is not relevant for NFC Tags, because they aren't just available as cards but also as keyfobs, wristbands, stickers and so on. Part 4 ist only relevant for NFC Tags used for security applications.

Further information: https://en.wikipedia.org/wiki/ISO/IEC_14443

ISO/IEC 15693

The international norm series ISO/IEC 15693 addresses the structure of contactless chip cards, more precisely of Vicinity Integrated Circuit Cards (VICC). In contrast to the aforementioned norm, the ISO/IEC 15693 addresses the structure of contactless chip cards with a reach up to several metres and not of Proximity Integrated Circuit Cards (PICC) which only have a reach of a few centimetres.

The norm also consists out of several parts:

• Part 1: Defines physical properties / measurements of transponder cards.
• Part 2: Specifies a frequency of 13.56 MHz and defines the available modulation procedures.
• Part 3: Describes the technical communication process, in particular the structure of data packages and available commands for request of readers. All commands apart from anticollision and sleep are optional. This way, it's possible to realize transponders providing data storage and also transponders which only contain an ID.

Summarized: NFC Tags following this specification such as the NXP ICODE SLIX are mainly used for industry applications like intelligent product labeling. Due to the optionality of most commands, it's not that easy to create a universal reader application which supports all NFC tags and their functions.

Further information: https://en.wikipedia.org/wiki/ISO/IEC_15693

NFC-Forum Tag Specification

The NFC-Forum Tag Specification defines Tag Types which should be interoperable with NFC devices. The specification differentiates tags based on memory capacity and configuration:

NFC-Forum Type 1: Includes tags complying with ISO/IEC 14443. Memory capacity between 96 bytes and 2 kilobytes. Can be encoded several times and a write-protection can be applied.
NFC-Forum Type 2: The same as Type 1, but includes only chips with a memory capacity between 48 bytes and 2 kilobytes.
NFC-Forum Type 3: Includes tags complying with the Japanese industry standard (JIS) FeliCa. Tags are pre-configured either as rewriteable or read-only. Typical tags have a memory capacity of up to 9 kilobytes. The theoretical limit is at 1 MB.
NFC-Forum Type 4: Includes tags complying with ISO/IEC 14443. Tags are pre-configured either as rewriteable or read-only. The theoretical limit of memory capacity is at 32 kilobytes.
NFC-Forum Type 5: Includes tags complying with ISO/IEC 15693.

Summarized: Typical NFC Tags belong to Tag Type 2, for example the NTAG21x series. These tags automatically fulfill at least the requirements of part 2 and 3 of the ISO/IEC 14443. Moreover, these tags can be encoded and write-protected by the user.

NDEF

As the name suggests, the NFC Data Exchange Format (NDEF) describes how data are stored on NFC Tags. Thus, NDEF is a standard on software level. While the hardware level is defined by ISO and the NFC-Forum, the NDEF standard defines how data is stored on a tag in a way that compatible devices are able to automatically interpret the stored data.

For example, NDEF defines how URLs, smart posters, vCards, texts or Mime Type information in general is stored. Every device complying with the NDEF specification is able to detect the stored data type and then, a corresponding action is triggered automatically. For example, if a tag storing a URL is scanned, the scanning device automatically opens the website.

Summarized: NDEF specifies how data are organized on NFC Tags in order to enable reading NFC devices to trigger the right actions.

NFC Standards - What should be considered?

A suitable NFC Tag should comply with the 14443 standard. Moreover, tags should comply with the NFC-Forum Type 2 specification. This guarantuees that the tag can be used for all common applications. If a tag should also be compatible with all NFC-enabled devices, the NFC Tag should be NDEF formatted.

The NFC Tags available in our shop comply with all previously mentioned standards. Furthermore, all NFC Tags are NDEF formatted before shipment.