NFC Protocol Technical Specifications
Defines an OSI layer-2 protocol to support peer-to-peer communication between two NFC-enabled devices, which is essential for any NFC applications that involve bi-directional communications. The specification defines two service types, connectionless and connection-oriented, organized into three link service classes: connectionless service only; connection-oriented service only; and both connectionless and connection-oriented service. The connectionless service offers minimal setup with no reliability or flow-control guarantees (deferring these issues to applications and to the reliability guarantees offered by ISO/IEC 18092 and ISO/IEC 14443 MAC layers). The connection-oriented service adds in-order, reliable delivery, flow-control, and session-based service layer multiplexing.
LLCP is a compact protocol, based on the industry standard IEEE 802.2, designed to support either small applications with limited data transport requirements, such as minor file transfers, or network protocols, such as OBEX and TCP/IP, which in turn provide a more robust service environment for applications. The NFC LLCP thus delivers a solid foundation for peer-to-peer applications, enhancing the basic functionality offered by ISO/IEC 18092, but without affecting the interoperability of legacy NFC applications or chipsets. Version 1.3 of the LLCP specification adds an unauthenticated secure data transport option to ensure privacy and confidentiality of messages exchanged between peer devices.
This specification addresses the digital protocol for NFC-enabled device communication, providing an implementation specification on top of the ISO/IEC 18092 and ISO/IEC 14443 standards. It harmonizes the integrated technologies, specifies implementation options and limits the interpretation of the standards; in essence, showing developers how to use NFC, ISO/IEC 14443 and JIS X6319-4 standards together to ensure global interoperability between different NFC devices, and between NFC devices and existing contactless infrastructure.
The specification defines the common feature set that can be used consistently and without further modification for major NFC applications in areas such as financial services and public transport. The specification covers the digital interface and the half-duplex transmission protocol of the NFC-enabled device in its four roles as Initiator, Target, Reader/Writer and Card Emulator. It includes bit level coding, bit rates, frame formats, protocols, and command sets, which are used by NFC-enabled devices to exchange data and bind to the LLCP protocol.
Version 2.0 of the Digital Protocol technical specification also adds ACM for P2P communication and NFC-V technology. Additionally, updates have been included based on ongoing alignment efforts with other organizations and standards, such as EMVCo, ISO/IEC 14443 and ISO/IEC 18092.
Version 2.1 of the Digital Protocol technical specification adds support for larger RF frames for the contactless ISO-DEP protocol compliant with ISO/IEC 14443 was added to optimize the overall transaction time for ISO-DEP.
The specification explains how the NFC Digital Protocol Specification can be used to set up the communication protocol with another NFC device or NFC Forum tag. It describes the building blocks, called Activities, for setting up the communication protocol. These Activities can be used as defined in this specification or can be modified to define other ways of setting up the communication protocol, covering the same or different use cases. Activities are combined in Profiles. Each Profile has specific Configuration Parameters and covers a particular use case. This document defines Profiles polling for an NFC device and establishment of Peer to Peer communication, polling for and reading NFC Data Exchange Format (NDEF) data from an NFC Forum tag, and polling for a NFC tag or NFC device in combination.
The combination of Activities and Profiles define a predictable behavior for an NFC Forum device. This does not limit NFC Forum devices from implementing other building blocks or defining other Profiles – for other use cases – on top of the existing ones.
Version 2.0 of the Activity technical specification has been extended to support ACM for P2P communication and NFC-V technology. Additionally, updates have been included based on ongoing alignment efforts with other organizations and standards, such as EMVCo, ISO/IEC 14443 and ISO/IEC 18092.
The Simple NDEF Exchange Protocol (SNEP) allows an application on an NFC-enabled device to exchange NFC Data Exchange Format (NDEF) messages with another NFC Forum device when operating in NFC Forum peer-to-peer mode. The protocol makes use of the Logical Link Control Protocol (LLCP) connection-oriented transport mode to provide a reliable data exchange.
This specification addresses the analog characteristics of the RF interface of the NFC-enabled device. The purpose of the specification is to characterize and specify the externally observable signals for an NFC-Enabled Device without specifying the design of the antenna of an NFC-Enabled Device. This includes power requirements (determining operating volume), transmission requirements, receiver requirements, and signal forms (time/frequency/modulation characteristics).
This specification is intended for use by manufacturers wanting to implement an NFC-enabled device. Its scope covers the analog interface of the NFC-enabled device in its five roles (Peer Mode Initiator, Peer Mode Target, Reader/Writer Mode, Wireless charging, and Card Emulation Mode) for all three technologies (NFC-A, NFC-B, and NFC-F) and for all the different bit rates (106kbps, 212kbps, and 424kbps).
The Analog 2.0 Specification introduced Active Communication Mode for P2P data exchange and NFC-V technology in poll mode. Version 2.0 ensures full interoperability with devices conformant to ISO/IEC 14443 or ISO/IEC 18092 by harmonizing the analog parameter for the contactless communication. This interoperability is important to enable the reliable usage of NFC devices with existing infrastructure using ISO compatible RF readers and/or cards (e.g. for contactless public transport applications). The 2.1 Version introduces some alignments to EMVCo and the NFC-V Listen mode requirements.
The NCI specification defines a standard interface within an NFC device between an NFC controller and the device’s main application processor. The NCI makes it easier for device manufacturers to integrate chipsets from different chip manufacturers, and it defines a common level of functionality and interoperability among the components within an NFC-enabled device. With the availability of the NCI, manufacturers have access to a standard interface they can use for whatever kind of NFC-enabled device they build – including mobile phones, PCs, tablets, printers, consumer electronics, and appliances. This will enable manufacturers to bring new NFC-enabled devices to market faster. The NCI provides users a logical interface that can be used with different physical transports, such as UART, SPI, and I2C.
NCI Version 2.0 introduces the concept of RF Interface Extensions to optimize for developers the data exchange for P2P and memory tag communications. The Listen Mode Routing mechanism has been extended to provide more flexibility for NFC devices with multiple secure elements. The new version also includes the option for NFC controllers to emulate NFC Forum tags autonomously, as well as a high-level RF interface to communicate with NFC Forum tags. NCI 2.0 supports Active Communication Mode (ACM) for P2P communication and Type V technology, allowing NFC devices to communicate with a broader range of devices and tags.
Version 2.1 of the NCI technical specification defines a standard interface within an NFC device between an NFC Controller and the device’s main application processor. This recent update to version 2.1 includes optimizations to improve performance.
NFC Data Exchange Specifications
Specifies a common data format for NFC Forum-compliant devices and NFC Forum-compliant tags.
NFC Forum Tag Type Technical Specifications
NFC Record Type Definition Technical Specifications
Technical specifications for Record Type Definitions (RTDs) and four specific RTDs: Text, URI, Smart Poster, and Generic Control.
Specifies the format and rules for building standard record types used by NFC Forum application definitions and third parties that are based on the NDEF data format. The RTD specification provides a way to efficiently define record formats for new applications and gives users the opportunity to create their own applications based on NFC Forum specifications.
Provides an efficient way to store text strings in multiple languages by using the RTD mechanism and NDEF format. An example of using this specification is included in the Smart Poster RTD.
Defines the Device Information record type, which conveys fundamental model and identity identification information. The purpose of the Device Information record is to convey host information in a record format that can be used across different carrier types or service types.
NFC Wireless Charging Specifications
Wireless Charging allows for wireless charging of small battery-powered devices like those found in many IoT devices, This approach can help avoid the need for a separate wireless charging unit for small devices if the device includes an NFC communication interface. For example, a Bluetooth headset which includes NFC technology for pairing could also use the NFC interface for wireless charging. In this case, the NFC antenna is used to exchange the pairing information and to transfer power.
This NFC specification uses the 13.56 MHz base frequency and leverages the NFC communication link to control the power transfer. NFC technology is unique in that it allows the transfer of power to an NFC tag to enable communication by providing a constant carrier signal. The WLC specification extends this communication functionality of NFC technology to enable wireless charging. The WLC specification ensures a safe charging process between two NFC-enabled devices in either static or negotiated modes. Static mode uses standard radio frequency (RF) field strength and provides a consistent power level. Negotiated mode uses a higher RF field supporting four power transfer classes of 250, 500, 750 and 1000 milliwatts.