Near-field communication

Near-field communication[] is a set of communication protocols that enables communication between two electronic devices over a distance of or less. NFC offers a low-speed connection through a simple setup that can be used for the bootstrapping of capable wireless connections. Like other proximity card technologies, NFC is based on inductive coupling between two electromagnetic coils present on an NFC-enabled device such as a smartphone. NFC communicating in one or both directions uses a frequency of 13.56 MHz in the globally available unlicensed radio frequency ISM band, compliant with the ISO/IEC 18000-3 air interface standard at data rates ranging from 106 to 848 kbit/s.
The #NFC Forum has helped define and promote the technology, setting standards for certifying device compliance. Secure communications are available by applying encryption algorithms as is done for credit cards and if they fit the criteria for being considered a personal area network.

NFC standards

NFC standards cover communications protocols and data exchange formats and are based on existing radio-frequency identification standards including ISO/IEC 14443 and FeliCa. The standards include ISO/IEC 18092 and those defined by the NFC Forum. In addition to the NFC Forum, the GSMA group defined a platform for the deployment of GSMA NFC Standards within mobile handsets. GSMA's efforts include Trusted Services Manager, Single Wire Protocol, testing/certification and secure element. NFC-enabled portable devices can be provided with application software, for example to read electronic tags or make payments when connected to an NFC-compliant system. These are standardized to NFC protocols, replacing proprietary technologies used by earlier systems.
A patent licensing program for NFC is under deployment by France Brevets, a patent fund created in 2011. This program was under development by Via Licensing Corporation, an independent subsidiary of Dolby Laboratories, and was terminated in May 2012. A platform-independent free and open source NFC library,, is available under the GNU Lesser General Public License.
Present and anticipated applications include contactless transactions, data exchange and simplified setup of more complex communications such as Wi-Fi. In addition, when one of the connected devices has Internet connectivity, the other can exchange data with online services.

NFC wireless charging (WLC)

Near-field communication technology not only supports data transmission but also enables wireless charging, providing a dual-functionality that is particularly beneficial for small portable devices. The NFC Forum has developed a specific wireless charging specification, known as NFC Wireless Charging, which allows devices to charge with up to 1W of power over distances of up to. This capability is especially suitable for smaller devices like earbuds, wearables, and other compact Internet of Things appliances.
Compared to the more widely known Qi wireless charging standard by the Wireless Power Consortium, which offers up to 15W of power over distances up to, NFC WLC provides a lower power output but benefits from a significantly smaller antenna size. This makes NFC WLC an ideal solution for devices where space is at a premium and high power charging is less critical.
The NFC Forum also facilitates a certification program, labeled as Test Release 13.1, ensuring that products adhere to the WLC 2.0 specification. This certification aims to establish trust and consistency across NFC implementations, minimizing risks for manufacturers and providing assurance to consumers about the reliability and functionality of their NFC-enabled wireless charging devices.

History

NFC is rooted in radio-frequency identification technology which allows compatible hardware to both supply power to and communicate with an otherwise unpowered and passive electronic tag using radio waves. This is used for identification, authentication and tracking. Similar ideas in advertising and industrial applications were not generally successful commercially, outpaced by technologies such as QR codes, barcodes and UHF RFID tags.

May 17, 1983: The first patent to be associated with the abbreviation "RFID" was granted to Charles Walton.
1997: Early form patented and first used in Star Wars character toys for Hasbro. The patent was originally held by Andrew White and Marc Borrett at Innovision Research and Technology. The device allowed data communication between two units in close proximity.
March 25, 2002: Philips and Sony agreed to establish a technology specification and created a technical outline. Philips Semiconductors applied for the six fundamental patents of NFC, invented by the Austrian and French engineers Franz Amtmann and Philippe Maugars who received the European Inventor Award in 2015.
December 8, 2003: NFC was approved as an ISO/IEC standard and later as an ECMA standard.
2004: Nokia, Philips and Sony established the NFC Forum
2004: Nokia launched NFC shell add-on for Nokia 5140 and later Nokia 3220 models, to be shipped in 2005.
2005: Mobile phone experimentations in transports, with payment in May in Hanau and as well validation aboard in October in Nice with Orange and payment in shops in October in Caen with first reception of "Fly Tag" informations
2006: Initial specifications for NFC Tags
2006: Specification for "SmartPoster" records
2007: Innovision's NFC tags used in the first consumer trial in the UK, in the Nokia 6131 handset.
2008: AirTag launched what it called the first NFC SDK.
2009: In January, NFC Forum released Peer-to-Peer standards to transfer contacts, URLs, initiate Bluetooth, etc.
2009: NFC first used in transports by China Unicom and Yucheng Transportation Card in the tramways and bus of Chongqing on 19 January 2009, then implemented for the first time in a metro network, by China Unicom in Beijing on 31 December 2010.
2010: Innovision released a suite of designs and patents for low cost, mass-market mobile phones and other devices.
2010: Nokia C7: First NFC-capable smartphone released. NFC feature was enabled by software update in early 2011.
2010: Samsung Nexus S: First Android NFC phone shown
May 21, 2010: Nice, France, launches, with "Cityzi", the "Nice City of contactless mobile" project, the first in Europe to provide inhabitants with NFC bank cards and mobile phones, and a "bouquet of services" covering transportation, tourism and student's services
2011: Independent development of lightweight NFC stacks addressed the resource constraints of early mobile secure elements. Engineers such as Dan Hughes worked on custom implementations to enable peer-to-peer payments on limited-memory devices prior to the standardization of host card emulation.
2011: Google I/O "How to NFC" demonstrated NFC to initiate a game and to share a contact, URL, app or video.
2011: NFC support becomes part of the Symbian mobile operating system with the release of Symbian Anna version.
2012: UK restaurant chain EAT. and Everything Everywhere, partner on the UK's first nationwide NFC-enabled smartposter campaign. A dedicated mobile phone app is triggered when the NFC-enabled mobile phone comes into contact with the smartposter.
2012: Sony introduced NFC "Smart Tags" to change modes and profiles on a Sony smartphone at close range, included with the Sony Xperia P Smartphone released the same year.
2013: Samsung and VISA announce their partnership to develop mobile payments.
2013: IBM scientists, in an effort to curb fraud and security breaches, develop an NFC-based mobile authentication security technology. This technology works on similar principles to dual-factor authentication security.
October 2014: Dinube becomes the first non-card payment network to introduce NFC contactless payments natively on a mobile device, i.e. no need for an external case attached or NFC 'sticker' nor for a card. Based on Host card emulation with its own application identifier, contactless payment was available on Android KitKat upwards and commercial release commenced in June 2015.
2014: AT&T, Verizon and T-Mobile released Softcard. It runs on NFC-enabled Android phones and iPhone 4 and iPhone 5 when an external NFC case is attached. The technology was purchased by Google and the service ended on March 31, 2015.
September 2015: Google's Android Pay function was launched, a direct rival to Apple Pay, and its roll-out across the US commenced.
November 2015: Swatch and Visa Inc. announced a partnership to enable NFC financial transactions using the "Swatch Bellamy" wristwatch. The system is currently online in Asia, through a partnership with China UnionPay and Bank of Communications. The partnership will bring the technology to the US, Brazil, and Switzerland.

Ultra-wideband another radio technology has been hailed as a future possible alternatives to NFC technology due to further distances of data transmission, as well as Bluetooth and wireless technology.

Design

NFC is a set of short-range wireless technologies, typically requiring a separation of or less. NFC operates at 13.56 MHz on ISO/IEC 18000-3 air interface and at rates ranging from 106 kbit/s to 424 kbit/s. NFC always involves an initiator and a target; the initiator actively generates an RF field that can power a passive target. This enables NFC targets to take very simple form factors such as unpowered tags, stickers, key fobs, or cards. NFC peer-to-peer communication is possible, provided both devices are powered.
NFC tags contain data and are typically read-only, but may be writable. They can be custom-encoded by their manufacturers or use NFC Forum specifications. The tags can securely store personal data such as debit and credit card information, loyalty program data, PINs and networking contacts, among other information. The NFC Forum defines five types of tags that provide different communication speeds and capabilities in terms of configurability, memory, security, data retention and write endurance.
As with proximity card technology, NFC uses inductive coupling between two nearby loop antennas effectively forming an air-core transformer. Because the distances involved are tiny compared to the wavelength of electromagnetic radiation of that frequency, the interaction is described as near field. An alternating magnetic field is the main coupling factor and almost no power is radiated in the form of radio waves ; that minimises interference between such devices and any radio communications at the same frequency or with other NFC devices much beyond its intended range. NFC operates within the globally available and unlicensed radio frequency ISM band of 13.56 MHz. Most of the RF energy is concentrated in the ±7 kHz bandwidth allocated for that band, but the emission's spectral width can be as wide as 1.8 MHz in order to support high data rates.
Working distance with compact standard antennas and realistic power levels could be up to about . Note that because the pickup antenna may be quenched in an eddy current by nearby metallic surfaces, the tags may require a minimum separation from such surfaces.
The ISO/IEC 18092 standard supports data rates of 106, 212 or 424 kbit/s.
The communication takes place between an active "initiator" device and a target device which may either be:
; Passive: The initiator device provides a carrier field and the target device, acting as a transponder, communicates by modulating the incident field. In this mode, the target device may draw its operating power from the initiator-provided magnetic field.
; Active: Both initiator and target device communicate by alternately generating their own fields. A device stops transmitting in order to receive data from the other. This mode requires that both devices include power supplies.

Speed	Active device	Passive device
424	Manchester, 10% ASK	Manchester, 10% ASK
212	Manchester, 10% ASK	Manchester, 10% ASK
106	Modified Miller, 100% ASK	Manchester, 10% ASK

NFC employs two different codings to transfer data. If an active device transfers data at 106 kbit/s, a modified Miller coding with 100 percent modulation is used. In all other cases Manchester coding is used with a modulation ratio of 10 percent.
Every active NFC device can work in one or more of three modes:
; NFC card emulation: Enables NFC-enabled devices such as smartphones to act like smart cards, allowing users to perform transactions such as payment or ticketing. See Host card emulation
; NFC reader/writer: Enables NFC-enabled devices to read information stored on inexpensive NFC tags embedded in labels or smart posters.
; NFC peer-to-peer:Enables two NFC-enabled devices to communicate with each other to exchange information in an ad hoc fashion.
NFC tags are passive data stores which can be read, and under some circumstances written to, by an NFC device. They typically contain data and are read-only in normal use, but may be rewritable. Applications include secure personal data storage. NFC tags can be custom-encoded by their manufacturers or use the industry specifications.