Near-field communication
[2] Like other proximity card technologies, NFC is based on inductive coupling between two electromagnetic coils present on a NFC-enabled device such as a smartphone.
[3][4] Secure communications are available by applying encryption algorithms as is done for credit cards[5] and if they fit the criteria for being considered a personal area network.
GSMA's efforts include Trusted Services Manager,[10][11] Single Wire Protocol, testing/certification and secure element.
[12] 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.
[13] A platform-independent free and open source NFC library, libnfc, is available under the GNU Lesser General Public License.
[14][15] Present and anticipated applications include contactless transactions, data exchange and simplified setup of more complex communications such as Wi-Fi.
[citation needed] Near-field communication (NFC) technology not only supports data transmission but also enables wireless charging, providing a dual-functionality that is particularly beneficial for small, portable devices.
[17] This capability is especially suitable for smaller devices like earbuds, wearables, and other compact Internet of Things (IoT) appliances.
[17] This makes NFC WLC an ideal solution for devices where space is at a premium and high power charging is less critical.
[17] The NFC Forum also facilitates a certification program, labeled as Test Release 13.1 (TR13.1), 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.
[17] NFC is rooted in radio-frequency identification technology (known as RFID) which allows compatible hardware to both supply power to and communicate with an otherwise unpowered and passive electronic tag using radio waves.
Similar ideas in advertising and industrial applications were not generally successful commercially, outpaced by technologies such as QR codes, barcodes and UHF RFID tags.
This enables NFC targets to take very simple form factors such as unpowered tags, stickers, key fobs, or cards.
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.
[57] 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 (radio waves) of that frequency (about 22 metres), 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 (which are electromagnetic waves, also involving an oscillating electric field); that minimises interference between such devices and any radio communications at the same frequency or with other NFC devices much beyond its intended range.
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[58] in order to support high data rates.
In "card emulation mode" an NFC device should transmit, at a minimum, a unique ID number to a reader.
[70] GSM is involved with several initiatives: StoLPaN (Store Logistics and Payment with NFC) is a pan-European consortium supported by the European Commission's Information Society Technologies program.
Its specifications include the five distinct tag types that provide different communication speeds and capabilities covering flexibility, memory, security, data retention and write endurance.
For example, Google's deployment of Host Card Emulation on Android KitKat provides for software control of a universal radio.
HCE allows any Android 4.4 app to emulate an NFC smart card, letting users initiate transactions with their device.
[82] Nokia, Samsung, BlackBerry and Sony[83] have used NFC technology to pair Bluetooth headsets, media players and speakers with one tap.
[56] NFC can be used for social networking, for sharing contacts, text messages and forums, links to photos, videos or files[78] and entering multiplayer mobile games.
NFC operates at slower speeds than Bluetooth and has a much shorter range, but consumes far less power and doesn't require pairing.
NFC's maximum working distance of less than 20 cm (7+7⁄8 in) reduces the likelihood of unwanted interception, making it particularly suitable for crowded areas that complicate correlating a signal with its transmitting physical device (and by extension, its user).
