Friday, 21 December 2012

What is NFC?

Near field communication (NFC) is a set of standards for smartphones and similar devices to establish radio communication with each other by touching them together or bringing them into close proximity, usually no more than a few centimeters. Present and anticipated applications include contactless transactions, data exchange, and simplified setup of more complex communications such as Wi-Fi.[1] Communication is also possible between an NFC device and an unpowered NFC chip, called a "tag".[2] NFC standards cover communications protocols and data exchange formats, and are based on existing radio-frequency identification (RFID) standards including ISO/IEC 14443 and FeliCa.[3] The standards include ISO/IEC 18092[4] and those defined by the NFC Forum, which was founded in 2004 by Nokia, Philips and Sony, and now has more than 160 members. The Forum also promotes NFC and certifies device compliance.[5]

 NFC builds upon RFID systems by allowing two-way communication between endpoints, where earlier systems such as contactless smart cards were one-way only.[6] Since unpowered NFC "tags" can also be read by NFC devices,[2] it is also capable of replacing earlier one-way applications.

 Commerce NFC devices can be used in contactless payment systems, similar to those currently used in credit cards and electronic ticket smartcards, and allow mobile payment to replace or supplement these systems. For example, Google Wallet allows consumers to store credit card and store loyalty card information in a virtual wallet and then use an NFC-enabled device at terminals that also accept MasterCard PayPass transactions.[7] Germany,[8] Austria,[9] Finland,[10] New Zealand,[11] and Italy[12] have trialed NFC ticketing systems for public transport, while China has brought it into service on buses across the country.[citation needed] India is implementing NFC based transactions in box offices for ticketing purposes.[13] History NFC traces its roots back to radio-frequency identification, or RFID. RFID allows a reader to send radio waves to a passive electronic tag for identification, authentication and tracking. 1983 The first patent to be associated with the abbreviation RFID was granted to Charles Walton.[19] 1995 wallet paying and receiving electronic, described in the report and annexes describing the invention of Gaston Schwabacher in 0017 patented protocol 24/01/1995 at INPI Brazil with the IP number 9500345 2004 Nokia, Philips and Sony established the Near Field Communication (NFC) Forum[20] 2006 Initial specifications for NFC Tags[21] 2006 Specification for "SmartPoster" records[22] 2006 Nokia 6131 was the first NFC phone[23] 2009 In January, NFC Forum released Peer-to-Peer standards to transfer contact, URL, initiate Bluetooth, etc.[24] 2010 Samsung Nexus S: First Android NFC phone shown[25][26] 2011 Google I/O "How to NFC" demonstrates NFC to initiate a game and to share a contact, URL, app, video, etc.[16] 2011 NFC support becomes part of the Symbian mobile operating system with the release of Symbian Anna version.[27] 2011 Research In Motion is the first company for its devices to be certified by MasterCard Worldwide, the functionality of PayPass[28] 2012 March. EAT, a well known UK restaurant chain and Everything Everywhere (Orange Mobile Network Operator) partner on the UK's first nationwide NFC enabled smartposter campaign. (lead by Rene' Batsford, Head of ICT for EAT, also known for deploying the UK's first nationwide contactless payment solution in 2008) A specially created mobile phone app is triggered when the NFC enabled mobile phone comes into contact with the smartposter.[29] 2012 Sony introduces the "Smart Tags", which use NFC technology to change modes and profiles on a Sony smartphone at close range, included in the package of (and "perfectly paired" with) the Sony Xperia P Smartphone released the same year.[30] 2012 Samsung introduces TecTile[31]; a set of MIFARE NFC stickers and a companion application for Android to read and write the TecTile stickers, and design macros that can be triggered by them.

Essential specifications

NFC is a set of short-range wireless technologies, typically requiring a distance of 4 cm 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 tags, stickers, key fobs, or cards that do not require batteries. NFC peer-to-peer communication is possible, provided both devices are powered.[6] A patent licensing program for NFC is currently under development by Via Licensing Corporation, an independent subsidiary of Dolby Laboratories. A public, platform-independent NFC library is released under the free GNU Lesser General Public License by the name libnfc.[32]
NFC tags contain data and are typically read-only, but may be rewriteable. They can be custom-encoded by their manufacturers or use the specifications provided by the NFC Forum, an industry association charged with promoting the technology and setting key standards. 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 four types of tags that provide different communication speeds and capabilities in terms of configurability, memory, security, data retention and write endurance. Tags currently offer between 96 and 4,096 bytes of memory.
  • As with proximity card technology, near-field communication uses magnetic induction between two loop antennas located within each other's near field, effectively forming an air-core transformer. It operates within the globally available and unlicensed radio frequency ISM band of 13.56 MHz. Most of the RF energy is concentrated in the allowed ±7 kHz bandwidth range, but the full spectral envelope may be as wide as 1.8 MHz when using ASK modulation.[33]
  • Theoretical working distance with compact standard antennas: up to 20 cm (practical working distance of about 4 centimetres)
  • Supported data rates: 106, 212 or 424 kbit/s (the bit rate 848 kbit/s is not compliant with the standard ISO/IEC 18092)
  • There are two modes:
    • Passive communication mode: The initiator device provides a carrier field and the target device answers by modulating the existing field. In this mode, the target device may draw its operating power from the initiator-provided electromagnetic field, thus making the target device a transponder.
    • Active communication mode: Both initiator and target device communicate by alternately generating their own fields. A device deactivates its RF field while it is waiting for data. In this mode, both devices typically have power supplies.
SpeedActive devicepassive device
424 kbit/sManchester, 10% ASKManchester, 10% ASK
212 kbit/sManchester, 10% ASKManchester, 10% ASK
106 kbit/sModified Miller, 100% ASKManchester, 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% modulation is used. In all other cases Manchester coding is used with a modulation ratio of 10%.
  • NFC devices are able to receive and transmit data at the same time. Thus, they can check for potential collisions, if the received signal frequency does not match with the transmitted signal's frequency.

[edit]Source : Wikipedia


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