Near Field Communication (NFC) - Online Article

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The current state of the consumer electronics can be characterized by moving from a single purpose device to a multifunctional device and by moving from isolated devices to a networked device. In this last respect, it is important that people are not faced with the complexities of setting up network connections between devices explicitly. Cumbersome network settings can be possibly dealt with in the computer world but certainly not in the consumer electronics world.
  This is the origin of the Near Field Communication Interface and Protocol (NFCIP-1) protocol. The protocol is targeted towards the consumer electronics users that will be able to use the secure means of communication between various devices without exerting much intellectual effort in configuring their “network”. The concept is strikingly simple: in order to make two devices communicate, bring them together or touch them to each other. This will engage the NFCIP-1 wireless devices’ interfaces between the devices and configure them to link up in a peer-to-peer network. The devices can also set up communication for longer range and faster protocols like Bluetooth or Wireless Ethernet (Wi-Fi) once the configuration data has been exchanged using NFC.

Near Field Communication (NFC) offers tremendous potential, not only because it can be rolled out for mass adoption, but because of the number of different ways in which it can be used to make life easier.

Near Field Communication (NFC) is a new, short-range wireless connectivity technology that evolved from a combination of existing contactless identification and interconnection technologies. Products with built-in NFC will dramatically simplify the way consumer devices interact with one another, helping people speed connections, receive and share information and even make fast and secure payments.

This article provides background on NFC including an explanation of what the technology can achieve how it works and where it could be used.

If you have a PC and a mobile phone equipped with NFC, you can easily download a new game from a website directly onto this mobile phone for your kid using NFC.   And this same principle will work for any sort of data transfer between two pieces of equipment when they support NFC. There is no need to set up communication manually provided that the applications are capable of handling the communication. This opens countless possibilities for content transfer and management of personal data stored within different types of consumer electronics equipment.

What is Near Field Communication (NFC) ?

Near Field Communication or NFC is a short-range high frequency wireless communication technology which enables the exchange of data between devices over about a 10 centimeter (around 4 inches) distance. The technology is a simple extension of the ISO 14443 proximity-card standard (contactless card, RFID) that combines the interface of a smartcard and a reader into a single device. An NFC device can communicate with both existing ISO 14443 smartcards and readers, as well as with other NFC devices, and is thereby compatible with existing contactless infrastructure already in use for public transportation and payment. NFC is primarily aimed at usage in mobile phones.

NFC is a short range wireless technology that allows communications to take place between devices that either touch or are momentarily held close together.
  The technology works via magnetic field induction and operates on an unlicensed radio frequency band. “Tags” are embedded within devices (these could be mobile devices such as mobile phones or PDAs, or NFC stations such as ticket barriers or cash registers). NFC enables devices that are held together to share information either in one direction or both.

NFC is based on Radio Frequency Identification (RFID) technology, which is compatible with most of the contactless transportation and ticketing solutions that are commonly used around the world to enable quick and smooth flow of people within public transportation systems or ticketed environments. NFC is an open platform technology and was approved as an ISO/IEC global standard in December 2003.

Why is NFC important ?

NFC is an important technology for a number of reasons:

     
  1. Reach and availability: NFC has the potential over time to be integrated into every mobile handset in the world. This would give the technology a potential reach as global as the mobile phone itself. By integrating NFC technology into a mobile handset, users could gain access to a number of new services via their phone.
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  3. Variety of use: NFC can be used for a number of tasks, from payment for goods to ticketing and from pairing devices to sharing information or discovering new services. Examples of these applications are outlined in this document.
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  5. Ease of use: Because NFC only requires that two devices touch in order to communicate, NFC can simplify many tasks, from opening a web browser on a mobile phone to pairing two Bluetooth devices automatically to accessing wireless hotspots simply and easily.
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  7. Security: NFC requires a user to actively wave or hold their mobile device against another device or NFC station to activate a service or to share information. In so doing, the technology requires the user to make a positive action to confirm the transaction or exchange. In addition it is possible to build multiple levels of security into an NFC enabled device.
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  9. Value added services: NFC enables users to access value added services that would otherwise be unavailable with a traditional ticket or payment card. Just as users of prepay mobile services are able to access their current credit balance through the phone’s menu system, so users of an NFC enabled phone will be able to access similar information through their device. Furthermore, NFC enabled devices could access the mobile network to add credit to the device when it runs out or is low, or alternatively on a set date each week or month.
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  11. Infrastructure: NFC is compatible with the current contactless infrastructure used as a platform for ticketing, transportation, and increasingly payment, across the world. NFC mobile devices could easily be made compatible with the major transport systems world-wide that use contactless access to services, for example those based on the MIFARE system. It is also compatible with the increasingly popular “wave to pay” credit and debit cards that are being rolled out in many countries. The roll out of NFC to existing contactless environments is straight forward. Users know how the system works and much of the infrastructure is in place already. The roll out of NFC is an extension to services that already exist, but enhanced with the additional element of a mobile phone’s user interface and a connection to the internet.

What you can do with NFC ?

     
  1. Make fast, convenient, and secure purchases by touching your mobile phone to NFC credit card readers.
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  3. NFC technology lets you use your mobile phone as a travel ticket – just touch and ride.
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  5. Visit your favorite websites, make phone calls, or send text messages just by tapping your mobile phone to service shortcut tags available from, for example, your service provider.
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  7. Explore mobile services like news, weather, and travel timetables by touching your mobile phone to posters embedded with service shortcut tags.
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  9. Share information and notes with your friends and colleagues just by touching your NFC mobile phones together.
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  11. Electronic ticketing — airline tickets, concert/event tickets, and others
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  13. Electronic money
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  15. Travel cards
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  17. Identity documents
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  19. Mobile commerce
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  21. Electronic keys — car keys, house/office keys, hotel room keys, etc.
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  23. NFC can be used to configure and initiate other wireless network connections such as Bluetooth, Wi-Fi or Ultra-wideband.

Essential Specifications

     
  1. Like ISO 14443, NFC communicates via magnetic field induction, where two loop antennas are 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, with a bandwidth of almost 2 MHz.
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  3. Working distance with compact standard antennas: up to 20 cm
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  5. Supported data rates: 106, 212, or 424 Kbit/s
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  7. There are two modes: 
       
    1. Passive Communication Mode: The Initiator device provides a carrier field and the target device answers by modulating 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.
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    3. Active Communication Mode: Both Initiator and Target device communicate by alternately generating their own field. A device deactivates its RF field while it is waiting for data. In this mode, both devices typically need to have a power supply.
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  9. 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%.
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  11. NFC devices are able to receive and transmit data at the same time. Thus, they can check the radio frequency field and detect a collision if the received signal does not match with the transmitted signal.

The Protocol

The protocol is based on a wireless interface. There are always two participating parties to the communication; hence the protocol is also known as peer-to-peer communication protocol. The protocol is designed to establish wireless network connections between computer peripherals and consumer electronic.

The interfaces operate in the unregulated RF band of 13.56 MHz. This means that no restrictions are applied and no licenses are required for the use of this RF band. Of course, each country imposes certain limitations on the electromagnetic emissions in this RF band. The limitations mean that in practice the distance at which the devices can connect to each other is restricted and this distance may vary from country to country. Generally speaking, we consider the operating distances of 0~20 cm.

As is often the case with the devices sharing a single RF band, the communication is half-duplex. The devices implement the “listen before talk” policy – any device must first listen on the carrier and start transmitting a signal only if no other device can be detected transmitting.

NFC protocol distinguishes between the Initiator and the Target of the communication. Any device may be either an Initiator or a Target. The Initiator, as follows from the name, is the device that initiates and controls the exchange of data. The Target is the device that answers the request from the Initiator.
  NFC protocol also distinguishes between two modes of operation: Active mode and Passive mode. All devices support both communication modes. The distinction is as follows:

     
  • In the Active mode of communication both devices generate their own RF field to carry the data.
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  • In the Passive mode of communication only one device generates the RF field while the other device uses load modulation to transfer the data. The protocol specifies that the Initiator is the device responsible to generate the RF field.
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  • The application chooses the initial communication speed from the set of 106, 212 and 424 Kbit/s. Subsequently the application and/or the communication environment may require speed adaptation, which can be done during communication.
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  • NFCIP-1 uses different modulation and bit encoding schemes depending on the speed. While establishing the communication, the Initiator starts the communication in a particular mode at a particular speed. The Target determines the current speed and the associated low-level protocol automatically and answers accordingly.
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  • The communication is terminated either on the command from the application or when devices move out of range.

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