NFC, or Near Field Communication, is a simple and intuitive technology that allows you to use your mobile phone for innovative purposes. An NFC tag may be connected to information such as another Web page, social networks and all sorts of other general information. Other fields in which NFC is beginning to develop are payment, door opening with secure contactless locks, connection to computers and many more. All of these actions have something in common: they require you to place your Smartphone (or any other NFC device) near (the N in NFC) the element with which you want to interact.
NFC provides the link between the physical world and the virtual world. When two devices are placed near each other, a virtual reaction occurs. Bluetooth and WiFi do not have this positioning facility.
In more technical terms, NFC defines the process by which two products communicate with each other. NFC is a derivative of RFID technology, which has a shorter action distance (10cm in theory, ~4 cm in reality) which uses low speeds (106-414 kbps) and a low friction installation (no discovery and no pairing), which then enables two devices to communicate automatically when they are near each other.
NFC uses passive (no power supply!) and random non-powered mechanisms: tags or stickers, sometimes called transponders or labels, all of which are on sale on this site. NFC tags are essentially "targets", which "want" to be touched by devices such as NFC Smartphones. These tags may contain data that provides you with access to information, applications or services.
NFC appears in many telephones, such as Apple, Nokia, HTC, Samsung, RIM (Blackberry). 600 million telephones with NFC technology are forecast to be sold by 2018.
The main use which people think of is payment. Contactless bank cards are becoming increasingly common and an NFC telephone may act like one. This means that when you are in a shop and you are ready to pay, rather than take out your standard credit card you can put your telephone near the "reader" and make your payment.
The second use which is frequently mentioned after payment is secure access control. Many offices and public spaces have contactless readers which keep doors locked and authorised people may use an access card to open the door. Once again, NFC telephones can act like access cards and open doors for you, when of course they are placed in the reader's NFC field (F NFC).
In technological terms, they are a type of RFID chip. They are designed to be used with an NFC Smartphone.
A Tag features three main parts: the chip, the antenna and the paper or vinyl sticker. NFC Tags tend to be self-adhesive, but don't really need to be. However, in our explanation we will start from the principle that they are.
The antenna captures the radio energy formed by the mobile telephone when it passes near the tag. This energy feeds the chip, which will receive enough power to start up and so be able to have a brief "conversation" with the mobile phone. The "thing" which makes NFC technology so special is that this communication uses the same radio waves as the chip's power so that everything can be done in one movement. In this way, it generally takes less than a second to read an NFC tag.
The antenna and the chip are "sandwiched" between two layers: one paper or vinyl layer with the graphics printed according to the consumer's desires and the other layer with the adhesive part of the sticker. This enables the NFC tag to be affixed to an appropriate location and the graphic enables users to identify the tags to be able to use them.
When the Tag is read as described above, the Tag data is then available for the phone and different processing options are possible. This can range from opening a web page to an automatic phone call or sending an SMS. This simplicity is obtained thanks to the standardisation of the NFC or NDEF coding format, as defined by the NFC Forum.
At the same time as NDEF, there are Tag type standards which define the different types of makes and the communication specifics of each one. All of this provides us with very simple mechanisms to read and write tags (writing is the same process but in reverse).
RFID is a general term which covers several types of chips and antennas. The radio frequencies, the reading distance and the chip data coding methods may vary hugely. NFC Tags are very well defined and specified by the NFC Forum, but are considered as a particular form of RFID specifications which enable them to be used in an open context.