What is NFC in general?
NFC (Near Field Communication) is translated as near field communication. This technology allows you to exchange data between devices that are at a distance of 10 cm.
One of the most popular uses of NFC is payment for goods and services.
Once register the card in the system, then bring the smartphone or smartwatch to the terminal, start the corresponding application, confirm the operation, for example, with a fingerprint – and you are done!
You must admit that today it is more difficult to forget a smartphone at home than a wallet. By the way, some payment systems allow you to transfer funds from a smartphone to a smartphone.
But in fact, NFC applications are much more. For example, technology transfers files from a device to a device or plays music by putting a smartphone on a column.
And you can also get data from the NFC tag if you bring it to the smartphone. Or provide an NFC chip with owner data as a document.
Chips are often embedded in passports, including Russian ones. If you have a smartphone with NFC, you can download an application like this and scan your zagran.
Finally, NFC chips are used as keys for accessing private data and as travel documents. And for contactless engine start.
How does NFC work in smartphones and not only?
NFC has expanded the ISO 14443 contactless card standard. It combines the interface of a smart card and a reader into one device.
The technology has become an extension of RFID. But if RFID’s radius of work can reach hundreds of meters, then the radius of operation of NFC is limited to about 10 cm to ensure the security of data transmission.
The basis of the technology is magnetic induction. If two loop antennas are positioned within each other’s near field, an air-core transformer is obtained.
NFC operates at a frequency of 13.56 MHz. For the data transfer to occur, you need a target (for example, a terminal) and a contact initiator (for example, a smartphone) that generates a radiofrequency field.
An example of a passive NFC tag with auto contact recording.
NFC mode of operation can be active and passive. The initiator creates the field in the passive mode, and the target modulates it, becoming a repeater. NFC tags and key cards function similarly.
In the active device, they interact in turn, creating and disconnecting their fields – this is how, for example, payment is made through the terminal from a smartphone. The power source is needed only by the initiator device.
Tags and other passive NFC batteries are not needed. But the smartphone, which acts as an initiator, is necessary. That is why paying for a discharged iPhone won’t work.
NFC data exchange occurs in a coded format. Depending on the data rate, different modulation factors may be used. If the received signal does not match the transmitted signal, a contradiction arises, and the operation is not completed.
Limitations and features of NFC in smartphones
An NFC smartphone can impersonate a payment card or travel card for public transport. But the data of a bank card during registration is not recorded in the smartphone’s memory but on a separate chip. It provides data encryption, controls the authentication process and payment transactions.
Also, a smartphone with NFC can work in reading mode. It scans NFC tags and presents information from them in a readable format.
In the Russian Federation, this is not too common, and in the West, NFC tags are often used instead of bar codes in supermarkets. You can find out what the product is, where it is made and how long it has. Advertising on NFC tags is also often shown.
Finally, the NFC in the smartphone can work in peer-to-peer mode. In this case, the two NFC devices exchange data. That is convenient, for example, if you want to transfer contacts or Wi-Fi settings from a gadget to a gadget.
The data transfer rate for an NFC connection is usually within 106-848 kbit / s. Not much, but for payments, transfer of contacts and settings, or listening to music is more than enough.
The NFC logo, which can be seen on smartphones and accessories right above the sensor.
Usually, the location of NFC in smartphones is marked with a special icon so as not to overshoot and position the device with the right side to the terminal or tag.
How does NFC work in your bank cards (Visa and MasterCard)
Payment giants have embedded NFC cards. That simplifies making payments and makes them safer.
We pay by simply attaching to the terminal a card or a smartphone that imitates it. You can set the amount in the settings, after which the airport will necessarily request a PIN code.
The difference between PayWave in Visa and Contactless in MasterCard (previously called PayPass) is minimal. Visa owns just one technology, the second is MasterCard, but they work similarly.