Near-Field Communication (NFC) is a short-range contactless communication technology that allows near-instant data transfer between devices. Various modern devices come with an integrated NFC microchip, including your smartphone. NFC operates over a very short distance of four centimetres and with speeds ranging from 106 kbit/s to 424 kbit/s. It uses a base frequency of 13.56 MHz.
NFC tag reading in iPhones was introduced with the iOS 13 update. If you own an iPhone 7 or a later version, you can use NFC in “Reader” mode with or without using a third-party application. The next major update of iOS 14 introduced “Reader/Writer” mode, allowing users to scan and modify the data in rewritable NFC tags. In short, iPhone 13 can make use of NFC technology.
How to Enable NFC in iPhone 13?
iPhone 13, one of the newer iPhone models, does not require the user to enable NFC manually. The latest versions of iOS come with a feature called ‘background tag reading,’ which allows the user to scan an NFC tag by hovering their phone above it. To modify an existing tag, you will need to install an NFC Tag Writing App.
Some older versions of iPhones need an NFC application to use the scanner; others only need to tap the NFC icon from the quick menu. If you have iOS 15 installed on your device, you do not need a dedicated app to use the NFC scanner.
If you wish to understand how background tag reading works, you will first need to learn how NFC technology functions in general.
NFC in Smartphones
If you have used your phone to make a transaction using Google Pay, or Apple Pay, then you have already used the NFC chip in your smartphone. NFC can also be used for quick data transfer between two smartphones or any NFC-enabled devices. Smartphones are manufactured with embedded NFC sensors which can be used as scanners to read/write NFC tags.
NFC readers are native to all iPhones from iPhone 7 onwards. iPhones with an NFC reader/writer can thus read and write information such as URLs and text on NFC tags. They also come with a background tag reading feature, which, when enabled, searches for nearby NFC tags when the screen is illuminated and does not require a specific application to be open.
Background tag reading operates under caveats; it is disabled when Apple Pay or Wallet is in use or when cameras are in use. Airplane mode disables background tag reading and does not work when the iPhone is locked after a restart. Moreover, when the system locates a compatible tag, it notifies the user and NFC scanning will only be done after the user taps on the notification banner.
How does NFC work?
NFC has evolved from the existing RFID technology. Radio Frequency Identification (RFID) uses electromagnetic waves emitted from a reader to identify or match information with an RFID tag. The RFID technology utilizes three components: a transmitter, a receiver, and a transponder. The transmitter emits radio waves to an RFID tag, which, upon receiving the signal, responds with the information stored in it.
As NFC is an extension of the RFID technology, it similarly uses tags and readers. Data in an NFC tag is stored as an NDEF record (NFC Data Exchange Format). NFC tags differ from RFID tags in that they are capable of storing encrypted information, making them more secure than their predecessors. This, however, does not make NFC-enabled devices invulnerable to security breaches. When operating in peer-to-peer mode, these devices, which usually contain personal information, are susceptible to cybercrime and digital pickpocketing.
NFC devices work in a short range of less than 4 cm to avoid accidental triggers and reduce the chances of human error. NFC scanner in iPhones also allows the user to read information from electronic tags affixed to real-world objects.
NFC tags are memory cards with integrated loop antennas that can only be powered up by inductive coupling when another NFC device is brought near. Unlike RFID, which only offers unidirectional data transfer, NFC can facilitate two-way data transfer. An iPhone can act as an NFC tag and a reader/writer. This lends versatility to the device, giving it access to all sorts of NFC-related applications.
NFC Operating Modes
The NFC Forum has defined several operating modes. Here are the three most commonly used operating modes in day-to-day life.
- Card Emulation Mode allows a smartphone or a wearable (like a smartwatch) to emulate a contactless card. Smartphones can emulate banking cards or even emulate contact tickets for public transit. This is also the most common operating mode, as NFC’s advent in the commercial markets was through the payment-card industry.
- Reader/Writer Mode allows an NFC-enabled device like a smartphone to read or write data to an NFC tag in NDEF format. Not all tags allow their data to be overwritten. As mentioned earlier, NFC tags can store encrypted data. One example for the use of such tags is for access control.
Rewritable NFC tags are easily available in the market and just as easy to use. They can be programmed to store information such as URLs, Wi-Fi configuration or Bluetooth pairing information.
- Peer-to-Peer Mode allows two NFC enabled devices to exchange data. Content such as photos, videos, and other file types can be transferred directly from one device to another. Peer-to-Peer mode also allows quick pairing to wireless devices such as speakers or headphones.
Implementing NFC in today’s world has more advantages than disadvantages. NFC technology has especially transformed the commerce industry by making contactless payments ubiquitous. NFC has also upped the security from its precursor, RFID technology, by using 128-bit or higher encryption to safeguard the privacy of transactions. Using a peer-to-peer connection, NFC also allows quick file transfer between two smartphones or similar devices.
These are only the most common and noticeable uses of the technology. NFC has provided many benefits to various fields. While it comes with its limitations, its usage will only continue to grow with time. In the future, smartphones and other NFC-enabled devices may be capable of doing much more than simply emulating an NFC reader/writer.