Definition of NFC in English

You may have noticed that there are more and more smartphones (and other devices) equipped with NFC. Acronym for Near Field Communication (something like Near Field Communication) from ABBREVIATIONFINDER, the name refers to a new wireless communication technology compared to Wi-Fi, for example, and, therefore, leaves several doubts in the air: what is NFC for? How does the technology work? Why is NFC so important? All this and a little more you will discover below.

What is NFC?

At first, we can view NFC as merely a wireless communication technology. But, in view of so many options for this purpose, such as Wi-Fi and Bluetooth , what are the advantages of its adoption? The answer lies not only in what technology is capable of, but mainly in how.


In a nutshell, NFC is a specification that allows wireless communication (wireless) between two devices through a simple approximation between them, without the user having to enter passwords, click on buttons or perform any similar action when establishing the connection. Hence the name: Near Field CommunicationNear Field Communication or Near Field Communication.

This means that as soon as the devices involved are close enough, communication is established automatically and triggers the corresponding action. These devices can be cell phones, tablets, badges, electronic ticket cards and any other item capable of supporting the installation of an NFC chip.

The distance that the devices must have between them to establish a connection is really short to make evident the intention of communication, without accidental connection: the maximum is somewhere around 10 centimeters. Despite this justification, such a limited scope seems to be quite disadvantageous, right? Not if you understand the applications of NFC.

What can NFC be used for?

NFC technology can be used in numerous applications, including the most critical ones, which involve sensitive user data and finances. An example comes from Google’s Android Pay service , which works with the possibility of the user using a smartphone with Android operating system (from version 4.4) to pay bills (mobile payment) instead of the credit card or even ” cash. ”

Like? It is simpler than it looks: the user approaches his smartphone to a receiver, which may be at a cash register in a market, for example (of course, both devices need to have an NFC chip); as soon as the communication is established (it takes only a few seconds), the device receives information regarding the process, such as the total purchase price.

When the user creates his account and installs Android Pay, the system validates the smartphone. Therefore, it is not necessary to enter passwords or perform biometric authentication on the service (except in special situations), for example. Just move the device closer to it with the unlocked device for the transaction to take place.

It is necessary to register at least one credit or debit card for Android Pay to work, but nothing prevents, in the future, the service or even similar tools that allow amounts to be debited directly from a bank account and that, to confirm the transaction, the application use some kind of biometric identification, for example.

Examples of NFC applications

At this point, you may already be able to imagine other applications for NFC. If negative, here are some more interesting ones:

Employee identification: NFC can be used on badges, for example, to identify an employee’s arrival at the company or his access to a certain sector;

Virtual tour guide: if the user is in a museum, he can approach his cell phone to a nearby receiver to have more information about the material on display on his device;

Advertising: while waiting for the bus, the user can approach his smartphone to a nearby advertising poster and, in doing so, obtain discounts at the advertiser’s store, for example;

Prices in stores: to know the price of a product on the shelf or even get more details (like list of ingredients), just bring the smartphone closer to the item for additional information to appear on the screen.

Japan is an example of a country that exploits NFC technology a lot. There, it is possible, among others, to pay a ticket for the Tokyo Metro by bringing the smartphone closer to a receiver at the turnstile or even buy items at vending machines (very common there) with the same gesture.

Emergence of NFC

It is no accident that Japan is one of the pioneer countries in the adoption of NFC: the technology took shape in 2002 at the hands of the Dutch Philips and the Japanese Sony. From the beginning, the idea was to make the technology used in mobile devices of the most varied types: cell phones, digital cameras, tablets, smartwatches, laptops, among others.

At the time, the two companies were determined to promote NFC, which is why they presented the technology specifications to ECMA International , the entity responsible for the standardization of communication and information systems. After a period of time devoted to dealing with technical issues, the technology received recognition by the ISO/IEC 18092 standard in 2003.

However, NFC only started to gain relevance in mid-2004, when the NFC Forum was created , an organization that brings together dozens of companies that are interested in the development and use of NFC-based applications. Among them are Google, PayPal, LG, American Express, Nokia, Samsung, Intel, NEC, Visa, Huawei and Qualcomm.

It is worth noting that NFC is, to some extent, based on RFID (Radio-Frequency Identification), a more consolidated technology that allows, as the name implies, radio frequency identification applications. As a result, companies that offer integrated RFID solutions also participate in the organization.

How does NFC work?

NFC is a technology created to allow communication between two devices, no more than that. The principle is simple: one of them plays the role of Initiator , responding for the task of initiating communication and controlling the exchange of information. The other plays the role of Target and must respond to the Initiator’s requests.

Communication is established by radio frequency, from the 13.56 MHz band, with the data transmission speed varying between 106, 212 and 424 Kb/s (kilobits per second). More recently, it has also become possible to work with the maximum rate of 848 Kb/s, although not officially. As already mentioned, the maximum distance between the two devices is usually 10 cm.

Transmission can occur in two ways:

Passive: in this mode, only one of the devices (normally the Initiator) generates the radio frequency signal for the connection. The second is only powered by this. With this, it is possible to place NFC tags on items that do not receive direct power, such as cards, packaging and posters (you will see some examples in the topic below);

Active: in active mode, both devices generate the radio signal. It is the mode that is used, for example, in a payment system involving a smartphone and a receiver at a store cashier.

It is also necessary to consider the existence of three modes of operation, which together increase the possibilities of using the standard:

Reading and writing: based on passive communication, it allows reading or changing existing data on an NFC device, such as a receiver that discounts credits registered on a travel card (such as the Single Ticket for the city of São Paulo);

Peer-to-peer: it is a mode for bireditional exchange of information between the two devices, that is, each one can both receive and send data to the other. It can be useful, for example, for exchanging files between two smartphones;

Card emulation: in this mode, the NFC device can pass for a smart card, so that the reader device cannot distinguish one from the other.

It is interesting to note that NFC has the ability to “maintain” communication even when the devices involved physically move away. In this case, the connection is established initially via NFC and, subsequently, a wireless communication technology with greater reach takes over: Bluetooth or Wi-Fi.

NFC tags

An idea that has considerably expanded the possibilities of using the technology are the so-called NFC Tags (also known as NFC Sticker, SmartTag NFC, NFC Stickers or NFC tags). In the form of a key ring or even a tag (as the name makes clear), these small NFC devices can be configured to perform various activities.

The NFC Tags are basically formed by a small radio chip accompanied by a simple antenna and some amount of memory for data storage. Typically, these devices work in passive mode, meaning there is no need to leave them constantly connected to a power source.

There are at least four categories of NFC Tags (not to mention types that were developed by certain manufacturers for specific purposes):

Type 1: normally stores between 96 bytes and 2 KB of data and has a speed of 106 Kb/s (kilobits per second);

Type 2: stores between 48 bytes and 2 KB of data and has a speed of 106 Kb/s. It is compatible with type 1;

Type 3: based on a Sony technology called FeliCa, this type usually stores 2 KB (but can reach 1 MB) and has a speed of 212 Kb/s. Compatibility with other standards exists, but is not guaranteed;

Type 4: stores up to 32 KB and has a speed between 106 Kb/s and 424 Kb/s. It is compatible with types 1 and 2.

It is possible to configure these types to have information recorded at the factory, making it read-only, or allowing rewriting of data. In the latter case, a tag can be removed from one application and transferred to another.

It is easier for you to understand how NFC Tags can be used with examples:

Disable notifications on your smartphone while sleeping: to do this, simply place an NFC Tag on the headboard of your bed and bring the device closer to it. When doing so, the smartphone will automatically disable notifications until the specified time;

Synchronize your car’s sound system with your smartphone: just have an NFC Tag on the vehicle’s dashboard. When you approach the smartphone, the device will automatically start transmitting music to the car via Bluetooth;

Release the Wi-Fi password: configure an NFC Tag in your room to automatically provide your Wi-Fi network password to your visitors. They will need to have compatible devices, of course;

Share 3G/4G with your notebook: you can tag your notebook. When approaching the smartphone, it will immediately activate a Wi-Fi network to share its 3G/4G connection with the device;

Send content to your smart TV: place an NFC Tag on the back of your smart TV. When approaching your smartphone or tablet, the device will automatically send video, audio or photos to the television via Wi-Fi Direct or Miracast, for example.

As the examples suggest, there are numerous applications for NFC Tags. With a little creativity, you can create several of them yourself. There are a lot of apps that allow you to make settings from your mobile device, as well as devices for that.

NFC security

When properly installed, NFC technology can greatly facilitate the user’s life because it is fast and does not have an overly complex implementation. However, there is little point in offering these advantages if the security aspect is not considered, is it not?

At first, the fact that communication between two NFC devices requires a very short distance is, in itself, an efficient form of security, after all, this mode of operation makes the signal interception considerably difficult, although it does not make this action impossible. In addition, it is important to take into account that if the user loses his mobile device, the person who finds it can impersonate him and cause him even greater inconvenience.

To deal with this, one of the weapons of NFC is the SWP (Single Wire Protocol) protocol. This is a standard that offers secure communication between the SIM card (the “cell phone chip”) and the device’s NFC chip. The problem is that the SWP is not widely adopted (at least it was not until the closing of this article) because it needs more tests and does not have a simple implementation.

For this reason, it is now more convenient to apply security procedures to applications, such as using encryption in transactions and authentication features. In the aforementioned Android Pay, for example, security features allow the user to block access to their data or even transfer it to another device in the event of loss or theft of the smartphone.