What is NFC (Near Field Communication)?


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

What is NFC?

At first, we may regard the NFC merely as a wireless communication technology. But, faced with so many options for this purpose, such as Wi-Fi and Bluetooth, what are the advantages of adopting it? The answer lies not only in what technology is capable of doing, but mainly in how.

In a nutshell, the NFC is a specification that allows wireless communication ( wireless ) between two devices through a simple approach between them, without the user having to enter passwords, click buttons or perform some similar action to establish the connection. Hence the name: Near 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 that can support the installation of an NFC chip.

The distance that 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 something around 10 centimeters. Despite this justification, such limited scope seems to be very disadvantageous, right? Not if you understand NFC applications.

What can NFC be used for?

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

As? It is simpler than it seems: the user approaches his smartphone from a receiver, which may be in the box of 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 the process information, such as the total value of the purchase.

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

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

Examples of NFC applications

By now, you may already be able to imagine other applications for the NFC. If negative, here are some interesting ones:

– Employee identification: NFC can be used on badges, for example, to identify the arrival of an employee to the company or its access to a specific sector;

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

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

– Prices in stores: To know the price of a product on the shelf or even get more details (such as ingredient list), just bring your 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 great deal. It is possible, among others, to pay a ticket from the Tokyo subway approaching the smartphone from a receiver in the ratchet or even buy items in sales machines (very common there) with the same gesture.

Emergence of the NFC

It is not by chance that Japan is one of the pioneer countries in the adoption of the 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 to be 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 standardizing communication and information systems. After a period of time devoted to the treatment of technical issues, the technology was recognized by ISO / IEC 18092 in 2003.

However, the NFC only gained momentum in mid-2004, when the NFC Forum was created, an organization that brings together dozens of companies 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 mentioning that the NFC is, to a certain extent, based on RFID ( Radio Frequency Identification ), a more consolidated technology that allows, as the name implies, radiofrequency identification applications. Because of this, companies that offer integrated solutions with RFID also participate in the organization.

How does NFC work?

NFC is a technology designed to allow communication between two devices, not more than that. The principle is simple: one of them plays the role of Initiator, responding to the task of initiating communication and controlling the exchange of information. The other plays the role of Target, responding to the Initiator’s requests.

The communication is established by radiofrequency, 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 been 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 (usually the Initiator) generates the radiofrequency signal of the connection. The second is only powered by this. With this, you can place NFC tags on items that do not receive direct power, such as cards, cartons, and posters (you’ll 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 in the box of a store.

There are also three modes of operation which together increase the possibilities of using the pattern:

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

– Peer-to-peer: it is a mode for binary 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 the exchange of files between two smartphones;

– Card emulation: in this mode, the NFC device can pass through a smart card, so that the reader can not 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 initially established via the NFC and later, a broader wireless communication technology takes over: Bluetooth or Wi-Fi.

NFC Tags

One idea that has greatly expanded the possibilities of using technology are the so-called NFC Tags(also known as NFC Sticker, NFC SmartTag, NFC Stickers or NFC tags). In keyring format or even a label (as the name makes clear), these small NFC devices can be configured to perform various activities.

NFC tags are basically formed by a small radio chip accompanied by a simple antenna and some amount of memory for data storage. Normally, these devices operate in the passive mode, ie it is not necessary to leave them permanently connected to a power source.

There are at least four categories of NFC Tags (not counting types that have been developed by certain manufacturers for specific purposes):

– Type 1: typically 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.

You can configure these types to have information recorded at the factory, allowing read-only, or allowing data rewriting. In the latter case, a Tag can be removed from one application and transferred to another.

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

– Turn off notifications on your smartphone while sleeping: just put an NFC Tag on the head of your bed and bring the device closer to it. Doing so will automatically disable your smartphone notifications until the specified time;

– Synchronize your car’s sound system with your smartphone: just have an NFC Tag on the dashboard. When you bring the smartphone closer, the device automatically starts transmitting music to the car via Bluetooth;

– Unlock the Wi-Fi password: Set up an NFC Tag in your room to automatically provide your Wi-Fi network password to your visitors. They will need to have compatible handsets, of course;

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

– Send content to your smart TV: put an NFC tag on the back of your smart TV. When you bring your smartphone or tablet closer, your device will automatically send video, audio, or photos to your 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 applications that allow you to make the settings from your mobile device as well as equipment fit for it.

NFC Security

When properly installed, NFC technology can make life much easier for the user because it is fast and does not have overly complex implementation. However, there is little point in offering such advantages if the security aspect is not considered, is it?

At first, the fact that communication between two NFC devices requires a very small distance is in itself an efficient form of security, after all, this mode of operation makes signal interception very 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 him can get past him and cause him even greater disorders.

To deal with this, one of the weapons of the NFC is the SWP ( Single Wire Protocol ) protocol. This is a standard that provides secure communication between the SIM card (the “cellular chip”) and the NFC chip of the device. 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 testing and not having simple implementation.

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