What is the difference between RFID and NFC ?

Behind these two words RFID and NFC there are two technologies at the same time really similar but also complementary. There are also two uses families that have not so much in common. Let’s try to understand more all of this !

      RFID 

We are first going to take a look at RFID definition, english acronym for Radio Frequency IDentification. It is any system in which a device has an electronic mechanism. Thanks to radio communication, a reader can question this mechanism remotely in order to recognize, identify, the device that carries it.

The device can be huge. So to speak, the plane transponder is the common ancestor to every nowadays RFID systems ! Evolution, electronics miniaturisation and control of electromagnetic waves established two separate branches.

In the active RFID branch, we find plane transponders, electronic road toll systems badges, but also all the systems based on Bluetooth Low Energy (BLE) or similar. According to the situation, the electronic mechanism will be named transponder, beacon or active tag but the principle stay the same: it includes a radio emitter and generates itself the wave that will allow the reader to see that it exists and to receive identification data to know which device is concerned.

In the passive RFID branch, the electronic mechanism carried by the device does not include a radio emitter and can’t generate any wave. It is most of the time a microscopic chip, without power, associated to an antenna of a few centimeters to create an electronic label or tag.

How will the tag be able to stand out for the reader if he is completely passive ?

Simply by acting like a small mirror that shipwrecked use to be noticed by boats. The mirror has no light source, like the tag has no radio emitter. However, by reflecting the light wave, the mirror allows the shipwrecked to be noticed, and to communicate by Morse. The tag bathe in the wave emitted by the reader and by retro modulating this wave he will be able to transmit a binary message…

Behind this concept, there are two technical implementation possibilities. The choice of one or another depends on the frequency.

At a high frequency, particularly in the UHF band section usable by RFID, around 868MHz in Europe and 910MHz in America, the reader and the tag use the electrical component of the radio wave, like the vast majority of radio systems that you use in your daily life. That is what the physicists call the far-field.

On the contrary, in low frequency, which is for RFID at 125 to 135 kHz, or at 13.56MHz, the reader and the tag use the magnetic component of the radio wave like a small processor. That is the near field.

And that is where the link with NFC becomes clear !

NFC

NFC stands for near field communication. NFC is the specific subgroup of RFID, the one that consists of communicating in passive and in a magnetic field, more specifically at 13.56MHz. It is a frequency that offers many advantages: it is free in the whole world, allows an interesting communication flow but stays reasonably complex technically speaking which makes it reachable and easy to miniaturise.

But from a user point of view, it is less simple.

For someone in the logistics or mass retail, an RFID label will be nothing more than a barcode remotely readable. Readers just read an item number and all the associated informations like which item it is, when and where has it been made, at which price it will be sold. All these data are stored in a database or a cloud service. For someone in the event industry that offers RFID badges at its visitors, the logic is different: the badge only provides a small amount of data, the number that will identify the visitor for example, and it is the information system that will store this data.

At the opposite side of the uses range, a transport or payment operator can’t let everything lay on an information system.

Transactions need to be realised offline to ensure network robustness, sufficient flow or to respect constraints regarding data privacy and files non-interconnection. The customer or user will have a contactless smartcard that can store a relatively high amount of data and ensure a high security level thanks to the use of cryptography.

From a layer communication point of view, the RFID at 13.56MHz and the contactless smartcard is the same thing. From an applicative point of view we see a large difference.

NFC can fill this gap or make it seem smaller to facilitate its understanding by the general public, to unify the ergonomy and to ensure the development of its uses.

For example, with an NFC smartphone you can pay or use public transportation, simply because the smartphone emulates the contactless smartcard at 13.56Mhz that the payment or validation terminal awaits.

With an NFC smartphone you can also read the RFID label at 13.56MHz that have been affixed to the product you just bought. If you want to download the manufacturer application  it will question its information system to tell you is the product is authentic and it can offer you a coupon on your next purchase.

To sum up, the vocabulary of NFC and RFID at 13.56 MHz cover the same concepts but in completely different use contexts. All SpringCard’s products in this frequency band can be used in both contexts. The RFID is a wider area with other frequencies like the UHF where SpringCard develops a new offer, and the world of the active RFID where in lots of situations the old proprietary systems are replaceable by BLE systems.

Published on 9/11/2018