The relationship and differences between RFID and NFC

The Internet of Things mainly consists of three key technologies: connection, identification, and data operation. The identification of objects is the first step in implementing the Internet of Things, which is to uniquely identify and distinguish each object.

The object identification technology represented by RFID used to be almost synonymous with the Internet of Things, and now the evolution technology of RFID, NFC, plays an important role in various fields. This article discusses the identification technology of IoT devices and the relationship between RFID and NFC.

RFID
Contactless Radio Frequency Identification (RFID) is essentially a wireless communication technology that transmits data through wireless electromagnetic waves. However, what sets RFID apart from general communication technology is its purpose, not making phone calls or sending text messages. RFID is primarily used to identify and track tags bound to objects, thereby achieving object management.
RFID technology is widely used in warehousing and logistics to track goods.
The RFID system uses tags to identify objects. In addition to tags, RFID systems also have a bidirectional wireless transceiver called an Interrogator/Reader, which sends signals to tags and reads their feedback.

The RFID system consists of a reader and a tag
RFID is divided into passive RFID and active RFID. Passive RFID generally refers to passive RFID without batteries, which relies entirely on receiving electromagnetic waves to drive the circuit to work, and the recognizable distance of the tag does not change. Active RFID systems generally refer to active RFID tags, whose recognizable distance will decrease as the battery level decreases.
ETC system using RFID technology makes passage more convenient
Active RFID generally has a relatively long recognition distance, such as ETC systems for highway toll booths and automatic parking lots, which generally use active RFID operating at 2.4GHz. However, there is a battery in the ETC tag. If the battery runs out of battery, it needs to be replaced in order to function.

RFID tags
The RFID tag consists of two parts: an integrated circuit (IC) and an antenna:
IC is used to store and process data, modulate and demodulate RF signals, and also needs to collect energy from the signals emitted by the reader to drive its own operation.
The function of an antenna is to transmit and receive wireless signals.
The EPC code format may gradually replace the traditional UPC code, which is the product barcode.

Data storage in RFID tags
The data format stored in RFID tags is generally EPC (Electronic Product Code) code. The EPC code can recognize all objects in the world. The structure of EPC codes is defined by the EPCglobal Tag Data Standard, which is a publicly available standard that can be downloaded for free from the EPCglobal Inc website.

NFC technology
Near Field Communication (NFC) is currently a very common communication interface for mobile phones. Smart devices can exchange data by getting closer to each other. NFC devices can also communicate with a passive NFC tag in the same way as RFID.

NFC communication methods
NFC technology has evolved from RFID technology, and in addition to communication protocols, NFC standards also specify data exchange formats. Combining induction card readers, induction cards, and point-to-point functionality on a single NFC chip, it can recognize and exchange data with compatible devices over short distances.

The difference between NFC and RFID

Working frequency band
NFC can be understood as a subset of RFID technology, using the 13.56MHz frequency band, while RFID also includes other frequency bands.
There are many working frequency bands for RFID, including 125KHz in the low frequency band, 13.56MHz in the high frequency band, 433.92MHz and 915MHz in the ultra-high frequency band, and 2.45GHz in the microwave frequency band.

Communication distance
NFC is known as near-field communication, and the communication distance is indeed very close, not exceeding 0.1m.
There are many types of RFID, and the recognizable distance also varies. Like RFID access cards, the recognition distance is similar to NFC. But for ETC application scenarios, it requires a relatively long recognition distance. The recognition distance of long-distance RFID can reach tens or even hundreds of meters.

Application scenarios
RFID, whether active or passive, is mainly used for object recognition. Logistics, transportation, and warehousing all widely use RFID technology to track goods.
The integration of NFC chips is higher, including the integration of card readers and tags. In addition, the bidirectional communication capability of NFC has been strengthened. That is to say, NFC can not only be used as a tag for recognition, but also as a bidirectional communication method for data exchange. Currently, NFC is most commonly used in the payment field.

NFC technology is widely used in payment scenarios
Overall, although NFC is developed based on RFID technology, it does not have a substitutive effect for different application scenarios. Moreover, there are still many application scenarios for RFID nowadays, and NFC cannot match them for the time being.
Even in the fields of payment and close range object recognition, QR codes can play the role of NFC in many scenarios. Currently, NFC is not a necessary communication interface for smartphones.