RFID vs NFC

What is RFID?

RFID is short for radio-frequency identification, which is similar to NFC an international transmission standard for contactless data exchange by radio. As NFC evolved from RFID both technologies have several similarities, but there also exist some important differences.

How does RFID work?

For a successful data exchange via RFID so called RFID transponders are needed. These transponders can be divided into active and passive transponders.

• Passive transponders contain the data, which is supposed be transmitted. However, they don’t have an own energy source. Therefore, they aren’t able to initiate a RFID connection on their own.
• Active transponders have an own energy source, which can be used to transmit an electromagnetic field. This way, the passive transponder receives enough energy to transmit the stored data.

In principle, data can only be transmitted from passive to active RFID transponders and not between two passive or two active ones. Moreover, not every RFID transponder is built in the same way, so characteristics vary between different transponder variants. For example, not all RFID transponders use the same radio frequency to establish connections. Therefore, the reach also differs between transponder variants.

RFID is commonly used in electronic retail security systems. Whereas the article surveillance is a passive transponder, the barrier at store exits is an active transponder. Once the passive transponder comes near the active one, a request to trigger an alarm signal is transmitted.

What’s the difference between RFID and NFC?

NFC is a specification of RFID and differs in some characteristics:

While NFC connections can only be established via very short distances (1-4 cm), RFID has a much higher reach. However, a limited reach can be quite useful for specific applications like contactless payment systems. The limited reach ensures that customers don’t pay unintentionally by standing somewhere near a point of sale. To the contrary, a customer only pays when a NFC-enabled card or smartphone is moved to within a few centimeters of a POS terminal (1-4 cm).

Moreover, NFC also allows connections between two active NFC transmitters (Peer-to-Peer communication). This way, two NFC-enabled smartphones can exchange data like contact information.

Last, NFC transmitters always communicate via the same radio frequency (13.56 kHz). Therefore, NFC transmitters don’t differ in their characteristics as much as RFID transponders.   

Summarized:

• NFC connections can only be established via very short distances.
• NFC also allows connections between two active NFC transmitters.
• NFC transmitters always use the same radio frequency to communicate with each other (13.56 kHz).

Further information

Wikipedia entry on Near Field Communication

Wikipedia entry on RFID