Intuitive, inherently secure and low power: NFC is a different kind of wireless. As proximity technology, it only works when two devices are brought close together so eavesdropping is almost impossible.

NFC Operating Modes

NFC is a specialized subset of RF identification (RFID). It operates at 13.56 MHz and performs many of the same functions as RFID tags and contactless smartcards. NFC operates in one of three communication modes: Read/Write, Peer-to-Peer, and Card Emulation.

Read and Write Mode

Read/Write Mode

In Read/Write mode, an NFC reader/writer reads data from NFC smart objects and acts upon that information. With an NFC-enabled phone, for example, users can automatically connect to websites via a retrieved URL, send short message service (SMS) texts without typing, obtain coupons, etc., all with only a touch of their device to the object.

Peer to Peer

Peer-to-Peer Mode

In Peer-to-Peer mode, any NFC-enabled reader/writer can communicate to another NFC reader/writer to exchange data with the same advantages of safety, security, intuitiveness, and simplicity inherent in Read/Write mode. In this mode, one of the reader/writers behaves as a tag, creating a communication link. For example, two devices (such as smartphones) with readers/writers can communicate with each other.

Card emulation mode

Card Emulation Mode

An NFC device in card emulation mode can replace a contactless smartcard, enabling NFC devices to be used within the existing contactless card infrastructure for operations such as ticketing, access control, transit, tollgates, and contactless payments.

Active or Passive Communication

NFC can use a passive or active communication scheme. In the passive scheme, the initiator provides power to the target. This saves energy, and is the reason why the target doesn't need its own power source. In the active scheme both devices require power, but more sophisticated interactions can take place.

Passive Communication Scheme

The initiating device produces a carrier field, and the target device, when introduced to this field, uses it to draw energy. The initiator transfers data by directly modulating the field, while the target transfers data by load-modulating the field. This method is compatible with contactless smartcard formats. Allows: Read/Write, Passive Peer-to-Peer, and Card Emulation mode

Active Communication Scheme

The initiator and the target each generate their own Radio Frequency (RF) field. Each side transmits data by modifying its own field with Amplitude Shift Key (ASK) modulation. To avoid collisions, only the sending device emits an electromagnetic field. The receiving device switches off its field to listen. The send/receive roles can be reversed as needed to support the transaction. Allows: Active Peer-to-Peer ModeCard Emulation mode

Wireless Protocols

Wireless connectivity comes in many forms, each with its own set of tradeoffs. NFC delivers short-range communication, similar to Bluetooth and WiFi, but with the ability to store and transmit data in much the same way that RFID tags and contactless smartcards do.

What's most important to know about NFC, it's perfectly compatible for any other wireless protocol. For example, tapping two NFC-enabled devices to each other is enough to establish a Bluetooth or WiFi connection, since the credentials will be exchanges automatically.

Technology Frequency Range Active Passive Typical devices & applications
(ISO/IEC 18092, NFC Forum)
13.56 MHz 10 cm

Smartphones, tablets, portable devices in a peer-to-peer network
Contactless (proximity) smartcards
(ISO/IEC 14443)
13.56 MHz 10 cm

Ticketing, payment, access, passports, etc.
(ISO/IEC 18000)
LF (120–150 KHz)
HF (13.56 MHz)
UHF (433–900 MHz)
<40 m

Tagging and tracking of goods and items for manufacturing logistics, retail, etc.
IrDA infrared 2.4 GHz <1 m

Remote controls, mobile phones, computers
(IEEE 802.15.1)
2.4 GHz >10 m

Smartphones, tablets, laptops, audio equipment, printers, other devices in a personal area network (PAN)
(IEEE 802.11)
2.4 GHz >100 m

Smartphones, tablets, laptops, routers, other devices in a local area network (LAN)
(IEEE 802.15.4)
2.4 GHz >100 m

Lighting networks, home automation, industrial control