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An Overview of Near-Field Communication

October 11, 2020 by Abdulwaliy Oyekunle

Near-field communication (NFC) is a connectivity technology that enables wireless communication between two NFC-enabled devices. Communication via NFC occurs at short range, low bandwidth, and at a high frequency between devices. We discuss NFC’s components, its operating modes, and more.

Main Components of NFC

Near-field communication technology originally emerged from existing wireless communication technology: radio frequency identification (RFID). RFID technology transmits and receives data through radio waves. The communication occurs between an RFID reader and a passive or active RFID tag. Like in RFID, communication in NFC technology occurs at the frequency of 13.56 megahertz. NFC has data transfer speed ranging from 106kbps to 424kbps.

The three major components of NFC technology are outlined below.

  • An NFC-enabled mobile phone, also known as an NFC mobile
  • An NFC tag, which is a passive RFID tag that has a memory for storing a small amount of data
  • An NFC reader, which is an active device: it can power up a passive NFC tag when placed in close proximity to it


The above-mentioned components interact with one another in close range for communication in NFC-relevant applications (such as card payments, as will be discussed later).

In NFC technology, interactions between components take different forms, such as touching, pointing, and scanning. Communication can be set up by an NFC reader that touches, or is pointed at, an NFC tag. Plus, an NFC-enabled smartphone can be made to scan for other components to set up a communication network.


A customer uses near-field communication (NFC) to make a contactless payment with her smartwatch—an example of NFC’s increasing use in the wearable technology market. Image Credit: Freepik.


Communication Modes in NFC

Again, communication occurs in the RF field when two NFC-enabled devices are in close proximity, and there are two modes of communication in NFC-enabled devices: the active communication mode and the passive communication mode.

The active communication mode occurs when the two NFC-enabled devices can generate an RF field for communication via an embedded power source, such as a battery. The passive communication mode occurs when only one of the NFC-enabled devices is able to generate an RF field for communication.

When it’s in the passive mode, however, the given NFC device that does not generate the RF field for communication does not have an embedded power source. Such technology is often simply called a passive device.

Of course, another form of communication in NFC concerns the interoperability between an active device (aka an initiator device) and a passive device (more specifically called a target device). The initiator device—say, an NFC reader—sends requests to a target device, and the target device, e.g. an NFC tag, responds to the former’s requests.


The Operating Modes in NFC

The operating modes in NFC determine what users can do in an NFC technology application. There are three operating modes: the reader/writer mode, the peer-to-peer mode, and the card emulation mode.


A collection of six passive NFC (near-field communication) tags. Image Credit: Pixabay.


Reader/writer Mode

In the reader/writer mode, users can utilise an NFC-enabled device to either read or write data from—or to—NFC tags. In this kind of application, the given NFC-enabled device is an initiator (aka active) active device, while the passive, target devices are the NFC tags (such as those pictured above). The maximum data transfer speed in this mode is 106 kbps, or kilobits per second.


Peer-to-peer Mode

The peer-to-peer mode operation occurs between active devices. In this mode, users employ two NFC-enabled mobile phones to establish a connection for requesting and sending data. The communication is usually achieved over a bidirectional, half-duplex channel. The maximum data transfer speed in this mode is 424 kbps.


An example of a near-field communication (NFC) device that uses the NFC-specific function: card emulation mode. Pictured: a payment is made between a customer’s NFC smartphone and a shopkeeper’s card reader. Image Credit: SeongJoon Cho/Bloomberg.


Card Emulation Mode

The card emulation mode allows users to use an NFC-enabled mobile phone as a contactless smart card. Communication in this mode is usually between an NFC-enabled mobile phone and an NFC reader. Users send requests via the NFC reader to communicate with a third-party service (for example, a payment service).


NFC Standardisation Bodies

Near-field communication requires intervention from governing bodies, who provide various standards for the technology’s ease of use and access. Such standards particularly concern the security and operating architectures of NFC components.

Three chief examples of NFC standardisation bodies and their roles are discussed in the next three subsections.


The NFC Forum

The aim of the NFC Forum is to improve the development of wireless connectivity via NFC technology. This body formulates the specifications that define a modular architecture for near-field communication devices. The reader/writer and peer-to-peer modes are standardised by the NFC Forum.



NFC technology can be operated in the card emulation mode, and accordingly, GlobalPlatform defines various NFC standards for smart card industries. For instance, the company provides the specifications for NFC interoperability with standard smart cards.


Ecma International

Standing for the ‘European Computer Manufacturers Association’, Ecma is a private organisation that provides standards (such as those relevant to NFC interfaces and protocols) for information and communication technology, or ICT, systems.


Five graphics taken from the NFC Forum’s website, each of which shows the various consumer applications of near-field communication. Image Credit: NFC Forum.


Security Issues of NFC

Despite its advancements and standardisation bodies, NFC technology remains vulnerable to attacks and security threats. In fact, each of the NFC operating modes have various forms of threats: attacks characteristic of NFC tags, for instance, are tag content changing and tag cloning. In tag content changing, the attacker manipulates the contents stored in the tags and changes the original data written into the tags.

Furthermore, NFC readers are susceptible to impersonation. In this scenario, attackers can assume the ownership of near-field communication readers and gain access to confidential information stored on the reader.


The Development of NFC-enabled Mobile Devices

The robust (despite their security concerns) features of NFC-enabled mobile devices are designed by electronic and communication engineers—particularly radio-frequency engineers, who contribute to the design and fabrication of NFC readers and tags.

Mobile devices with NFC technology are developed using electronic components, such as integrated circuits and antennas (certain engineers also integrate a secure element in the given NFC device to protect the product’s data storage).

All in all, near-field communication technology is employed by many different types of engineers, and the aforementioned applications and developments of NFC are just some of the reasons that the technology is set to enhance wireless communication indefinitely.

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