What is NFC?

NFC (Near Field Communication), jointly developed by Philips and Sony, is a contactless identification and interconnection technology that enables close wireless communication between mobile devices, consumer electronics, PCs, and smart control tools. NFC provides a simple, close proximity-based solution that allows consumers to exchange information, access content and services simply and intuitively.

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NFC integrates contactless card reader, contactless card, and peer-to-peer functions into a single chip, creating countless new opportunities for consumers’ lifestyles. This is an open interface platform that can set up wireless networks quickly and actively. It is also a virtual connector for existing cellular networks, Bluetooth, and wireless 802.11 devices.

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What is The Range of NFC?
Theoretically, the maximum NFC tag range is 20 cm. But, in the real world, you would rarely find a reader of that range. This makes sense because NFC technology should be used at a relatively close distance for security reasons.

At a shorter identification distance, NFC can diminish the probability of undesirable capture, especially to prevent our credit cards or bank cards from being remotely stolen by criminals. Mostly it requires you to tap the tag, which makes it more secure to pay with NFC.

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NFC VS RFID: What's the difference?
Like RFID, NFC information is also transmitted by electromagnetic induction coupling in the wireless frequency part of the spectrum. RFID stands for Radio-Frequency Identification and it uses electromagnetic waves to capture and interpret data. For the technology to work, you must have an RFID tag and an RFID reader. But there is still a big difference between the two. NFC is very much like RFID, but NFC is limited to communication within four inches. Most people consider NFC’s small radius a major security benefit and it’s one of the reasons that NFC is taking off as a secure alternative to credit cards. But the technology can be used for more than making purchases at Bloomingdales. NFC can transfer data like videos, contact information, and photos between two NFC enabled devices.

1.  NFC is a wireless connection technology that provides easy, secure, and rapid communication. Its transmission range is smaller than that of RFID, and RFID can reach several meters or even dozens of meters. However, NFC adopts the unique signal attenuation technology and has some advantages that RFID does not have. For example, short distance, high bandwidth, low energy consumption, etc.

2.  NFC is compatible with the existing contactless smart card technology and has become a formal standard supported by more and more major manufacturers.

3.  NFC is also a short-range connection protocol that provides easy, secure, rapid, and automatic communication between various devices. Compared with other connection methods in the wireless world, NFC is a kind of close private communication.

4.  RFID is more used in production, logistics, tracking, asset management, while NFC plays a huge role in access control, public transportation, mobile payment, and other fields.

How does NFC work?
NFC is a short-range high-frequency radio technology. The NFCIP-1 standard stipulates that the communication distance of NFC is within 10 cm, the operating frequency is 13.56MHz, and the transmission speed is 106Kbit/s, 212Kbit/s, or 424Kbit/s. The NFCIP-1 standard specifies the transmission speed, codec method, modulation scheme, and frame format of the RF interface of NFC equipment in detail. It also defines the transmission protocol of NFC, including startup protocol and data exchange method.

NFC communication technology evolved from contactless RFID and is backward compatible with RFID, which is mainly used to provide M2M (Machine to Machine) communication in handheld devices such as mobile phones.

 

There are three main working modes of NFC terminals:

1.  NFC Active Mode
Because both the originating device and the target device must actively generate RF fields when sending data to each other, so this mode is called active mode. They both need power supply devices to provide the energy to generate RF fields and can take turns transmitting signals to each other.

The NFC terminal can act as a card reader and emit RF fields to identify and read/write other NFC device information. This mode of communication is the standard model for peer-to-peer communication and can achieve very fast connection rates.

2.  NFC Passive Mode
In NFC passive mode, the NFC originating device (also known as the primary device) needs a power supply device. The master device uses the power supply device to provide the RF field and sends the data to the NFC target device (also known as the slave device).

The RF field generated by the primary device is used to power the circuit of the slave device. Data sent by the primary device is received. Load modulation is used to transmit data from the slave device back to the primary device at the same speed.

Because this working mode does not generate the RF field from the device, but passively receives the RF field generated by the master device, it is called passive mode. In this mode, the NFC master device can detect a non-contact card or NFC target device and establish a connection with it.

3.  Bidirectional Mode
In this mode, both NFC devices are in the active mode that they can actively emit RF fields to establish peer-to-peer communication.  NFC-enable devices can exchange data in active or passive mode.

In passive mode, the device that initiates NFC communication, also known as the NFC sponsor, provides the RF field throughout the communication process.

At present, our common NFC working mode is the passive mode, very suitable for swiping the mobile phone to take the bus, shopping, etc.  Active mode is commonly seen in reading NFC tag information. And the bidirectional mode is mostly used for information exchange, such as exchanging business cards.

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