Three minutes to understand NFC

The topic we are going to talk about today is NFC. For it, I believe that everyone will not be unfamiliar. As a convenient communication technology, NFC has been quietly serving everyone for many years. In our lives, we will see it from time to time. For example, subway, bus, mobile payment, but who invented NFC? When was it invented? What technology is it based on? What are the advantages and disadvantages? I believe most of my classmates are unclear. Today, I will tell you about it.

The birth of NFC

NFC, the full name is Near Field Communication, which is called "near field communication", also called "near-range wireless communication". It was born in 2003 and was jointly developed by two mobile device giants, Philips and Sony. At that time, Philips sent a team to Japan to retreat with SONY engineers for three months, and took out such a big move, that is, NFC. In 2004, the two giants, together with Nokia, created the NFC Forum and began promoting NFC applications. Since then, NFC as a baby has started his difficult growth process.

What is NFC technology?

NFC is a short-range high-frequency wireless communication technology that allows non-contact point-to-point data transmission between electronic devices. Did you notice these few keywords? Short distance, high frequency, non-contact, point to point. Speaking of NFC, you have to talk about its big brother, which is RFID.

RFID, Radio Frequency Identification, also known as radio frequency identification. As the name implies, RFID works by attaching an RFID circuit containing an RFID RF portion and an antenna loop to an item. After the item carrying the tag enters a specific magnetic field that is artificially set, a signal of a specific frequency is emitted, and the reader can obtain information that the item was previously written. It's a bit like a badge hanging on the neck of a staff member, and you are his supervisor. When he enters your sight, you can know his name occupation and other information, and you can also rewrite the contents of his badge.

If RFID is a person wearing a badge to facilitate others to understand him, then NFC is that both people wear badges, and they can change the contents of the badge and change the information received by the other party after seeing the other party.

NFC and RFID look similar on the physical level, but they are actually two completely different fields, because RFID is essentially a recognition technology, and NFC is a communication technology. At the beginning of NFC, it was compatible with Sony's FeliCaTM standard and ISO14443 A, B, which is Philips' MIFARE standard. In the industry, it is abbreviated as Type A, Type B and Type F, where A and B are Mifare standards and F is Felica standard.

NFC has three modes of operation:

Active mode

In active mode, the NFC terminal can act as a card reader and issue a radio frequency field to identify and read/write other NFC device information.

2. Passive mode

This mode is exactly the opposite of the active mode. At this time, the NFC terminal is simulated as a card, which only passively responds to the RF field emitted by other devices and is read/written.

3. Two-way mode

In this mode, both parties of the NFC terminal actively send out the RF field to establish peer-to-peer communication. Equivalent to two NFC devices are in active mode.

Take the passive mode as an example: a device that initiates NFC communication, also known as an NFC-initiated device, provides an RF-field throughout the communication process. It can select one of 106kbps, 212kbps or 424kbps to send data to another device. The other device, called the NFC target device, does not have to generate a radio frequency field, but uses load modulation technology to transmit data back to the initiating device at the same speed. Both achieve communication. Mobile devices operate primarily in passive mode, which significantly reduces power consumption and extends battery life.

NFC development

After the release of NFC, the two giants can be said to be full of confidence, I believe this is another product that can change the world. After all, NFC is not only more secure than Bluetooth, but it takes less than 0.1 seconds to establish a connection. Not to mention the card simulation function of NFC, so that the hand Ji can become a bus card, an access card or even a bank ka at the same time, it can be said that NFC all-round rolling Bluetooth. But in fact, NFC has not stepped out of the promotion step. Although NFC is more convenient and safer, and the cost is lower than that of Bluetooth, it is necessary to establish a connection at close range or even contact. Moreover, NFC is not satisfactory in terms of file transfer speed. NFC can theoretically only reach 868 Kbps in transmission speed, while Bluetooth can reach 2.1 Mbps.

Japan may be said to be the home of NFC, and it is also the most important promotion area of ​​NFC in the early days. Under the joint promotion of manufacturers, merchants, operators and even banks, Japan’s hand ji has already integrated bus card and bank ka functions. But outside of Japan, NFC is bleak, especially in Europe. Due to Nokia's high licensing and server costs, the lack of Nokia's technical support has led many developers to stay away from NFC.

NFC is mainly popular in Asia, although Nokia has launched the world's first NFC product - Nokia 3220, and almost NFC as a standard. But because there is no really useful function, NFC can only be used as a gimmick, gradually faded out of people's attention.

NFC freshman

Nowadays, with the popularity of mobile payment, NFC technology has re-entered the attention of major manufacturers. Compared with the current scan code-payment mode, NFC's contact payment mode is obviously faster and safer, and NFC technology is no longer the technology of dragon slaughter.

NFC now has two main application areas:

Card simulation

This is one of the earliest features of NFC. Let the hand ji be used as a bus card and bank ka, which can greatly reduce the number of cards that need to be carried in the current travel. However, due to software issues, this feature has not been popular in the early days.

Now the function has finally received enough software support, Xiaomi, Huawei, Samsung, Nubia, Yijia, Meizu and other hand-made manufacturers have launched a proprietary APP that can simulate bus cards. Unfortunately, this feature can only be used in several first-tier cities, and it takes time to popularize. As for the bank ka simulation, only Alipay, Samsung Pay, Mi Pay, Huawei Wallet and other APP support are currently available.

file transfer

Similar to the hand ji Bluetooth, after the two hands are turned on, the NFC function is turned on, the hand ji is close to establish a connection, and then the file can be transmitted or received. However, as mentioned earlier, NFC is not as fast as Bluetooth, but NFC can be used as a pre-link for Bluetooth. Nowadays, many cameras and photo printers also transmit images quickly through NFC. After all, it is very convenient and fast.

In addition, more and more NFC applications are being discovered. For example, the popular shared bike is now. Mobai and ofo two shared bicycles also released a new model that supports NFC. Users can skip the scanning code step and directly unlock the hand ji close to the smart lock, so that the user experience is better, but the function still exists. Certain limitations.

Subject to the imperfections in infrastructure and industry chains, NFC is far from being able to perform its full function. For example, NFC business cards, through the NFC tag to dian, access to the network, and even through the NFC tag to obtain product information, etc., many functions are still in the research and development stage, did not enter our lives. Let us give it a little more time, maybe in the near future, it will usher in its own spring.