What is the Near-field Communication?
The full name of NFC technology is Near Field Communication Technology. NFC is developed on the basis of non-contact radio frequency identification (RFID) technology and combined with wireless interconnection technology. It provides a very safe and fast communication method for various electronic products that are becoming more and more popular in our daily lives.
The near field in NFC refers to radio waves near the electromagnetic field. Because radio waves are actually electromagnetic waves, they follow Maxwell’s equations. Electric and magnetic fields will always alternate energy conversion during the process of propagating from the transmitting antenna to the receiving antenna, and they will enhance each other during the conversion.
For example, the radio signals used by our mobile phones are transmitted using this principle. This method is called far-field communication.
Within 10 wavelengths of electromagnetic waves, the electric field and the magnetic field are independent of each other. At this time, the electric field does not have much meaning, but the magnetic field can be used for short-distance communication, which we call near-field communication.
Near-field communication business combines near-field communication technology and mobile communication technology to realize multiple functions such as electronic payment, identity authentication, ticketing, data exchange, anti-counterfeiting, and advertising and is a new type of business in the field of mobile communications.
Near-field communication services have enhanced the functions of mobile phones, making users’ consumption behaviors gradually electronic, and establishing a new type of user consumption and business models.
The application of NFC technology has received widespread attention worldwide. Different roles such as domestic and foreign telecom operators and mobile phone manufacturers have launched application trials one after another, and some international associations have also actively carried out standardization work.
Near-field communication technical background
According to relevant information, around 2003, Sony and Philips Semiconductors (now NXP NXP Semiconductors) cooperated to develop a safer and faster technology based on non-contact RF card technology, and compatible wireless communication technology.
After several months of research and development, the two parties jointly released a wireless communication technology compatible with the IS014443 contactless card protocol, named NFC (Near Field Communication), and the specific communication specification is called the NFCIP-1 specification.
Not long after the release of the NFC technology, both parties submitted a draft standard to the European Computer Manufacturers Association (ECMA), applied to become a near-field communication standard, and was quickly recognized as the ECMA.340 standard, and then submitted a standard application to ISO/IEC with the help of ECMA. And was finally recognized as the ISO/IEC18092 standard.
Near-field communication technical standard
Near-field communication technology is a standard jointly developed by Nokia, Philips, and Sony. It promotes standardization under the framework of ISO 18092, ECMA 340, and ETSI TS 102 190. It is also compatible with the widely used ISO 14443, The infrastructure of Type-A, ISO 15693, B, and Felica standard contactless smart cards.
On December 8, 2003, it passed the audit of ISO/IEC (International Organization for Standardization/International Electrotechnical Commission) and became an international standard. It was recognized as a European standard by ECMA (European Computer Manufacturers Association) on March 18, 2004. It has passed The standards listed in ISO/IEC 18092 (NFCIP-1), ECMA-340, ECMA-352, ECMA-356, ECMA-362, and ISO/IEC 21481 (NFCIP-2).
The near-field communication standard specifies the modulation scheme, coding, transmission speed, and frame format of the radio frequency interface of the near-field communication equipment in detail, as well as the initialization scheme and conditions required for data conflict control during the initialization process of the active and passive near field communication modes. In addition, it also defines the transmission protocol including protocol activation and data exchange methods.
NFC working principle
NFC is a short-distance high-frequency radio technology. The NFCIP-1 standard stipulates that the communication distance of NFC is within 10 cm, the operating frequency is 13.56 MHz, 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 radio frequency interface of NFC devices in detail. This standard also defines the NFC transmission protocol, including the activation protocol and data exchange method.
NFC working modes are divided into passive mode and active mode. In the passive mode, the NFC initiator device (also called the master device) needs a power supply device. The master device uses the energy of the power supply device to provide a radio frequency field and sends data to the NFC target device (also called a slave device). The transmission rate needs to be 106kbps, 212kbps, or 424kbps, choose one of them.
The slave device does not generate a radio frequency field, so there is no need for a power supply device. Instead, the radio frequency field generated by the master device is converted into electrical energy to supply power to the circuit of the slave device, receive data sent by the master device, use load modulation technology, and transfer data from the device back to the master device at the same speed.
Because the slave device does not generate the radiofrequency field in this working mode, but passively receives the radiofrequency field generated by the master device, it is called passive mode. In this mode, the NFC master device can detect contactless cards or NFC target devices, and establish a connection.
In the active mode, both the initiator and the target device must actively generate a radio frequency field when sending data to each other, so it is called the active mode, and they both require a power supply device to provide energy to generate the radiofrequency field. This communication mode is a standard mode for peer-to-peer network communication and can obtain very fast connection rates.
Main application form
In order to be compatible with contactless smart cards, the NFC standard specifies a flexible gateway system, which is specifically divided into three working modes: point-to-point communication mode, reader mode, and NFC card simulation mode.
Point-to-point form
Point-to-point mode, in which two NFC devices can exchange data. For example, multiple digital cameras and mobile phones with NFC functions can use NFC technology for wireless interconnection to realize data exchange such as virtual business cards or digital photos.
For the point-to-point form, the key is to connect two devices with the NFC function, so that the data transmission between points can be realized. After taking the point-to-point form as the premise, NFC-enabled mobile phones and computers, and other related devices can truly achieve point-to-point wireless connection and data transmission, and in subsequent associated applications, it can be used not only for local applications but also for network applications.
Therefore, point-to-point applications play a very important role in the rapid Bluetooth connection between different devices and the transmission of communication data.
Reader mode
Read/write mode. In this mode, the NFC device is used as a contactless reader. For example, a mobile phone that supports NFC plays the role of a reader when interacting with tags, and a mobile phone with NFC enabled can read and write tags that support the NFC data format standard.
The NFC communication in card reader mode is used as a non-contact card reader, which can read relevant information from exhibition information electronic tags, movie posters, advertising pages, etc. NFC mobile phones in card reader mode can collect data resources from TAG and complete information processing functions according to certain application requirements. Some application functions can be directly completed locally, and some need to be combined with mobile communication networks such as TD-LTE.
NFC application areas based on the card reader mode include advertisement reading, ticket reading, movie theater ticket sales, etc. For example, a TAG tag is affixed to the back of a movie poster. At this time, the user can bring a mobile phone that supports the NFC protocol to obtain movie information or connect to buy movie tickets.
The NFC mode of the card reader can also support the acquisition of bus station information and tourist attractions map information, and improve the convenience of people’s travel and transportation.
Card simulation form
Analog card mode, this mode is to simulate a device with NFC function as a tag or contactless card. For example, a mobile phone that supports NFC can be read as an access card, bank card, etc.
The key to the card simulation form is to simulate the device with NFC function and turn it into a non-contact card mode, such as bank cards and access control cards.
This form is mainly used in non-contact mobile payments such as shopping malls or transportation. In the specific application process, users only need to put their mobile phone or other related electronic devices close to the card reader and enter the corresponding password at the same time to complete the transaction.
Regarding the card in the form of card simulation, the key is to perform power supply processing through the RF domain of the contactless card reader, so that the NFC device can continue to work even if the NFC device has no power.
In addition, for the application of card simulation form, data can also be collected in related equipment with NFC function, and then the data can be transmitted to the corresponding processing system for relevant processing, and this form can also be applied to forbidden systems and local payments And so on.
Near-field communication NFC’s feature
Near-field communication is a short-range wireless communication technology developed based on RFID technology. Like RFID, near-field communication information is also transmitted through electromagnetic induction coupling in the wireless frequency part of the spectrum, but there is still a big difference between the two.
The transmission range of near-field communication is smaller than that of RFID. The transmission range of RFID can reach 0~1m. However, due to the unique signal attenuation technology adopted by near-field communication, near-field communication has low cost, high bandwidth, and energy consumption compared with RFID, the low-level characteristics.
The main features of near-field communication technology are as follows.
(1) Wireless communication technology used for short-distance (within 10cm) secure communication.
(2) Radiofrequency: 13.56MHz.
(3) Radiofrequency compatibility: ISO 14443, ISO 15693, Felica standards.
(4) Data transmission speed: 106kbit/s, 212 kbit/s, 424kbit/s.
Comparison of NFC and other technologies
The current short-range wireless communication technologies include RFID, Bluetooth, infrared, etc. NFC is a short-range high-frequency wireless communication technology that allows non-contact point-to-point data transmission between electronic devices.
Its working frequency is 13.56MHz, the communication distance is 0-20cm (most products are within 10cm in fact), and the transmission rate can be 106kbit/s, 212kbit/s, 424 kbit/s, and 848kbit/s.
In addition to NFC, NFC technology also mainly includes radio frequency identification (RFID), Bluetooth, ZigBee, infrared, Wi-Fi, and other technologies. Each of the above technologies has its own characteristics and advantages. The following figure shows the performance comparison of NFC and six other short-range wireless communication technologies on the listed frequency bands.
It can be seen that NFC technology has extremely high security, performance advantages in short-distance communication, and more importantly, lower cost. Therefore, since its appearance in 2003, it has received the attention and support of many enterprises.
The following is an analysis and comparison of the characteristics of each communication technology and NFC technology.
Comparison of NFC and RFID
First, the working mode is different. NFC integrates point-to-point communication functions, reader functions, and non-contact card functions into a single chip, while RFID consists of two parts: a reader and a tag. NFC technology can both read and write, while RFID can only read and determine information.
Second, the transmission distance is different. The transmission distance of NFC is much smaller than that of RFID. The transmission distance of NFC is only 10 cm. The transmission distance of RFID can reach several meters or even tens of meters. NFC is a short-distance private communication method. Compared with RFID, NFC has the characteristics of short distance, high bandwidth, low energy consumption, and high security.
Third, the application areas are different. NFC is more used in the field of consumer electronics, playing a huge role in access control, public transportation, mobile payment, and other fields; RFID is better at long-distance identification and is more used in production, logistics, tracking, and asset management.
Comparison of NFC and Bluetooth
Both NFC and Bluetooth are short-range communication technologies. Compared with Bluetooth, which was integrated into mobile phones for a long time and has been popularized, NFC has only been integrated into mobile phones in recent years and has only been integrated into a few mobile phones so far.
First, the establishment time is different. The NFC communication setup procedure is simple, and the communication establishment time is very short, only about 0.1s; while the Bluetooth communication setup procedure is relatively complicated, and the communication establishment time is longer, about 6s.
Second, the transmission distance is different. The NFC transmission distance is only 10cm, while the Bluetooth transmission distance can reach 10m. However, NFC is slightly better than Bluetooth in terms of transmission power consumption and security.
Third, the transmission speed and operating frequency are different. The NFC operating frequency is 13.56 MHz and the maximum transmission speed is 424 Kbit/s, while the Bluetooth operating frequency is 2.4 GHz and the transmission speed can reach 2.1 Mbit/s.
Comparison of NFC and infrared
Compared with infrared transmission, NFC has the same transmission distance but is faster than infrared transmission. The maximum transmission speed of NFC can reach 424 Kbit/s, while the transmission speed of infrared is about 100Kbit/s. The setup time of NFC is slightly faster than infrared, the setup time of NFC is 0.1s, and the setup time of infrared transmission is 0.5s. Infrared transmission must be strictly aligned to transmit data, and there can be no obstacles in the middle, while NFC has no such restriction; in addition, NFC is more secure and reliable than infrared.
NFC applications
As a near-field communication technology, NFC has a wide range of applications. NFC applications can be divided into four basic types. The following is an introduction and analysis of these four basic application types.
Payment application
NFC payment mainly refers to applications where a mobile phone with NFC function is virtualized into a bank card, all-in-one card, etc.
The application of NFC virtualized into a bank card is called an open-loop application. Ideally, a mobile phone with an NFC function can be used as a bank card to swipe the mobile phone on POS machines in supermarkets and shopping malls.
The application of NFC virtualized into a one-card card is called a closed-loop application. With the continuous maturity of the popularization of NFC mobile phones, the all-in-one card system will gradually support the application of NFC mobile phones.
Security application
NFC security applications are mainly to virtualize mobile phones into access control cards, electronic tickets, etc. The application of NFC in security systems is an important field of NFC applications in the future, and the prospects are very broad.
In this field, it can directly bring economic benefits to users of the technology, giving them more motivation to upgrade existing equipment and technology.
The use of mobile phone virtual cards can reduce the use of access control cards or magnetic card tickets, directly reduce the cost of use, and can also appropriately increase the degree of automation, reduce personnel costs and improve efficiency.
Label application
The application of the NFC tag is to write some information into an NFC tag, the user only needs to use the NFC mobile phone in the NFC tag.
Besides this What is Near-field Communication article, you may also be interested in the below articles.
Internal Antenna VS. External Antenna
LTE Vs. 5G: Is 5G Better Than LTE?
