RFID concept

Radio frequency identification, or RFID, is the abbreviation of Radio Frequency Identification, also known as radio frequency identification. It is a communication technology that can identify specific targets and read and write related data through radio signals without establishing mechanical or optical between the system and the specific target. contact.

Use of RFID

Passive RFID products are the earliest developed products, and they are also the most mature products in the market. For example, bus cards, canteen meal cards, bank cards, hotel access cards, second-generation ID cards, etc., can be seen everywhere in our daily life, and belong to the close-contact type. The main working frequency of its products are low frequency 125KHZ, high frequency 13.56MHZ, ultra high frequency 433MHZ, ultra high frequency 915MHZ.

Active RFID products have been slowly developed in recent years, and their long-distance automatic identification characteristics determine their huge application space and market potential. In the field of remote automatic identification, such as smart prisons, smart hospitals, smart parking lots, intelligent transportation, smart cities, smart earth and Internet of Things, there are major applications. Active RFID has sprung up in this field and belongs to the category of remote automatic identification. The main working frequency of the product is UHF 433MHZ, microwave 2.45GHZ and 5.8GHZ.

How RFID works

The basic working principle of RFID technology is not complicated: after the tag enters the magnetic field, it receives the RF signal from the reader, and sends the product information (passive tag or passive tag) stored in the chip by the energy obtained by the induced current, or by The tag actively sends a signal of a certain frequency (Active Tag, active tag or active tag), and the reader reads the information and decodes it, and sends it to the central information system for data processing. A complete RFID system consists of three parts: the reader and the electronic tag, the so-called transponder and application software system. The working principle is that the Reader emits a specific frequency of radio wave energy to drive the circuit. The internal data is sent out, and the Reader receives the interpretation data in sequence, and sends it to the application for corresponding processing.

The reader can be a read or read/write device depending on the structure and technology used, and is an RFID system information control and processing center. The reader usually consists of a coupling module, a transceiver module, a control module, and an interface unit. The half-duplex communication is generally used for information exchange between the reader and the transponder, while the reader provides energy and timing by coupling to the passive transponder. In practical applications, management functions such as collection, processing, and remote transmission of object identification information can be further implemented through Ethernet or WLAN. The transponder is the information carrier of the RFID system, and the transponder is mostly composed of a coupling element (coil, microstrip antenna, etc.) and a microchip to form a passive unit.

RFID technology standard

container

The ISO TC 104 Technical Committee is responsible for the development of container standards and is the highest authority for container manufacturing and operation. The standards related to RFID are developed by the Fourth Subcommittee (SC4). Includes the following criteria:

1) ISO 6346 container-code, ID and identification symbols, developed in 1995

This standard provides a container identification system. Container identification systems are used for a wide range of purposes, such as in documents, controls, and communications (including automated data processing), as the container itself displays. The mandatory identification in the container identification plus optional features in the Automatic Equipment Identification (EII) and EDI (Electronic Data Interchange) applications. The standard specifies the coding system for data such as container size, type, etc. plus the corresponding marking method, physical indication of operational markings and container markings.

2) ISO 10374 container automatic identification standard, formulated in 1991, revised in 1995

The standard is based on a microwave transponder's automatic container identification system, which looks at the container as a fixed asset. The transponder is an active device with an operating frequency of 850 MHz to 950 Mhz and 2.4 GHz to 2.5 GHz. As long as the transponder is in this field, it is activated and responds with backscatter modulation using a deformed FSK subcarrier. The signal is modulated between two subcarrier frequencies of 40 kHz and 20 kHz. Because it was formulated in 1991, the term RFID has not been used. In fact, active transponders are today's active RFID tags. This standard is used in conjunction with ISO 6346 for the identification of containers, ISO 6346 specifies optical identification, and ISO 10374 uses microwaves to characterize optically recognized information.

3) ISO 18185, draft official standard for container electronics (land, sea, air)

The standard is used by customs to monitor container handling [9] and consists of seven parts: air interface communication protocol, application requirements, environmental characteristics, data protection, sensors, information exchange message sets, physical layer characteristics requirements.

The air interface protocols covered by the above two standards do not reference the ISO/IEC 18000 series air interface protocols, mainly because they were developed earlier than the ISO/IEC 18000 series air interface protocol.

Logistics management

In order to enable RFID to play an important role in the entire logistics supply chain, the ISO TC 122 Packaging Technical Committee and the ISO TC 104 Freight Container Technical Committee have established a joint working group JWG to develop a series of standards for the logistics supply chain. The working group formulates six application standards according to application requirements, freight containers, loading units, transportation units, product packaging, and single-product five-level logistics units.

1) ISO 17358 application requirements

This is the application requirements standard for supply chain RFID, hosted by the TC 122 Technical Committee, and is in the process of being developed. The standard defines parameters for each level of the supply chain logistics unit, defining environmental identification and data flow.

2) ISO 17363 ~ 17367 series of standards

The supply chain RFID logistics unit series standards regulate the RFID applications of freight containers, recyclable transport units, transport units, product packaging, and product labels. The standard content of this series is basically the same, such as the air interface protocol adopts ISO/IEC 18000 series standards. There are differences in the specific regulations, and supplementary provisions are made for different use objects, such as the use of environmental conditions, the size of the label, the position of the label, and the like, and the carrier frequency of the electronic label is different according to the difference of the object. The electronic labels used in freight containers, recyclable transport units and transport units must be reused, product packaging is subject to actual conditions, and product labels are usually one-off. Also consider the integrity of the data, visual identification and so on. Recyclable units require high data capacity, security, and communication distance. This series of standards is in the process of being developed.

What needs to be noted here is the relationship between ISO 10374, ISO 18185 and ISO 17363. They are all for containers, but ISO 10374 is for the management of the container itself, ISO 18185 is for customs to monitor containers, and ISO 17363 is for supply. For the purpose of chain management, readable and writable RFID identification tags and shipping labels are used on freight containers.

Animal management

ISO TC 23/SC 19 is responsible for the development of standards for animal management RFID, including ISO 11784/11785 and ISO 14223.

ISO 11784 coding structure

It specifies the 64-bit encoding structure of the animal radio frequency identification code. The animal radio frequency identification code requires mutual recognition between the reader and the electronic tag. Usually the bitstream containing the data is added to the encoded data needed to ensure that the data is correct. The code structure is 64 bits, of which 27 to 64 bits can be defined by each country.

Retailer

According to estimates by retail analysts at Sanford C. Bernstein, Wal-Mart can save $8.35 billion annually through the use of RFID, most of which is due to labor costs that do not require manual inspection of incoming bar codes. While other analysts believe that the $8 billion figure is too optimistic, there is no doubt that RFID can help solve two of the biggest challenges in the retail industry: goods out of stock and wear and tear (products lost due to theft and supply chain disruption) Wal-Mart's loss is almost $2 billion a year. If a legitimate company's turnover can reach this figure, it can rank 694th in the list of the 1000 largest companies in the United States. Researchers estimate that this RFID technology can help reduce theft and inventory levels by 25%.