Radio frequency identification (RFID) technology is a recognition technology, and the corresponding identification technology also includes one-dimensional bar code, two-dimensional bar code, optical recognition technology and the like.
A typical RFID system consists of electronic tags, readers and information processing systems as shown in Figure 1. When an item with a radio frequency identification tag (hereinafter referred to as a tag) passes through a specific information reading device (hereinafter referred to as a reader/writer), the tag is activated by the reader and the radio wave is used to start transmitting the information carried in the tag to the reading and writing device. The computer and the computer system complete the automatic collection of information. The electronic tag can be carried by a person and used as a credit card, such as an ID card, or attached to an item such as a bar code on a product package. The RFID computer system undertakes the corresponding information control and processing work according to the requirements.
RFID technology is not a completely new technology, its application can be traced back to the military facilities of the British Air Force Base during the Second World War. In recent years, with the development of microelectronics, computer and network technology, the application range and depth of RFID technology have been rapidly developed. The successful application of RFID technology in the US war in Iraq and the influencing large enterprises around the world plan to use RFID systems in retail stores and warehouses in the next few years, making this technology quickly become the focus of global attention and is listed as 21 One of the most promising important industries and applied technologies of the century.
Table 1 gives an overview of the development of RFID technology. It is worth noting that RFID has developed to a very critical stage, which is the stage of forming a global standard. Although large-scale applications have not yet been formed, many related systems are still experimental or verified, but RFID is going to be applied on a large scale. The development trend has become clear.
From a technical point of view, the most essential feature of RFID is wireless communication technology and identification technology. There are many technical implementation methods, and there are many application forms. However, from the perspective of technology development, the RFID technology currently used has evolved from two technical fields: automatic identification technology and non-contact smart card technology.
Based on RFID technology and adding different technical features, there will be a variety of extended application areas with different names, as shown in Figure 2.
The degree of intelligence in Figure 2 mainly includes: the chip's re-writable technology, the security technology between the chip and the reader, the high-speed data transmission technology, and the technology to transmit other dynamic information under passive or low-power conditions. Wait. The low price depends mainly on the size of the chip, the cost of the antenna package and other factors.
It can be seen that low-cost labels are widely used in logistics management, while RFID technology for electronic payment needs to consider authentication and duplicate record storage, which is not very sensitive to price; label identification and wireless transmission are also A better carrier for transmitting environmental parameters, which is the technical basis for RFID to be a future sensor network; in addition, RFID technology can also be applied to the field of short-range wireless communication, and it is a candidate technology for home networks like Bluetooth and other technologies.
At this stage, RFID technology, which is inexpensive and has a suitable transmission distance and can be widely used in logistics management, is the research focus of current standardization organizations and industry alliances, and is also the focus of competition between international standardization organizations and industry alliances.
2 RFID standardizationThe international standardization bodies related to RFID technology and applications are: International Organization for Standardization (ISO), International Electrotechnical Commission (IEC), International Telecommunications Union (ITU), World Union Postal (UPU). There are also other regional standardization bodies such as CEN; national standardization bodies such as BSI, ANSI, DIN; industry alliances such as ATA, AIAG, EIA, etc.; these institutions are developing regional, national or industry alliances related to RFID. Standards and hope to be promoted to international standards through different channels.
The industry alliances related to RFID technology are mainly EPCglobal and Ubiquitous ID Center. EPCglobal is an independent non-profit organization jointly established by the United States Unified Code Committee (UCC) and the European Article Number (EAN) organization. UCC and EAN are respectively promoting the North American and European bar code coding organizations. EPCglobal is currently promoting the networked application of RFID electronic tags, inheriting the technical standards of the companies in the unified industry organized by AutoIDcenter, and establishing the company (ie EPCglobal Inc) to unify research standards and promote commercial applications, in addition to the EPCgobal number. Registration management organization.
The RFID system is mainly composed of two parts: data acquisition and back-end database network application system. The standards that have been released or are currently being developed are mainly related to data collection. There are mainly air interfaces between electronic tags and readers, data exchange protocols between readers and computers, RFID tags and reading and writing. Performance and conformance test specifications and data content coding standards for RFID tags.
The International Organization for Standardization ISO and EPCglobal have formed multiple standards for the air interface of RFID, as shown in Figure 3. The existing RFID technology works in multiple wireless frequency ranges. Common operating frequencies are: low frequency 125 kHz and 134.2 kHz; high frequency 13.56 MHz; ultra high frequency 433 MHz, 860 MHz to 930 MHz, 2.45 GHz, etc. There are also a variety of RFID technology standards coexisting at the same frequency. For example, 13.56 MHz has ISO14443 TypeA, TypeB, ISO15693, ISO18000-3 and other standards. Different standards use wireless modulation, baseband coding format, transmission protocol and transmission distance. There are differences, and different standards of RFID tags and readers cannot communicate.
2.1 ISO/IEC RFID International Standardization Status
Within the scope of the ISO/IEC JTC31 group, the research on RFID technology and applications is relatively complete under the scope of the ISO 18000 series of standards [1-6]. Many RFID technologies and application standards are still being developed and have not yet been released. In addition, ISO/IEC SC17, TC122 and other working groups have also issued some standards, these standards are relatively mature, and have been used in some industries.
According to the ISO/IEC JTC31 RFID technology standardization work plan, ISO divides the international standards of RFID into four aspects: air interface standard, data structure standard, conformance test standard and application standard. The conformance test standard is mainly for air interface and data transmission test standards between electronic tags and cards. In addition, the logical architecture of the other three types of standards is shown in Figure 4.
Figure 5 shows the work of ISO/IEC in the field of RFID technology standardization.
There are a number of basic patents involved in the ISO air interface standard issued by ISO. There are already some company patent statements in the text of the ISO/IEC 18000 series of standards. The basic policy of the ISO organization on intellectual property rights is that patent holders will be licensed on the basis of fairness, reasonableness, and non-discrimination.
2.2 EPC standard system
EPCglobal is an industry alliance that promotes the networked application of RFID electronic tags. It not only releases the technical standards for EPC electronic tags and readers, but also promotes the network management and application of RFID in the field of logistics management. EPCgobal number registration management organization. EPCglobal's scope of research can be easily summarized as: electronic tags (including the technical characteristics of electronic tags and readers), EPC, target naming service (ONS) (similar to the Internet's Domain Name Server (NDS) system, enabling logistics links to Share the origin information of EPC products, etc.), and standardize the language (PML) that describes the item information.
The standardized structural framework of EPCglobal is shown in Figure 6.
It can be seen that the standardization work of the EPCglobal system is in four aspects:
Technical requirements for the carrying of article code information for electronic tags and readers;
EPC electronic label information specification, that is, the rules for item coding;
EPCglobal provides business aspects, which are divided into item code allocation management and target naming business;
Software standards are divided into application layer events (data collection and refresh related to logistics management) and EPC information business level (information description corresponding to item information).
Compared with ISO, the EPCglobal standard has slightly different air interface technical requirements for electronic tags and readers; in the EPC electronic tag information specification, it is required to accept only the codes recognized by EPCglobal, and the progress in software standardization is faster than ISO; At the same time, the EPC article code distribution management rules and the target naming business measures were formulated to promote the EPCglobal business.
In addition, EPC defines the types of electronic tags, which are divided into read-only, passive, semi-active, broadband point-to-point communication active with additional functions and communication with different levels of electronic tags. Five categories, such as passive tags, are shown in Figure 7.
At this stage, the focus of the EPC alliance is to promote read-only level 0 (Class 0) and Class 1 electronic tags or electronic tags with a small number of additional features. As you can see in the ClassIV and ClassV phases, electronic tags will evolve toward point-to-point broadband communications and communication between electronic tags.
2.3 RFID China Standardization
China has a certain foundation in the standardization research of RFID technology and applications. At present, research and formulation of relevant standards has been carried out from various aspects. Application standards such as "Technical Specifications for Integrated Circuit Card Modules" and "Application Technology for IC Cards for Construction" have been formulated and widely used. In terms of technical standards, the early work of national standards has been completed in accordance with the ISO/IEC15693 series of standards, and work is underway to develop national standards in accordance with the ISO/IEC 18000 series of standards. In addition, the research work on the framework of China's RFID standard system has been basically completed. In addition, at the end of April 2007, the Ministry of Information Industry issued the Notice on the Release of the Trial Provisions for the Application of Radio Frequency Identification (RFID) Technology in the 800/900 MHz Band, according to the Ministry of Information Industry's 800/900 MHz Band Radio Frequency Identification (RFID) Technology Application Regulations. (Trial), China's 800/900 MHz RFID technology trial frequency is 840 ~ 845 MHz and 920 ~ 925 MHz, the transmission power is 2 W.
3 ConclusionSince the 1990s, RFID technology has developed rapidly. Developed countries and regions have applied it to many fields and actively promoted the internationalization of relevant technologies and application standards. In recent years, China has initially carried out research and development and industrialization of RFID-related technologies, and has begun to apply in some areas. At present, RFID technology is developing rapidly, but it is not yet mature. It is necessary for China to seize this opportunity to focus on the research and development of RFID core technologies, formulate technical standards in line with China's national conditions, and promote the formation of a competitive industrial chain, so that China has a place in this field. .
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