RFID射频识别技术介绍.doc

Introduction Chapter RFID Basics1.1 Definition of RFID What is RFID， Radio Frequency Identification RFID is the abbreviation, that is, radio frequency identification, commonly known as RFID. RFID is the main core components of an electronic tag, less than 2 mm in diameter just by a few centimeters to several meters distance away from the radio waves emitted sensor, can read information stored in electronic tags, identification tag representative of the goods, people and equipment status. 1.2 RFID radio frequency identification technology, the concept of Radio Frequency Identification RFID is a non-contact automatic identification technology that automatically recognizes through the target RF signal and access to relevant data, identification of the work without human intervention, can work in all kinds of environments. RFID technology can identify fast moving objects and can also identify multiple tags, the operation quickly and conveniently. Ferguson, chief scientist of Accenture Labs is a breakthrough that the RFID technology: First, the individual can be identified very specific objects, rather than bar codes can only be identified as a class of objects; second, the use of radio frequency can read data through the external materials, but must rely on laser to read bar code information; Third, multiple objects simultaneously literacy, and bar code can only be read one by one. In addition, the amount of information stored is also very large. 1.3 RFIDs basic components The most basic RFID system consists of three components: Tag (Tag): the coupling components and chips, and each tag has a unique electronic code, attachedto the object identified target audience; Reader (Reader): read (sometimes also write) tags for a device that can be designed for handheldAntenna (Antenna): the label and pass RF signals between the reader. 1.4 RFID technology, the basic working principle The basic principle of RFID technology is not complex: labels into the magnetic field, the receiver RF signals emitted by interpretation, by virtue of induced current obtained by sending out the energy stored in the chip in the product information (Passive Tag, passive tags or passive tags) , or take the initiative to send a frequency signal (Active Tag, active tags or active tags); readers to read the information and decode the information sent to the central data processing system related. Chapter RFID technology standards2.1 RFID Overview of relevant standards Abstract RFID technology and its application to the relevant standards for a structured sort, and analyze the RFID-related standards in Chinas development, RFID standard of social factors, such as a standard drive. Standards to ensure that the conduct work together, to achieve economies of scale, work to implement the security and many other areas. The main purpose of RFID standardization through the development, distribution and implementation of standards to resolve coding, communications, air interface and data sharing issues such as maximum promote RFID technology and related system. But if the criterion used by the early, may restrict development and progress of technology; if used too late, then may limit the application of technology, lead to dangerous incidents and unnecessary overhead. In fact, RFID related standards related to many of its specific application, such as: electronic toll collection system, pet identification, cargo container identification and smart card applications. The RFID is mainly used for logistics management, etc., need to tag to achieve data sharing. Currently, many RFID-related ISO standards are being developed, including recycled shipping containers, returnable transport single items, transport units, product packaging, product identification and electronic container seals and so on. From GS1 (e-commerce, goods identification, global data synchronization exchange standards organization), EPC Global and ISO to a number of national and local organizations (such as Japan, UID, etc.) and other US IEEE and AIM Global RFID-related standards have been involved in Development of these. As WiFi, WiMax, Bluetooth, ZigBee, dedicated short range communication protocol (DSRC) and other short-range wireless communication protocol is being used for RFID systems or RFID devices into them, which makes the practical application of RFID, etc. have become more complex. In addition, RFID which interface the interface between the short-range wireless communications (Near Field Communication, NFC) for use has its root: its use of RFID devices usually the best frequency. Expert analysis of a reference for the industry, RFID and standard relations can be run from a deal with the following questions: (1) technology - such as the interface and transfer technologies. For example, the middleware technology-RFID middleware, RFID tags and applications to play an intermediary role between, from an application client uses a set of middleware provides a common application program interface (API), which can be connected to the RFID reader, read RFID tag data. RFID middleware using program logic and memory to transfer him (Store-and-Forward) functions to provide order of message flow with data flow design and management. (2) consistency. Mainly refers to its ability to support multiple encoding formats, such as support for EPC, DOD and other provisions of encoding formats, including EPCglobal tag data format required by the standard. (3) performance - particularly refers to the structure and content of data, or data encoding and memory allocation. (4) battery assisted and sensor fusion. Currently, RFID gradually with the integration of sensing, positioning items using RFID triangulation and more complex technology, and some RFID technology instead of using sensor chips. For example, to achieve the temperature and strain sensing of surface acoustic wave (SAW) tags used in RFID technology. However, almost all of the sensor system, including active RFID and so need to get energy from the battery. (A) ISO / IEC standards related to RFID ISO / IEC RFID standards have been introduced in the main concern of basic building blocks, air interface, data structures involved and their implementation. Concrete can be divided into technical standards, data content standards, consistent application of standards and standard four. 2.2 RFID technology standard Aspects RFID reader sends a frequency known as the RFID system frequency or carrier frequency. RFID carrier frequency are basically three areas: low-frequency (30kHz 300kHz), high frequency (3MHz 30MHz) and UHF (300MHz 3GHz). Common frequency with low-frequency 125kHz and 134.2kHz, high frequency 13.56MHz, UHF 433Mhz, 860MHz 930MHz, 2.45GHz so. The low frequency RFID system is mainly used for short-range, low-cost applications, such as most of the access control, campus cards, gas, water, etc.; high-frequency system is required to transmit large amounts of data for application systems; ultra-high frequency system applications read and write at a longer distance and higher access speed of the occasion, the direction of the antenna beam is narrow and the price is high, train control, highway toll applications and other system. Also worth mentioning that in the supply chain application, EPC Global EPC provides for carrier frequency of 13.56MHz and 860MHz 930MHz two bands, which use the standard 13.56MHz frequency prototype is ISO/IEC15693, has revenues to the ISO / IEC18000-3 in. The frequency application has been very mature. And 860 930MHz frequency band applications are more complex, the international use of the frequency of the different countries: the United States for the 915MHz, Europe 869MHz, while the country caused by the GSM, CDMA and other occupation, is still to be determined. Common international standards for RFID at present mainly used for animal identification in the ISO 11784 and 11785 for contactless smart cards ISO 10536 (Close coupled cards), ISO 15693 (Vicinity cards), ISO 14443 (Proximity cards), for container identification The ISO 10374, etc. Some standards are being formed and perfected, such as supply chain, ISO 18000 for passive UHF (860Mhz 930Mhz carrier frequency) of the C1G2 standard would be formally launched soon, our own national standards would be introduced as early as the end of this year . Following several criteria to be brief on this. ISO 11784 and ISO 11785 Provisions of ISO 11784 and 11785 respectively, the animal identification code structure and technical guidelines, standards of style size transponder not be provided, so you can designed for animals involved in various forms, such as glass tubes, ear tag or collar and so on. Technical guidelines for data transfer method transponder and reader specifications. Operating frequency 134.2KHz, data transmission has two full-duplex and half duplex, differential phase data reader source said. Transponder using FSK modulation, NRZ coding. Because of the transponder long charging time and frequency constraints, communication rate lower. ISO 10536, ISO 15693 and ISO 14443 ISO 10536 standards for major development in 1992 and 1995, due to the high cost of this card, contactless IC card, compared with the advantages of small, so this card has never been on the market. ISO 14443 and ISO 15693 standards for operation in 1995, a single system to enter the market in 1999, the completion of the two standards is after 2000. Both of which 13.56MHz carrier frequency alternating signal: ISO15693 read and write distance, of course, also with the application of antenna shape and the transmitted power; and ISO 14443 reader from slightly close, but was widely applied in the current second-generation e-ID standard used in ISO 14443 TYPE B protocol. ISO14443 defined TYPE A, TYPE B are two types of agreements. Communication rate of 106kbits / s, mainly in their different carrier modulation depth and position of the encoding. Transmission from PCD to PICC signal, TYPE A encoding a modified Miller, 100% modulation depth of ASK signal; TYPE B are encoded using NRZ modulation depth of 10% of the ASK signal. Transmission from PICC to PCD signals, both of which transmit signals by modulating the carrier, subcarrier frequency are all 847KHz. TYPE A with switch keying (On-Off keying) of Manchester encoding; TYPE B of BPSK with NRZ-L coding. Compared with TYPE A TYPE B, as modulation depth and the different encoding with transmit power without interruption, the rate higher, the advantages of stronger anti-interference ability. ISO 15693 standard specifies the carrier frequency also 13.56MHz, VCD and the VICC using ASK modulation for all modulation depth of 10% and 100%, VICC two modulation depth must be correct decoding. Transmit the signal from VCD to VICC when encoding for the two: 256 1 and 4 1. Both of which the fixed period of time to position coding. Both the choice of encoding and modulation depth. 10% ASK modulation of priority in the use of long-distance mode, in which combinations, and the carrier signal of field strength than the lower sideband modulation wave field strength to allow full use of license magnetic field intensity on the IC card to provide energy. On the contrary, readers of 4 1 code can be 100% ASK modulation and a combination of shorter distances in the role of readers in the vicinity or in use by shielding. Transmit the signal from VICC to VCD, use sub-carrier load modulation. Resistance or capacitance impedance of the sub-carrier modulation frequency of the clock in turned on and off. The subcarrier data stream itself is encoded in the Manchester modulated clock in the use of ASK or FSK modulation. Modulation choice is sent by the reader in the FLAG byte transfer protocol tag bit to indicate, therefore, VICC always supports two methods: ASK (sub-carrier frequency of 424KHz) and FSK (sub-carrier frequency 424/484KHz ). The choice of the same data rate in bits by the FLAG to show, and it must support two rates: high-speed and low speed. The two rate used subcarrier according to different rates of slightly different when the low single sub-carrier for the 6.62kbits / s, high-speed for the 26.48kbits / s; when the dual sub-carrier respectively 6.67kbits / s and 26.69kbits / s. Visible, ISO 15693 application more flexible, operating from far and, more importantly, it is compatible with the ISO 18000-3, ISO 15693 standards in the future to understand about our countrys national standard is useful, because certainly our national standards and Most compatible with ISO 18000. In the same period of time if there is more than one VICC or PICC same response, it indicates a collision. The core of RFID anti-collision technology, which is contactless IC card and the main difference. ISO 14443-3 provides TYPE B TYPE A and anti-collision mechanism. Both anti-collision mechanism works differently: the former is based on the bit collision detection protocol, and TYPE B through a series of command sequences to complete anti-collision; ISO 15693 by round search mechanism, time-sharing manner inquiries anti-collision mechanism, the third in a standard Some have detailed requirements. Anti-collision mechanism allows read and write while in the region more than the correct operation of the card is possible only with the algorithm programmed to automatically select one of the first reading of a card reading and writing. This will not only facilitate the operation, but also to improve the operation speed. If the hardware co-Keyong some algorithms to achieve more rapid identification card, such as TIs R6C interface chip has a decoding error indication pin, which allows more rapid identification card: When the collision arises pin change, Ci Shi record low UID bit is used to query, and then based on the increase in the low median query until no collision occurs, so that you can identify all the cards. 2.3 RFID front-end technical standard system outlined Abstract the most commonly used international standards for RFID are mainly used for animal identification in the ISO 11784 and 11785 for contactless smart cards ISO 10536, ISO 15693, ISO 14443, ISO 10374 for the container and so identified. RFID technology has many outstanding advantages: realization of a passive and contactless operation, application convenience, no mechanical wear, long life equipment directly to end users without opening up the physical interface, to better ensure the safety of equipment; data security In addition to the password protected area label, the data part of the safety management can be a number of algorithms such as DES, RSA, DSA, MD5, etc., reading and writing equipment and mutual authentication between cards can achieve secure communication and storage; total cost has been on the decline among closer contact IC card costs and even lower, to lay the foundation for many of its applications; application Ling Yu Ye is very wide, RFID technology Yijing logistics management, production station Shibie, green animal Yangzhigeti Ji Lu tracking, vehicle security control, identity card, a large number of successful application fields of public transportation. 2.5 RFID-related standards of social factors Wireless communication management - such as ETSI (RFID RF Express Note: The European Telecommunications Standards Institute), FCC (RFID RF Express Note: Federal Communications Commission) and other related requirements; Human health - mainly the ICNIRP (International Commission on Non-Ionizing Radiation Protection), a World Health Organization and other institutions to provide information on Non-Ionizing Radiation Protection of the proposed independent body of the relevant requirements, many countries use the recommended standards as the countrys radiation specifications. The main is the operating frequency, power, radio waves and other health effects of radiation standards. Privacy. Privacy problem solving based on the principle of consent, that is, whether the user or consumer level of tolerance. Data security-OECD (RFID RF Express Note: Organization for Economic Cooperation and Development) has released the relevant documents, providing information systems and network security guidelines. And ISO 17799 (information security management practices code) similar to, is not mandatory to follow these guidelines, but these guidelines are for the information security program to provide a solid foundation. 2.6 RFID-related standards for the operation in China RFID technology in the first 10 years, the RFID technologies unprecedented warm discussion of international standards, the International Organization for Standardization ISO / IEC JTCl SC31 lower RFID Standardization Committee set up working group WG4. China RFID-related standardization activities, appointed by the beacon Automatic Identification and Data Collection Sub-Committee, Counterpart International ISO / IEC JTC1 SC31, for bar code and radio frequency part of the national standards for the centralized management. EAN bar code and national standards authorities in the field is the Standardization Administration, the national standard RF Ministry of Information Industry and the State authorities is the Standardization Administration, the field of technical focal points appointed by the beacon automatic identification and data collection technology sub-committee responsible for . China ISO / IEC JTC1 SC31 secretariat Article Numbering Centre of China. Article Numbering Centre of China affiliated to the China Association for Automatic Identification Technology in 2003, began to organize their radio working group began tracking and senior industry experts to conduct research of international standard ISO/IEC18000, has completed work on the draft standards, ISO18000-related national standard developed Committee this year and officially approved