RFID: tags for all # 1
RFID (Radio Frequency Identification) is a method of remotely storing and retrieving data using devices called RFID tags. An RFID tag is a small object that can be associated or combined with a product, person, animal. RFID tags contain antennas that allow them to receive and send a radio frequency identification signal requested from an RFID transceiver. Passive tags do not need an internal power source, whereas active tags need it.
Story
It is believed that the first known device was a tool for espionage and was invented by Lev Teremin for the Soviet government in 1945. Theremin's device was an eavesdropping device, not an identification tag. The technology used in RFID was in use in the early 1920s (according to one source, although the same source claims that RFID systems appeared only in the late 60s.). A similar technology, the IFF pulse transceiver, was invented by the British in 1939 and was commonly used by allies in World War II to identify aircraft in the friend-foe system. Another early work on RFID research is the significant work of Harry Stockman, entitled "Communication by Means of Reflected Power" (October 1948). However, it took another 13 years of significant progress in many areas before RFID technology became a reality.
Types of RFID tags
As we said, RFID tags can be active or passive.
Passive RFID tags do not have an internal power source. Electric charge is obtained with the incoming radio signal; it provides sufficient power to transmit the response. The expected response of a passive RFID tag (power limited signal) is a summary — usually an ID number (GUID). Lack of power means that the device can be quite small: there is a commercially available product that can be implanted under the skin. For 2005, the smallest commercially available device 0.4x0.4 mm, which is thinner than a sheet of paper, such devices are almost invisible. In practice, passive tags are read from a distance of approximately 10 millimeters to 6 meters.
Active RFID tags, on the other hand, have an internal power source and may have a farther range and more memory than passive tags, since it is possible to store information sent through a transceiver. Now the smallest active tags are the size of a coin. Many active tags have a range of tens of meters, and the battery lasts up to 10 years.
Since passive tags are cheaper to produce and do not have a battery, most RFID tags belong to the passive variety. For 2004, these tags cost from 40 cents. While it is quite expensive for mass use, however, with significant production volumes (10 billion units per year), the cost of one tag can fall to 5 cents. While this is the most optimistic forecast, analysts from Gartner and Forrester Research agree that the price is less than 10 cents (production volume of 1 billion units) is achievable in 6-8 years, other analysts believe that such prices are achievable within 10-15 years.
While the cost advantages of passive tags over active ones are significant, other factors, including accuracy, reliability of operation in certain environments, for example, in water and metal, and reliability, make the use of active tags fairly common today.
There are 4 different types of tags that are commonly used. They are divided into categories based on their radio frequency: low frequency tags (125 or 134.2 kHz), high frequency tags (13.56 MHz), ultra high frequency tags (UHF marks, 868-956 MHz), and microwave marks (2.45 GHz). UHF stamps cannot be used everywhere, as there are no general rules for their use.
There are also some devices-transponders and cards with contactless chips that perform similar functions.
RFID system
An RFID system can consist of several components: tags, tag readers, edge servers, middleware, and application software.
The purpose of the RFID system is to start the transfer of information by a mobile device called a brand. The information is read by an RFID reader and processed according to the needs of specific applications. The information transmitted by the brand can provide identification and location information, or specific features of the marked product, such as price, color, date of purchase, etc. The use of RFID in tracking and access applications first appeared in the 1980s. RFID quickly attracted attention because of its ability to track moving objects. As the technology has been improved, its distribution begins and more and more active users appear in the RFID tags.
In a typical RFID system, individual objects are equipped with small, inexpensive brands. The brand contains a transponder with a digital memory chip, which gives a unique electronic product code. The requesting device, an antenna combined with a transceiver and a decoder, emits a signal that activates the RFID tag so that it can read and write information to itself. When the RFID tag passes through the electromagnetic zone, it detects the activation signal of the reader. The reading device decrypts the information encoded in the chip and the information is sent to the server for processing.
Take, for example, books in a library. A security arch can detect whether a book has been properly framed for receipt. When users return items, part of the security work is to re-set the label, and the item record in the integrated library system is automatically updated. In some RFIDs, a return receipt can be generated, and the book itself can be placed in a rack with returnable equipment.
Current usage
Example: 13.56 MHz tags are placed in recipes for veterans with poor eyesight. Medicines of the Department of Veterans Affairs are now supplied with active tags. These devices store information such as: medication name, instructions, precautions, and others. Low-frequency RFID tags are commonly used to identify animals. Pets can be implanted with small chips that will allow them to quickly return to the owner if they are lost. By the way, beer kegs are also tracked using low-frequency RFID tags. In America, two types of RFID tags are used: 125 kHz (original standard) and 134.2 kHz (international standard).
High-frequency RFID tags are used in library books and bookstores, satellite tracking, access control, air cargo tracking, equipment tracking. High-frequency tags are widely used in identifying badges, taking the place of earlier magnetic stripe cards. These badges for confirming the authenticity of the carrier do not need to be attached to the reader, but rather just pass next to it. An American Express Blue credit card includes a high-frequency RFID tag for ExpressPay.
UHF RFID tags are commonly used in satellite and container tracking, as well as for monitoring trucks and trailers for freight.
Often, it is assumed that RFID tags are barcode replacement. They may never replace entire barcodes, partly due to their higher price. For some cheap goods, the high cost of the label is unacceptable, despite all the advantages that the label provides (imagine at least an inventory in the store). You can also take into account that the storage of information on individual goods takes a rather different place, so the most likely situation is tracking batches of goods starting from pallets or expensive, piece goods.
Microwave RFID tags are used in long-term access control for vehicles. For example, RFID tags are used for electronic toll collection at intercity and international toll stations on roads. Tags are read remotely when cars pass through the cab, and the tag information is used to write off the fee from an already prepared invoice. The system helps to speed up the movement of vehicles through duty collection points. Sensors, such as seismic sensors, can be read using an RFID transceiver, which greatly simplifies the collection of remote information.
In January 2003, Michelin began testing RFID transponders embedded in buses. Now the manufacturer offers tires with RFID-tags. Starting in 2004, the Smart Key option is available for the Toyota Prius and some Lexus models. The key fob uses an active RFID circuit that allows the machine to confirm the presence of a key within 3 feet of the sensor. The driver can open the door and start the car while the key remains in the wallet or pocket.
Implants for people
Implantable RFID chips designed for animal labeling are now also used by humans. An early experiment with an RFID implant was conducted by English cybernetic scientist Kevin Warwick, who implanted the chip in his hand in 1988. Thanks to the used digital solution, Kevin solved the problem of providing access to the house, computer access, storage of medical records, and working with various law enforcement applications. Baja Beach Club in Barcelona uses an implantable chip to identify VIP customers, who in turn use it to pay for drinks. The Mexico City police station implanted approximately 170 of its chip officers to allow access to police databases and to be able to track them in the event of abduction. Amal Graafstra, a Washington, born businessman, implanted an RFID chip in his left hand in early 2005. The chip size was 12mm in length and 2mm in width.
(To be continued)
Posted by: angelshirl
Date: 10/17/2005 18: 52: 09 ©
http://www.xakep.ru/post/28394/default.asp?print=true
