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Learn the basics of RFID technology, including system architecture, frequency bands, tag characteristics, data carrying options, and more. Discover the advantages of RFID over barcodes and explore various applications.
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Introduction to RFID RFID Programming University of Houston Bauer College of Business Spring 2007
Some links… • www.rfidjournal.com • www.computerworld.com • www.rfidusa.com • www.uh.edu/gartner
Definition • RFID (Radio Frequency Identification) is a technology used for electronic and wireless identification of objects, humans and animals
Carrier Frequencies • What is frequency? • Refers to the property of radio waves used to transmit data
Carrier Frequency • RFID systems may use a particular frequency band depending on: • Application • Legislature • Cost considerations
Frequency and bandwidth • Frequency is of primary importance when determining data transfer rates (bandwidth) • The higher the frequency, the higher the data transfer rate
Range • Range – the working distance between a tag and a reader Range
Range and Power Levels • The range that can be achieved in an RFID system is determined by • The power available at the reader • The power available within the tag • The environmental conditions and structures
Material Propagation • The absorption rate for water and other non-conductive substances is lower by a factor of 100 000 at 100 kHz than it is at 1 GHz • LF systems are primarily used due to their high propagation of substances
Electromagnetic Interference • Electromagnetic Interference - Interference caused when the radio waves of one device distort the waves of another. • Cells phones, wireless computers and even robots in factories can produce radio waves that interfere with RFID tags. • EI is likely to be an issue for UHF systems
Tags Characteristics • Means by which transponder is powered • Data carrying options • Data read rates • Programming options • Physical forms • Costs
Active and Passive Tags • Active tags • Powered by an internal battery • Finite lifetime (because of battery) • Greater range • Better noise immunity • Higher data transmission rates
Active and Passive Tags • Passive tags • Operate without battery • Derive power from the field generate by the reader • Less expensive • Unlimited life • Require more powerful readers • Orientation sensitivity
Data Carrying Options • A tag can contain • An identifier • 1bit – 128 bits • Portable data files • Example: 64 K
Data Read Rate • Data read rate is linked to frequency • The higher the frequency, the higher the read rate
Data Programming Options • Read-only • Cheap • Write once read many • Read/write • Expensive
Why Use Read/Write Tags? • Greater flexibility • Customers may change requirements • Standards may change • Database dependence • Ownership issues • Lag times
Tag Physical Forms • Disk and Coins – can be attached to an item by a fastening screw
Tag Physical Forms • Keys or Key Fobs, Watches – access control
Smart Labels • A bar code can be printed on an RFID label
Tag Physical Forms • Glass Transponders can be implanted under skin
What’s so special about RFID? • Line of sight is not required • Longer read ranges • Faster: hundreds of items can be scanned in one read
Principles of Profitable RFID Use • Enterprise value of data collection • Example: a big retailer working with a small supplier • The data collection process is relatively chaotic • Example: Battlefield • Making libraries chaotic • The exact configuration of goods must be maintained • Example: Auto industry
Inventory tracking • RFID tag data capacity is big enough that any tag will have a unique code, while current bar codes are limited to a single type code for all instances of a particular product. • The uniqueness of RFID tags means that a product may be individually tracked as it moves from location to location, finally ending up in the consumer's hands. This may help companies to combat theft and other forms of product loss. • the visibility provided by RFID allows an accurate knowledge on the inventory level by eliminating the discrepancy between inventory record and physical inventory. • In an academic studyperformed at Wal-Mart, RFID reduced Out of Stocks by 30 percent for products selling between 0.1 and 15 units a day. • It has also been proposed to use RFID for POS store checkout to replace the cashier with an automatic system which needs no barcode scanning. However, this is not likely to be possible without a significant reduction in the cost of current tags
Some applications • Transportation payments • High-frequency RFID tags are used in library tracking, pallet tracking, building access control, airline baggage tracking, and apparel and pharmaceutical items tracking. • High-frequency tags are widely used in identification badges, replacing earlier magnetic stripe cards. These badges need only be held within a certain distance of the reader to authenticate the holder. • UHF RFID tags are commonly used commercially in case, pallet, and shipping container tracking, and truck and trailer tracking in shipping yards. • Since the 1990s RFID tags have been used in car keys. Without the correct RFID, the car will not start. The driver can open the doors and start the car with the key in a purse or pocket.
A business example • The most notablebusiness advantage to RFID is the ability for enabling quicker location ofproduct and faster turn-around getting the product onto the shopfloor for people to buy. • Take one business example: Items shipped to a store come in brownboxes. Big boxes, small boxes, and all of them brown boxes. • When pallets arrive at a store, theyget placed in the storeroomwaiting for theevening shift to comeplace the items onto theshop floor. • By using RFID,it’s possible to do somethingrather special.Whenan item is no longer on theshelf, an associate can usea mobile reader to findnew stock in the backroom without having toread the labels on all of those brown boxes. • In essence, the non line-of-site advantage of RFID significantly assists in locating products.Alternative techniques rely on additionallabor and negate the sales advantageof ensuring the shelf is always full, butRFID reduces the burden on labor and providesa tangible, positive ROI.
RFID Growth • Several market research firms predict that ~2007 RFID market will reach ~$3 billion • The lowest cost of Gen2 EPC inlay is offered by SmartCode at a price of 5 cents apiece in volumes of 100 million or more
Standards • The manufacturer, distributorand retailer must all have systems that arecompatible with one another. • This doesn’tjust apply to back-end systems, but to thetags themselves if RFID is to be effective. • Some of the early compatibility issues werevery fundamental — such as the frequencythe tags operate on. • For the most part, the869 to 915 MHz tags prevailed, but still leftthe hurdle of the actual tag content. • Itbecame obvious that tag formats, just likebarcode formats, needed standardization. • This was addressed through the ElectronicProduct Codes (EPCglobal), an industrybody that sets these electronic standards.
Standards • However, having the frequency and tagformat agree only buys so much if the air protocolto get the data isn’t established. • Untilrecently it was difficult to guarantee that areader from one manufacturer would workwith a tag from another, until the EPCGeneration 2 air specification. • Now, both tagand reader vendors all signed up to maketheir equipment compatible • All manufacturers has cross compatible offerings.
Standards • While the EPC now has a standardadopted by the vendors in the US andEurope, there continue to be difficultieswith international compatibility. Almost allof the participants in EPC are from the U.S.and Europe, while a significant portion ofmanufactured goods are no longer made inthose member countries. • As respected asEPC may be, it would require a higherauthority to mandate a world-wide standard. • That’s where the InternationalStandards Organization (ISO) comes in. • The EPC Generation 2 specification wassubmitted to ISO and just recently itbecame an approved standard with the designationISO/IEC 18000 to 6C. • With ISOapproval, it’s now possible to buy a compliantReaderand tag that works the worldover.
Regulations • Europe facessignificant problems with reader performancedegradation in environments where high numbers of readers are used together. • Thisperformance degradation issue originates from the fact that the EU has a more limitedrange of spectrum that’s legally assigned forRFID use compared to the USA.
Regulations • In North America, UHF can be used unlicensed for 902 – 928 MHz (±13 MHz from the 915 MHz center frequency), but restrictions exist for transmission power. • In Europe, RFID and other low-power radio applications are regulated by ETSI recommendations EN 300 220 and EN 302 208, and ERO recommendation 70 03, allowing RFID operation with somewhat complex band restrictions from 865–868 MHz. • Readers are required to monitor a channel before transmitting ("Listen Before Talk"); this requirement has led to some restrictions on performance, the resolution of which is a subject of current research. • The North American UHF standard is not accepted in France as it interferes with its military bands. • For China and Japan, there is no regulation for the use of UHF. Each application for UHF in these countries needs a site license, which needs to be applied for at the local authorities, and can be revoked. • For Australia and New Zealand, 918 – 926 MHz are unlicensed, but restrictions exist for transmission power.
Privacy • Since the owner of an item will not necessarily be aware of the presence of a RFID tag and the tag can be read at a distance without the knowledge of the individual, it becomes possible to gather sensitive data about an individual without consent. (Ex. Scanning your home, medical records) • A number of products are available on the market in the US that will allow a concerned carrier of RFID-enabled cards to shield their data • Shielding is again a function of the frequency being used. • Low-frequency tags, like those used in implantable devices for humans and pets, are relatively resistant to shielding, though thick metal foil will prevent most reads. • High frequency tags (13.56 MHz — smart cards and access badges) are more sensitive to shielding and are difficult to read when within a few centimetres of a metal surface.