Frequently Asked Questions (FAQs)

Q: What is Automatic Identification?
A: Automatic identification, ("auto ID" for short), is the name for technologies that enable machine identification of objects. Technologies include barcodes, smart cards, voice or speech pattern recognition, biometrics (fingerprint scanners, hand geometry readers, facial geometry readers, retina scanners), optical character recognition (OCR) scanning, and radio frequency identification (RFID). One goal of auto ID is to minimize human intervention in identifying objects, which increases efficiency, reduces data entry errors, and frees up employees to do other tasks. For example, an auto ID system identifies items, captures info such as product number, and passes the data to a computer without having an employee enter it manually.

Q: What is RFID?
A: Radio frequency identification, or RFID, uses radio waves to automatically identify objects. Item data is stored on a microchip attached to an antenna, (called an "RFID transponder" or "RFID tag"). The tag transmits the data to a reader when it passes within range, and the reader can convert the signal to digital information that can be used by a computer for further processing.

Q: How does an RFID system work?
A: The most basic RFID system consists of a tag and an interrogator (sometimes called a reader). The reader sends out radio waves. The antenna on the tag is tuned to receive these waves. The tag modulates the waves and sends a response back to the reader in the form of radio waves. The reader converts the new waves into digital data. Of course, more complex systems will have a computer network and specialized software on the "back end" to process the digital data.

Q: Are the radio waves in an RFID system dangerous?
A: RFID waves are similar to radio waves used to broadcast commercial AM talk shows or FM music, and are no more dangerous than those types of signals.

Q: Is RFID better than barcode?
A: A RFID system isn't necessarily "better" than barcode. They are different technologies used for the same general purpose: To identify items. Barcodes are "line-of-sight," meaning a reader or scanner for a bar code must have an unobstructed "view" of it to capture the data it contains. Typically, a worker maneuvers a scanner or the item into a position where the barcode can be read. RFID, on the other hand, isn’t line-of-sight. RFID tags can be read as long as they are within range of a reader. Imagine taking a big screen TV through a barcode checkout. The clerk would have to either extend the barcode scanner out, and maneuver around until he got a good read on the barcode, or ask you to manhandle the bow around until the same read could be made. The same scenario in an RFID system would not require any maneuvering of either the reader or the box the TV is packed in. The RFID tag would simply pass within range of a reader, and the data would be passed.

Q: Will RFID replace barcode?
A: Probably not right away, if ever. Barcode is inexpensive and in widespread use, making it easy to implement and use. There are also certain standards for barcodes that ensure one barcode produced at one factory will be able to be read at many other places. RFID is more expensive, with readers costing hundreds if not thousands of dollars, and individual tags costing anywhere from 50 cents to 20 dollars (or more). RFID manufacturers, users, developers and integrators also have yet to settle on any standard, so competition is fierce to gain "market share" and other competitive advantages. A de facto standard exists in the Electronic Product Code (EPC), but it has not neen adopted officially by any governing body as an official standard. While companies jockey for position in the RFID world, and standards remain "loose" or "undefined," there is very little competitive advantage RFID has over barcode, except in operational efficiency. Most likely, RFID and barcode will "peacefully coexist" for a long time.

Q: What are some of the advantages of RFID systems?
A: RFID is a proven technology that's been around since at least World War II. Radio waves travel through most non-metallic materials, so they can be embedded in packaging or encased in protective plastic for weather-proofing and greater durability. And tags have microchips that can store a unique serial number for every product manufactured around the world, as well as other data. Barcodes, on the other hand, are subject to weathering, abrasions, temperature extremes and good old wear-and-tear.

Q: What are some of the disadvantages of RFID systems?
A: Up to now, it's been too expensive and too limited to be practical for many commercial applications. But if tags can be made cheaply enough, they can solve many of the problems associated with bar codes. The current goal of most RFID tag manufacturers and system users is to see the cost of tags go to about $0.05 per tag, which would make it economically feasible to place them on individual items. Currently, because of the relative high cost of tags, they are used only on cartons or pallets, or on certain high-value items. One other issue is that products which pass from a supplier to a value-added manufacturer to a retailer require some sort of "standard" so every entity along the product's life span can read and use the RFID data. To date, no such standard has been settled upon, although the de facto Electronic Product Code (EPC) standard has been adopted in several high-visibility projects, namely WalMart's 2005 mandate for its top 100 suppliers to use RFID in their supply chain operations.

There are also some technical issues that RFID systems face. Metal packaging tends to reflect RFID waves, and liquids tend to absorb them, making accurate "reads" a problem. Another technical issue involves the orientation of the antenna to the tag to ensure readability. Yet another issue is how to handle the very fast reading of data, and the inevitiable "collisions" that occur when two or more tags are read simultaneously.

And don't forget social issues, as well. Many consumer groups object to the use of RFID tags, viewing them as an unwarranted intrusion into privacy. Using RFID-derived data, a company can monitor individual item purchases, and if the RFID data is associated with a specific consumer, that person could be subject to "SPAM ads" that target his or her buying patterns that are derived from the RFID data. Imagine a shopper who enters a store, and based on past purchases, is bombarded with ads for products that he or she may not need or want right at the moment. Such concerns have prompted many pilot projects in Europe and America to abandon RFID tagging of individual products at the retail or "shelf" level, and restrict RFID use to "warehouse" or "back end" operations where individual consumers are not yet involved.

Q: What frequencies are used in RFID systems?
A: RFID systems use many different frequencies, but the most widely used are low-frequency ("LF," around 125 KHz), high-frequency ("HF," 13.56 MHz) and ultra-high frequency ("UHF," from 850 to 900 MHz). Microwave frequency (2.45 GHz) is also used. RFID waves act differently at different frequencies, so it's important to pick the right frequency for the right job. RFID tags and readers have to be tuned to the same frequency to perform correctly.

Q: Which frequency should I use?
A: Different frequencies have different operational characteristics that make them more suitable for different applications. For example, low-frequency (LF) tags are less expensive than ultra high frequency (UHF) tags, use less power and can better penetrate non-metallic products. LF tags would be used for scanning objects with high-water content, such as fruit or vegetables, at close range. UHF tags typically are longer range and can transmit product data faster. But UHF tags use more power and have a harder time passing through some packaging materials. UHF tags radiate in a more "directed path," so they require a realatively unobstructed path between the tag and reader. UHF tags might be better for scanning cartons or pallets of products as they pass through a shipping bay door into a storage facility.

Q: Do all countries use the same RFID frequencies?
A: Most countries have assigned certain portions of the radio spectrum for certain applications. For example, 13.56 MHz is used around the world for high-frequency RFID systems. But UHF RFID systems have only been around since the mid-1990s and countries have not agreed on a UHF spectrum for RFID. Europe uses 868 MHz for UHF and the U.S. uses 915 MHz. Governments also regulate the power of the readers to limit interference with other devices.

Q: Since RFID has problems working around metal and water, can I use it to track cans or liquid products?
A: Yes, you can, but you have to pay special attention to system design to work around inherent limitations. Radio waves bounce off metal and are absorbed by water at ultra-high frequencies. Tracking metal cans or bottles of liquids is therefore more difficult, but good system design and engineering can overcome these problems. Using low-frequency (LF) and high-frequency (HF) tags work better on liquid products or in metal containers, and the distance from the reader can affect tracking.

Q: What’s the difference between passive and active RFID tags?
A: Active RFID tags have a power supply, usually a battery, which is used to run the chip and to broadcast a signal to a reader, (in much the same way a cellular phone transmits signals to a cell tower). Passive tags have no on-board power source. Passive tags draw power from the reader, which sends out RFID waves that induce a current in the tag's antenna. Semi-passive tags use an on-board power source, but transmit by using power from the reader. Active tags are longer ranged than passive tags, meaning they can be read from longer distances, often hundreds of feet or more. Active and semi-passive tags are used for tracking high-value products over long ranges, such as railroad cars in a railway yard, but they cost a lot, sometimes as much as $20 or more per tag, making them too expensive to put on low-cost items. A lot of companies focus on passive UHF tags, which cost less than 50 cents per tag. Their read range is shorter than active tags - usually less than 20 feet - but they are much less expensive than active tags and are disposable.

Q: What is an Electronic Product Code?
A: The Electronic Product Code (EPC) was developed by the Auto-ID Center as a rough equivalent of a Universal Product Code (UPC) barcode. The EPC allows each individual product to be identitifed in relation to the company, product, and unique serial number. The EPC Generation 1 tags had 64-bit and 96-bit versions, with the 96-bit version capable of providing unique identifiers for 268 million companies, each with up to 16 million object classes, with 68 billion available serial numbers in each object class. Generation 2 tags will have 256-bit data capacities.

Q: How much information can an RFID tag store?
A: Depends on the tag itself. Most tags would have about 2KB of data - enough for some basic information about the item. A typical tag would relate to a database on a computer network that contains expanded product information, much like a current barcode. Some tags, however, can act as "portable databases," and can transport huge volumes of information embedded in the tag itself. For example, an RFID-tagged package of hamburger with a high-capacity tag might contain data about the farm in the state the cow was raised in, the date it was butchered, the plant where it was processed in, the warehouse it was stored in, the date it was processed, the date and time it was packaged, and the expected expiration date. An RFID system could use data from such a high-capacity tag to check meat in cases of contamination or recall, and easily pull them from retail shelves.

Q: What’s the difference between read-only and read-write tags?
A: RFID tags can be read-write or read-only. Read-write tags mean you can add or write over information to the tag when the tag is within range of a reader. Read-only tags are encoded at time of manufacture, and their data can thern never been changed.

Q: What is an RFID collision?
A: Two types occure: Reader collisions, and tag collisions. When two readers overlap in coverage areas, a reader collision occurs when their signals interfere with each other. To avoid the problem, integrators use time division multiple access (TDMA), where readers are programmed to read at different times, rather than both trying to read simultaneously. But using TDMA may mean that any RFID tag in an area where two readers overlap will be read twice. So the system has to be set up so that if one reader reads a tag another reader does not read it again.

Tag collision occurs when reading multiple chips in the same reader area, as more than one chip reflects back a signal at the same time, confusing the reader. Hardware vendors have developed different proprietary systems for having the tags respond to the reader one at a time, avoiding tag collisions.

Q: What is the read range for a typical RFID tag?
A: The read range of passive tags (tags without on-board power supplies) depends on a lot of factors: the system frequency used, the power level of the reader, and interference from metal objects or other devices which generate radio frequencies. Generally, low-frequency (LF) tags have read ranges of less than 12 inches. High frequency (HF) tags have a read range of less than three feet, and UHF tags have read ranges up to about 20 feet. When users require longer range reads, such as for tracking railway cars in a depot, active tags (using on-board power) can yield read ranges of 300 feet or more.

Q: What are the standards for RFID?
A: International standards have been adopted for very specific applications, such as tracking livestock. Other standards initiatives are being proposed all the time. The International Organization for Standardization (ISO) is working on standards for high-frequency tags (ISO 18000-3) and ultra-high frequency tags (ISO 18000-6). EPCglobal, a joint technology venture composed of a number of leading RFID manufacturers and EPC proponents, has its own standards process, and intends to submit EPC protocols to ISO as proposed international standards.

But because the market is young and so many companies are competing for market share, there are really only broad standards for implementing RFID systems. Different combinations of RFID tags and readers may yield different results, and the different results may or may not fit ideally into a market as a convenient solution for any given application. For example, to implement a livestock tracking solution, different hardware manufacturers, software manufacturers, systems integrators and consultants will likely recommend a broad array of solutions, depending on the variables of the situation, project, or environment. Short answer: It's very "wide open" right now, and there's no one, "right" answer for RFID implementation.

Q: What are some of the most common applications for RFID?
A: RFID may be used for anything from managing security access at a facility to tracking cargo containers to managing warehouses. Truly, you are limited only by your imagination - and currently, a couple of pesky laws of physics! The most common apps are tracking goods in the supply chain, such as levels of raw materials used in production, the disposition of components in the production process, and the location of finished products at warehouses, shipping points, distribution centers, and delivered at retail outlets.

Q: What are intelligent software agents?
A: Software agents are programs that automate decision making by establishing a set of rules that are processed periodically or when conditions dictate. For example, if a package comes along a RFID-enabled conveyor belt, depending on the RFID tag data, it may be directed to a boxing machine or to a shrink wrapping machine. Because RFID data is so readily available, the sheer volume would quickly overwhelm any human being working as a monitor. Software agents allow routine actions to be performed based on well-defined logical rules, and can also alert human managers to situations where attention is needed, as in faulty tags, non-functioning machinery, or other non-routine incidents. In some applications, these software agents are called "savants."