What is RFID?*

In the simplest sense, Radio Frequency IDentification (RFID) is a method of remotely storing and retrieving data using devices called RFID tags. An RFID tag is a small object, often embedded in an adhesive sticker, that can be attached to a product or incorporated into a product's packaging. RFID tags contain antennas to enable them to receive and respond to radio frequency queries from an RFID transceiver (a transmitter-receiver often referred to as an RFID "reader" or an RFID "interrogator").

In many respects RFID is the leading edge of Information Technology - it is the integration and miniaturization of both digital and Radio Frequency (and other analog) technologies that will dramatically extend the reach of applications within companies and throughout industries, and also between industries.  RFID is the state of the art in commercially viable, cost-reduced, and extremely small computing technology integrated with radio frequency transceivers.  With an RFID tag, almost every article of every product will potentially have the ability to receive, store, process, retrieve, and transmit information - starting with, but not limited to, the unique ID of each article of virtually every commercial product.  Some day it may be cost-effective for individual pieces of paper to contain an RFID tag.  Additionally, RFID has the potential to lead to many applications that extend beyond conventional commercial products. 

  Types of RFID Tags

RFID tags can be either active or passive.

Passive RFID tags do not have their own power supply: the minute electrical current induced in the antenna by the incoming radio-frequency scan provides enough power for the tag to send a response. Due to power and cost concerns, the response of a passive RFID tag is necessarily brief, typically just an ID number (GUID). Lack of its own power supply makes the device quite small: commercially available products exist that can be embedded under the skin.

Active RFID tags, on the other hand, must have a power source, and may have longer ranges and larger memories than passive tags, as well as the ability to store additional information sent by the transceiver.

As passive tags are much cheaper to manufacture, the vast majority of RFID tags in existence are of the passive variety.

There are four different kinds of tags commonly in use, their differences based in part on the level of their radio frequency:  Low frequency tags (between 125 to 134 kilohertz), High frequency tags (13.56 megahertz), UHF tags (868 to 956 megahertz), and Microwave tags (2.45 gigahertz).

  Current Usage

Low-frequency RFID tags are commonly used for animal identification, beer keg tracking, and automobile key-and-lock, anti-theft systems. Pets are often embedded with small chips so that they may be returned to their owners if lost, though in the U.S. both the old 125kHz standard and new international 134.5kHz standard are in use, sometimes making it difficult to scan a squirming pet twice, carry two scanners, or have a dual scanner on hand.

High-frequency RFID tags are used in library book or bookstore tracking, pallet tracking, building access control, airline baggage tracking, and apparel item 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 pallet and container tracking, and truck and trailer tracking in shipping yards.

Microwave RFID tags are used in long range access control for vehicles, an example being General Motors' OnStar system.

Some toll booths, such as those used in California's FasTrak system and in Dallas, TX are equipped to read data from RFID tags as vehicles pass.  The RFID tag is logically connected to a prepaid account that is debited to pay for the toll. The fact that appropriately-equipped vehicles no longer need to stop to pay the toll helps to reduce traffic congestion.

Some kinds of sensors, such as temperture sensors, may be read using RFID transceivers, greatly simplifying remote data collection.

  Potential Uses

RFID tags are often envisioned as a replacement for UPC bar-codes, having a number of important advantages over the older bar-code technology. RFID codes are long enough that every RFID tag may have a unique code, while UPC codes are limited to a single 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. It has also been proposed to use RFID for point-of-sale store checkout to replace the cashier with an automatic system, with the option of erasing all RFID tags at checkout and paying by credit card or inserting money into a payment machine. This has to a limited extent already been implemented at some stores.

Many somewhat far-fetched uses, such as allowing a refrigerator to track the expiration dates of the food it contains, have also been proposed, but few have moved beyond the prototype stage.

  Controversy

The use of RFID technology has engendered some controversy. Most concerns revolve around the fact that RFID tags affixed to products remain functional even after the products have been purchased and taken home. Although RFID tags are only officially intended for short-distance use, they can be interrogated from great distances by anyone with a high-gain antenna, potentially allowing the contents of a house to be scanned at a distance.

Three key privacy concerns regarding RFID are:

The purchaser of an item will not necessarily be aware of the
    presence of the  tag or be able to remove it

The tag can be read at a distance without the knowledge of
    the individual

If a tagged item is paid for by credit card then it would
    theoretically be possible to tie the unique ID of the item to the
    identity of the purchaser

At a 2003 California Senate hearing Senator Debra Bowen summarized the concerns thus: "How would you like it if, for instance, one day you realized your underwear was reporting on your whereabouts?"

  Summary

The applications for RFID are limited only by increasingly easier levels of cost-justification and people's imagination.  Virtually every item with a unique serial number (or name) will have the potential to become an intelligent wireless node on a private intranet, a private extranet, or the public Internet.

  External Links

• The Association for Automatic Identification and Data Capture Technologies (http://www.aimglobal.org/technologies/rfid/) an industry webpage about RFID
• Declan McCullagh: "Are spy chips set to go commercial?" (http://zdnet.com.com/2100-1107-980345.html) ZDNet editorial, January 13, 2003.
• RFID Journal: Michelin Embeds RFID Tags in Tires (http://www.rfidjournal.com/article/articleview/269/1/1/)
• General article in Security Focus (http://securityfocus.com/columnists/169)
• EE Times - Euro banknotes to embed RFID chips in 2005 (http://www.eetimes.com/story/OEG20011219S0016) December 19, 2001.
• Techworld.com - RFID tags to make it into bank notes (http://www.techworld.com/news/index.cfm?fuseaction=displaynews&NewsID=412) September 2, 2003.
• RFID Log (http://www.rfidlog.com/) Industry news service on RFID innovation, implementation and legal processes.
• The RFID Gazette (http://www.rfidgazette.org/) RFID news updated daily.
• RFIDbuzz (http://www.rfidbuzz.com/) Views on RFID with contributors largely from industry backgrounds.
• RFIDbuzz wiki (http://www.rfidbuzz.com/wiki/) a Wiki dedicated to the promotion RFID: Actors in the marketplace, standards, technologies and more.
• NCR Self-Checkout (http://www.ncr.com/products/hardware/sa_selfchk.htm)
• See privacy weblinks for privacy rights organizations on the topic
• commercially available: http://www.4verichip.com/verichip.htm
• Wired News (http://www.wired.com/news/technology/0,1282,60898,00.html) has an article about the use of RFID technology in an inner city school.