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What is RFID?

Here's a plain-English explanation of what radio frequency identification is and why it's suddenly become an important technology.
By Bob Violino
Jan 16, 2005Radio frequency identification (RFID) is a generic term that is used to describe a system that transmits the identity (in the form of a unique serial number) of an object or person wirelessly, using radio waves. It's grouped under the broad category of automatic identification technologies.

Auto-ID technologies include bar codes, optical character readers and some biometric technologies, such as retinal scans. The auto-ID technologies have been used to reduce the amount of time and labor needed to input data manually and to improve data accuracy.

Some auto-ID technologies, such as bar code systems, often require a person to manually scan a label or tag to capture the data. RFID is designed to enable readers to capture data on tags and transmit it to a computer system—without needing a person to be involved.

Antennas read passive tags on cases stacked on a pallet
A typical RFID tag consists of a microchip attached to a radio antenna mounted on a substrate. (For more detail and for information about tags that don’t use silicon chips, read “The Basics of RFID Technology.”) The chip can store as much as 2 kilobytes of data. For example, information about a product or shipment—date of manufacture, destination and sell-by date—can be written to a tag.

To retrieve the data stored on an RFID tag, you need a reader. A typical reader is a device that has one or more antennas that emit radio waves and receive signals back from the tag. The reader then passes the information in digital form to a computer system.

RFID technology has been used by thousands of companies for a decade or more. (RFID Business Applications spells out some of the ways the technology has been and will be used.) The technology is not new (see The History of RFID), so why is it taking off now?

Until recently, the cost of RFID has limited its use. For many applications, such as tracking parts for just-in-time manufacturing, companies could justify the cost of tags—a dollar or more per tag—by the savings an RFID system could generate. And when RFID was used to track assets or reusable containers within a company’s own four walls, the tags could be reused.

But for tracking goods in open supply chains, where RFID tags are put on cases and pallets of products by one company and read by another, cost has been a major obstacle to adoption. Tags must, in effect, be disposable because the company putting them on cannot recycle them. They get thrown out with the box. (Tags built into pallets could be reused, and some companies are looking to develop ways to recycle tags on corrugated cases.)

The Auto-ID Center
In 1999, the Uniform Code Council and EAN International teamed with Gillette and Procter & Gamble to fund the Auto-ID Center at the Massachusetts Institute of Technology. The center changed the equation by working with private industry to develop an RFID tag that would be very low cost (the goal was five cents) when manufactured in high volumes. That way, companies could put tags on everything they own and then connect them to the Internet through a secure network. The center eventual gained the backing of the U.S. Department of Defense and some 100 global companies, including Kimberly-Clark, Metro, Target, Tesco, Unilever, Wal-Mart. These companies were attracted to RFID because it held out the potential of offering perfect supply chain visibility—the ability to know the precise location of any product anywhere in the supply chain at any time.

The 5-cent tag is still several years away. Today tags cost from 20 to 40 cents, depending on their features and packaging. (For more on this, see RFID Costs and Components). The Auto-ID Center's contribution went beyond trying to create an inexpensive tag. It developed the Electronic Product Code (EPC), a numbering scheme that makes it possible to put a unique serial number on every item manufactured. It developed a way for tags and readers to communicate (the air interface protocol) and designed a network infrastructure that stores information in a secure Internet database. A virtually unlimited amount of data associated with a tag’s serial number can be stored online, and anyone with access privileges can retrieve it.


Mark Meyer 2005-09-18 11:20:38 PM
RFID 101 This is a very good article. For someone like me, who does not have any knowledge of RFID, it gives a wonderful introduction and application of how RFID works and how it can be used in the future. It also tells the problems that are currently faced by the Industry to implement the RFID solution.
hadi aghaie 2014-03-07 02:12:31 PM
excellent knowledge to share with us thanks a lot, very great article
prakhar yadav 2015-11-27 02:41:33 AM
No doubt rfid technology became more popular due to its different features .and we being a part of rfid organization we also provide rfid services and software solutions.
Dan Miller 2016-12-20 07:31:20 AM
It would be nice to see this updated.
Gustave Ujeneza 2018-08-29 11:39:28 AM
That is great! well explained and now I start to get what RFID is and how much useful is. Thanks.

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