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What is RFID?
RFID stands for radio frequency identification.
It is an automatic identification technology whereby digital data
encoded in an RFID tag or "smart label" is captured by a reader
using radio waves. Put simply, RFID is similar to bar code technology
but uses radio waves to capture data from tags, rather than optically
scanning the bar codes on a label. RFID does not require the tag
or label to be seen to read its stored data-that's one of the
key characteristics of an RFID system.
What is an RFID tag?
RFID tags consist of an integrated circuit
(IC) attached to an antenna-typically a small coil of wires-plus
some protective packaging (like a plastic card) as determined
by the application requirements. RFID tags can come in many forms
and sizes. Some can be as small as a grain of rice. Data is stored
in the IC and transmitted through the antenna to a reader. RFID
tags are either "passive" (no battery) or "active" (self-powered
by a battery). Tags also can be read-only (stored data can be
read but not changed), read/write (stored data can be altered
or re-written), or a combination, in which some data is permanently
stored while other memory is left accessible for later encoding
and updates.
What is a "smart label"?
"Smart labels" are a particularly innovative form of RFID tag and
operate in much the same way. However, a smart label consists of an
adhesive label that is embedded with an ultra-thin RFID tag "inlay" (the
tag IC plus printed antenna). Smart labels combine the read range
and unattended processing capability of RFID with the convenience
and flexibility of on-demand label printing. Smart labels also can
be pre-printed and pre-coded for use. In on-demand applications, the
tag inlay can be encoded with fixed or variable data and tested before
the label is printed, while the label can contain all the bar codes,
text, and graphics used in established applications. Smart labels
are called "smart" because of the flexible capabilities provided by
the silicon chip embedded in the tag inlay. A read/write smart label
also can be programmed and reprogrammed in use, following initial
coding during the label production process.
What is an RFID reader?
A reader is basically a radio frequency (RF)
transmitter and receiver, controlled by a microprocessor or digital
signal processor. The reader, using an attached antenna, captures
data from tags then passes the data to a computer for processing.
As with tags, readers come in a wide range of sizes and offer
different features. Readers can be affixed in a stationary position
(for example, beside a conveyor belt in a factory or dock doors
in a warehouse), portable (integrated into a mobile computer that
also might be used for scanning bar codes), or even embedded in
electronic equipment such as print-on-demand label printers.
How does RFID work?
Information is sent to and read from RFID tags
by a reader using radio waves. In passive systems, which are the
most common, an RFID reader transmits an energy field that "wakes
up" the tag and provides the power for the tag to operate. In
active systems, a battery in the tag is used to boost the effective
operating range of the tag and to offer additional features over
passive tags, such as temperature sensing. Data collected from
tags is then passed through familiar communication interfaces
(cable or wireless) to host computer systems in the same manner
that data scanned from bar code labels is captured and passed
to computer systems for interpretation, storage, and action.
Where is RFID used?
Currently, the most common uses are found in
work-in-process tracking, security and access control systems,
closed-loop asset management, and car immobilizers, as well as
pay-at-the-pump and freeway toll passes. For example, the Ford
Motor Co. uses RFID to track engine blocks through its harsh production
process; Gap Inc. has used RFID to track denim jeans through its
supply chain to the in-store display shelf; Exxon Mobil Corp.'s
Speedpass cashless payment system uses RFID technology; and RFID
tags are applied to the shoelaces of all competitors in the Boston
Marathon to track them at points throughout the course and to
identify them the instant they cross the finish line.
How does RFID differ from bar coding?
Conceptually, bar coding and RFID are quite
similar; both are intended to provide rapid and reliable item
identification and tracking capabilities. The primary difference
between the two technologies is that bar coding scans a printed
label with optical laser or imaging technology, while RFID scans,
or interrogates, a tag using radio frequency signals. Because
of the low cost of bar code labels, established standards, and
global deployment, bar coding is widely accepted while, in general,
RFID has been limited to niche applications. Furthermore, just
as there are different bar code symbologies in use today, there
are different RFID standards regarding the way data is captured
from tags-the RF communications protocol.
What information is stored on a smart label or tag?
Data stored in a tag will be determined by
the application of the system and appropriate standards. For example,
a tag could provide identification for an item being manufactured,
goods in transit, or even the short-range location and identity
of a vehicle, animal, or individual. This fundamental data often
is referred to as a "license plate code," similar to the information
that is stored on a bar code label. When linked to a database,
additional information may be accessed through the reader such
as item stock number, current location, status, selling price,
and batch code. Alternatively, an RFID tag may carry specific
information or instructions immediately available upon reading,
without the need to reference a database to determine the meaning
of a code. For example, the desired color of paint on a car that
is entering the paint assembly area on the production line, or
a manifest to accompany a shipment of goods.
What are some of the key attributes of RFID?
Key attributes of RFID include:
- Because tag data is transmitted and received by radio frequency,
RFID does not require line-of-sight to read and write the tag
data. RF signals also are capable of traveling through a wide
array of non-metallic materials.
- Most RFID systems can simultaneously capture data from many
tags within range of the antenna. This unique feature is known
as "simultaneous identification."
- RFID tags can be read very rapidly. RFID readers are capable
of capturing tag identification codes at a rate of up to 1,000
tags per second.
- RFID tags can be encased in hardened plastic coatings making
them extremely durable and able to be tracked through harsh
production processes. They can be read through grease, dirt,
and paint.
- RFID tags can store large amounts of data. High-end RFID
tags can contain up to one megabyte of memory (one million
characters), although most tags only contain a small fraction
of this memory, perhaps as little as 64 bits.
- Some RFID tags are able to support read/write operations,
enabling real-time information updates as a tagged item moves
through the supply chain.
Can RFID track me?
At the retail level, RFID is no more invasive
than the bar code is today. Even though RFID uses radio frequency,
the relatively short read ranges do not make it practical for
use as a remote surveillance device. RFID is not-and should
not be compared to-the Global Positioning System (GPS).
Will RFID replace bar codes?
No. RFID and bar coding are considered complementary
data capture technologies. Even with large-scale adoption of
RFID, there will be a continued need for bar coding to co-exist
with RFID into the foreseeable future. The unique attributes
of RFID make it an enabler of new applications, especially
where the technical fit and operational benefits of the technology
make it a better solution than what is in use currently.
What is EPC RFID?
The Electronic Product Code (EPC) is a new
product numbering standard under development by the Uniform
Code Council and EAN International that can be used to detect,
track, and control a variety of items using RFID technology.
The initiative started as an end-user driven research project
at the Auto-ID Center of MIT. The EPC structure can distinguish
unique items of the same type. For example, two DVD videos
have the same standardized universal product code (UPC) for
the purposes of trade. Typically represented in a bar code,
the UPC allows computer systems to determine the manufacturer
of the DVD, the title of the film, and apply prescribed business
rules to facilitate the trade or sale. EPC essentially extends
the UPC code so that two DVD videos of the same title can be
distinguished one from another, allowing the individual item
to be uniquely identified.
Associated with EPC RFID developments are new Internet
services that enable individual items to be tracked and traced globally
across traditional industry boundaries. This approach to a standardized,
RFID-based, Internet-connected data capture system is called the EPC
Network, and is being commercialized by EAN and UCC. For more information
about EPC RFID, visit www.zebra.com/epc or www.uc-council.org/autoid/index.html.
About Zebra Technologies
Zebra Technologies is a leader in developing
innovative and reliable on-demand printing solutions for business
improvement and security applications. Zebra's customers include
more than 90 percent of the Fortune 500, as well as a growing
base of mid-market and government organizations in 100 countries
worldwide. Specialty printing applications featuring Zebra
products deliver enhanced security, increased productivity,
improved quality, lower costs, and better customer service.
The company has sold more than 3 million thermal bar code label,
RFID "smart" label, receipt, and card printers, plus wireless
mobile solutions, software, connectivity accessories, and printing
supplies. For more information visit www.zebra.com.
About Zebra RFID Solutions
Zebra is a pioneer in the targeted adoption
of RFID in the global business marketplace. Its RFID solutions
are a natural extension of Zebra's rich heritage as a leader
in specialty printing. Zebra's RFID solutions include: RFID products
consisting of printers/encoders, smart labels, and software;
integration and professional services partnerships; and educational
resources. Global and national organizations leverage Zebra's
RFID solutions to gain greater supply chain and other business
efficiencies throughout the enterprise; a quick, pragmatic approach
to RFID implementation; and an ROI-based model for RFID initiatives.
More information is available online at www.rfid.zebra.com. |
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