RFID refers to technologies that
utilize radio waves to automatically identify individual items. RFID
allows information to be collected quickly and automatically and does not
require contact or line-of-sight. The reader generates an electromagnetic
field through its antenna. Once the tag enters the detection area, it
becomes active when receiving a signal through its own antenna. This signal
is used to turn on the tag's transmitter and allows the tag to communicate
and exchange information with the reader. The reader then transmits the data
to a computer or server for processing, management, and tracking.
Using an
RFID reader and software (also
available from “TagYourStuff”)
our clients will be able to record and update the inventory of these tagged
assets by simply walking through their home or place of business. Valuables
and important assets tagged with an RFID label from
“TagYourStuff”
will enable item level record keeping for ownership
identification, security, insurance, and inventory tracking purposes.
 Radio
frequency identification, or RFID, is a generic term for technologies that use
radio waves to automatically identify people or objects. There are several
methods of identification, but the most common is to store a serial number that
identifies a person or object, and perhaps other information, on a microchip
that is attached to an antenna (the chip and the antenna together are called an
RFID transponder or an RFID tag). The antenna enables the chip to transmit the
identification information to a reader. The reader converts the radio waves
reflected back from the RFID tag into digital information that can then be
passed on to computers that can make use of it.
An
RFID system consists of a tag, which is made up of a microchip with an antenna,
and an interrogator or reader with an antenna. The reader sends out
electromagnetic waves. The tag antenna is tuned to receive these waves. A
passive RFID tag draws power from field created by the reader and uses it to
power the microchip’s circuits. The chip then modulates the waves that the tag
sends back to the reader and the reader converts the new waves into digital data
for use in the application. 
Microchips in RFID tags can be read-write or read-only. With read-write chips,
you can add information to the tag or write over existing information when the
tag is within range of a reader, or interrogator. Read-write tags usually have a
serial number that can't be written over. Additional blocks of data can be used
to store additional information about the items the tag is attached to. Some
read-only microchips have information stored on them during the manufacturing
process. The information on such chips can never been changed. Other tags can
have a serial number written to it once and then that information can't be
overwritten later.
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Everything
you want to know about RFID and
MORE.......
RFID 101 |
RFID Vs Bar Codes
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RFID Challenges |
RFID Frequency |
Active Vs Passive |
EPC
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Tag Data |
Read only Vs Read-Write Tags |
RFID Standards |
RFID Leaders |
Applications for RFID |
RFID Users |
Sensors
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Software Agents
Energy Harvesting |
RFID Future
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RFID |
Automatic identification, or auto ID for short,
is the broad term given to a host of technologies that are used to
help machines identify objects. Auto identification is often coupled
with automatic data capture. That is, companies want to identify
items, capture information about them and somehow get the data into
a computer without having employees type it in. The aim of most
auto-ID systems is to increase efficiency, reduce data entry errors,
and free up staff to perform more value-added functions, such as
providing customer service. There are a host of technologies that
fall under the auto-ID umbrella. These include bar codes, smart
cards, voice recognition, some biometric technologies (retinal
scans, for instance), optical character recognition, and radio
frequency identification (RFID).
Radio frequency identification, or RFID, is a generic term for
technologies that use radio waves to automatically identify people
or objects. There are several methods of identification, but the
most common is to store a serial number that identifies a person or
object, and perhaps other information, on a microchip that is
attached to an antenna (the chip and the antenna together are called
an RFID transponder or an RFID tag). The antenna enables the chip to
transmit the identification information to a reader. The reader
converts the radio waves reflected back from the RFID tag into
digital information that can then be passed on to computers that can
make use of it.
An RFID system consists of a tag, which is made up of a microchip
with an antenna, and an interrogator or reader with an antenna. The
reader sends out electromagnetic waves. The tag antenna is tuned to
receive these waves. A passive RFID tag draws power from field
created by the reader and uses it to power the microchip’s circuits.
The chip then modulates the waves that the tag sends back to the
reader and the reader converts the new waves into digital data.
RFID uses the low-end of the electromagnetic
spectrum. The waves coming from readers are no more dangerous than
the waves coming to your car radio.
RFID is a proven technology that's been around
since at least the 1970s. 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. 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.
If RFID has been around so long and is so
great, why aren’t all companies using it?
Many companies have invested in RFID systems to get the advantages
they offer. These investments are usually made in closed-loop
systems—that is, when a company is tracking goods that never leave
its own control. That’s because all existing RFID systems use
proprietary technology, which means that if company A puts an RFID
tag on a product, it can’t be read by Company B unless they both use
the same RFID system from the same vendor. But most companies don’t
have closed-loop systems, and many of the benefits of tracking items
come from tracking them as they move from one company to another and
even one country to another.
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RFID Vs
Bar Codes |
RFID is not necessarily "better" than bar
codes. The two are different technologies and have different
applications, which sometimes overlap. The big difference between
the two is bar codes are line-of-sight technology. That is, a
scanner has to "see" the bar code to read it, which means people
usually have to orient the bar code towards a scanner for it to be
read. Radio frequency identification, by contrast, doesn’t require
line of sight. RFID tags can be read as long as they are within
range of a reader. Bar codes have other shortcomings as well. If a
label is ripped, soiled or falls off, there is no way to scan the
item. And standard bar codes identify only the manufacturer and
product, not the unique item. The bar code on one milk carton is the
same as every other, making it impossible to identify which one
might pass its expiration date first.
Probably not. Bar codes are inexpensive and effective for certain
tasks. It is likely that RFID and bar codes will coexist for many
years.
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RFID
Challenges |
Another problem is cost. RFID readers typically
cost $1,000 or more. Companies would need thousands of readers to
cover all their factories, warehouses and stores. RFID tags are also
fairly expensive – 20 cents or more – which makes them impractical
for identifying millions of items that cost only a few dollars (see
below).
RFID doesn’t work around metal and water.
Radio waves bounce off metal and are absorbed by water at
ultra-high frequencies. That makes tracking metal products or those
with high water content problematic, but good system design and
engineering can overcome this shortcoming. Low- and high-frequency
tags work better on products with water and metal. In fact, there
are applications in which low-frequency RFID tags are actually
embedded in metal auto parts to track them.
One problem encountered with RFID is the signal from one
reader can interfere with the signal from another where coverage
overlaps. This is called reader collision. One way to avoid the
problem is to use a technique called time division multiple access,
or TDMA. In simple terms, the readers are instructed to read at
different times, rather than both trying to read at the same time.
This ensures that they don't interfere with each other. But it means
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.
Another problem readers have is reading a lot of chips in the same
field. Tag collision occurs when more than one chip reflects back a
signal at the same time, confusing the reader. Different vendors
have developed different systems for having the tags respond to the
reader one at a time. Since they can be read in milliseconds, it
appears that all the tags are being read simultaneously.
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RFID Frequency
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Just as your radio tunes in to different
frequency to hear different channels, RFID tags and readers have to
be tuned to the same frequency to communicate. RFID systems use many
different frequencies, but generally the most common are low-
(around 125 KHz), high- (13.56 MHz) and ultra-high frequency, or UHF
(850-900 MHz). Microwave (2.45 GHz) is also used in some
applications. Radio waves behave differently at different frequency,
so you have to choose the right frequency for the right application.
Different frequencies have different characteristics that make them
more useful for different applications. For instance, low-frequency
tags are cheaper than ultra high frequency (UHF) tags, use less
power and are better able to penetrate non-metallic substances. They
are ideal for scanning objects with high-water content, such as
fruit, at close range. UHF frequencies typically offer better range
and can transfer data faster. But they use more power and are less
likely to pass through materials. And because they tend to be more
"directed," they require a clear path between the tag and reader.
UHF tags might be better for scanning boxes of goods as they pass
through a bay door into a warehouse. It is probably best to work
with a consultant, integrator or vendor that can help you choose the
right frequency for your application.
Most countries have assigned the 125 kHz or 134 kHz area of the
radio spectrum for low-frequency systems, and 13.56 MHz is used
around the world for high-frequency systems. But UHF RFID systems
have only been around since the mid-1990s and countries have not
agreed on a single area of the UHF spectrum for RFID. Europe uses
868 MHz for UHF and the U.S. uses 915 MHz. Until recently, Japan did
not allow any use of the UHF spectrum for RFID, but it is looking to
open up the 960MHz area for RFID. Many other devices use the UHF
spectrum, so it will take years for all governments to agree on a
single UHF band for RFID. Government’s also regulate the power of
the readers to limit interference with other devices. Some groups,
such as the Global Commerce Initiative, are trying to encourage
governments to agree on frequencies and output. Tag and reader
makers are also trying to develop systems that can work at more than
one frequency, to get around the problem.
RFID doesn’t work around metal and water.
Radio waves bounce off metal and are absorbed by water at
ultra-high frequencies. That makes tracking metal products or those
with high water content problematic, but good system design and
engineering can overcome this shortcoming. Low- and high-frequency
tags work better on products with water and metal. In fact, there
are applications in which low-frequency RFID tags are actually
embedded in metal auto parts to track them.
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Active Vs. Passive Tags |
Active RFID tags have a battery, which is used
to run the microchip's circuitry and to broadcast a signal to a
reader (the way a cell phone transmits signals to a base station).
Passive tags have no battery. Instead, they draw power from the
reader, which sends out electromagnetic waves that induce a current
in the tag's antenna. Semi-passive tags use a battery to run the
chip's circuitry, but communicate by drawing power from the reader.
Active and semi-passive tags are useful for tracking high-value
goods that need to be scanned over long ranges, such as railway cars
on a track, but they cost a dollar or more, making them too
expensive to put on low-cost items.
The read range of passive tags (tags without
batteries) depends on many factors: the frequency of operation, the
power of the reader, interference from metal objects or other RF
devices. In general, low-frequency tags are read from a foot or
less. High frequency tags are read from about three feet and UHF
tags are read from 10 to 20 feet. Where longer ranges are needed,
such as for tracking railway cars, active tags use batteries to
boost read ranges to 300 feet or more.
Companies are focusing on passive UHF tags,
which cost under a 50 cents today in volumes of 1 million tags or
more. Their read range isn't as far -- typically less than 20 feet
vs. 100 feet or more for active tags -- but they are far less
expensive than active tags and can be disposed of with the product
packaging.
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EPC |
The Electronic Product Code, or RFID, was
developed by the Auto-ID Center as a successor to the bar code. It
is a numbering scheme that will be used to identify products as they
move through the global supply chain. For more on EPC technology,
see Electronic Product Code FAQs.
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Tag Data |
Tags store information and it depends on the
vendor and the application, but typically a tag would carry no more
than 2KB of data—enough to store some basic information about the
item it is on. Companies are now looking at using a simple "license
plate" tag that contains only a 96-bit serial number. The simple
tags are cheaper to manufacture and are more useful for applications
where the tag will be disposed of with the product packaging.
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Read only Vs Read-Write Tags
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Microchips in RFID tags can be read-write or
read-only. With read-write chips, you can add information to the tag
or write over existing information when the tag is within range of a
reader, or interrogator. Read-write tags usually have a serial
number that can't be written over. Additional blocks of data can be
used to store additional information about the items the tag is
attached to. Some read-only microchips have information stored on
them during the manufacturing process. The information on such chips
can never been changed. Other tags can have a serial number written
to it once and then that information can't be overwritten later.
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RFID Standards |
Yes. International standards have been adopted
for some very specific applications, such as tracking animals. Many
other standards initiatives are under way. The International
Organization for Standardization (ISO) is working on standards for
tracking goods in the supply chain using high-frequency tags (ISO
18000-3) and ultra-high frequency tags (ISO 18000-6). EPC global, a
joint venture set up to commercialize Electronic Product Code
technologies, has its own standards process, which was used to
create bar code standards. EPC global intends to submit EPC
protocols to ISO so that they can become international standards.
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RFID Leaders |
There are many different RFID vendors with
different areas of expertise. RFID Journal has compiled a searchable
database and director of vendors around the world. Click on Find a
Vendor in the left-hand navigation bar to locate the type of vendor
you are looking for.
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RFID Applications |
RFID is used for everything from tracking cows
and pets to triggering equipment down oil wells. It may sound trite,
but the applications are limited only by people’s imagination. The
most common applications are tracking goods in the supply chain,
reusable containers, high value tools and other assets, and parts
moving to a manufacturing production line. RFID is also used for
security (including controlling access to buildings and networks)
and payment systems that let customers pay for items without using
cash.
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RFID Users |
Thousands of companies around the world use
RFID today to improve internal efficiencies. Club Car, a maker of
golf carts uses RFID to improve efficiency on its production line.
Paramount Farms—one of the world’s largest suppliers of
pistachios—uses RFID to manage its harvest more efficiently (see
Farm Harvests RFID’s Benefits). NYK Logistics uses RFID to
improve the throughput of containers at its busy Long Beach, Calif.,
distribution center (see
Logistics Gets Cheaper by the Yard). And many other companies
are using RFID for a wide variety of applications.
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RFID and Sensors |
Some companies are combining RFID tags with
sensors that detect and record temperature, movement, even
radiation. One day, the same tags used to track items moving through
the supply chain may also alert staff if they are not stored at the
right temperature, if meat has gone bad, or even if someone has
injected a biological agent into food.
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Software Agents |
Software agents are basically autonomous
applications that automate decision making by establishing a set of
rules. For instance, if X happens, do Y. They are important to RFID
because humans will be overwhelmed by the amount of data coming from
RFID tags and the speed at which it comes (real-time in many cases).
So agents will likely be used to automate routine decisions and
alert employees when a situation requires their attention. SAP and a
company called BiosGroup are working on an automated replenishment
system in which software agents would make decisions when trends
indicate a product will be out of stock.
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Energy
Harvesting |
Most passive RFID tags simply reflect back
waves from the reader. Energy harvesting is a technique in which
energy from the reader is gathered by the tagged, stored momentarily
and transmitted back at a different frequency. This method may
improve the performance of passive RFID tags dramatically.
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The Future
of RFID
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RFID technology is a labor-saving technology so
it's likely that some workers will laid off. That's because fewer
workers will be needed to scan bar codes. But the transition from
bar codes to RFID could take a decade or more, so it is unlikely
that RFID will lead to wide-scale displacement of workers. The
technology will likely create new jobs, just as Internet
technologies creating new jobs, from Web developers to warehouse
workers managing inventory for online stores such as Amazon.com. The
jobs that will be affected by RFID are those that involve scanning
bar codes. Most of those jobs also have other components, such as
moving products or restocking shelves. Those jobs will not go away
because of RFID.
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