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| Radio Frequency Identification (RFID)
is a means of identifying a person or object using a radio
frequency transmission, typically at 125 kHz (LF), 13.56 MHz
(HF), 800-900 MHz (UHF) and 2.45 GHz. The dominant frequencies,
which are being embraced by the market, are 13.56 MHz, the
globally available frequency for item level tracking, and
UHF, for longer read-range passive RFID applications (i.e.
pallet tracking). |
| Barcode 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. RFID
tag, by contrast, 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. |
| The basic concept of RFID was derived
from radio identification technology of aircraft during World
war II and recently, this system has been come into the spotlight
as the new technology related the security and cost-saving.
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| The remaining basic problems is to spend
lots of seed money and system cost. To operate the system
perfectly, it is necessary to takes the time to attach the
tag every product. To solve this problem, RFID suppliers are
aiming at lowering the cost under 5 cents and reducing the
setting time. |
| RFID has evolved rapidly over the last
few years from a niche technology
RFID applications expect to increase the various industries
from the retailing and logistics industry. Currently it
can be adopted from factory automation, product location,
pallet, container, logistics, food, healthcare, aircraft,
medicine, library, postal office, supply chain management.
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- RFID tags are affixed to objects and
stored information may be written and rewritten to an embedded
chip in the tag.
- Tags can be read remotely when they detect a radio frequency
signal from a reader over a range of distances.
- Readers then either send tag information over the enterprise
network to back-end systems for processing or display it to
the end user. |
Read Only - Stores information
(a unique serial number) that can never be changed unless
the chip is reprogrammed electronically. Sometimes referred
to as Write Once, Read Many (WORM), read only tags are currently
the most popular and least expensive kind of tag.
Read/Write - new information can be added,
or existing information written over when the chip is within
range of a reader. Generally more expensive than read-only
chips and are used to track high- priced, valuable items.
Capacity: The chip size and price are primarily determined
by memory
capacity - which can range from 16 bytes to 256kb
or more. Permanently encoded read-only chips that only define
the identity of an object are used in price sensitive mass
applications with low local information requirements. If data
is to be written back to the transponder for read/write capability,
EEPROM or RAM memory is required. |
| RFID Tags are classified the Active
and Passive tag by tag battery and the round, coin, label,
card and bar type by the Tag size and type as below:
Classification
|
Feature
|
Tag
Battery
|
Active Tag
|
■ Including battery, long reading range
■ High price, limited life time, use for UHF |
| Passive Tag |
■ No battery, 10m reading range
■ Low price, semi-permanent (about 10years) |
Tag Size and Type
|
Round Type(mm～cm)
|
■ Leisure Management i.e. Clothes
■ Listing Tag
■ Internal tag |
Coin Type(mm～cm)
|
■ Animal management
■ Pallet Management |
Label Type(mm×cmm)
|
■ POS collect product
■ Document and cargo management |
Card Type(85×54×mm)
|
■ Ticket, Telephone card
■ Check-in & out control |
Bar Type(50×50×10mm)
|
■ FA
■ Vehicle & Container Management |
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Active RFID uses an internal power source,
such as a battery, within the tag to continuously power the
tag and its RF communication circuitry.
Active tags have a read range of up to 100 meters and can
be read reliably because they broadcast a signal to the reader
(some systems can be affected by rain). They generally cost
high depending on the amount of memory, the battery life required,
whether , whether the tag includes an on-board temperature
sensor or other sensors, and the ruggedness required. A thicker,
more durable plastic housing will increase the cost.
Passive RFID tags have no power source and no transmitter.
They are cheaper than active tags and require no maintenance,
which is why retailers and manufacturers are looking to
use passive tags in their supply chains. They have a much
shorter read range than active tags. |
| There are four main frequency bands
of operation, Low (around 125KHz), High (13.54MHz), Ultra
High (850-910 MHz) and Microwave (2.45 GHz). There is no
one frequency band that is better than another as each has
its own advantages in particular applications. Radio waves
behave differently at different frequency, so you have to
choose the right frequency for the right application. Additionally,
the Radio Spectrum allocates usage for various frequencies
to different applications around the world and not all power
limits are the same.
With the broad spectrum of applications within the RFID
industry, products covering various frequency ranges are
necessary. For each frequency, operating characteristics
and regulations differ, making each frequency appropriate
for particular applications. For example:
Frequency
|
Application
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Under 135 kHz
|
Animal Management, Security, ID Card, FA, etc.
|
13.56 MHz
|
Bus card, ID Card, Access card, Security, Logistics,
Library, Cloth, etc. |
UHF (860～960 MHz)
|
Logistics, Vehicle, Retailing, SCM, etc. |
2.45 GHz
|
Anti-counterfeit, SCM, Logistics, Parking lot, etc |
433 MHz
|
Container, Vehicle (with active tag), etc. |
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| Generally, the passive tag of UHF(860～960
MHz) costs from 50cent to USD 5.00 and active tag is about
USD10.00. The price of UHF/ 2.45GHz RFID Reader is about USD5,000
up to USD10,000. In the future, this systems is expected to
fall around USD2,000 if it would be becoming more common in
Korea. |
| EPCTM Generation 2 is the standard ratified
by EPC globalTM for the air-interface protocol utilized in
the second generation of Electronic Product Code UHF RFID
technology. The UHF Generation 2 protocol is a consensus standard
that describes the core capabilities required to meet the
performance needs set by the end user community, a consortium
of suppliers and retail outlets. This EPCTM standard is expected
to be used as a base platform upon which RFID readers and
tags and future improvements can be built, ensuring complete
interoperability and setting minimum operational expectations
for various components in the EPCglobalTM Network, including
the various necessary hardware components and software components. |
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