RFID (Radio Frequency IDentification) is an
automatic identification method consisting of several components such as tags,
tag readers, edge servers, middleware, and application software. Among these the
three important components are RFID tag (also known as transponder), RFID reader
(also known as transceiver or interrogator) and software for data processing. An
RFID tag is a small object that can be attached to or embedded into a product,
animal, or person. It consists of a tiny chip where the data is stored and an
antenna to enable it to receive and respond to radio-frequency queries from an
The tags contain Electronic Product Code (EPC) and the information related to
the product like the name of the company, batch and year of manufacturing,
price, etc. There are four main frequency bands for RFID tags commonly in use.
They are categorised by their radio frequency: low frequency tags (125 or 134.2
kHz), high frequency tags (13.56 MHz), UHF tags (868 to 956 MHz), and microwave
tags (2.45 GHz or 5.8 GHz). RFID tags can be active, semi-passive (ie,
semi-active) or passive.
RFID Tag with Chip and Antenna
Passive RFID tags have no internal power supply. The minute electrical current
induced in the antenna by the incoming radio frequency signal provides just
enough power for the integrated circuit (IC) in the tag to power up and transmit
a response. Most passive tags signal by backscattering the carrier signal from
the reader. This means that the aerial (antenna) has to be designed to both
collect power from the incoming signal and also to transmit the outbound
The tag chip can contain nonvolatile EEPROM (Electrically Erasable Programmable
Read-Only Memory) for storing data. Lack of an onboard power supply means that
the device can be quite small: commercially available products exist that can be
embedded under the skin. As of 2005, the smallest such device commercially
available measured 0.4 mm × 0.4 mm, and is thinner than a sheet of paper; such
devices are practically invisible. Passive tags have practical read distances
ranging from about 2 mm up to about few metres depending on the chosen radio
frequency. Semi-passive RFID tags are very similar to passive tags except for
the addition of a small battery. This battery allows the tag IC to be constantly
powered. This removes the need for the aerial to be designed to collect power
from the incoming signal. Aerials can therefore be optimised for the
Semi-passive RFID tags are faster in response as compared to passive tags.
Active RFID tags or beacons, on the other hand, have an internal power source,
which is used to power any ICs and generate the outgoing signal. They may have
longer range and larger memories than the passive tags, as well as the ability
to store additional information sent by the transceiver. At present, the
smallest active tags are about the size of a coin. Many active tags have
practical ranges of tens of metres, and a battery life of up to 10 years.
Because passive tags are cheaper to manufacture and have no battery, the
majority of RFID tags in existence are of the passive variety.
Working of an RFID system
Readers communicate with a tag, which contains digital information. Readers are
just like the barcode sensors, which broadcast a radio signal through the antena
to the tag. The tag then responds to the radiowave, and the data can be read
from the chip of the tag. Simultaneously data from multiple tags can be studied.
Readers also decode the signal provided by the tags and transmit to the CPU. A
suitable software receives and interprets the information collected from the
tags and stores it. Simultaneously, multiple data can be collected and stored
with much accuracy as compared to the existing barcode systems.
Applications of RFID
RFID in production
Inside the stores of the production department the stock level can be quickly
monitored which helps in a real-time and efficient inventory management. The
location and movement of the components, semi-finished and the finished products
can be detected by the RFID system, which helps in production monitoring and
control. The performance of departments and the individuals can be evaluated by
the rate of movement of the garment components from the departments or
individuals. This helps in improving the productivity and the quality. In the
packing floor the mixing of different styles and sizes can be avoided by RFID
tags. Also the number of pieces in packed cartons can be counted without
opening, which saves time and labour.
RFID in retail
It can be used in retail to monitor and control the floor level out-of-stocks (OOS).
It is mostly required where there is high product display density, low staffing
level and chances of mishandling is very high. The stock level of the items is
properly maintained and the items can be grouped according to their demand.
Similarly while receiving the goods at the store the accuracy of the deliveries
can be ensured quickly with less labour. Mostly the retailers verify the
accuracy and integrity of the shipment by open-box audit prior to stocking or
storing of goods. But now it is possible to read all the items packed inside the
carton without opening, which saves time and labour cost. So the RFID provides a
new horizon to the retailers in receiving of materials, which eliminates the
invoice disputes, mixing of different quality products, etc.
The theft of garments from the fitting room can be prevented by mounting a small
reader at the entry point of the room. The tag information of the garment is
captured when the customer takes the garment to the fitting room. The items that
are taken to the fitting room but not come out are reported as potential loss
items. So the RFID can be used to identify the missing merchandise and
prosecution of the shoplifters.
The store merchandise recovery and replenishment process presently used is
completely manual, unsystematic and ineffective. Also it requires a very long
time and high labour force and some popular items are not replenished for weeks.
This can be overcome by RFID technology. The tags help to estimate the stock
level frequently and there is an in-stock position improvement up to 30%.
This has a positive impact on sales and customer satisfaction. It prevents the
fashion or the seasonal merchandise to lie undetected in the back room and to be
sold at significant markdowns thus improving the profit margin. Also at the
point of sales the RFID tag can be read quickly and it avoids the physical
handling of the product as in barcode system. Also the customers can be informed
about the status of merchandise by interactive display screens. The tags can be
placed at the side seams or hem or in a paper cartoon label without affecting
the aesthetic appeal or the comfort properties.
RFID has also many other applications in various fields. Low-frequency RFID tags
are commonly used for animal identification. Pets can be implanted with small
chips so that they may be returned to their owners if lost. High-frequency RFID
tags are used in library book tracking, object tracking in stores, building
access control, airline baggage tracking, etc. The American Express Blue credit
card now includes a high-frequency RFID tag, a feature American Express called
UHF RFID tags are commonly used commercially in pallet and container tracking,
and truck and trailer tracking in shipping yards. The tags with a frequency of
13.56 MHz are being placed on prescriptions for Visually Impaired Veterans. The
Department of Veterans Affairs Outpatient Pharmacies is now supplying the tags
with label information stored inside that can be read by a battery powered and
talking prescription reader. This reader speaks information such as: Drug Name,
Instruction, Warnings, etc. Microwave RFID tags are used in long range access
control for vehicles.
The RFID tags can be used for toll collection at toll booths. The tags are read
remotely as vehicles pass through the booths, and tag information is used to
debit the toll from a prepaid account. The system helps to speed traffic at toll
plazas. The smart key concept adopted by Toyota Prius and some Lexus models use
an RFID circuit which allows the car to sense the presence of the key within 3
feet of the sensor. The driver can open the doors and drive the car when the key
is inside the pocket or the handbag. Also it can be implanted on the skin of a
patient in hospital for related information and proper identification. The tag
can be implanted on soldiers at the time of war to trace the missing soldiers.
Advantages of RFID over Barcodes
Barcode systems though used for product information, inventory control, etc have
some drawbacks as compared to RFID. The amount of information stored in a
barcode is very less as compared to RFID. RFID can store up to 1000 bytes of
data. An RFID is specific to each item, whereas the barcode is not. Barcode
needs human interaction for proper operation. It requires time-of-sight access
to an optical scanner for the product related information. The barcode is to be
replaced if the information it contains needs modification, but in RFID it can
be modified at stages of the supply chain by the interaction between the
microchip and the reader software. The barcode system is less accurate as
compared to RFID.
Limitations of RFID
Though RFID technology has already been applied effectively, it has certain
technological barriers that still need to be overcome to optimise its
application. These lacunas are high investment, lack of security and privacy,
and some related to the technology of RFID.
Although there is a great potential of RFID in the local logistics
sector, the major drawback is the cost of the RFID tag, which is higher
as compared to barcode system. So industrial leaders are concerned about
the return on investment and net profit by investing the extra cost in
the existing system. The cost depends on the volume of usage. The lowest
cost tags available on the market are as low as 7.2 cents each in
volumes of 10 million units or more. The average cost of a RFID tag is
around 30 to 40 cents if the volume is not sufficienly large but the
cost is only 4 cents for a barcode. The companies like Wal-Mart,
Benetton, Prada are trying to still reduce the price. After the price is
reduced all the retailers and manufacturers can implement the
technology. Apart from the initial cost, there is cost involved in
maintenance and upkeeping of the system. RFID tags are expected to
completely replace the barcode system in future.
Security and Privacy:
The security and privacy of the RFID against unauthorised readers is in
debate from the very beginning. There is a great challenge to the
consumer privacy. The consumers using the product with RFID tags can be
traced easily. The RFID tag broadcasts the ID serial number or the
Electronic Product Code (EPC) to the nearby reader. There is a very high
chance of privacy violations. The size of the dress a women wants can be
publicly readable by any nearby scanner. Due to this problem the cloth
retailer Benetton has planned to withdraw the use of RFID tags in its
apparel products. CASPIAN (Consumers Against Supermarket Policy Invasion
and Numbering) group, based in US has claimed that RFID tags embedded in
items can track the consumers creating unwanted surveillance and an
invasion of privacy. Many security measures have been proposed for RFID
in various literatures to overcome the above problem. The simplest is
the "Kill Tag" approach in which the tag is electronically
deactivated after the item is being sold out. The tag also can be
removed physically from the product before they are placed on the hand
of the consumers. The other approaches are Cryptographic approach, Hash
Function approach, Faraday Cage approach, Randomised Hash Lock, backward
channel XORing, Active Jamming approach, Regulation approach, etc.
As the RFID is based on the concept of Radio Frequency, it can be
interfered with other radio transmissions, metals, liquids, etc. The
degree of interference depends upon the frequency of the tag and the
mso-fareast-font-family:"Times New Roman";mso-ansi-language:EN-US;mso-fareast-language:
EN-US;mso-bidi-language:AR-SA">Lack of standardisation:
RFID is at the infancy stage and there are many hurdles ahead of it.
There are many versions of RFID that operate at different frequencies
and need different software and readers. So the need is to be agreed
upon one or group of frequencies to have interoperability between the
manufacturers, retailers and distributors.
mso-fareast-font-family:"Times New Roman";mso-ansi-language:EN-US;mso-fareast-language:
Though the RFID cannot completely replace the barcode technology due to higher
cost accuracy, speed and the return on investment is high in RFID system. The
retailers, manufacturers and consumer goods companies like CVS, Tesco, Prada,
Benetton, Wal-Mart and Procter & Gamble are now implementing the technology
and exploring the impact of the technology on their business. Others can also
take advantage of RFID. The basis of success lies in understanding the
technology and other features to minimise the potential problems. It is high
time that Indian apparel industry should start utilising the new technology such
as RFID in various applications such as manufacturing, and storing purposes.
Creigh-Tyte A: RFID Technology, a Tale of
Villains and Heroes, Textile Asia, September 2005, pp 61-64.
Wong K, Hui P and Chan A: Data Protection in the
RFID Era, Textile Asia, October 2004, pp 25-27.
Amrohvi I A: RFID Technologies Tagging the World,
'It', October 2005, pp 50-54.
Bhagwat V M: RFID for Textile Supply Chain
Management, Clothesline, June 2005, pp 81-83.
Rajkishore Nayak, K N Chatterjee, and Tanuj
Gupta are with the Technological Institute of Textile & Sciences, Bhiwani
127 021. Asimananda Khandual is with the University Institute of Chemical
Technology, Mumbai 400 019.