• In a typical RFID system, individual objects are equipped
with a small, inexpensive tag.
• The tag contains a transponder with a digital memory
chip that is given a unique electronic product code.
• A reader, which has an antenna, a transceiver and
decoder, emits a signal.
• The RFID tag detects the reader's activation signal and
sends its own signal out through its antenna.
• The reader receives the signal sent by the tag, decodes
the data, and passes them to the host computer.
• The application software on the host processes the data.
Information transmitted by a tag
• Other attributes of a
product, e.g., price, color, date of
• It has no internal power supply.
• Its antenna receives the radio frequency signal
from a reader, which induces just enough power
for the integrated circuit in the tag to power up
and transmit a response.
• The antenna collects power from the incoming
signal and also transmits the outbound signal.
• The response of a passive RFID tag includes an
ID number. It can also contain other data.
Passive RFID (cont.)
• The device can be quite small: it can be embedded in a
sticker, or under the skin. As of 2006, the smallest such
devices (without antennas) measured 0.15 mm × 0.15
mm, and are thinner than a sheet of paper.
• The lowest cost EPC (a standard for RFID) RFID
tags, which are the standard chosen by Wal-
Mart, DOD, Target, Tesco in the UK and Metro AG in
Germany, are available today at a price of 5 cents each.
• The addition of the antenna creates a tag that varies
from the size of a postage stamp to the size of a post
• Passive tags have practical read distances ranging from
about 10 cm (4 in.) up to a few meters depending on the
chosen radio frequency and antenna design/size.
• Active RFID tags have their own internal power source to
power ICs that generate the outgoing signal.
• Active tags are typically much more reliable (e.g. fewer
errors) than passive tags due to the ability for active tags
to conduct a "session" with a reader.
• Active tags also transmit more powerful signals than
passive tags, allowing them to be more effective in water
(including humans/cattle bodies, which are mostly
water), metal (shipping containers, vehicles).
• Many active tags have practical ranges of hundreds of
meters, and a battery life of up to 10 years.
• RFID tags are being embedded in passports issued by
• The first RFID passports ("e-passports") were issued by
Malaysia in 1998. In addition to information also
contained on the visual data page of the
passport, Malaysian e-passports record the travel history
(time, date, and place) of entries and exits from the
• RFID tags are included in new UK and some new US
passports, beginning in 2006. The tags will store the
same information that is printed within the passport and
will also include a digital picture of the owner.
• The passports will incorporate a thin metal lining to make
it more difficult for unauthorized readers to "skim"
information when the passport is closed.
• The Moscow Metro, the world's busiest, was the first system in
Europe to introduce RFID smartcards in 1998.
• The UK devised a credit-card-like pass for public transportation
• Since 2002, in Taipei, Taiwan the transportation system uses RFID
operated cards as fare collection. The Easy Card, is charged at local
convenience stores and metro stations, and can be used in
Metro, buses, parking lots and taxis.
• In Hong Kong, mass transit is paid for almost exclusively through the
use of an RFID technology, called the Octopus Card. Originally it
was launched in September 1997 exclusively for transit fare
collection, but has grown to be similar to a cash card, and can be
used in vending machines, fast-food restaurants and supermarkets.
• The New York City Subway is conducting a trial during
2006, utilizing PayPass by MasterCard as fare payment.
• The Canadian Cattle Identification Agency began using
RFID tags as a replacement for barcode tags. The tags
are required to identify a bovine's herd of origin.
• RFID tags are used in libraries and bookstores.
• High-frequency RFID tags are used for pallet
tracking, building access control, airline baggage
tracking, and apparel and pharmaceutical item tracking.
• High-frequency tags are widely used in identification
badges, replacing magnetic stripe cards. These badges
need only be held within a certain distance of the reader
to authenticate the holder.
• UHF RFID tags are commonly used commercially in
case, pallet, and shipping container tracking, and truck
and trailer tracking in shipping yards.
Application—Supply Chain Mgmt
• Since January, 2005, Wal-Mart has required its top 100 suppliers to
apply RFID labels to all shipments improve supply chain
• The United States Department of Defense has published similar
• To meet this requirement, vendors use RFID printer/encoders to
label cases and pallets that require EPC tags for Wal-Mart. These
smart labels are produced by embedding RFID inlays inside the
label material, and then printing bar code and other visible
information on the surface of the label.
• Due to the size of these two organizations, their RFID mandates
impact thousands of companies worldwide. The deadlines have
been extended several times because many vendors face significant
difficulties implementing RFID systems.
• In practice, the successful read rates currently run only 80%, due to
radio wave attenuation caused by the products and packaging.
• Implantable RFID chips designed for animal tagging are
now being used in humans.
• An early experiment with RFID implants was conducted
by British professor of cybernetics Kevin Warwick, who
implanted a chip in his arm in 1998.
• Night clubs in Barcelona, Spain and in Rotterdam, The
Netherlands, use an implantable chip to identify their VIP
customers, who in turn use it to pay for drinks.
• In 2004, the Mexican Attorney General's office implanted
18 of its staff members with tags to control access to a
secure data room.