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1. RADIO FREQUENCY IDENTIFICATION (RFID)
RFID:
RFID can be defined in the following manner
RFID is the wireless non-contact use of radio-frequency electromagnetic fields to transfer data, for the purpose of
automatically identifying and tracking tags attached to objects.
Also RFID can be defined as
RFID is an automatic identification method using radio waves.
An RFID tag is a device that can store and transmit data to a reader in a contact less manner using radio waves. It means
that a RFID tag does not need any contact to transmit data to a reader with the help of radio waves.Unlike a barcode, the
tag does not need to be within line of sight of the reader and may be embedded in the tracked object.
APPLICATIONS OF RFID:
RFID can be used in a variety of applications such as:
 Access management
 Tracking of goods
 Tracking of persons and animals
 Toll collection and contactless payment
 Machine readable travel documents
 Smart dust (for massively distributed sensor networks)
 Tracking sports memorabilia to verify authenticity
 Airport baggage tracking logistics
RFID FREQUENCY BANDS:
RFID frequency bands
Band Regulations Range Data speed Remarks
Approximate tag
cost
in volume (2006)
US $
120–150 kHz (LF) Unregulated 10 cm Low
Animal identification, factory
data collection
$1
13.56 MHz (HF)
ISM band
worldwide
1 m
Low to
moderate
Smart cards (MIFARE, ISO/IEC
14443)
$0.50
433 MHz (UHF)
Short Range
Devices
1–100
m
Moderate
Defense applications, with active
tags
$5
865-868 MHz (Europe)
902-928 MHz (North
America) UHF
ISM band 1–2 m
Moderate to
high
EAN, various standards
$0.15 (passive
tags)
2450-5800 MHz
(microwave)
ISM band 1–2 m High
802.11 WLAN, Bluetooth
standards
$25 (active tags)

2. 3.1–10 GHz (microwave) Ultra wide band
to 200
M
High
requires semi-active or active
tags
$5 projected
The above table clearly explains the frequency ranges, the band regulations, data speed, applications of particular
frequency band and the cost of the tag.
A radio-frequency identification system uses tags, or labels attached to the objects to be identified. Two-way radio
transmitter-receivers called interrogators or readers send a signal to the tag and read its response. The readers generally
transmit their observations to a computer system running RFID software or RFID middleware.
RFID systems typically come in three configurations. One is a Passive Reader Active Tag (PRAT) system that has a passive
reader which only receives radio signals from active tags (battery operated, transmit only). The reception range of a PRAT
system reader can be adjusted from 1-2,000 feet. Thereby allowing for great flexibility in applications such as asset
protection and supervision. Another configuration is an Active Reader Passive Tag (ARPT) system that has an active
reader, which transmits interrogator signals and also receives authentication replies from passive tags. Finally, there is
the Active Reader Active Tag (ARAT) system in which active tags are awoken with an interrogator signal from the active
reader. A variation of this system could also use a Battery Assisted Passive (BAP) tag which acts like a passive tag but has a
small battery to power the tag's return reporting signal.
Tags may either be read-only, having a factory-assigned serial number that is used as a key into a database, or may be
read/write, where object-specific data can be written into the tag by the system user. Field programmable tags may be
writing-once, read-multiple; "blank" tags may be written with an electronic product code by the user.
The tag's information is stored electronically in a non-volatile memory. The RFID tag includes a small RF transmitter and
receiver. An RFID reader transmits an encoded radio signal to interrogate the tag. The tag receives the message and
responds with its identification information. This may be only a unique tag serial number, or may be product-related
information such as a stock number, lot or batch number, production date, or other specific information.
RFID tags contain at least two parts: an integrated circuit for storing and processing
information, modulating and demodulating a radio-frequency (RF) signal, collecting DC power from the incident reader
signal, and other specialized functions; and antenna for receiving and transmitting the signal.
ADANTAGES:
* The read only tag code data is 100% secure and cannot be changed or duplicated.
*Tags are available in a great range of types, sizes and materials.
*No need for physical contact between the data carrier and the communication device.
*The tags can be used repeatedly
*Relatively low maintenance cost.
*Extremely low error rate.
*RFID technology is a labor-saving technology. This translates to cost savings.
RFID vs. Barcodes Comparison:
RFID and barcodes are similar in that they are both data collection technologies, meaning they automate the process of
collecting data. However, they also differ significantly in many areas. Although this comparison primarily focuses on the
advantages of RFID over barcodes, RFID will not completely replace barcode technology. Barcodes offer some advantages
over RFID, most notably their low cost.

3. COMPARISION STATISTICS:
 RFID is 15-20 times faster than manual and barcode processes for inventorying IT assets.
 Some companies experience a 95% reduction in time using RFID
 The #1 RFID application being deployed is IT asset tracking
FUTURE SCOPE
The world will be very different once readers and RFID tags are everywhere. In an RFID enhanced future, the benefits
would assure not just to business, but also to consumers. If the usage of RFID tags increases it will be very beneficial in
several aspects. Also the readers need to find many applications in several fields.