3. Introduction
• Works on the principle of bi-directional radio
frequency communication.
• An Alternative for barcode and optical
technologies.
• Automatic Identification.
4. Object
• To carry data in suitable transponder
(Tag) and to retrieve the data by machine
readable means satisfy particular
application need.
• Communicating the data between the tag
and reader
5. What is RFID?
• Stands for Radio Frequency Identification
• Uses radio waves for identification
• One form of Automatic Identification
• Provides unique identification an object.
6. RFID – What is it?
• Radio Frequency Identification Device
• Holds a small amount of unique data – a
serial number or other unique attribute of
the item
• The data can be read from a distance – no
contact or even line of sight necessary
7. Working of RFID
A RFID system has three parts:
• A transponder – the radio frequency tag- that
has been programmed with information.
• A scanning antenna
• A transceiver with a decoder to interpret the
data
10. Modulation
• The process of superimposing the data up
on a carrier wave for its transfer between
the communicating components through
the separating medium- air.
• Amplitude shift keying - ASK
• Frequency shift keying - FSK
• Phase shift keying - PSK
11. Encoding
• The various encoding algorithm methods
select on the basis of
• Cost of implementation
• Band width
12. Wireless communication
• The data communication is wireless and
the types of RFID based on
communication pattern are
• Inductive coupling
• Propagation Coupling.
13. Inductive coupling
• Operate on the principle of resonance.
• Inductive coupled TAGS are passive.
• Single micro chip and large area coil
function as antenna.
• Operate at low and medium frequencies.
16. Propagation Coupling
• It use electric field propagation properties of
radio signal to convey energy and data to TAG
and data from the TAG.
• Propagation coupled TAGS may be either passive
( no battery) or active ( battery powered).
• TAGS can be programmed by the reader.
• Used at high frequencies and increased range.
19. Carrier frequency
• The radio frequency communication channels is
on the basis of frequency allocation and is
generally controlled by govt. with different part
of the electromagnetic spectrum being assigned
to different purpose.
• For RFID, frequency ranges are generally
classified as Low, Medium and High.
20. Data transfer rate and
bandwidth
• The rate of data transfer between the TAG and
READER is influenced by the frequency of carrier
wave used to carry the data .
• The higher the frequency, higher the data
transfer rate.
• The bandwidth available within the frequency
spectrum needs to be at least twice the bit rate
required for the application.
21. Frequency Bands
Frequency
Band
Characteristic
s
Typical
Application
Low
100-500 KHz
Inter mediate
10-15 MHz
High
850-950 MHz
2.4-5.8 GHz
Short to medium read
range, low reading
speed
Short to medium read
range, potentially
inexpensive, medium
reading speed
Long read range,
line of site required,
expensive
Access control
Animal identification
Inventory control
Access control
Smart Cards
Rail road car
monitoring, toll
collection systems
22. Transponder / TAG
• Derived from Transmitter / Responder.
• It responds to a transmitted request for data, by
the READER .
• They are fabricated as low power integrated
circuits suitable data transfer and power
generation ( for passive TAG )
• The TAGS are distinguished entirely by the
manner in which the device derives its power.
23. Tag is a device used to transmit information such as a
serial number to the reader in a contact less manner
Classified as :
Passive – energy from reader
Active - battery
Semi-passive – battery and energy from reader
RFID Tag
24. Types of RF Tags
• Active Tags
• Passive Tags
• Semi Passive RF Tags
• The first function of the reader is to activate the TAG
in the reading volume by creating an electromagnetic
field.
25. Active RFID Tags
• Battery Powered tags
• More expensive
• Shorter life span
26. Passive RFID Tags
• Tag contains antenna and
a small data chip
• Tag is powered by the
electromagnetic field
generated in doorways,
reflecting back a weak
signal containing data
27. RFID Tag Attributes
Active RFID Passive RFID
Tag Power Source Internal to tag Energy transferred using
RF from reader
Tag Battery Yes No
Availability of Power Continuous Only in field of reader
Required signal strength
to Tag
Very Low Very High
Range Up to 100m Up to 3-5m, usually less
28. Range and Power Levels of RFID
The range that can be achieved in an RFID
system is essentially determined by:
• The power available at the reader/interrogator
to communicate with the tag(s)
• The power available within the tag to respond
• The environmental condition and structures,
the former being more significant at higher
frequencies including signal to noise ratio.
29. How far can a passive tag be read?
Assume distance limited by power available to run the tag’s circuits.
meters
in
distance
MHz)
(915
frequency
meters/s
10
3
(meters)
wavelength
dBi)
(1
gain
antenna
tag
dBi)
(6
gain
antenna
reader
watt)
(1
power
nsmit
reader tra
needed)
W
(100
tag
to
available
power
4
8
2
2
2
r
f
x
c
f
c
G
G
P
P
r
G
G
P
P
T
R
R
T
T
R
R
T
31. EPC Code
• 613.23000.123456.123456789 (96 bits)
• Header – defines data type (8 bits)
• EPC Manager – describes originator of EPC
(Product manufacturer) (34 bits)
• Object Class - Could describe the product
type (20 Bits)
• Serial Number – Unique ID for that
product item (34 Bits)
33. RFID Uses
• Retail & Distribution
• Contact less Payment
• Keyless Entry
• Livestock Tagging
• Pharmaceuticals
• Logistics Assets (containers, trailers)
• Pet Identification
34. Animal Identification Standards
• International standard 134.2 kHz
– ISO 11784: “Radio-frequency identification of
animals” – code structure
– ISO 11785: “Radio-frequency identification of
animals” – Technical concept
– ISO 14223: “Radio-frequency identification of
animals” – Advanced transponders
• U.S. standard 125 kHz
• At these frequencies the RF can penetrate mud, blood,
and water
35. RFID Security and Privacy Threats
• Security threats to the RFID system
• Privacy threats by the RFID system
36. Security Threats to RFID
• A competitor or thief performs an unauthorized
inventory of a store by scanning tags with an
unauthorized reader to determine the types and
quantities of items leading to information disclosure.
• An attacker modifies the EPC number on tags ,
tampering data, in supply chain disrupting business
operations and causing a loss of revenue.
• An attacker modifies a high-priced item’s EPC
number to be the EPC number of a lower cost item.
37. Privacy Threats by RFID
• A bomb in a restaurant explodes when there are five or more
Americans with RFID-enabled passports detected.
• A fixed reader at any retail counter could identify the tags of a
person and show the similar products on the nearby screen to a
person to provide individualized marketing.
• A sufficiently powerful directed reader reads tags in your
house or car.
38. EPC vs.
UPC (Barcodes)
• Both are forms of Automatic identification technologies
• Universal Product Code (UPC) require line of sight and
manual scanning whereas EPC do not
• UPC require optical reader to read whereas EPC reader
reads via radio waves
• EPC tags possess a memory and can be written while
UPC do not
• EPC tags cost 5 cents, UPC tags cost 1/10 cent
39. Advantages of RFID
RFID systems offer a number of advantages over
current ID systems such as barcodes or magnetic
cards. These include;
• Hands Free Operation
• Write Ability
• Security
• No need for intrinsic energy source
• Adaptability
• Noncontact, non-line of sight nature of technology
40. Summary
• RFID will rapidly expand as the cost of tag
will reduce over time.
• Industry experts predict substantial growth in
material.
• RFID will be next technological wave for
automatic data capture industry
41. References
[1] 7th International IEEE conference on E-
Commerce Technology 2005
[2] The 2004 IEEE International Conference on
e-Technology, e-Commerce and e-Service
(EEE-04)
[3] Klaus Finkenzeller, RFID handbook, John
Wiley and Sons, 2001
[4] Materials from Internet
