RFID Review
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Transcript of RFID Review
RFID Review
科法所 李啟民R94a41002
Dec. 27, 2005
Outline
Introduction Operation Techniques Conclusions References
Introduction RFID technology has been commercially available for
over two decades, tracing its roots back to military
Identification Friend or Foe (IFF) systems of the 1940s.
Introduction-Applications
Electronic Toll Collection (ETC ) Railway car identification and tracking Asset identification and tracking Item management for retail, health care, and
logistics applications Access Control Animal identification Security
Basic Operations
Reader and Tags (Label)
Reader and Tag (Label)
Backscatter Transmission
Backscatter Transmission
Transponder/ Tag An RFID device that did not actively transmit to a reader
was known as a tag. An RFID device that actively transmitted to a reader was k
nown as a transponder (TRANSmitter + resPONDER). For the purposes of this overview, an RFID device that acti
vely transmits to a reader is termed an “active” tag; an RFID device that only reflects or backscatters transmission from a reader is termed “passive.”
Tag
Antenna
Each RFID system includes at least one antenna to transmit and receive the RF signals.
In some systems, a single antenna transmits and receives the signals; in other systems, one antenna transmits and one antenna receives the signals.
The quantity and type of antennas used depend on the application.
RF Transceiver The RF transceiver is the source of the RF energy
used to activate and power the passive RFID tags. The RF transceiver may be enclosed in the same
cabinet as the reader or it may be a separate piece of equipment.
When provided as a separate piece of equipment, the transceiver is commonly referred to as an RF module.
The transceiver filters and amplifies the backscatter signal from a passive RFID tag.
RFID Electronic coding system
Two coding systems in current RFID system One is the Ubiquitous ID ( UID ) coding syste
m used in Japan. The other is the EPC coding system used in US, E
uro and China.
EPC Structure EPC Structure (Electronic Product Code)
EPC Structure a header, defining the variety of EPC among a number of
possible structures; a domain manager number which is effectively a manufa
cturer number; an object class and a serial number which define product
type and product number
EPC Class
RFID v.s. Bar Code
Modulation Techniques RFID systems usually employ modulation techniques
and coding schemes that are simple to produce. For example, in ISO 18000 Type C
Double Side Band-Amplitude Shift Keying (DSB-ASK), Single Side Band-ASK (SSB-ASK) Phase Reversal-ASK (PR-ASK). FHSS and DSSS
Frequency Hopping SS
Direct Sequence SS
In DSSS, the rate of the spreading code signal is called the chip rate. The ratio of chip rate and data rate is the processing gain of spreading factor.
CDMA Concept
Receiver of a DSSS signal
FHSS/ DSSS In frequency hopping, the carrier frequency of the
modulated information signal is not constant but changes periodically.
The set of available frequencies the carrier can attain is called the hop-set.
FH system uses only a small part of the bandwidth when it transmits while a DS system occupies the whole frequency band.
FHSS/ DSSS
Time /Frequency Occupancy of FH and DS signals
RFID Standards The International Standards Organization (ISO) has three s
tandards for RFID: ISO 14443 (for contactless systems), ISO 15693 (for vicinity systems, such as ID badges), and ISO 18000 (to specify the air interface for a variety of
RFID applications). A not-for-profit organization, EPCglobal, has developed a
widely accepted standard for product identification.
Spectrum In Us, FCC uses 902 - 928 MHz spectrum In Euro, ETSI adopts 866 - 868 MHz In Japan, 950 - 956 MHz and 2.45 GHz 、 13.56 MHz are
available In China, spectrum 900 MHz
Operating Frequency of RFID
Conclusions
RFID is a convenient and low cost technique that can applied to many short range wireless applications 。
Standardization is still an important issue to realize.
Privacy concerns
References EPC Tag Data Standards Version 1.1 Rev.1.24, Standard Specification
01 April 2004 13.56 MHz ISM Band Class 1Radio Frequency Technical report, Ident
ification Tag Interface Specification: Candidate Recommendation, Version 1.0.0
A COMPARISON OF HF AND UHF RFID TECHNOLOGIES By Philips Semiconductors.
Landt, J. “The history of RFID”, Potentials, IEEE Volume 24, Issue 4, Oct.-Nov. 2005 Page(s):8 – 11, Digital Object Identifier 10.1109/MP.2005.1549751
RFID: a technical overview and its application to the enterpriseWeinstein, R.; IT Professional, Volume 7, Issue 3, May-June 2005 Page(s):27 - 33 , Digital Object Identifier 10.1109/MITP.2005.69