MIIMn0012_8.2.2_AirinterfaceChanwonPark_r1.ppt

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Mobile RFID Technology
IT RD Global Leader
Air Interface Protocol for Mobile RFID
October 30, 2007
Chan-Won Park(cwp_at_etri.re.kr)
Telematics ? USN Research Division
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? ?
Necessity Of Standardization for Mobile RFID
air interface
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Analysis of Air-Interface performance
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Mobile RFID
Air Interface Issues for Mobile RFID
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Necessity of Standardization for Mobile RFID air
interface

• Differences of Mobile RFID and Other RFID
  Services

Taxi safety service
Tour information service
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Analysis of air interface Performance
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Analysis of Air Interface Performance for UHF RFID

• Link budget analysis about reader and tag with
  Interference

• Link budget conditions of air-channel
• Tx/Rx frequency 911.85MHz
• Distance from reader to tag 2m, Distance from
  reader to interference reader 2m
• Reader transmitting power 500mW (27dBm)
• Reader antenna gain - 4dBi(0.398 loss), Tag
  antenna gain - 2dBi(0.631 loss)
• Reflection loss of tag antenna -10dB(1/10)
  loss under Matched Condition
• 
  -3dB(1/2) loss under Reflecting Condition

By pas loss model equation of Friis fundaments

• Path loss between reader and tag model
• Received power of tag antenna Prec-tag 500mW
  X (0.398) X (0.631) X ( 0.33/4/?/2)2
  21.70uW
• Received power of tag chip 21.70uW X (1-0.1)
  19.53uW (minimum power for tag operation)
• Reflection power of tag 21.70uW X (1-0.5)
  1.09uW
• Received power of reader antenna Prec-Reader
  1.09uW X (0.631) X (0.398) X ( 0.33/4/?/2)2
  0.74nW
• 
  -61.3dBm

• Path loss from interference reader to reader
  model
• Received power of reader antenna
• Prec-Reader 500mW X (0.398) X (0.398) X (
  0.33/4/?/2)2 13.69uW
• 
  -18.63dBm

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Analysis of Air Interface Performance for UHF RFID

• Relationship between PER(Packet Error Rate) and
  SNR(Signal to Noise Rate)

Source Marvin Simon, Some Interesting
Observations for Certain Line Codes ith
Application to RFID, IEEE TR.COMM.
VOL54, NO.4, 2006
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Analysis of Air Interface Performance for UHF RFID

• Interference Analysis in environment using
  Multiple Reader Mode Spectrum

• Channel space 500kHz

11.8dB
11.8dB
11.8dB
Interference
Tag response
500kHz
500kHz
500kHz
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Analysis of Air Interface Performance for UHF RFID

• Interference Analysis in environment using
  Multiple Reader Mode Spectrum

• Channel space 200kHz

11.8dB
11.8dB
11.8dB
Tag response
Interference
200kHz
200kHz
200kHz
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Analysis of Air Interface Performance for UHF RFID

• Interference Analysis in environment using Dense
  Reader Mode Spectrum

• Channel space 500kHz

5.8dB
5.8dB
Tag response
Tag response
Reader CW
Reader ERP27dBm Ant. Gain -4dBi Reader to Tag
2m TX data rate 100kbps LF 250kHz(M4) RX
data rate 62.5kbps
Tag response of dense mode reader (M4, Miller)
Dense mode mobile reader interference (PR-ASK)
Freq KHz
500 kHz
FDM with channel boundary backscatter
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Analysis of Air Interface Performance for UHF RFID

• Interference Analysis in environment using Dense
  Reader Mode Spectrum

• Channel space 200kHz

5.8dB
Tag response
Tag response
Reader CW
Reader ERP27dBm Ant. Gain -4dBi Reader to Tag
2m TX data rate 40kbps LF 300kHz(M4) RX
data rate 75kbps
Tag response of dense mode reader (M4,Miller)
Dense mode mobile reader iInterference (PR-ASK)
Freq KHz
200kHz
200kHz
200kHz
FDM on alternative channel backscatter
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Analysis of Air Interface Performance for UHF RFID

• Analysis of Mobile RFID Performance with FHSS

• Simulation configuration
• Multi-reader mode
• The first interrogation of all reader start
  simultaneously,
• and then they interrogate with random time.
• 1 reader / zone, 10 tags / zone
• 8 x 8 zone

8-interference neighbor zones
4-interference neighbor zones
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Analysis of Air Interface Performance for UHF RFID

• Simulation Results

• No. of channels ? ? Performance ?
• No. of neighbors ? ? Performance ?

• 4 interference neighbor need 10 channel for
  access tag in 2 retries
• 8 interference neighbor need 13 channel for
  access tag in 2 retries

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Analysis of Air Interface Performance for UHF RFID

• Analysis of Mobile RFID Performance with LBT

• Simulation configuration
• Multi-reader mode
• The first interrogation of all reader start
  simultaneously,
• and then they interrogate with random time.
• One channel check time for LbT 0.5ms
• Time for tag access 50ms
• Random back-off time random time in 0250ms
• 10 tags / zone
• 8 x 8 zone

8-interference neighbor zones
4-interference neighbor zones
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Analysis of Air Interface Performance for UHF RFID

• Simulation Results

(Number of channel 4)
(Number of channel 6)

• No. of channels ? ? Performance ?
• No. of readers per zone ? ? Performance ?
• If there are many readers in zone, take more the
  completion time.

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Analysis of Air Interface Performance for UHF RFID

• Power Emission of Mobile RFID

• The Mobile RFID need to limit the output power
  under 27dBm(ERP)

MR Output Levels ? SRs SNR?
Mobile Interference
Interference Mobile Reader
(DSB-ASK) Ant_Gain -4dBi TX data-rate
40kbps LF 40kHz(M1) RX data-rate
40kbps Reader to interference 2m
2m
Stionary Reader
Stionary Reader ERP 30dBm(DSB-ASK) Ant_Gain
6dBi TX data-rate 40kbps LF 40kHz(M1) RX
data-rate 40kbps
2m
MR Mobile Reader, SR Stationary Reader
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Air Interface Protocol Issues for Mobile RFID
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Air Interface Protocol Issues for Mobile RFID