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					RFID and Positioning
                     Outline
• RFID Introduction
• Indoor Localization
• RFID positioning Algorithm
  – LANDMARC
  – RFID-Based 3-D Positioning Schemes
• RFID application
                     Outline
• RFID Introduction
• Indoor Localization
• RFID positioning Algorithm
  – LANDMARC
  – RFID-Based 3-D Positioning Schemes
• RFID application
                    RFID
• Automatic identification technology
• Transponder, interigator, antennaReaderRF
                Characteristics

•   No line-of-sight required
•   Multiple simultaneous reads
•   Long read range(active tag)
•   Long life span
•   Very low cost
•   No (so) orientation sensitive
             RFID Localization
• An important application of RFID
  – Localization (warehouse, shipping container, ……)
                     Outline
• RFID Introduction
• Indoor Localization
• RFID positioning Algorithm
  – LANDMARC
  – RFID-Based 3-D Positioning Schemes
• RFID application
             Indoor Localization
• Infrared
  – Active Badge
  – IR emitter communicate with a network of sensors in
    the building
  – Line-of-sight required, transmission range is short
• IEEE 802.11
  – RADAR
  – Combine empirical measurement and signal strength
    modeling to determine location
  – NIC needed, not practical for small device
           Indoor Localization
• Ultrasonic
  – Cricket Location Support System & Active Bat
    Location System
  – Use time-of-arrival to measure distances
  – High accuracy, expensive
• RFID
  – LANDARC
  – Use RFID tags as reference tags
  – Coarse accuracy, 2-D
                     Outline
• RFID Introduction
• Indoor Localization
• RFID positioning Algorithm
  – LANDMARC
  – RFID-Based 3-D Positioning Schemes
• RFID application
                               LANDMARC




本圖取自”LANDMARC: Indoor Location Sensing Using Active RFID”, Wireless Networks, Vol. 10, 701-710, 2004.
                   LANDMARC
• Methodology       Define :
  Suppose :          Signal Strength Vector of
   n RF readers       tracking tags
   m reference tags   Su  ( Su1 , Su 2 ,..., Sun ) u  (1, u )
   u tracking tags   Signal Strength Vector of
                      reference tags
                       m  ( m1 ,  m 2 ,...,  mn ) m (1, m)
                   LANDMARC
Define :
 Euclidean distance in signal strength between a
 tracking tag and a reference tag j

               i 1 ( ji  S ui ) 2
                  n
      Euj                              j  (1, m)

 When there are m reference tags, a tracking tag
 has its E vector as
      Eu  ( Eu1 , Eu 2 ,..., Eum )
                               LANDMARC
•   To determine the weights assigned to
    different neighbors
                      1       2
                          Ei
       wj 
              
                  k
                           1        2
                i 1
                               Ei

•   Tracking tag location:

     ( x, y)  i 1 wi ( xi , yi )
                          k
                     Outline
• RFID Introduction
• Indoor Localization
• RFID positioning Algorithm
  – LANDMARC
  – RFID-Based 3-D Positioning Schemes
• RFID application
 Active Scheme Setup




本圖修改自“RFID-Based 3-D Positioning Schemes”, Infocom 2007.
Effective Reference Tag Set
Effective Reference Tag Set
Coordinate Calculation
Compensate Degree of Irregularity
• Problem
  – Diff. antenna gains and
    path loss in different
    directions
  – Imperfect circle
• Solution
  – Low cost antenna array
    with multiple radiation
    elements
  – Superpose responses

                              本圖取改自“RFID-Based 3-D Positioning Schemes”, Infocom 2007.
Passive SchemeDetails
                   Outline
• RFID Introduction
• Indoor Localization
• RFID positioning Algorithm
  – LANDMARC
  – RFID-Based 3-D Positioning Schemes
• Conclusion
                  Conclusion
LANDMARC Advantage:
  – No need for a large number of expensive RFID
    reader.
  – Environmental dynamic can easily be
    accommodated.
  – Location information is more accurate and reliable.
                           Conclusion
• Although active RFID is not designed for accurate indoor
  location sensing, LANDMARC approach does show that active
  RFID is a viable cost-effective candidate for indoor location
  sensing.

• Three problem :
   – SSI & Power level
   – Long latency
   – Variation of the behavior of tags
                        Conclusion
• Proposed two 3-D positioning schemes
  – Both schemes are based on nonlinear
    optimization methods




          本圖取改自“RFID-Based 3-D Positioning Schemes”, Infocom 2007.
                 Reference
• [1] LIONEL M. NI, YUNHAO LIU, YIU CHO LAU,
  ABHISHEK P. PATIL, “LANDMARC: indoor
  location sensing using active RFID ”, in PerCom
  2003
• [2] Chong Wang, Hongyi Wu, and Nian-Feng
  Tzeng, “RFID-Based 3-D Positioning Schemes”,
  in INFOCOM 2007

				
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posted:3/3/2013
language:Latin
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