1. RFID and Positioning

2. Outline RFID Introduction Indoor Localization RFID positioning Algorithm – LANDMARC – RFID-Based 3-D Positioning Schemes RFID application

3. Outline RFID Introduction Indoor Localization RFID positioning Algorithm – LANDMARC – RFID-Based 3-D Positioning Schemes RFID application

4. RFID Automatic identification technology Transponder, interigator, antennaReaderRF

5. Characteristics No line-of-sight required Multiple simultaneous reads Long read range(active tag) Long life span Very low cost No (so) orientation sensitive

6. RFID Localization An important application of RFID – Localization (warehouse, shipping container, ……)

7. Outline RFID Introduction Indoor Localization RFID positioning Algorithm – LANDMARC – RFID-Based 3-D Positioning Schemes RFID application

8. 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

9. 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

10. Outline RFID Introduction Indoor Localization RFID positioning Algorithm – LANDMARC – RFID-Based 3-D Positioning Schemes RFID application

11. LANDMARC 本圖取自 ”LANDMARC: Indoor Location Sensing Using Active RFID”, Wireless Networks, Vol. 10, 701-710, 2004.

12. LANDMARC Define : Signal Strength Vector of tracking tags Signal Strength Vector of reference tags Methodology Suppose : n RF readers m reference tags u tracking tags

13. LANDMARC Define : Euclidean distance in signal strength between a tracking tag and a reference tag j When there are m reference tags, a tracking tag has its E vector as

14. LANDMARC To determine the weights assigned to different neighbors Tracking tag location:

15. Outline RFID Introduction Indoor Localization RFID positioning Algorithm – LANDMARC – RFID-Based 3-D Positioning Schemes RFID application

16. Active Scheme Setup 本圖修改自 “RFID-Based 3-D Positioning Schemes”, Infocom 2007.

17. Effective Reference Tag Set

19. Coordinate Calculation

20. 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.

21. Passive SchemeDetails

22. Outline RFID Introduction Indoor Localization RFID positioning Algorithm – LANDMARC – RFID-Based 3-D Positioning Schemes Conclusion

23. 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.

24. 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

25. 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.

26. 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