This video forms part of the showcase event held by the Intelligent Airport (TINA) project: http://intelligentairport.org.uk. University College London (UCL) developed a passenger tracking system based on active RFID tags.

1. Demonstration of an Indoor Real-Time Location System with Optical Fibre BackboneChin-Pang Liu, Yanchuan Huang, Tabassam Ismail, Paul Brennan and Alwyn SeedsUCL Department of Electronic and Electrical EngineeringUniversity College LondonTorrington Place, London WC1E 7JE, United Kingdomchliu@ee.ucl.ac.uk

2. Outline Introduction Principle of location finding and algorithm The active transmit-only tag Experimental arrangement, signal processing & results Conclusion and acknowledgements

3. Introduction Tracking of individuals and goods is often required for safety, security and asset management purposes. GPS works fine outdoors but not indoors, e.g. airport passenger terminal. WLAN, cellular and Bluetooth do not have sufficient accuracy (>50m) In The Intelligent Networked Airport (TINA) project, it is envisaged that An optical fibre backbone will carry growing amount of data traffic at airports; Air passengers will be given RFID embedded boarding passes so they can be tracked. First demonstration of an indoor location system with optical fibre backbone

6. Only the 80 s down-chirp is used for the TDOA measurement.Battery powered Analog Devices AD9910 direct digital synthesizer (DDS) evaluation board. Programmed FM chirp from 216.5 MHz to 300 MHz with 900 MHz sampling clock. 900 MHz Clock Bandpass filtered and amplified DDS output spectrum Frequency (Hz) Fundamental chirp Image chirps

7. Experimental Arrangement Test venue: A 6.6m-by-15.6m area within a large café.

8. Measurement of TDOA RFID tag AU 1 AU 2 Time difference of arrival between two similar chirp signals can be found by multiplying them together. Freq. T2 T1 T2  T1 = t Time FFT Amplitude However, if the received signals contain multipath interference, this method will fail! Freq.

12. Mean error distance: 1.1 m or better @ 29 out of 30 locations

13. Overall positional error: 0.72 m RMSUpper no.: Mean error distance (m) Lower no.: Standard deviation (m)

14. TINA Showcase Demonstration Extension of existing single tag detection to two tags using both positive and negative chirp rates simultaneously. This demo lays the foundation for future location systems capable of identifying and locating large numbers of active tags carried by air-passengers, staff, vehicles and/or equipment at airports.

15. Conclusions First indoor real-time location system with an optical fibre backbone. Overall positional error: 0.72 m RMS. Dedicated ICs can reduce tag size, costs and power consumption. An additional AU can improve accuracy and reliability by providing information redundancy. Use of smart antennas could provide angle of arrival (AOA) information and together with the TDOA data make the system more robust.

16. Acknowledgements UK EPSRC Grant (EP/D076722/1) as part of The INtelligent Airport (TINA) project. The authors would like to thank ZinWave for providing the hub and antenna units.