1. SULS UbiLearn2006 1 The Design Concept of a Simple Ubiquitous Learning System – SULS 一個簡易的無所不在學習系統 SULS 之設計概念 江振瑞 葉明貴 黃宇立 中央大學 資訊工程系

2. SULS UbiLearn2006 2 Outline Introduction Preliminary SULS Application scenario Conclusion

3. SULS UbiLearn2006 3 Outline Introduction Preliminary SULS Application scenario Conclusion

4. SULS UbiLearn2006 4 Introduction(1/4) The improvement of Wireless communications and Micro Electro-Mechanical Systems (MEMS) leads to an age of Ubiquitous Computing

5. SULS UbiLearn2006 5 Introduction(2/4) Learning Systems also step from e-Learning, Mobile-Learning to Ubiquitous Learninging With the help of the positioning ability of learning devices and smart objects, the ubiquitous learning system become context aware

6. SULS UbiLearn2006 6 Introduction(3/4)

7. SULS UbiLearn2006 7 Introduction(4/4) A design concept, SULS – Simple Ubiquitous Learning System, is proposed here to support ubiquitous learning

8. SULS UbiLearn2006 8 Outline Introduction Preliminary SULS Application scenario Conclusion

9. SULS UbiLearn2006 9 Preliminary(1/7) GPS (Global Positioning System) Line-of-sight between satellite and point node synchronous timer around three satellites APS (Ad-hoc Positioning System) Not need LOS and synchronous timer Based on DVRP( D istance V ector R outing P rotocol) and the trilateration positioning technology DV-Distance, one of the APS methods, is used in SULS

10. SULS UbiLearn2006 10 Preliminary(2/7) Anchor node Broadcast it’s Position Anchor node RSSI(received signal strength indicator)

11. SULS UbiLearn2006 11 Preliminary(3/7) Anchor node

12. SULS UbiLearn2006 12 Preliminary(4/7) RFID (radio frequency identity) Compose of reader, tag and application

13. SULS UbiLearn2006 13 Preliminary(5/7) RFID (radio frequency identity) Three kinds of tag Passive tag –no self battery –the simplest one semi-active tag active tag

14. SULS UbiLearn2006 14 Preliminary(6/7) RFID (radio frequency identity) How passive tag works?

15. SULS UbiLearn2006 15 Preliminary(7/7) RFID(radio frequency identity) Working frequencies in the worldwide 135KHz 13.5MHz 433.92MHz 860~930MHz(UHF) 2.45GHz and 5.8GHz The UHF tag can be read at a distance about 10m.

16. SULS UbiLearn2006 16 Outline Introduction Preliminary SULS Application scenario Conclusion

17. SULS UbiLearn2006 17 SULS(1/7) SULS Simple Ubiquitous Learning System integrates two existent technologies APS RFID three newly developed technologies Farthest tag forwarding Tag-assisted positioning Multi-media data in-network cache

18. SULS UbiLearn2006 18 SULS(2/7) Farthest tag forwarding Back-off time = ((L-R)/L) x B Where R:signal source distance L:the farthest signal distance B:the maximum back-off time

19. SULS UbiLearn2006 19 SULS(3/7) The farthest signal distance 250 m 200 m 50 m The farthest signal distance= 250 m –Far away from 50m  ((250-50)/250)B=0.8B –Far away from 200m  ((250-200)/250B=0.2B

20. SULS UbiLearn2006 20 GUIDE NODE:Node equipped with RFID reader SULS(4/7)

21. SULS UbiLearn2006 21 SULS(5/7) Tag-assisted positioning Anchor node can be located by GPS Tags that have position information and are attached to smart objects Other nodes can be located by three GUIDE NODEs

22. SULS UbiLearn2006 22 SULS(6/7) Multi-media data in-network cache GUIDE NODE has multi-media data of smart objects Use cache to reduce network traffic and GUIDE NODE loading

23. SULS UbiLearn2006 23 GUIDE NODE:Node equipped with RFID reader & multimedia library SULS(7/7)

24. SULS UbiLearn2006 24 Outline Introduction Preliminary SULS Application scenario Conclusion

25. SULS UbiLearn2006 25 Application scenario

26. SULS UbiLearn2006 26 Outline Introduction Preliminary SULS Application scenario Conclusion

27. SULS UbiLearn2006 27 Conclusion SULS a Simple Ubiquitous Learning System a low cost and efficient Ubiquitous Learning system use simple devices –Learning devices with mobile ability –Few have RFID readers (plus GPS) three newly developed technologies –Farthest tag forwarding –Tag-assisted positioning –Multi-media data in-network cache

28. SULS UbiLearn2006 28 Thanks for Your Listening!