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

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. Outline • Introduction • Preliminary • SULS • Application scenario • Conclusion

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

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

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. Introduction(3/4)

7. Introduction(4/4) • A design concept, SULS –Simple UbiquitousLearningSystem, is proposed here to support ubiquitous learning

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

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(Distance Vector Routing Protocol) and the trilateration positioning technology • DV-Distance, one of the APS methods, is used in SULS

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

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

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

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

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. Outline • Introduction • Preliminary • SULS • Application scenario • Conclusion

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(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. 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 SULS(3/7) 50 m The farthest signal distance 250 m 200 m

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

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(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(7/7) GUIDE NODE:Node equipped with RFID reader & multimedia library

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

25. Application scenario

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

27. Conclusion • SULS • a SimpleUbiquitousLearning 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. Thanks for Your Listening!