1. Quorum-based Power-Saving Multicast Protocols in the Asynchronous Ad Hoc Network Yu-Chen Kuo Department of Computer Science and Information Management Soochow University Computer Networks, vol. 54, no. 11, August 2010, pp. 1911-1922

2. Outline Introduction Problem Quorum-based asynchronous power-saving protocol –Rotation m-closure property –Uniform k-arbiter quorum systems –CRT quorum systems Performance Evaluation Conclusion

3. Introduction 802.11 wireless hosts –batteries to supply their limited power Critical issue –how to extend the lifetime of wireless hosts

4. Introduction IEEE 802.11 defines the power-saving (PS) mode for wireless hosts to reduce the usage of radio activity. Station ATIM Window Beacon Interval 0 PS Mode Beacon DATA Window ATIM Window Beacon Interval 1 Active Mode Beacon DATA Window … ATIM Window Beacon Interval k Active Mode Beacon DATA Window

5. Introduction IEEE 802.11 defines the power-saving (PS) mode for wireless hosts to reduce the usage of radio activity. ATIM Window Beacon Interval PS Mode Beacon DATA Window Station A ATIM Window Beacon Interval Active Mode ATIM DATA Window Station B ACK Active Mode

6. Introduction Quorum systems –Random selection –Intersection 123 456 789 123 456 789 Station A ATIM Window Beacon Intervals 3 and 4 Active Mode ATIM DATA Window Station B ACK Active Mode Host AHost B Quorum Interval (A): 1, 2, 3, 4, 7 Quorum Interval (B): 3, 4, 5, 6, 9

7. Problem How to apply the quorum-based power-saving protocol for –Asynchronous networks –Multicast Quorum systems U={0, 1, 2, 3} C={{0,1}, {0,2}, {0,3}} Q 1 ={0,2}, Q 2 ={0,1}, Q 3 ={0,3} Clock drift r 3 = 3

8. Problem How to apply the quorum-based power-saving protocol for –Asynchronous networks –Multicast B C D A B C D A t B CD

9. Problem How to apply the quorum-based power-saving protocol for –Asynchronous networks –Multicast Busy waiting

10. Goals To design quorum-based power-saving multicast protocols in the asynchronous –Quorum systems –Clock drift –Multicast

11. Rotation m-closure property Quorum system C under U={0, 1, 2, …, N-1} Quorums Q  C Clock drift r Quorum systems U={0, 1, 2, 3} C={{0,1}, {0,2}, {0,3}} Q 1 ={0,2}, Q 2 ={0,1}, Q 3 ={0,3} Clock drift r 3 = 3

12. Rotation m-closure property Intersection property Quorum systems U={0, 1, 2, 3} C={{0,1}, {0,2}, {0,3}} Q 1 ={0,2}, Q 2 ={0,1}, Q 3 ={0,3} Clock drift r 3 = 3

13. Rotation m-closure property Rotation closure property  

14. Rotation m-closure property To multicast for m hosts at the same time  

15. Uniform k-arbiter Quorum Systems Quorum system C under U={0, 1, 2, …, N-1} Quorums Q  C Clock drift r Uniform k-arbiter:

16. Uniform k-arbiter Quorum Systems, k: number of multicast members Quorum systems U={0, 1, 2, 3, 4, 5, 6, 7, 8} Q 1 ={0, 1, 2, 4, 5, 7, 8} Q 2 ={0, 2, 3, 5, 6, 7, 8} Q 3 ={0, 1, 2, 3, 4, 5, 6} Clock drift r 2 = 1 Clock drift r 3 = 8 123456789 H1H1 H2H2 H3H3 Sender 1

17. Compare with Busy waiting Uniform k-arbiter Busy waiting

18. CRT Quorum Systems Chinese Reminder Theorem H 1 : p 1 =5, r 1 =0 H 2 : p 2 =3, r 2 =1 H 3 : p 3 =2, r 3 =8 論文例子有問題

19. Performance Evaluation NS2 –100 hosts in 200m*200m –Transmission range: 250m –Transmission rate: 2 Mbps –Battery power: 1000 J

20. Performance Evaluation

23. 線條趨勢與先前相同

24. Performance Evaluation 線條趨勢與先前相同

25. Performance Evaluation 線條趨勢與先前相同

26. Performance Evaluation 線條趨勢與先前相同

27. Performance Evaluation 線條趨勢與先前相同

28. Performance Evaluation 線條趨勢與先前相同

29. Conclusion This paper proposes a quorum-based power saving protocols –Asynchronous networks –For multicast TheEND Thanks for your attention !