1. 1 The Design of the Power Saving Mechanisms in IEEE 802.16e Networks (Defense) Student: Lei Yan ( 嚴雷 ) Advisor: Dr. Ho-Ting Wu ( 吳和庭 ) Date: 2009/07/23 Institute of Computer Science and Information Engineering, National Taipei University of Technology

2. 2 Outlines  Backgrounds and motivation  Spec-defined power saving mechanism  Proposed power saving mechanism  Performance evaluation  Conclusion and future works

3. 3 Brief of IEEE 802.16  Also called “WiMAX” (Worldwide Interoperability for Microwave Access)  The “wireless” last mile technology  Low cost and free to geographical limits  Includes PHY/MAC solutions  Higher transmission rate than 3.5G  Ideal transmission rate and coverage: 75 Mbps and 50 km  Now been merchandised in Taiwan

4. 4 Layering related to connections  Convergence sublayer  Classification  Common Part sublayer  Establishment  Change  Deletion  Call admission control (CAC)  Bandwidth allocation (BWA)  Packet scheduling  Security sublayer  Encryption/Decryption for data MAC Common Part Sublayer (CPS)

5. 5 Frame structure of WiMAX

6. 6 Outlines  Backgrounds and motivation  Spec-defined power saving mechanism  Proposed power saving mechanism  Performance evaluation  Conclusion and future works

7. 7 Renaming for QoS metrics: Power saving class (PSC) HTTP BE FTP NRTVR nrtPS MPEG RTVR rtPS VoIP (silence suppressi on) ERTVR ertPS VoIP UGS Usage Service type for power saving Service type PSCReal-time Non-Real time PSC I NRTVR (nrtPS) BE PSC II UGS RTVR (rtPS) PSC III ERTVR (ertPS)

8. 8 States of a MS with power saving function

9. 9 Outlines  Backgrounds and motivation  Spec-defined power saving mechanism  Proposed power saving mechanism  Performance evaluation  Conclusion and future works

10. 10 What our research work has done?  Includes UGS/ertPS, rtPS, nrtPS, and BE for both UL/DL traffics  Integrated consideration to CENTRALLY arrange calls to prolong sleep durations  Complete solution (CAC + BWA + packet scheduling)  Reduction of ON-OFF alternations in MS  Q: Why packet scheduling for power saving?  A: Since BS can control all states for MS PRECISELY with time

11. 11 Structure of our research work

12. 12 Assumptions for our research work  Frame overflow is allowed (to schedule across the bound between frames)  Merge the listening duration into ON- state duration

13. 13 BWA and scheduling

14. 14 Judgment in the proposed BWA algorithm  (5) determines the credit. (6) is the stabilized version of (7)

15. 15 Deployed packet scheduling algorithm  Round-Robin fashion for the scheduling  Pros: In the algorithm itself, all MSs have intact sleep duration (intuitive design)  Cons: No guarantee for UGS/ertPS delay  Special assumption: all delay bounds are set and equal to DUGS (100 ms)

16. 16 Outlines  Backgrounds and motivation  Spec-defined power saving mechanism  Proposed power saving mechanism  Performance evaluation  Conclusion and future works

17. 17 System structure of our research work

18. 18 Parameters for simulation Number of BS1 Number of MS20~200 System capacity (Mbps)50 Frame duration (ms)5 Capacity per frame (byte)31250 Amplification ratio5, 10, 15, and 20 Simulation duration (sec)500 Call duration (sec)Uniform(60,200)

19. 19 Parameters for simulation (cont.) Service type UGSertPSrtPSnrtPSBE Delay bound (ms) 100 200300400 Transmission rate required in call request (kbps) 64 Uniform(48, 60) Bandwidth request size per frame (byte) 40 Uniform(30, 50) Arrival rate 0.44 0.030.020.20 ON/OFF ratio for ertPS 0.4/0.6

20. 20 The traditional WiMAX scheme we compare to  No BWA and scheduling (no packet dropping rate/delay)  We amplified the negative credit to reduce packet dropping/delay ItemsProposedTraditional CAC algorithm in use Traditional Aggregation for grant size YESNO Adaptively adjust the grant size YESNO Frame overflowAllowedNot allowed RF device is allowed to be turned off YESNO

21. 21 Three scenarios for our comparison

22. 22 Flow chart of the program

23. 23 Increase of sleeping ratio  Heavier loading causes longer C but reduce number of cycle (number of granting for MSs) => avg. proportion in ON-state is decreased

24. 24 Scenario 1: AMP=15

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26. 26 Scenario 2: AMP=20

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30. 30 Scenario 3: MS=120

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32. 32 Scenario 4: MS=200

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36. 36 Outlines  Backgrounds and motivation  Spec-defined power saving mechanism  Proposed power saving mechanism  Performance evaluation  Conclusion and future works

37. 37 Conclusion  Although the power saving based WiMAX scheme introduces packet dropping and delay than the traditional one, the power consumption is decreased  Our proposed WiMAX scheme prolongs sleep duration and decreases ON-OFF alternation for MSs  Proposed BWA + scheduling is better than NO BWA + scheduling in both packet dropping rate and delay  The current judgment for parameters can make MSs sleep at most 15 frames with tolerable packet dropping rate

38. 38 Future works  Further judgment for parameters to make the packet dropping rate tolerable when AMP=20  Use the LMS algorithm as substitute for BWA  Implement the other two packet scheduling algorithm for alternative

39. 39 Thank you!!  Your suggestion is my treasure!!