1 Advisor: Dr. Kai-Wei Ke Speaker: Ming-Chia Hsieh Date: 30/07/2006 A Dynamic Uplink/Downlink BWA and Packet Scheduling Mechanism in WiMAX

2 Outline  Background  WiMAX Standard Overview  Proposed Architecture  Simulation  Conclusion

3 WiMAX Overview  WiMAX? (Worldwide Interoperability for Microwave Access)  Wireless broadband network connection technique.  Replace last mile.  Cost saving  Easy to deploy

4 Basic WiMAX Network Architecture Subscribe Station (SS) Subscribe Station Wireless link Base Station (BS) Subscribe Station Core network Wired/wireless links Users

5 Outline  Background  WiMAX Standard Introduction  Frame Structure.  Generic / Request Header  Service Classes.  QoS Procedure.  Proposed Architecture  Simulation  Conclusion

6 Frame Structure adaptive Frame jFrame j+1Frame j-1 PS 0PS N-1 Downlink SubframeUplink Subframe N = (Rate x Frame Duration) / 4

7 Downlink subframe Preamble Broadcast Control DIUC = 0 TDM DIUC a Preamble DL_MAPUL_MAP Transition Gap

8 Uplink Subframe Initial Ranging Opportunities (UIUC = 2) Request Contention Opps (UIUC = 1) SS 1 Scheduled Data (UIUC = i) ● ● ●● ● ● SSTG Transmit/Receive Transition Gap Access Burst Collision BW Request

9 UL/DL Map Frame n-1Frame n DL-MAP ATDD Split DL-MAP Frame Control Downlink Subframe Uplink Subframe UL-MAP ATDD Split

10 Outline  Background  WiMAX Standard Introduction  Frame Structure.  Generic / Request Header  Service Classes.  QoS Procedure.  Proposed Architecture  Simulation  Conclusion

11 Rsv (1) Generic MAC header HT = 0(1)EC(1) Type (6) CI (1) EKS (2) Rsv (1) LEN MSB(3) LEN LSB (8) CID MSB(8) HCS (8)CID LSB (8) (#) number of bits

12 Bandwidth request header format HT = 1 (1)EC(1) Type (3)BR MSB(11) BR LSB (8)CID MSB(8) CID LSB (8)HCS (8)

13 Outline  Background  WiMAX Standard Introduction  Frame Structure.  Generic / Request Header  Service Classes.  QoS Procedure.  Proposed Architecture  Simulation  Conclusion

14 Service Classes  UGS Constant bit rate, fixed packet length (ex. VoIP)  rtPS variable bit rate, variable packet length (ex. MPEG)  nrtPS Delay tolerated (ex. FTP)  BE Best-Effort (ex. HTTP)

15 Outline  Background  WiMAX Standard Introduction  Frame Structure.  Generic / Request Header  Service Classes.  QoS Architecture  Proposed Architecture  Simulation  Conclusion

16 IEEE QoS Architecture Subscriber Station (SS)Base Station (BS) Application Connection Classifier UGSrtPSnrtPS BE Admission Control (undefined by IEEE) Connection Request Connection Response BW Request Scheduler UL-MAP Data Transmission Uplink Packet Scheduling( UPS) (Undefined by IEEE)

17 IEEE Procedures BS Send UL/DL Map BS Send DL Data SSs Send BW requests SSs Send UL Data BS Run BWA BS Receives BW Req. SSs Receive UL/DL Map SS Receive UL Data BS Receives UL Data

18 Outline  Background  WiMAX Standard Introduction  Proposed Architecture  Proposed Architecture.  Request Maker  Bandwidth Allocation Description  Packet Scheduling Description  Simulation  Conclusion

19 Proposed QoS Architecture Upstream BS Request DB SS BW Request BWA MAP Generator Packet Scheduler DL/UL MAP UGS rtPS nrtPS BE Downstream Classifier Packet Scheduler Request Maker UGS rtPS nrtPS BE Classifier

20 Problem & Solution of BWA

21 Outline  Background  WiMAX Standard Introduction  Proposed Algorithm  Proposed Architecture.  Request Maker  Bandwidth Allocation Description  Packet Scheduling Description  Simulation  Conclusion

22 Request Maker Connections CID:001, BW: 100Kb CID:002, BW: 150Kb CID:005, BW: 50Kb Bandwidth request message SS BS LatencyCID , CID:001, BW 50Kb CID:002, BW 50Kb CID:003, BW 50Kb CID:004, BW 50Kb CID:005, BW 50Kb

23 Request Database CID : 0011 (UGS) TotalNeeded7000KbTotalDelivery3000Kb Arrival Time 70 毫秒 100 毫秒 130 毫秒 140 毫秒 Deadline 130 毫秒 160 毫秒 190 毫秒 200 毫秒 Bandwidth1000Kb2000Kb500Kb1000Kb

24 Outline  Background  WiMAX Standard Introduction  Proposed Algorithm  Proposed Architecture.  Request Maker  Bandwidth Allocation Description  Packet Scheduling Description  Simulation  Conclusion  Reference

25 Bandwidth Allocation Procedures DL Emg(UGS) UL Emg(UGS) DL Emg(rtPS) UL Emg(rtPS) DL NEmg(UGS) UL NEmg(UGS) DL NEmg(rtPS) UL NEmg(rtPS) DL nrtPS UL nrtPS DL BE UL BE

26 BWA for Non-Real-time  Sort By Satisfaction rate.  Allocate bandwidth from lower satisfaction  Total BW for nrtPS = 2/3 remaining bandwidth.  Individual Station ： Min(Max_BW_For_nrtPS, nrtPS_Loading).  Total BW for BE = remaining – nrtPS  Individual Station: Min(Max_BW_For_BE, BE_Loading).

27 Outline  Background  WiMAX Standard Introduction  Proposed Algorithm  Proposed Architecture.  Bandwidth Allocation Description  Packet Scheduling Description  Performance evaluation

28 Packet Scheduling  Restrict by the DL/UL Map  Gets bandwidth of each Service Classes, and pick packets in the HOL of the corresponding queue and sends at appropriated PS

29 Outline  Background  WiMAX Standard Introduction  Proposed Algorithm  Performance evaluation-via simulation  Conclusion

30 Environment Setting  Packets: Poison Arrival  Connection: Poison Arrival  Compare my algorithm to [3] which is following the rules of spec.  BW: 10Mbps  BS: 1, SS: 5  Queue: no limit length

31 Drop Rate (UGS, rtPS)

32 Drop Rate (only UGS)

33 Delay of real-time service

34 Delay of non-real-time service

35 Bandwidth util. of Proposed BWA

36 Compare of Bandwidth Util.

37 Fairness of real-time service Normalized Offered load(50%) Normalized Offered load(100%) Normalized Offered load(150%)

38 Outline  Background  WiMAX Standard Introduction  Proposed Algorithm  Simulation  Conclusion

39 Conclustion  Provide Delay and Drop_Rate guarantee for UGS and rtPS  nrtPS has more bandwidth than BE  Even in overloading, nrtPS and BE can get some bandwidth.

40 Outline  Background  WiMAX Standard Introduction  Proposed Algorithm  Simulation  Conclusion  Reference

41 reference  IEEE  GuoSong Chu, Deng Wang, and Shunliang Mei, “A QoS Architecture for the MAC Protocol of IEEE BWA System,” IEEE 2002 International Conference on Vol. 1, 29 June-1 July 2002 pp ,  Dong-Hoon Cho, Jung-Hoon Song, Min-Su Kim, and Kim-Jun Han, “Performance Analysis of the IEEE Wireless Metropolitan Area Network,” First International Conference on Distributed Frameworks for Multimedia Applications (DFMA’05), pp ,  Kitti Wonghavarawat and Aura Ganz, “Packet Scheduling for QoS support in IEEE broadband wireless access system,” International Journal of Communication Systems Vol. 16, Issue 1, pp  Kin K. Leung and Arty Srivastava, “Dynamic Allocation of Downlink and Uplink Resource for Broadband Services in Fixed Wireless Networks,” IEEE Journal on Selected Areas in Communications Vol. 17 No. 5, May 1999.

42 Q&A

43 Virtual Map SS1 UGS SS2 UGS SS3 UGS SS4 UGS SS1 rtPS SS2 rtPS SS3 rtPS