1. Downlink Scheduling for Multimedia Multicast/Broadcast over Mobile WiMAX Connection-oriented Multi- state Adaptation Source:IEEE Wireless Communications Magazine,2009/8 Authors:Hongfei Du, Jiangchuan Liu, Jie Liang Student ID:M9756003 Reporter: Chang, Yi Jui 2016/3/151

2. Outline  Introduction  Background  QoS Scheduling in WiMAX  Connection-Oriented Multi-State Optimization  Performance Analysis  Conclusion 2016/3/152

3. Introduction  WiMAX lie in its cost-competitive deployment and comprehensive quality of service support for large numbers of heterogeneous mobile devices with high-data rate wireless access.  Digital multimedia broadcasting (DMB) have offered the network operator a platform to deliver multimedia services to a mass market. 2016/3/153

4. Introduction  A novel concept of connection-oriented service flow, supporting QoS for both uplink and downlink on a per service flow basis.  A viable end-to-end cross-layer framework, connection-oriented multistate adaptation(CMA), which adopts the service- oriented design on per-service-flow connections carrying multisession MBS. 2016/3/154

5. Background-Overview 2016/3/155 Multicast/broadcast WiMAX system architecture for MBS service delivery

6. Background-Overview  The 802.16e radio interface adopts orthogonal frequency-division multiple access(OFDMA).  WiMAX system in point-to-multipoint (PMP) mode, where the QoS is mainly enforced by the MAC and APP layers. 2016/3/156

7. Background-Medium Access Control  WiMAX supports two types of scheduling: downlink scheduling and uplink request scheduling.  The downlink scheduling in the base station (BS) determines the burst profile and transmission period for each connection for downlink traffic based on the QoS profile as well as channel/queuing related criteria. 2016/3/157

8. Background-MAC 2016/3/158 Downlink scheduling procedures at the BS

9. QoS Scheduling:QoS Mechanism  Unsolicited grant service (UGS)  T1/E1 transport  Extended real-time polling service (ertPS)  voice of IP (VoIP)  Real-time polling service (rtPS)  MPEG audio/video streaming  Non-real-time polling service (nrtPS)  FTP  Best effort (BE)  HTTP, e-mail 2016/3/159

10. QoS Scheduling:State-of-The-Art  Important design issues:  QoS differentiation: class, heterogeneous types  connection-oriented: scheduling and flow differentiation  Guarantee: monitor instantaneous performance  Scheduler: channel vibrations, queuing dynamics  Adapt transmitter side settings dynamically 2016/3/1510

11. Connection-Oriented Multi-State Optimization  Optimization Criteria  Problem Formulation  Queuing State  Effective Reception  Adaptive Queue Prioritization  Source Coding Adaptation 2016/3/1511

12. Optimization Criteria  QoS profile (P QoS )  E2E delay factor (F ED ),  E2E packet loss rate (PLR) factor (F EP )  E2E throughput factor (F ET )  P QoS (i) = F ED (i) ⋅ F EP (i) ⋅ F ET (i)  Queuing state profile (P QS )  Channel state profile (P CS ) 2016/3/1512

13. Problem Formulation  an m × n multistate metric, where m is the number of functions in layers considered, and n is the total number of active connections.  Dynamic metric  Threshold metric  Distortion metric  Adaptation metric 2016/3/1513

14. Problem Formulation 2016/3/1514 Connection-oriented multistate adaptation

15. Queuing State  Queuing delay factor (F QD )  Buffer occupancy factor (F BO )  Overflow probability factor (F OP )  P QS (i) = F QD (i) ⋅ F BO (i) ⋅ F OP (i)  In order to incorporate bursty traffic loads induced by VBR video streams. 2016/3/1515

16. Effective Reception  E2E delay factor:  It is defined as the estimated historical mean delay performance over the maximum delay constraints.  E2E throughput factor  calculated as the ratio between the total bits released to the total bits that have been successfully scheduled and delivered to users up to the current scheduling slot.  E2E PLR factor: packet loss performance 2016/3/1516

17. Adaptive Queue Prioritization 2016/3/1517 The proposed CMA scheduling framework

18. Source Coding Adaptation  Scalable Video Coding (SVC) extension of H.264/AVC for cross-layer optimization.  With SVC, a MBS video stream is split into a base layer (BL) and multiple enhancement layers (ELs) that refine the video quality.  All MC/BC connections to be originated from a single BS with no connection sharing or handoff events. 2016/3/1518

19. Performance Analysis  Two parts  H.264/MPEG-4 AVC JM reference software  System-level simulation model in NS2  Four schemes and CMA scheme  Weighted Round Robin(WRR): proportion, weight  Weighted Fair Queue(WFQ): regulating, weight  Earliest Deadline First (EDF): deadline, packet  Max C/I: upper bound of system capacity 2016/3/1519

20. Performance Analysis 2016/3/1520 The 95th percentile CDF of E2E delay for rtPS services under different downlink scheduling schemes

21. Performance Analysis 2016/3/1521 Variance of overall throughput ratios under different downlink scheduling schemes

22. Conclusion  The framework performs simultaneous adaptations across protocol stacks on source coding, queue prioritization, flow queuing, and scheduling.  The heterogeneity in wireless link variations, queue fluctuations, and reception diversities are incorporated. 2016/3/1522