1. An Adaptive Deficit-based Scheduler for IEEE 802.16e Networks Nararat RUANGCHAIJATUPON and Yusheng JI The Graduate University for Advanced Studies National Institute of Informatics (NII), Japan The 24 th Asia-Pacific Advanced Network Meeting August 27 – 31, 2007, Xi ’ an, P.R. China

2. August 27-31, 200724th APAN Meeting2 IEEE 802.16e TDD mode  Uplink and Downlink share the same frequency but not in the same time  Transmission units are in frames Downlink subframe & Uplink subframe  Subframe is divided into minislots  MAP message at the beginning of each frame DL-MAP & UL-MAP

3. August 27-31, 200724th APAN Meeting3 WiMAX TDD Frame Structure

4. August 27-31, 200724th APAN Meeting4 Scheduling services in IEEE 802.16e  Unsolicited Grant Service (UGS)  Extended Real-Time Polling Service (ertPS)  Real-Time Polling Service (rtPS)  Non Real-Time Polling Service (nrtPS)  Best Effort Service (BE)

5. August 27-31, 200724th APAN Meeting5 Scheduling services in IEEE 802.16e (cont.)  Unsolicited Grant Service (UGS) Real-time application with fixed data rate, fixed size data packet  Extended Real-Time Polling Service (ertPS) Real-time application with fixed data rate, variable size data packet

6. August 27-31, 200724th APAN Meeting6 Scheduling services in IEEE 802.16e (cont.)  Real-Time Polling Service (rtPS) Real-time application with fixed data rate, variable size data packet  Non Real-Time Polling Service (nrtPS) Delay-tolerant application with variable size data packets, which required minimum data rate  Best Effort Service (BE) Application with no minimum service level

7. August 27-31, 200724th APAN Meeting7 Request message(s)  Dynamic Service Addition (DSA)  Dynamic Service Change (DSC)  Dynamic Service Delete (DSD)

8. August 27-31, 200724th APAN Meeting8 QoS parameters  Maximum Sustained Traffic Rate (r max )  Minimum Reserved Traffic Rate (r min )  Maximum Latency (t latency )  Minimum Tolerable Traffic Rate (r tol ) with time base (t tol ) The minimum amount of traffic served (in bits) during an arbitrary time interval should not be less than (r tol x t tol )

9. August 27-31, 200724th APAN Meeting9 Admission control  Total bandwidth (BW total )  A new flow j is accepted if: BE flows are always accepted as its r min always equals to zero

10. August 27-31, 200724th APAN Meeting10 Parameters and states  Connection ’ s limited queue size  Burst state Connection queue size is more than its limited queue size  Non-burst state Connection queue size is equal or less than its limited queue size

11. August 27-31, 200724th APAN Meeting11 Proposed scheduling scheme  All flows are in non-burst state  A flow is in burst state Tolerable group Guaranteed group Burst group Scheduler with EDF … DL UGS Flow 1 Flow n DL BE RR Adaptive DRR Queue size limit FIFO UL UGS DL ertPS, rtPS, nrtPS Flow n Adaptive DRR UL ertPS, rtPS, nrtPS UL BE RR … … …

12. August 27-31, 200724th APAN Meeting12 Adaptive quantum  Tolerable category  Guaranteed category

13. August 27-31, 200724th APAN Meeting13 Adaptive quantum (cont.)  Burst category If Else Employ max-min allocation

14. August 27-31, 200724th APAN Meeting14 Simulation Setup  Single base station  Frame duration: 2.5 ms  Number of slots per frame: 175,000  Total bandwidth : 75 Mbps PHY/MAC control message takes 5 Mbps  One minislot represents a single physical slot (PS) with a baud rate of one  Traffic utilization is 85.71 %

15. August 27-31, 200724th APAN Meeting15 Traffic and request generators

16. August 27-31, 200724th APAN Meeting16 Simulation results

17. August 27-31, 200724th APAN Meeting17 Simulation results (cont.)

18. August 27-31, 200724th APAN Meeting18 Fairness “A scheduler is considered to be fair if the difference in normalized service received by different flows is bounded.”

19. August 27-31, 200724th APAN Meeting19 Conclusion  An adaptive deficit-based scheduler for IEEE 802.16e adapts the allocation appropriately to the input traffic and uplink request  The proposed scheme also shows better performance in fairness  Further work must be done on unbalance traffic and cross-layer scheduling

20. Thank you very much  Questions and Answers