1. 2001/11/29Chin-Kai Wu, CS, NTHU1 Design and Simulation of an Efficient Real-Time Traffic Scheduler with Jitter and Delay Guarantees Fu-Ming Tsou, Hong-Bin Chiou, and Zsehong Tsai, Member, IEEE IEEE TRANSACTIONS ON MULTIMEDIA, VOL. 2, NO. 4, DECEMBER 2000

2. 2001/11/29Chin-Kai Wu, CS, NTHU2 Outline Introduction Multilayer Gated Frame Queueing (MGFQ) Due-date Calculation Procedure Due-date Calculation Jitter Bound Design Issue Simulation

3. 2001/11/29Chin-Kai Wu, CS, NTHU3 Introduction Scheduling Algorithms WFQ, WRR Simply deal with the reduction of implementation complexity JEDD Supporting both flexible delay and jitter guarantees, but with high implementation complexity DFQ Low implementation, but leads to the limitation on the scalability and granularity of jitter level Multilayer Gated Frame Queueing (MGFQ) proposed

4. 2001/11/29Chin-Kai Wu, CS, NTHU4 Operation of MGFQ FIFO with same QoS parameter Jitter bound of all VPs in Group i are within [(i - 1)T + 1, iT] Temporary-queue i buffers the cells with due-dates were in the interval [iT + 1, (i + 1)T] in the last refreshing-period FP informs DDCs to open the “gate” with period T PPD, APPD scheme to discard packets

5. 2001/11/29Chin-Kai Wu, CS, NTHU5 Operation of MGFQ (Cont’d)

6. 2001/11/29Chin-Kai Wu, CS, NTHU6 Operation of MGFQ (Cont’d)

7. 2001/11/29Chin-Kai Wu, CS, NTHU7 Due-date Calculation Procedure

8. 2001/11/29Chin-Kai Wu, CS, NTHU8 Due-date Calculation

9. 2001/11/29Chin-Kai Wu, CS, NTHU9 Jitter Bound

10. 2001/11/29Chin-Kai Wu, CS, NTHU10 Design Issue Suppose the local jitter bound assigned to VP i at the egress node H is J H. Then, the end-to-end transmission delay (CTD) of VP i is Therefore, the end-to-end jitter bound [or called Cell Delay Variation (CDV)] is

11. 2001/11/29Chin-Kai Wu, CS, NTHU11 Simulation Model

12. 2001/11/29Chin-Kai Wu, CS, NTHU12 Cell Delay Distribution

13. 2001/11/29Chin-Kai Wu, CS, NTHU13 Cell Delay Metrics

14. 2001/11/29Chin-Kai Wu, CS, NTHU14 Cell Overdue Ratio

15. 2001/11/29Chin-Kai Wu, CS, NTHU15 Impact of Congestion