1. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 1 CC/RR Performance Evaluation - Revisited Javier del Prado and Sunghyun Choi Philips Research USA Briarcliff Manor, New York sunghyun.choi@philips.com

2. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 2 Simulation Goal In 01/571r0 the results showed a better performance with CC/RR compared to straight PCF –Straight PCF does poll all the stations These results were not enough to validate the CC/RR mechanism –HCF should not implement a straight polling, so it is not a good comparison We show new scenarios with more simulation results for further discussion

3. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 3 Simulation Model Used the simulation model provided by AT&T The results in 01/571 were obtained with the same simulation model Modified to support new scenarios It supports: –DCF –PCF (or HCF without TXOP, working in CFP only) –CC/RR –Direct STA-to-STA transmission

4. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 4 Simulation Scenarios 1 AP, 6 voice STAs and 23 FTP heavy and HTTP heavy STAs The application parameters are taken from 01/571r1. –All the application start after 100 sec from the simulation start. The WLAN parameters are the same as in 01/571r1. –Beacon interval of 20 ms with CFP of 18 ms

5. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 5 Simulation Scenarios

6. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 6 Simulation Scenarios

7. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 7 Simulation Scenarios 4 different simulation scenarios: 1)Standing Poll (legacy PCF) -All STA & AP set for Standing Poll -All STA are polled using “Round Robin” -One STA is polled continuously while it has more data -The CFP ends when all STA have been polled 2)CC/RR -All STA & AP set for CC/RR -CC Parameters chosen from 01/571r0 -Polling list updated using RR information -The STAs are polled while enough time in the CFP Simulated in 01/571r0

8. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 8 Simulation Scenarios New simulation scenarios: 3) Polling only voice stations and downlink traffic to voice stations during CFP -Data downlink traffic transmitted during CP -After polling all voice stations, CFP ends -“Round Robin” polling -A voice STA is polled while it has more data to send 4) Polling voice stations and all downlink traffic during CFP -Uplink data traffic is transmitted during CP

9. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 9 Throughput (moving average of 240)

10. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 10 Load (moving average of 240)

11. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 11 Data Dropped AP

12. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 12 Delay (global)

13. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 13 Delay (II) (without Standing Poll)

14. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 14 Control Traffic Received at AP

15. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 15 Control Traffic sent by AP

16. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 16 Media Access Delay at Voice STA 1

17. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 17 Media Access Delay at Voice STA #19

18. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 18 Voice Throughput per STA

19. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 19 FTP Traffic served (moving average of 240)

20. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 20 HTTP Traffic served (moving average of 240)

21. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 21 FTP download time (moving average of 10)

22. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 22 HTTP Page Response Time (moving average of 10)

23. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 23 HTTP Object Response Time (moving average of 10)

24. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 24 Conclusions (I) The scenario was designed to demonstrate the utility of CC/RR. However, comparable performance was achieved without CC/RR. –CC/RR mechanism may even degrade the overall performance in some cases due to the unnecessary overhead. Parameterized QoS streaming will not need the CC/RR mechanism. Resource request can be done via QoS Null or another management frame.

25. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 25 Conclusions (II) We believe that the performance w/o CC/RR can be better via more intelligent scheduling Note that … –HC can poll voice STAs during the CP (not implemented in the current simulation model) –HC can get information in the QoS control field of data frames (not implemented in the current simulation model) CC/RR complexity is not justified!

26. doc.:IEEE 802.11-02/223r1 Submission March 2002 J. del Prado and S. Choi, Philips Slide 26 Motion Instruct editor to remove all the references to CC/RR & CCI mechanism in the draft This motion directly addresses the following comments : –785 (Ecclesine), 783, 786, 1085 (Sanwalka), 787 (Singla), 788 (Stephans), 932,1667 (Chesson), 2000 (Choi), 1662 (Diepstraten), 1666 (Myles), 1856 (Willams)