1. EDCF / EPCF Comparisons
Month 2000
doc.: IEEE /xxx
September 2002
EDCF / EPCF Comparisons
Author:
Matthew Sherman
AT&T Labs - Research
180 Park Avenue
Florham Park, NJ
Date: September 8, 2002
Matthew Sherman, AT&T Labs - Research
John Doe, His Company

2. Purpose of Document Quick comparison of EDCF with EPCF
Month 2000
doc.: IEEE /xxx
September 2002
Purpose of Document
Quick comparison of EDCF with EPCF
Mostly for new comers
Matthew Sherman, AT&T Labs - Research
John Doe, His Company

3. Background Few comparisons of E-DCF and HCF
Month 2000
doc.: IEEE /xxx
September 2002
Background
Few comparisons of E-DCF and HCF
AT&T has simulated both E-DCF and E-PCF
E-DCF simulations – eg. 01/004 and 01/019
E-PCF simulations – eg. 02/303, 02/304, 02/305
E-PCF just like HCF except CF access only during CFP
HCF should perform even better since less constrained
Easier for AT&T to simulate E-PCF
AT&T’s original interest before HCF created
AT&T never provided head to head comparison
First such comparisons by AT&T
Matthew Sherman, AT&T Labs - Research
John Doe, His Company

4. Simulation Scenario Same parameters as in 01/004
Month 2000
doc.: IEEE /xxx
September 2002
Simulation Scenario
Same parameters as in 01/004
01/004 did not use PHY
Ran CC/RR/EDCF code
with b PHY
with b access parameters but no modeling of PHY overhead
Some output statistics different as well
Matthew Sherman, AT&T Labs - Research
John Doe, His Company

5. Plots Collected Matched plots in 01/004 as closely as possible
September 2002
Plots Collected
Matched plots in 01/004 as closely as possible
Statistics not identical to CC/RR/EDCF model
Stuck with Throughput (Goodput), Media Access Delay, and Data Dropped
“Streams” here correlate to “Calls” in 01/004
Streams are renumbered (relative to Calls) to correlate with when streams start
Matthew Sherman, AT&T Labs - Research

6. E-PCF sims of E-DCF Scenarios
September 2002
E-PCF sims of E-DCF Scenarios
Configured code to run E-DCF Scenarios using E-PCF
20 msec Beacon Period (18 msec CFP)
E-DCF simulations used 100 msec Beacon Period
Standing Poll (no CC/RR)
Addresses arranged according to priority
Priority based scheduler
no attempt at fairness
Matthew Sherman, AT&T Labs - Research

7. Traffic loading Same EDCF parameters for classes as 00/004
September 2002
Traffic loading
2.5 Mbps
LOW
Traffic Category
AIFS
CW MIN
CW MAX PF
TOP
PIFS 15
1023
1.5
MEDIUM
DIFS 31
2.0
LOW
DIFS +1
5.0 Mbps
TOP
5.0 Mbps
MEDIUM
2.5 Mbps
LOW 30 90
150
Time (sec)
Same EDCF parameters for classes as 00/004
Matthew Sherman, AT&T Labs - Research

8. E-PCF simulations of E-DCF scenarios
September 2002
E-PCF simulations of E-DCF scenarios
Matthew Sherman, AT&T Labs - Research

9. Throughput E-DCF E-PCF September 2002
Matthew Sherman, AT&T Labs - Research

10. Media Access Delay E-DCF E-PCF September 2002
Matthew Sherman, AT&T Labs - Research

11. Media Access Delay (Zoomed)
September 2002
Media Access Delay (Zoomed)
E-DCF
E-PCF
Matthew Sherman, AT&T Labs - Research

12. Data Dropped E-DCF E-PCF September 2002
Matthew Sherman, AT&T Labs - Research

13. September 2002
Data Analysis – E-PCF
Dramatic performance differences between E-DCF and E-PCF
High priority delays / drops much better for E-PCF
Difference between acceptable / unacceptable Voice
E-DCF much more sensitive to overload
E-PCF drops less data in general
No “fairness” between classes in E-PCF
Could be fixed with more advanced scheduler
HCF would be better still
Matthew Sherman, AT&T Labs - Research

14. E-PCF simulations of E-DCF scenarios (No PHY)
September 2002
E-PCF simulations of E-DCF scenarios (No PHY)
Matthew Sherman, AT&T Labs - Research

15. Throughput E-DCF E-PCF September 2002
Matthew Sherman, AT&T Labs - Research

16. Media Access Delay E-DCF E-PCF September 2002
Matthew Sherman, AT&T Labs - Research

17. Media Access Delay (Zoomed)
September 2002
Media Access Delay (Zoomed)
E-DCF
E-PCF
Matthew Sherman, AT&T Labs - Research

18. Data Dropped E-DCF E-PCF September 2002
Matthew Sherman, AT&T Labs - Research

19. Data Analysis – E-PCF (no PHY)
September 2002
Data Analysis – E-PCF (no PHY)
While the E-DCF performance degradation is not as sever as with the PHY it is still substantial
All the comments identified for the simulations with a PHY would still apply
Matthew Sherman, AT&T Labs - Research