1. EDCF TXOP Bursting Simulation Results
Month 1998
doc.: IEEE /xxx
January 2002
EDCF TXOP Bursting Simulation Results
Javier del Prado and Sunghyun Choi
Philips Research USA
Briarcliff Manor, New York
S. Choi, Philips

2. References IEEE 802.11e QoS draft D2.0
January 2002
References
IEEE e QoS draft D2.0
IEEE /566r3: “Multiple Frame Exchanges during EDCF TXOP”
S. Choi, Philips

3. January 2002
Problem Statement
Per e/D2.0, QSTA cannot transmit multiple MSDUs within an EDCF TXOP
Why not?
As showed in 01/566r3, EDCF TXOP bursting has some advantages while adding minimum complexity
S. Choi, Philips

4. Advantages of EDCF TXOP Bursting
January 2002
Advantages of EDCF TXOP Bursting
Reduce network overhead:
Without bursting available, a QSTA must backoff after each MSDU transmission
Multiple transmissions using SIFS
Burst Acknowledgement can be used
Bandwidth fairness among the same priority queues, independent from the frame sizes
The HCF polled access is not affected since the EDCF TXOP is limited by the “CP TXOP limit” determined by the HC
S. Choi, Philips

5. Simulation scenario Fixed data rate of 11 Mbps
January 2002
Simulation scenario
Fixed data rate of 11 Mbps
8 QSTAs: 4 voice QSTAs, 4 video QSTAs
Traffic pattern:
S. Choi, Philips

6. Simulation scenario I EDCF parameters:
January 2002
Simulation scenario I
EDCF parameters:
Simulations for different TXOP lengths
S. Choi, Philips

7. Simulation results I Global Throughput No Bursting 3.5 ms 5 ms
January 2002
Simulation results I
Global Throughput
2 frames of video per TXOP
3 frames of video per TXOP
No Bursting
3.5 ms
5 ms
S. Choi, Philips

8. Simulation results I Global Data Dropped No Bursting 3.5 ms 5 ms
January 2002
Simulation results I
Global Data Dropped
No Bursting
3.5 ms
5 ms
S. Choi, Philips

9. Simulation results I Delay Voice No Bursting 3.5 ms 5 ms January 2002
S. Choi, Philips

10. Simulation results I Delay Video No Bursting 3.5 ms 5 ms January 2002
S. Choi, Philips

11. Simulation results I Throughput video streams No Bursting 3.5 ms 5 ms
January 2002
Simulation results I
Throughput video streams
No Bursting
3.5 ms
5 ms
S. Choi, Philips

12. Simulation scenario II
January 2002
Simulation scenario II
EDCF parameters:
S. Choi, Philips

13. Simulation results II Global Throughput 3.5 ms 5 ms
January 2002
Simulation results II
Global Throughput
3 frames of video per TXOP
2 frames of video per TXOP
3.5 ms
5 ms
S. Choi, Philips

14. Simulation results II Data Dropped 3.5 ms 5 ms January 2002
S. Choi, Philips

15. Simulation results II Delay Voice 3.5 ms 5 ms January 2002
S. Choi, Philips

16. Simulation results II Delay Video 3.5 ms 5 ms January 2002
S. Choi, Philips

17. Simulation scenario III
January 2002
Simulation scenario III
6 QSTAs, 1 priority
Traffic patterns:
3 QSTAs for each set of traffic pattern
Network overloaded
S. Choi, Philips

18. Simulation results III
January 2002
Simulation results III
Throughput - No Bursting
Video 1
Video 2
S. Choi, Philips

19. Simulation results III
January 2002
Simulation results III
Throughput - 7 ms TXOP
Video 1
Video 2
S. Choi, Philips

20. January 2002
Conclusions
EDCF TXOP Bursting increases global throughput when the network is highly loaded
It reduces the global delay
It may increase the delay of streams with low load. This delay can be reduced by adapting the EDCF parameters (as shown in scenario II)
Provides bandwidth fairness among queues with the same priority and different frame sizes (as shown in scenario III)
S. Choi, Philips

21. January 2002
Conclusions II
In general, we observe a better performance in scenario II in terms of throughput and delay due to a lower probability of collision between QSTAs
The HCF polled access performance should not be affected since the HC controls the duration of the EDCF TXOP
Minimum complexity added optionally as EDCF TXOP bursting will be optional !
S. Choi, Philips