1. Alternate EDCA Parameter Set
July 2009
doc.: IEEE /0048r1
Jan 2010
Alternate EDCA Parameter Set
Date:
Authors:
Alex Ashley, NDS Ltd
Alex Ashley, NDS Ltd

2. July 2009
doc.: IEEE /0048r1
Jan 2010
Abstract
This proposal fulfils the PAR objective of the 11aa task group:
Intra-Access Category prioritization of transport streams by modifying EDCA timing and parameter selection without any requirement for deep packet inspection
This proposal allows the creation of up to 2 extra EDCA parameter sets to facilitate intra-access category prioritization.
Alex Ashley, NDS Ltd
Alex Ashley, NDS Ltd

3. Jan 2010
Use Cases
Prioritize all packets in a video stream above/below another video stream
In EDCA and EDCA-AC modes
The higher priority video has a greater chance of channel access
Alex Ashley, NDS Ltd

4. History Implementation for Intra-AC Differentiated Services
Jan 2010
History
Implementation for Intra-AC Differentiated Services
IEEE /0022r0
Using packet drop precedence for graceful degradation
IEEE /0764r1
Drop Precedence in wireless, wired-wireless networks
IEEE /0264r0
Thursday March 12 TGaa AVB meeting
IEEE /0371r0
Stream Classification Service
IEEE /0725r0
Alex Ashley, NDS Ltd

5. Alternate EDCA Parameter Set
Jan 2010
Alternate EDCA Parameter Set
Up to two extra EDCA parameter records
AAC_VI, AAC_VO
Signalled in beacon, probe response, (re)association response
Similar structure to EDCA (WMM) Parameter Set
Alternate Priority Info field used to indicate presence of AAC VI/VO
Alex Ashley, NDS Ltd

6. Alternate EDCA Parameter Set
Jan 2010
Alternate EDCA Parameter Set
User Priority -> AC mapping expanded to use these extra EDCA parameters, when supported
Frames are still sent using existing four EDCAF
Extra ACs map to existing EDCAF for transmission
Alex Ashley, NDS Ltd

7. Frames are sent using existing four EDCAF
Jan 2010
Frames are sent using existing four EDCAF VO VI BE BK
Mapping to
Access Category
Transmit queues
for ACs
EDCA functions with internal collision resolution
(MSDU, UP)
AC_BK
AC_BE
AC_VI
AAC_VI
AC_VO
AAC_VO
Scheduler gives higher priority to MSDU from the highest UP
Figure 9-17—Reference implementation model
Alex Ashley, NDS Ltd

8. Stream Classification Service Interaction
July 2009
Month Year
doc.: IEEE yy/xxxxr0
doc.: IEEE /0048r1
Jan 2010
Stream Classification Service Interaction
The Intra-Access Category Priority element can be used to select use of the alternate EDCA parameter set for a classified stream
Removes need to always use table 9-1 mapping
For an accepted SCS,
the AP shall process subsequent unicast MSDUs that match the classifier specified in the SCS Descriptor. The processing of matching MSDUs depends upon the access policy assigned to the MSDU:
For MSDUs that are not part of a TS, the User Priority subfield of the Intra-Access Priority element is used as the UP of these MSDUs.
For MSDUs that are not part of a TS, or MSDUs that are part of a TS that uses EDCA or HEMM as the Access Policy, the Alternate Priority subfield of the Intra-Access Priority element is used to select the EDCA Parameter Set for these MSDUs, if the MIB attribute dot11RobustAVStreamingAlternateEDCAEnabled is true.
All matching MSDUs are tagged with their drop eligibility using the value from the Drop Eligibility subfield of the Intra-Access Priority element
Slide 8
Alex Ashley, NDS Ltd
Page 8
Alex Ashley, NDS Ltd
John Doe, Some Company

9. Changes from previous proposal
Jan 2010
Changes from previous proposal
Shorter Alternate EDCA Parameter Set
AAC_BE and AAC_BK removed. AAC_VI / AAC_VO only included in element when supported
Removed need for extra EDCAF
Makes it possible to implement on existing h/w
Removed requirement to use CL for AAC_VI
Controlled Load (CL) has defined meaning in enterprise networks
Added default EDCA parameters for AAC_VI and AAC_VO
Same as AC_VI and AC_VO (to allow for implementation on existing h/w that can’t support extra EDCA timing parameters)
Alex Ashley, NDS Ltd

10. July 2009
doc.: IEEE /0048r1
Jan 2010
Conclusions
This proposal fulfils the PAR objective of the 11aa task group:
Intra-Access Category prioritization of transport streams by modifying EDCA timing and parameter selection without any requirement for deep packet inspection
Creation of up to two extra EDCA parameter sets to facilitate intra-access category prioritization
This proposal scales from existing h/w that just add prioritized queuing in front of existing EDCA, to implementations providing full per-AC queuing and timing
Alex Ashley, NDS Ltd
Alex Ashley, NDS Ltd

11. References 11-09-0850r1 “Alternate EDCA Parameter Set”
Jan 2010
References
r1 “Alternate EDCA Parameter Set”
r0 “Stream Classification Service”
11-09/0022r0 “Implementation for Intra-AC Differentiated Services”
11-08/0764r1 “Using packet drop precedence for graceful degradation”
11-09/0264r0 “Drop Precedence in wireless, wired-wireless networks”
11-09/0371r0 “TGaa minutes for Vancouver”
Alex Ashley, NDS Ltd

12. July 2009
doc.: IEEE /0048r1
Jan 2010
Motion
Move to incorporate the text changes in aa-alternate-edca-parameter-set.doc into the TGaa draft
Moved:
Seconded:
Result:
Alex Ashley, NDS Ltd
Alex Ashley, NDS Ltd