At today’s meeting it was again discussed that Beacons should be explicitly allowed to transmit after PIFS. It was expressed that many APs do it anyway and also that the Spec is unclear.
A proposed resolution was to add Beacons to the list of PIFS allowed at 10.3.2.3.4
I am against this for the following reasons:
1. The Standard is clear that AC_VO shall be used for Beacons.
10.2.3.2 P1710L34 clearly states that AC_VO shall be used for Management Frames that are not individually addressed.
AND for QMF (QoS Management Frames), Table 11-16 P2434L43 clearly states Beacons go at AC_VO.
2. AC-VO is effectively PIFS 25% of the time anyway.
3. Why reward “bad behavior”? Many devices may cheat on EDCA back-off (as has been reported several times) but we do not say “OK do what you like”.
4. It is a major change to an operation that creates two distinct classes of APs. AC_VO has effectively worked for 15 years or so.
5. As acknowledged in the proposed addition to the PIFS list, this may make things worse. We are then effectively saying EDCA is not working. Contention is a basic part of 802.11, changing this for Beacons is the thin edge of the wedge (see #3)
6. Simply adding Beacons to the PIFS list does not work either; further changes would be required at 10.2.3.2, and 11.24.1.2. Then, I believe we open a new can of worms.
In addition I have not heard any argument that is persuasive that we need to do this. Does it make us look better or worse in the eyes of other users of the band? Does it not look suspicious that we make such a (major) change now that removes contention for a packet that is prevalent in the medium?
Hence, I am against making a change that specifically allows beacons at PIFS. Beacons at AC_VO is fine, and has been for 15 years.
Thanks
Graham
From: Dorothy Stanley [mailto:dstanley1389@xxxxxxxxx]
Sent: Wednesday, September 16, 2020 9:21 AM
To: STDS-802-11-TGM@xxxxxxxxxxxxxxxxx
Subject: Re: [STDS-802-11-TGM] Updated version of the resolution to CID 5018 (1454/r2)
--- This message came from the IEEE 802.11 Task Group M Technical Reflector ---
Updated version of the resolution to CID 5018 (Table D-4 for 802.11ah STAs) with changes discussed on today's call:
--
To unsubscribe from the STDS-802-11-TGM list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGM&A=1
To unsubscribe from the STDS-802-11-TGM list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGM&A=1