| Thread Links | Date Links | ||||
|---|---|---|---|---|---|
| Thread Prev | Thread Next | Thread Index | Date Prev | Date Next | Date Index |
|
Hi Ahmed, Thanks for your responses. I have added my reasonings for recommending negotiation based channel switching: 1. As you are probably well aware, 6GHz operation was added at a late stage of 11ax (After D2.0) and not all aspects were fully discussed (including TDLS off-channel switching). For that reason, just because this was not included in 11ax,
is not a valid reason for this not be considered for 11be. As per 11.20.6.2 (General behavior on the off-channel), in the DFS band, the TDLS STA initiating the channel switch has to be the DFS Owner: The TDLS peer STA initiating the switch to the channel where radar detection is required by regulation shall be the
DFS owner. However for the 6 GHz band, the onus of checking AFC (whether a channel may be used) is on the AP and hence I think the simplest solution is for the STAs to check with the AP. The alternative would be the STA itself checks with AFC (which
is probably out of scope of .11). Also, channel switching is not frequent, so the overhead of checking with AP is minimal. Btw, using your own argument, why is the “channel switch notification” required then? What is the AP expected to do with this notification? It is not very clear from your CR. 2. I was referring to other non-AP MLD’s NSTR links with the AP (not the non-AP MLD performing the channel switch). >> We wanted to follow the baseline of TDLS operation by making it as independent as possible from AP's control. The concern is that if we allow negotiation on
channel switch and AP keeps rejecting the channel switch, then TDLS link may deteriorate especially if it carries latency-sensitive traffic. I agree that as much as possible we should follow the baseline, but if the AP rejects the channel switch request, there will likely be a very good good reason for it (e.g., the channel is restricted/licensed). The cost of a P2P link deteriorating
is much less than the cost of illegal usage of a licensed channel in my humble opinion. If the quality of the off-channel link is very important, I would think that is an even stronger reason to make sure that it is a good channel to switch to. Regards, Rojan From: Ahmed Ibrahim <0000162d12c1fcf3-dmarc-request@xxxxxxxxxxxxxxxxx>
Hi Rojan, Thank you for your timely review of the CR. I have two follow-up questions regarding what you are proposing of making the channel switching negotiation-based instead of announcement-based. 1- Our understanding for AFC/DFS issue is that it is still valid for legacy TDLS (introduced in 11ax). TDLS channel switching between STAs is notification-based without checking
back with the AP. This is why we followed the same route as 11ax of making channel switching notification-based. Why do you think that AFC/DFS issue is specific to 11be but not in 11ax? 2- Why wouldn't the non-AP MLD be aware of NSTR conditions? Non-AP MLD should have knowledge about NSTR link pairs and channels. It may not know the status of the other link
in the NSTR link pair but this is why the notification is used. We wanted to follow the baseline of TDLS operation by making it as independent as possible from AP's control. The concern is that if we allow negotiation on channel switch
and AP keeps rejecting the channel switch, then TDLS link may deteriorate especially if it carries latency-sensitive traffic. Please let me know your thoughts. Thank you. Ahmed On Wednesday, April 13, 2022, 09:34:37 PM MDT, Rojan Chitrakar <rojan.chitrakar@xxxxxxxxxxxxxxxx> wrote:
Hi Ahmed, Thanks for sharing, I have made some comments, please see attached. For ease of discussion, I have also copied the comment here: Not clear what is AP MLD’s action upon receiving the TDLS Channel Switch Notification frame? I think a simple “notification” is not enough,
a two way “permission” frame exchange would be better, i.e., the non-AP seeks permission from the AP-MLD prior to switching to an TDLS off-channel. This is especially true for the 6 GHz band, or even in 5 GHz DFS channels, in which the channel needs to be
checked prior to using the channel (e.g., with AFC). Even for “regular” channels/links, it would be good to check with AP prior to switching, e.g., the link may be part of a NSTR link pair, and non-AP STA may not be aware etc. Since AP would have such knowledge,
it would make sense that the AP decides whether an off-channel may be used (rather than the non-AP checking it self). For this reason, highly encourage to consider two way explicit “permission” exchange with the AP rather than a simple “notification”. Regards, Rojan From: Ahmed Ibrahim <0000162d12c1fcf3-dmarc-request@xxxxxxxxxxxxxxxxx>
Hi Everyone, I have uploaded a CR for some TDLS CIDs (CIDs 4033, 4590, 4593). Would you please let me know if you have comments/suggestions/questions to make convergence faster? Thank you. Ahmed To unsubscribe from the STDS-802-11-TGBE list, click the following link:
https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGBE&A=1 To unsubscribe from the STDS-802-11-TGBE list, click the following link:
https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGBE&A=1
To unsubscribe from the STDS-802-11-TGBE list, click the following link:
https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGBE&A=1 To unsubscribe from the STDS-802-11-TGBE list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGBE&A=1 |