Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

Re: [STDS-802-11-TGBE] 11-20-0066-03-00be-multi-link-tim



Hi Yunbo,

 

Thank you very much for your suggestion.

Not sure if I understand your suggestion correctly, but it looks you want to allow assigning AID per each TID for a non-AP MLD.

But in my opinion, the most frequent and meaningful usage case is that all TIDs are mapped to all links, which even doesn’t require any TID to link mapping indication at all.

Also, TID to link mapping can happen more frequently during a non-AP MLD’s association with an AP MLD.

So, I’m not quite convinced of having many AIDs for a non-AP MLD for this purpose.

 

Thanks,

Young Hoon

 

 

From: Liyunbo <liyunbo@xxxxxxxxxx>
Sent: Tuesday, May 26, 2020 7:06 PM
To: Young Hoon Kwon <younghoon.kwon@xxxxxxx>; STDS-802-11-TGBE@xxxxxxxxxxxxxxxxx
Subject:
: [STDS-802-11-TGBE] 11-20-0066-03-00be-multi-link-tim

 

Hi Yong Hoon,

 

Thanks for the reply. I have several further comments/questions:

 

For your design, when a TID is mapping to multiple links, how does the AP MLD choose which links to set to 1? If AP set all mapped links to 1, then STA MLD needs to wake up all mapped links every time (because STA MLD doesn’t know the TID information). It may not efficient to save power for STA MLD.

 

As I understanding, currently there are two types of indication. Type 1 is assign a AID for one TID, and TID grouping can further reduce the overhead. Type 2 is assign a AID for STA MLD, and then indicate link or TID for the STA MLD. Type 2 is what you proposed. For me, Type 1 also has its advantages:

1)       it doesn’t need to introduce new LMB field (or elements),

2)       different STA MLD can has different number of signaling bits, based on the number of TIDs it supports. So for a STA MLD it only needs n1 bits for signaling in Type1, n1=the number of TIDs it support. While a STA MLD needs (1+n2) bits for signaling in Type 2, n2 is the maximum number of TIDs that all associated STA MLD supports. So for signaling overhead point of view, which type is more efficient will depends on scenarios.

 

So if you want to run SP in next MAC meeting, can I suggest to change one AID for a STA MLD to “one or more AID(s) for a STA MLD” in straw poll before fully discussed?

 

Regards,

Yunbo

 

发件人: Young Hoon Kwon [mailto:younghoon.kwon@xxxxxxx]
发送时间: 2020526 12:47
收件人: Liyunbo <liyunbo@xxxxxxxxxx>; STDS-802-11-TGBE@xxxxxxxxxxxxxxxxx
主题: RE: [STDS-802-11-TGBE] 11-20-0066-03-00be-multi-link-tim

 

Hi Yunbo,

 

Thank you very much for your comments.

Please see my answers in line below.

 

BR,

Young Hoon

 

From: Liyunbo <liyunbo@xxxxxxxxxx>
Sent: Sunday, May 24, 2020 7:48 PM
To: STDS-802-11-TGBE@xxxxxxxxxxxxxxxxx
Subject: [STDS-802-11-TGBE] 11-20-0066-03-00be-multi-link-tim

 

Hi Young Hoon,

 

Thanks for sharing the presentation 0066. Since we didn’t have time to fully discussion, I use this e-mail thread to continue the discussion. I have two questions, would you please clarify, thanks.

 

1)       In side 3, you mentioned “The AP MLD needs to indicate which link the AP MLD has buffered BU to transmit, especially when different TIDs are mapped to different links”. In MLD, when the BU of one TID is mapping to multiple links, how AP decide which links to indicated in LMB? When the STA MLD receive the signaling, it still doesn’t know what TID the BU belongs to, so how the STA MLD decide to wake up on which links? I think may be a better way is to indicate the TID, so the STA MLD can clearly know it should wakeup on which links (base on the Traffic requirement, battery level, and other internal conditions). Because power save is an issue for at STA MLD side, not at AP MLD side, so it may be better to STA MLD to do the decision. During the teleconference, many people asked the similar questions in the chat window.

[YKWON] As I mentioned during the call, indicating TID instead of link can also be another option. But, the issue is that overhead. Due to overhead limit I would expect that one bit indication for each TID is too much, and thus, a set of TIDs may need to be grouped together for the indication. In this case, as there’s still uncertainty which TID to be used, similar issues are still there. We can certainly have further discussion on how to indicate TID/link when we first agree on the first step of having per-MLD level AID.

 

2)       In your design, each legacy STA  also needs to use 3 bit in LMB subfield. So in a scenario that only a small percent of STAs are EHT MLD, AP needs to still need to allocate 3 bits for each legacy STA in LMB subfield. It will be a large overhead. It has similar issue for STA MLD that only mapping on one or two links.

[YKWON] The way I showed in this slides deck is just an example of doing TID to link mapping, and there’s other ways of improving/optimizing the overall performance on link indication side. For example, an AP MLD can assign AIDs greater than a threshold for non-AP MLDs (AID for legacy STAs can be assigned to be less than the threshold in this case), and the AP MLD indicate the LMB only for those STAs that AID is greater than the threshold. I didn’t elaborate on the link mapping side a lot as we think at least in R1 the most common operation scenario is the case that all TIDs are mapped to all links.

 

 

Regards,

Yunbo


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