Re: [STDS-802-11-TGBE] Multi-AP set definition discussion

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

HI Cheng Chen,

Thanks for your comment. See my feedback in line.

Best Regards

Yonggang Fang

ZTE (TX)

Original Mail

Sender: Chen,Cheng <cheng.chen@xxxxxxxxx>

To: STDS-802-11-TGBE@xxxxxxxxxxxxxxxxx <STDS-802-11-TGBE@xxxxxxxxxxxxxxxxx>;

Date: 2020/07/19 21:53

Subject: Re: [STDS-802-11-TGBE] Multi-AP set definition discussion

Hi Yonggang ,

Thanks for initiating the discussions.

I think we are aligned on the point that we need to define a “super set” (Multi-AP Candidate Set in DCN 1961, 617, Coordinated AP set in DCN 596 ) that is relatively static and include all APs that could potentially initiate or participate in Multi-AP transmissions. The primary difference is that whether we need another dynamic set to define the APs which actually participate in a TXOP . As I commented last time, I do not think we need to define such a dynamic set which would vary from TXOP to TXOP . The reasons are as follows.

When we already define a super set of APs that could potentially perform Multi-AP transmissions, the APs would know the capabilities of the other APs in the same set because we already agreed that there will be capabilities advertisement.

An EHT AP supporting the Multi-AP coordination can send a frame (e.g., Beacon or other management frame) including capabilities of Multi-AP transmission schemes [1].

Therefore, once an AP capable of being a sharing AP obtains a TXOP , it can initiate some form of Multi-AP transmission with other APs in the same Coordinated AP Set based on the capabilities it learned. At the end of the day, we will anyway need to define a Multi-AP Trigger frame or Multi-AP Announcement frame at the start of the TXOP for the sharing AP to indicate which shared APs it would like to perform the Multi-AP operations with. This frame would explicitly identify those participating APs in the shared TXOP . In this sense, I do not see any need to define a Multi-AP Active/Operation set particularly for each TXOP .

Think about similar scenarios in single-AP case. An AP learn the capabilities of all STAs . Whenever an AP wants to perform some type of transmissions to a set of STAs , it will automatically select the target STAs based on the capabilities. But did we define a STA Active/Operation set for each TXOP for each operation? For example, when an AP wants to transmit DL OFDMA to a set of STAs , did we define a STA Active/Operation set for DL OFDMA ? Similarly, we did not define a STA set for STAs supporting 160 MHz; we did not define a STA set for STAs supporting 2 SS; we did not define a STA set for STAs supporting BQR…If we need to define a STA/AP Active/Operation Set for every single operation that may dynamically change in every single TXOP , think about how many such AP Active/Operation sets we will end up with.

[YG ] The Multi-AP is different from the single AP. In Multi-AP, a STA could be served by multiple member APs. Therefore Multi-AP needs the coordination of transmissions on the shared resources among the multiple member APs. When the set of multi-APs serve different STAs, it is possible that some member APs from the "candidate AP set" serves one STA, while other member APs serves another STA in the TXOP . Therefore it needs to define different AP subsets within the candidate AP set to distinguish them for serving different STAs.

Best,

Cheng

From: Yonggang Fang <yfang@xxxxxxxxx>

Sent: Sunday, July 19, 2020 3:34 PM
To : STDS-802-11-TGBE@xxxxxxxxxxxxxxxxx
Subject: [STDS-802-11-TGBE] Multi-AP set definition discussion

Hi Cheng Chen, Oren and all,

I would like to use the email thread to discuss AP candidate set related to contributions (1961r4, 596r0 and 617r2) based on the action in 802.11be joint meeting.

In the 1961, it proposes two types of multi-AP sets

•Multi-AP Candidate Set : a set of APs are formed statically within a coverage area, and can discover each other, establish a connection and share the frequency and time resources.

•Multi-AP Active Set: a subset of the multi-AP candidate set, and formed dynamically to communicate to a STA or a group of STAs within a TXOP .

In 617, it proposes two types of AP sets

•Multi-AP Candidate Set (M-AP-CS) is established by a Coordinator AP and contains the following participants:

–The Coordinator AP

–One or more Coordinated AP(s) that has a reliable link with the Coordinator AP

Coordinator AP and Coordinated AP(s) associated STA’s who are targeted to participate in Multi-AP Operation procedures.

•Multi-AP Operation Set (M-AP-OS)is a dynamic sub group of M-AP-CS and include the following participants:

–The Sharing AP who obtained TXOP to be utilized for Multi-AP Transmission

–Shared AP(s) and STA(s) that participate in the upcoming Multi-AP Transmission.

In 596, it proposes one Multi-AP set, i.e. AP candidate or coordinated set

•A Coordinated AP Set is a set ofAPs that can initiate or participate in coordinated AP transmissions.

•An AP in a Coordinated AP Set can participate as a shared AP in coordinated AP transmission initiated by a sharing AP in the same Coordinated AP Set.

•At least one AP in a Coordinated AP Set shall be capable of being a sharing AP.

I think a couple of issues to be clarified:

1) one Multi-AP set or two Multi-AP sets

2) the name of Multi-AP set(s)

3) how to form the Multi-AP set(s)

Any comment and suggestion?

Best Regards

Yonggang Fang

ZTE (TX)

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