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Re: [STDS-802-11-TGBN] UHR eCU: table showing when & where to carry the UHR Parameters Update element


Gentle reminder - @TTT members for enhanced critical updates feature


From: Abhishek Patil <appatil@xxxxxxxxxxxxxxxx>
Sent: Wednesday, October 28, 2026 12:28 AM
To: STDS-802-11-TGBN@xxxxxxxxxxxxxxxxx <stds-802-11-tgbn@xxxxxxxxxxxxxxxxx>
Subject: UHR eCU: table showing when & where to carry the UHR Parameters Update element


Hi TTT members for enhanced critical updates feature,

Based on several requests and some offline discussions, I have prepared the following two tables that show the expected behavior at the AP side during different phases of an on-going critical updates procedure. 

The first table shows when & where the UHR Parameters Updates element is included within various mgmt. frames of a UHR AP while an eCU procedure is on-going.


Frame
From start of advance notification until the effective TBTT
From the effective TBTT until first DTIM TBTT
After the first DTIM TBTT (if PUNI≠0)
Otherwise (i.e., when PUNI == 0)
Remark
Beacon and Probe Response (affected or reporting AP)
ECUF = 1
ECUF = 0
ECUF = 1 until the first DTIM Beacon after the effective TBTT; 0 thereafter.
Beacon sent by the affected AP
UPUE outside Basic MLE; EAUI (in Common Info of Basic MLE ) = 1
UPUE not included; EAUI (in Basic, MLE Common Info) = 0

UHR Operation element carried in the Beacon of affected AP does not include the UHR Operation Parameters field.
Beacon of a reporting AP
UPUE within affected link's profile; EAUI (in RNR TBTT Information field of affected link) = 1
UPUE not included; EAUI (in RNR TBTT Information field of affected link) = 0
Probe Response sent by the affected AP
UPUE outside Basic MLE; EAUI (in Common Info of Basic, MLE) = 1
UPUE not included; EAUI (in Common Info of Basic MLE) = 0
UHR Operation element carried in Probe Response of affected AP includes UHR Operation Parameters field which contains the latest parameters at and after the effective TBTT. Therefore, it is redundant to include UPUE after effective TBTT.
Probe Response sent by a reporting AP (not carrying complete profile of affected link)
UPUE within affected link's profile; EAUI (in RNR TBTT Information field of affected link) = 1
UPUE not included; EAUI (in RNR TBTT Information field of affected link) = 0
UHR Operation element is not present in a partial profile of the affected carried within the Basic MLE contained in the beacon for the reporting AP.
Multi-link probe response sent by a reporting AP (carrying complete profile of affected link)
UPUE within affected link's profile;
EAUI (in RNR TBTT Information field of affected link) = 1
UPUE not included; EAUI (in RNR TBTT Information field of affected link) = 0
UHR Operation element is present in a complete profile of the affected carried within the Basic MLE contained in the beacon for the reporting AP. Therefore, it is redundant to include UPUE after the effective TBTT.
(Re)Association Response sent by affected AP
UPUE outside Basic MLE; EAUI (in Common Info of Basic, MLE) = 1
UPUE not included; EAUI (in Common Info of Basic MLE) = 0
Response carries a complete profile (which includes a complete UHR Operation element) for every link. Therefore, it is redundant to include UPUE after the effective TBTT.
(Re)Association Response sent by reporting AP
UPUE within affected link's profile in Basic MLE
UPUE not included; EAUI (in STA Info of Basic MLE) = 0
Link Reconfiguration Response (adding affected link)
UPUE within affected link's profile in Basic MLE
Added link's profile is complete and carries the full UHR Operation element once the update takes effect. Therefore, it is redundant to include UPUE after the effective TBTT.

PUNI

= Post Update Notification Interval

UPUE
= UHR Parameters Update element
ECUF
= Enhanced Critical Updates Flag

MLE
 = Multi-Link element
EAUI
= Enhanced All Updates Included

RNR
= Reduced Neighbor Report element


The second table shows the inclusion of CU information in PVB of TIM element at different times. 

Scenario
From start of advance notification until the effective TBTT
From that TBTT until the Update Indication In TIM Interval has elapsed
After the Update Indication In TIM Interval has elapsed, until the next advance notification begins
Critical update at any AP affiliated with the same AP MLD as the affected AP*, including the affected AP itself (see NOTE)
Present (Critical Update Type = 1; Critical Update Counter incremented once)
Not included, unless the Partial Virtual Bitmap field already starts before bit 56
*  “Any AP affiliated with the same AP MLD as the affected AP” includes the affected AP itself. The affected AP may correspond to the transmitted BSSID of a multiple BSSID set, in which case there is a single TIM element for the entire set, and a critical update at any nontransmitted BSSID of that set (if applicable) is reflected in that single TIM element.
 
I will be including these tables in an upcoming CR doc. Sharing it beforehand to solicit any suggestions/feedback​.

Regards,
Abhi


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