3GPP 24.501 v20.0.0 — the document's own text
5.3.27.3 Core network assistance for low power wake up signal with paging subgrouping (LP-WUSPS)
Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).
The UE supporting LP-WUS and the network supporting LP-WUS may support LP-WUSPS assistance information (see 3GPP TS 23.501 [8]).
If the UE supports LP-WUSPS assistance information, the UE indicates its capability to support LP-WUSPS assistance information during the registration procedure for either initial registration or mobility registration update. If the UE indicates support of LP-WUSPS assistance information the UE can include its UE paging probability information in the Requested LP-WUSPS assistance information IE in the REGISTRATION REQUEST message.
If the UE indicates support of LP-WUSPS assistance information and the network supports and accepts the use of LP-WUSPS assistance information for the UE and the network does not determine to disable LP-WUS for the UE, the network provides to the UE the Negotiated LP-WUSPS assistance information IE, including the LP-WUSPS assistance information, in the REGISTRATION ACCEPT message. The LP-WUSPS assistance information includes the LP-WUSPS paging subgroup ID. The UE NAS layer shall indicate the LP-WUSPS assistance information to the lower layers. The network shall store the UE support indication of LP-WUSPS assistance information and the LP-WUSPS assistance information in the 5GMM context of the UE.
The UE shall use the LP-WUSPS assistance information only if the UE received the Negotiated LP-WUSPS assistance information IE during the last registration procedure for either initial registration or mobility registration update. If the UE did not receive the Negotiated LP-WUSPS assistance information IE during the last registration procedure for either initial registration or mobility registration update, the UE shall delete any existing LP-WUSPS assistance information received from the network.
If the network did not accept the use of LP-WUSPS assistance information during the registration procedure for either initial registration or mobility registration update, the network shall delete the LP-WUSPS assistance information stored in the 5GMM context of the UE, if available.
If the Negotiated LP-WUSPS assistance information IE was provided in the REGISTRATION ACCEPT message of the last registration procedure for either initial registration or mobility registration update, the network can provide updated LP-WUSPS assistance information to the UE by including the Updated LP-WUSPS assistance information IE in the CONFIGURATION UPDATE COMMAND message.