3GPP 24.501 v20.0.0 — the document's own text

5.4.4.2 Generic UE configuration update procedure initiated by the network

Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).

The AMF shall initiate the generic UE configuration update procedure by sending the CONFIGURATION UPDATE COMMAND message to the UE.

The AMF shall in the CONFIGURATION UPDATE COMMAND message either:

include one or more of the following parameters: 5G-GUTI, TAI list, allowed NSSAI that may include the mapped S-NSSAI(s), LADN information, extended LADN information, service area list, MICO indication, NITZ information, configured NSSAI that may include the mapped S-NSSAI(s), NSSRG information, S-NSSAI location validity information, S-NSSAI time validity information, rejected S-NSSAI(s) in the Rejected NSSAI IE or in the Extended rejected NSSAI IE, network slicing subscription change indication, operator-defined access category definitions, SMS indication, "CAG information list", UE radio capability ID, 5GS registration result, UE radio capability ID deletion indication, truncated 5G-S-TMSI configuration, T3447 value, "list of PLMN(s) to be used in disaster condition", disaster roaming wait range, disaster return wait range, PEIPS assistance information, the priority indicator, service-level-AA container, the NSAG information, alternative NSSAI, partially allowed NSSAI, partially rejected NSSAI, on-demand NSSAI, feature authorization indication, discontinuous coverage maximum time offset, access technology utilization control information, LP-WUSPS assistance information, or LP-WUS status;
include the Configuration update indication IE with the Registration requested bit set to "registration requested"; or
include a combination of both a) and b).

If the UE is registering or registered for onboarding services in SNPN, the serving SNPN shall not provide the configured NSSAI, the allowed NSSAI or the rejected NSSAI to the UE.

If the UE supports extended rejected NSSAI, the rejected S-NSSAI(s) shall be included in the Extended rejected NSSAI IE. Otherwise, the rejected S-NSSAI(s) shall be included in the Rejected NSSAI IE.

If the Extended rejected NSSAI IE is included in the CONFIGURATION UPDATE COMMAND message and mapped S-NSSAI(s) are required as specified in clause 4.6.1, the AMF shall provide mapped S-NSSAI(s) for the rejected NSSAI.

If an acknowledgement from the UE is requested, the AMF shall indicate "acknowledgement requested" in the Acknowledgement bit of the Configuration update indication IE in the CONFIGURATION UPDATE COMMAND message and shall start timer T3555. Acknowledgement shall be requested for all parameters except when only NITZ information is included.

To initiate parameter re-negotiation between the UE and network, the AMF shall indicate "registration requested" in the Registration requested bit of the Configuration update indication IE in the CONFIGURATION UPDATE COMMAND message.

NOTE 1: Generic UE configuration update procedure can be initiated by the AMF for updating the emergency number list, the extended emergency number list or both by indicating "registration requested" in the Registration requested bit of the Configuration update indication IE in the CONFIGURATION UPDATE COMMAND message to the UE.

If a new allowed NSSAI information or AMF re-configuration of supported S-NSSAIs requires an AMF relocation, the AMF shall indicate "registration requested" in the Registration requested bit of the Configuration update indication IE and include the Allowed NSSAI IE in the CONFIGURATION UPDATE COMMAND message.

If the AMF includes a new allowed NSSAI in the CONFIGURATION UPDATE COMMAND message and the subscription information includes the NSSRG information, then the S-NSSAIs of the allowed NSSAI shall be associated with at least one common NSSRG value. If the network has pending NSSAI, the S-NSSAIs in the pending NSSAI and allowed NSSAI shall be associated with at least one common NSSRG value.

If the AMF includes a new partially allowed NSSAI and the new partially allowed NSSAI requires an AMF relocation, the AMF shall indicate "registration requested" in the Registration requested bit of the Configuration update indication IE and include the Partially allowed NSSAI IE in the CONFIGURATION UPDATE COMMAND message.

If the AMF includes a new configured NSSAI in the CONFIGURATION UPDATE COMMAND message and the new configured NSSAI requires an AMF relocation as specified in 3GPP TS 23.501 [8], the AMF shall indicate "registration requested" in the Registration requested bit of the Configuration update indication IE in the message.

If the AMF includes a new configured NSSAI in the CONFIGURATION UPDATE COMMAND message, the subscription information includes the NSSRG information, and the UE has set the NSSRG bit in the 5GMM capability IE of the REGISTRATION REQUEST message to:

"NSSRG supported", then the AMF shall include the NSSRG information in the CONFIGURATION UPDATE COMMAND message; or
"NSSRG not supported", then the configured NSSAI shall include one or more S-NSSAIs each of which is associated with all the NSSRG value(s) of the default S-NSSAI(s), or the configured NSSAI shall include, based on the indication received from the UDM as specified in 3GPP TS 23.501 [8], all subscribed S-NSSAIs even if these S-NSSAIs do not share any common NSSRG value.

If the AMF needs to update the NSSRG information and the UE has set the NSSRG bit to "NSSRG supported" in the 5GMM capability IE of the REGISTRATION REQUEST message, then the AMF shall include the new NSSRG information in the CONFIGURATION UPDATE COMMAND message.

If the AMF includes a new NSSRG information in the CONFIGURATION UPDATE COMMAND message and the AMF determines that the UE needs to provide a new requested NSSAI due to no NSSRG value common to all the S-NSSAI(s) of the allowed NSSAI based on the new NSSRG information, then the CONFIGURATION UPDATE COMMAND message shall indicate "registration requested" in the Registration requested bit of the Configuration update indication IE.

If the UE supports S-NSSAI time validity information and the AMF needs to update the S-NSSAI time validity information, then the AMF shall include the new S-NSSAI time validity information in the CONFIGURATION UPDATE COMMAND message.

If the AMF needs to update the S-NSSAI location validity information toward a UE which has set the SLVI bit to "S-NSSAI location validity information supported" in the 5GMM capability IE of the REGISTRATION REQUEST message, then the AMF shall include the new S-NSSAI location validity information in the CONFIGURATION UPDATE COMMAND message.

If the CONFIGURATION UPDATE COMMAND message is initiated only due to changes to the allowed NSSAI and these changes require the UE to initiate a registration procedure, but the AMF is unable to determine an allowed NSSAI for the UE as specified in 3GPP TS 23.501 [8], then the CONFIGURATION UPDATE COMMAND message shall indicate "registration requested" in the Registration requested bit of the Configuration update indication IE, and shall not contain any other parameters.

If the slice deregistration inactivity timer has expired, the UE does not support network slice usage control and the AMF removes the on-demand S-NSSAI from the allowed NSSAI over the corresponding access type, the AMF shall include the new allowed NSSAI in the CONFIGURATION UPDATE COMMAND message.

If:

the AMF needs to enforce a change in the restriction on the use of enhanced coverage or use of CE mode B as described in clause 5.3.18;
the AMF decides to inform a UE in 5GMM-CONNECTED mode and registered for disaster roaming services, that a disaster condition is no longer applicable; or
the AMF needs to redirect the UE to EPC as described in clause 4.8.4A.2;

NOTE 1A: The case of the AMF triggering a generic UE configuration update procedure to inform a UE registered for disaster roaming services that a disaster condition is no longer applicable, is only applicable for a UE already in 5GMM-CONNECTED mode.

the AMF shall indicate "registration requested" in the Registration requested bit of the Configuration update indication IE and "release of N1 NAS signalling connection not required" in the Signalling connection maintain request bit of the Additional configuration indication IE in the CONFIGURATION UPDATE COMMAND message.

If the AMF needs to change the SMSF associated with the UE, the AMF may indicate "registration requested" in the Registration requested bit of the Configuration update indication IE and "release of N1 NAS signalling connection not required" in the Signalling connection maintain request bit of the Additional configuration indication IE in the CONFIGURATION UPDATE COMMAND message.

If a network slice-specific authentication and authorization procedure for an S-NSSAI is completed as a:

success, the AMF shall include this S-NSSAI in the allowed NSSAI over the same access of the requested S-NSSAI or in the partially allowed NSSAI over 3GPP access; or
failure, the AMF shall include this S-NSSAI in the rejected NSSAI for the failed or revoked NSSAA with the rejection cause "S-NSSAI not available due to the failed or revoked network slice-specific authentication and authorization" over either 3GPP access or non-3GPP access.

If authorization is revoked for an S-NSSAI that is in the current allowed NSSAI for an access type, the AMF shall:

provide a new allowed NSSAI to the UE, excluding the S-NSSAI for which authorization is revoked; and
provide a new rejected NSSAI for the failed or revoked NSSAA, including the S-NSSAI in the rejected NSSAI for which the authorization is revoked, with the rejection cause "S-NSSAI not available due to the failed or revoked network slice-specific authentication and authorization".

The allowed NSSAI, the partially allowed NSSAI and the rejected NSSAI shall be included in the CONFIGURATION UPDATE COMMAND message to reflect the result of the procedures subject to network slice-specific authentication and authorization.

NOTE 2: If there are multiple S-NSSAIs subject to network slice-specific authentication and authorization, it is implementation specific if the AMF informs the UE about the outcome of the procedures in one or more CONFIGURATION UPDATE COMMAND messages.

If the AMF includes the Network slicing indication IE in the CONFIGURATION UPDATE COMMAND message with the Network slicing subscription change indication set to "Network slicing subscription changed", and changes to the allowed NSSAI require the UE to initiate a registration procedure, but the AMF is unable to determine an allowed NSSAI for the UE as specified in 3GPP TS 23.501 [8], then the CONFIGURATION UPDATE COMMAND message shall additionally indicate "registration requested" in the Registration requested bit of the Configuration update indication IE and shall not include an allowed NSSAI.

If EAC mode is activated for an S-NSSAI, the AMF shall perform NSAC for the S-NSSAI subject to NSAC before such S-NSSAI is included in the allowed NSSAI in the CONFIGURATION UPDATE COMMAND message. If EAC mode is deactivated for an S-NSSAI, the AMF shall perform NSAC for the S-NSSAI subject to NSAC after such S-NSSAI is included in the allowed NSSAI in the CONFIGURATION UPDATE COMMAND message.

If the UE supports extended rejected NSSAI and the AMF determines that maximum number of UEs reached for one or more S-NSSAI(s) in the allowed NSSAI as specified in clause 4.6.2.5, the AMF shall include the rejected NSSAI containing one or more S-NSSAIs with the rejection cause "S-NSSAI not available due to maximum number of UEs reached" in the Extended rejected NSSAI IE in the CONFIGURATION UPDATE COMMAND message. In addition, the AMF may include a back-off timer value for each S-NSSAI with the rejection cause "S-NSSAI not available due to maximum number of UEs reached" included in the Extended rejected NSSAI IE of the CONFIGURATION UPDATE COMMAND message. To avoid that large numbers of UEs simultaneously initiate deferred requests, the network should select the value for the backoff timer for each S-NSSAI for the informed UEs so that timeouts are not synchronised.

If the UE does not indicate support for extended rejected NSSAI and the maximum number of UEs has been reached, the AMF should include the rejected NSSAI containing one or more S-NSSAIs with the rejection cause "S-NSSAI not available in the current registration area" in the Rejected NSSAI IE and should not include these S-NSSAIs in the allowed NSSAI in the CONFIGURATION UPDATE COMMAND message. In addition, the AMF may based on the network policies start a local implementation specific timer for the UE per rejected S-NSSAI and upon expiration of the local implementation specific timer, the AMF may remove the rejected S-NSSAI from the rejected NSSAI and update to the UE by initiating the generic UE configuration update procedure.

NOTE 3: Based on network policies, the AMF can include the S-NSSAI(s) for which the maximum number of UEs has been reached in the rejected NSSAI with rejection causes other than "S-NSSAI not available in the current registration area".

If the UE has set the NSAG bit to "NSAG supported" in the 5GMM capability IE of the REGISTRATION REQUEST message, the AMF may include the NSAG information IE in the CONFIGURATION UPDATE COMMAND message. Up to 4 NSAG entries are allowed to be associated with a TAI list in the NSAG information IE.

NOTE 3A: How the AMF selects NSAG entries to be included in the NSAG information IE is implementation specific, e.g. take the NSAG priority and the current registration area into account.

NOTE 3B: If the NSAG for the PLMN and its equivalent PLMN(s) have different associations with S-NSSAIs, then the AMF includes a TAI list for the NSAG entry in the NSAG information IE.

If the UE supports network slice replacement and the AMF determines to provide the mapping information between the S-NSSAI to be replaced and the alternative S-NSSAI to the UE, then the AMF shall include the Alternative NSSAI IE, the Allowed NSSAI IE or the Partially allowed NSSAI IE including the alternative S-NSSAI, if not included in the current allowed NSSAI or the current partially allowed NSSAI, and the Configured NSSAI IE including the alternative S-NSSAI, if not included in the current configured NSSAI, in the CONFIGURATION UPDATE COMMAND message. If the AMF determines that the replaced S-NSSAI is available, then the AMF shall provide the updated alternative NSSAI excluding the replaced S-NSSAI and the corresponding alternative S-NSSAI in the Alternative NSSAI IE in the CONFIGURATION UPDATE COMMAND message. If the AMF determines that all the replaced S-NSSAI(s) are available, then the AMF shall provide the Alternative NSSAI IE with Length of Alternative NSSAI contents set to 0 in the CONFIGURATION UPDATE COMMAND message. If the AMF determines that the replaced S-NSSAI is not supported due to the UE moving outside of NS-AoS of the S-NSSAI while the alternative S-NSSAI is available, then the AMF shall provide the updated allowed NSSAI and partially allowed NSSAI, if available, excluding the replaced S-NSSAI, if included, in the allowed NSSAI or partially allowed NSSAI in the CONFIGURATION UPDATE COMMAND message.

If the UE supports partial network slice and the AMF needs to update the partially allowed NSSAI, partially rejected NSSAI or both, then the AMF shall include the Partially allowed NSSAI IE, the Partially rejected NSSAI IE or both, in the CONFIGURATION UPDATE COMMAND message.

If the UE supports network slice usage control and the AMF needs to update the on-demand NSSAI, the AMF shall include the On-demand NSSAI IE in the CONFIGURATION UPDATE COMMAND message.

If the AMF needs to update the LADN information, the AMF shall include the LADN information in the LADN information IE of the CONFIGURATION UPDATE COMMAND message.

If the UE supports LADN per DNN and S-NSSAI and the AMF needs to update the extended LADN information, the AMF shall include the extended LADN information in the Extended LADN information IE of the CONFIGURATION UPDATE COMMAND message.

If:

the UE does not support LADN per DNN and S-NSSAI;
the UE is subscribed to the LADN DNN for a single S-NSSAI only; and
the AMF only has the extended LADN information;

the AMF may decide to provide the LADN service area for that LADN DNN of the extended LADN information as the LADN information and include the LADN information in the LADN information IE of the CONFIGURATION UPDATE COMMAND message.

NOTE 3C: If the LADN service area is configured per DNN and S-NSSAI, in order to serve the UEs that do not support LADN per DNN and S-NSSAI, it is recommended that the LADN DNN is only served by a single S-NSSAI.

NOTE 3D: In case of the UE is subscribed to the LADN DNN for multiple S-NSSAIs, the AMF can treat this as no extended LADN information is available.

NOTE 3E: The AMF allocates the LADN service area and the TAI list associated with the S-NSSAI in the partially allowed NSSAI independently, if applicable.

If the UE does not support LADN per DNN and S-NSSAI and the AMF has neither the LADN information nor the extended LADN information, the AMF shall not provide any LADN information to the UE.

If the AMF needs to update the "CAG information list", the AMF shall include the CAG information list IE or the Extended CAG information list IE in the CONFIGURATION UPDATE COMMAND message.

NOTE 4: If the UE supports extended CAG information list, the CAG information list can be included either in the CAG information list IE or Extended CAG information list IE.

If the UE does not support extended CAG information list, the CAG information list shall not be included in the Extended CAG information list IE.

If the AMF needs to update the "CAG information list", the UE has an emergency PDU session, and the AMF can determine that the UE is in

a CAG cell and none of the CAG-ID(s) supported by the CAG cell is authorized based on the "allowed CAG list" for the current PLMN in the updated "CAG information list"; or
a non-CAG cell and the entry for the current PLMN in the updated "CAG information list" includes an "indication that the UE is only allowed to access 5GS via CAG cells";

the AMF may indicate to the SMF to perform a local release of:

all non-emergency single access PDU sessions associated with 3GPP access;
all MA PDU sessions without a PDN connection established as a user-plane resource and without user plane resources established on non-3GPP access; and
the 3GPP access user plane resources of all those MA PDU sessions with user plane resources established on both accesses.

The AMF shall not indicate to the SMF to release the emergency PDU session. If the AMF indicated to the SMF to perform a local release of:

all single access non-emergency PDU sessions associated with 3GPP access;
all MA PDU sessions without a PDN connection established as a user-plane resource and without user plane resources established on non-3GPP access; and
the 3GPP access user plane resources of all those MA PDU sessions with user plane resources established on both accesses;

the network shall behave as if the UE is registered for emergency services over 3GPP access and shall set the emergency registered bit of the 5GS registration result IE to "Registered for emergency services" in the CONFIGURATION UPDATE COMMAND message.

If the AMF is initiating the generic UE configuration update procedure to indicate to a UE which is registered for disaster roaming services, and which has an ongoing emergency PDU session, that the UE is registered for emergency services as described in clause 4.24, the AMF shall set the emergency registered bit of the 5GS registration result IE to "Registered for emergency services" in the CONFIGURATION UPDATE COMMAND message.

If the AMF:

updated the "CAG information list" to remove one or more CAG-ID(s) authorized based on the Allowed CAG list for the serving PLMN or an equivalent PLMN; or
updated the "CAG information list" to set the "indication that the UE is only allowed to access 5GS via CAG cells" for the serving PLMN or an equivalent PLMN which was not set before,

then upon completion of the configuration update procedure and if the UE does not have an emergency PDU session, the AMF shall initiate the release of the N1 NAS signalling connection according to clause 5.3.1.3.

If the AMF needs to update the truncated 5G-S-TMSI configuration for a UE in NB-N1 mode using control plane CIoT 5GS optimization, the AMF shall include the Truncated 5G-S-TMSI configuration IE in the CONFIGURATION UPDATE COMMAND message.

If the AMF includes a UE radio capability ID deletion indication IE in the CONFIGURATION UPDATE COMMAND message, the AMF shall indicate "registration requested" in the Registration requested bit of the Configuration update indication IE.

If the UE is not in NB-N1 mode and the UE supports RACS, the AMF may include either a UE radio capability ID IE or a UE radio capability ID deletion indication IE in the CONFIGURATION UPDATE COMMAND message.

During an established 5GMM context, the network may send none, one, or more CONFIGURATION UPDATE COMMAND messages to the UE. If more than one CONFIGURATION UPDATE COMMAND message is sent, the messages need not have the same content.

Upon receipt of the result of the UUAA-MM procedure from the UAS-NF, the AMF shall include:

the service-level-AA response with the SLAR field set to:

"Service level authentication and authorization was successful" if the AMF detects the UUAA-MM procedure has succeeded; or
"Service level authentication and authorization was not successful or service level authorization is revoked" if the AMF detects the UUAA-MM procedure has failed;

if the CAA-level UAV ID is provided by the UAS-NF, the service-level device ID with the value set to the CAA-level UAV ID; and;
if a payload is received from the UAS-NF:

the service-level-AA payload with the value set to the payload; and
if a payload type associated with the payload is received, the service-level-AA payload type with the values set to the payload type; and
if the payload type associated with the payload is for C2 authorization payload, the service-level-AA response with C2AR field set to either "C2 authorization was successful" or "C2 authorization was not successful or C2 authorization is revoked" according to the authorization result received from the UAS-NF;

in the Service-level-AA container IE of the CONFIGURATION UPDATE COMMAND message.

NOTE 5: UAS security information can be included in the UUAA payload by the USS as specified in 3GPP TS 33.256 [24B].

NOTE 5A0: A list of USS addresses, where each entry contains a USS address and a corresponding geographical area, can be included in the UUAA payload by the USS as specified in 3GPP TS 23.256 [6AB].

NOTE 5A: The service-level-AA payload associated with the payload type "C2 authorization payload" can include pairing information for the direct C2 communication, or the security information as specified in TS 33.256 [24B], or both.

NOTE 6: If the AMF receives the HTTP code set to "4xx" or "5xx" as specified in 3GPP TS 29.500 [20AA] or the AMF detects that the UUAA-MM failure as specified in 3GPP TS 29.256 [21B], then the AMF considers the UUAA-MM procedure has failed.

If the AMF needs to deliver to the UE the UUAA revocation notification received from the UAS-NF, the AMF shall include the service-level-AA response with SLAR set to "Service level authentication and authorization was not successful or service level authorization is revoked" in the Service-level-AA container IE of the CONFIGURATION UPDATE COMMAND message.

If the UE supports UAS services and UAS services become enabled for the UE (e.g. because of the aerial subscription becomes a part of the UE subscription data retrieved from the UDM), the AMF may include the service-level-AA service status indication with UAS field set to "UAS services enabled" in the Service-level-AA container IE of the CONFIGURATION UPDATE COMMAND message.

If the UE supports MINT, MINT-EPS or both, the AMF may include the List of PLMNs to be used in disaster condition IE in the CONFIGURATION UPDATE COMMAND message.

If the UE supports MINT, MINT-EPS or both, the AMF may include the Disaster roaming wait range IE in the CONFIGURATION UPDATE COMMAND message.

If the UE supports MINT, MINT-EPS or both, the AMF may include the Disaster return wait range IE in the CONFIGURATION UPDATE COMMAND message.

NOTE 7: The AMF can determine the content of the "list of PLMN(s) to be used in disaster condition", the value of the disaster roaming wait range and the value of the disaster return wait range based on the network local configuration.

If the UE supports discontinuous coverage, the AMF may include the Discontinuous coverage maximum time offset IE in the CONFIGURATION UPDATE COMMAND message.

If the UE supports and the network supports and accepts the use of the PEIPS assistance information, and the AMF needs to update the PEIPS assistance information, the AMF shall include the PEIPS assistance information in the Updated PEIPS assistance information IE of the CONFIGURATION UPDATE COMMAND message.

If the AMF needs to inform the UE that the use of access identity 1 is valid or is no longer valid, then,

if the UE supports MPS indicator update via the UE configuration update procedure, the AMF:

informs the UE by setting the MPS indicator bit of the Priority indicator IE to "Access identity 1 valid" or "Access identity 1 not valid" respectively, in the CONFIGURATION UPDATE COMMAND message. Based on operator policy, the AMF sets the MPS indicator bit in the CONFIGURATION UPDATE COMMAND message based on the MPS priority information in the user's subscription context obtained from the UDM; or
indicates "registration requested" in the Registration requested bit of the Configuration update indication IE in the CONFIGURATION UPDATE COMMAND message; or

if the UE supports MCS indicator update via the UE configuration update procedure, the AMF:

informs the UE by setting the MCS indicator bit of the Priority indicator IE to "Access identity 2 valid" or "Access identity 2 not valid" respectively, in the CONFIGURATION UPDATE COMMAND message. Based on operator policy, the AMF sets the MCS indicator bit in the CONFIGURATION UPDATE COMMAND message based on the MCS priority information in the user's subscription context obtained from the UDM; or
indicates "registration requested" in the Registration requested bit of the Configuration update indication IE in the CONFIGURATION UPDATE COMMAND message; or

otherwise, the AMF shall indicate "registration requested" in the Registration requested bit of the Configuration update indication IE in the CONFIGURATION UPDATE COMMAND message.

If the UE has set the Reconnection to the network due to RAN timing synchronization status change (RANtiming) bit to "Reconnection to the network due to RAN timing synchronization status change supported" in the 5GMM capability IE of the REGISTRATION REQUEST message, the AMF may include the RAN timing synchronization IE with the RecReq bit set to "Reconnection requested" in the CONFIGURATION UPDATE COMMAND message.

When the UE is operating as an MBSR and its status of the MBSR authorization changes to not authorized for MBSR operation based on the UE subscription and local policy and the UE is allowed to operate as a UE, then the AMF shall include the Feature authorization indication IE in the CONFIGURATION UPDATE COMMAND message and shall set the MBSRAI field to "not authorized to operate as MBSR but allowed to operate as a UE", and the AMF can request the SMF to release the PDU session for OAM access (see 3GPP TS 23.501 [8]) provided in the serving PLMN. When the UE that was not allowed for MBSR operation becomes to be allowed for MBSR operation based on the UE subscription and local policy, then the AMF shall include the Feature authorization indication IE in the CONFIGURATION UPDATE COMMAND message and shall set the MBSRAI field to "authorized to operate as MBSR".

If the UE supports access technology utilization control and the AMF needs to update the access technology utilization control information, the AMF shall include the Access technology utilization control IE with the length of access technology utilization control contents field set to a non-zero value in the CONFIGURATION UPDATE COMMAND message. If the UE supports access technology utilization control and the AMF needs to indicate to the UE to remove the access technology utilization control information, the AMF shall include the Access technology utilization control IE with the length of access technology utilization control contents field set to zero in the CONFIGURATION UPDATE COMMAND message.

NOTE 8: As an implementation option, the type of access technology utilization control is not set to "current PLMN and its equivalent PLMN(s)" by the AMF in the Access technology utilization control IE if the AMF does not include a list of equivalent PLMNs in the last REGISTRATION ACCEPT message.

If the UE supports and the network supports and accepts the use of the LP-WUSPS assistance information, and the AMF needs to update the LP-WUSPS assistance information, the AMF shall include the LP-WUSPS assistance information in the Updated LP-WUSPS assistance information IE with the length of LP-WUSPS assistance information contents field set to a non-zero value in the CONFIGURATION UPDATE COMMAND message. If the UE supports the LP-WUSPS assistance information and the AMF needs to remove the LP-WUSPS assistance information from the UE, the AMF shall include the Updated LP-WUSPS assistance information IE with the length of LP-WUSPS assistance information contents field set to zero in the CONFIGURATION UPDATE COMMAND message.

If the UE supports LP-WUS disabling and LP-WUS is disabled for the UE, the AMF shall include the LP-WUS status IE with "LP-WUS disabled" in the CONFIGURATION UPDATE COMMAND message. If the UE supports LP-WUS disabling and the LP-WUS is enabled for the UE, the AMF shall include the LP-WUS status IE with "LP-WUS enabled" in the CONFIGURATION UPDATE COMMAND message.

If the AMF needs to inform the UE of the operator policy on UE exemption for service area restrictions, and if the UE supports HPAEP, the AMF may do so by setting the HPASE bit of the Feature authorization indication IE in the CONFIGURATION UPDATE COMMAND message.