Content for  TS 38.413  Word version:  18.0.0

The purpose of the PDU Session Resource Modify procedure is to enable configuration modifications of already established PDU session(s) for a given UE. It is also to enable the setup, modification and release of the QoS flow for already established PDU session(s). The procedure uses UE-associated signalling.

The AMF initiates the procedure by sending a PDU SESSION RESOURCE MODIFY REQUEST message to the NG-RAN node. The PDU SESSION RESOURCE MODIFY REQUEST message shall contain the information required by the NG-RAN node, which may trigger the NG-RAN configuration modification for the existing PDU sessions listed in the PDU Session Resource Modify Request List IE. Upon reception of the PDU SESSION RESOURCE MODIFY REQUEST message, if the NG-RAN configuration is triggered to be modified and if resources are available for the modified NG-RAN configuration, the NG-RAN node shall execute the configuration modification for the requested PDU session. If the RAN Paging Priority IE is included in the PDU SESSION RESOURCE MODIFY REQUEST message, the NG-RAN node may use it to determine a priority for paging the UE in RRC_INACTIVE state. For each PDU session, if the S-NSSAI IE is included in the PDU Session Resource Modify Request Item IE contained in the PDU SESSION RESOURCE MODIFY REQUEST message, the NG-RAN node shall replace the previously provided S-NSSAI by the received S-NSSAI for the concerned PDU session and use it as specified in TS 23.502. For each PDU session, if the Network Instance IE is included in the PDU Session Resource Modify Request Transfer IE contained in the PDU SESSION RESOURCE MODIFY REQUEST message and the Common Network Instance IE is not present, the NG-RAN node shall, if supported, use it as specified in TS 23.501. For each PDU session, if the Common Network Instance IE is included in the PDU Session Resource Modify Request Transfer IE or in the Additional UL NG-U UP TNL Information IE, or in the Additional Redundant UL NG-U UP TNL Information IE contained in the PDU SESSION RESOURCE MODIFY REQUEST message, the NG-RAN node shall, if supported, use it when selecting transport network resource for the concerned NG-U transport bearer as specified in TS 23.501. For each PDU session, if the Redundant Common Network Instance IE is included in the PDU Session Resource Modify Request Transfer IE contained in the PDU SESSION RESOURCE MODIFY REQUEST message, the NG-RAN node shall, if supported, use it for the redundant transmission as specified in TS 23.501. For each PDU session, if the TSC Traffic Characteristics IE is included in the PDU Session Resource Modify Request Transfer IE contained in the PDU SESSION RESOURCE MODIFY REQUEST message, the NG-RAN node shall, if supported, store it and use it as specified in TS 23.501. If the RAN Feedback Type IE is included in the TSC Traffic Characteristics IE, the NG-RAN node shall, if supported, take this information into account when determining the feedback to provide in the TSC Traffic Characteristics Feedback IE in the PDU Session Resource Modify Response Transfer IE in the PDU SESSION RESOURCE MODIFY RESPONSE message as specified in TS 23.501. For each PDU session, if the Redundant QoS Flow Indicator IE is included and set to "false" for all QoS flows, the NG-RAN node shall, if supported, stop the redundant transmission and release the redundant tunnel for the concerned PDU session as specified in TS 23.501. For each PDU session, if the Downlink TL Container IE for a QoS flow is included in the PDU Session Resource Modify Request Transfer IE contained in the PDU SESSION RESOURCE MODIFY REQUEST message, the NG-RAN node shall, if supported, handle it as specified in TS 23.501 and shall include the Uplink TL Container IE for the indicated QoS flow in the PDU Session Resource Modify Response Transfer IE as specified in TS 23.501. For each PDU session in the PDU SESSION RESOURCE MODIFY REQUEST message, if the Alternative QoS Parameters Set List IE is included in the GBR QoS Flow Information IE in the PDU Session Resource Modify Request Transfer IE of the PDU SESSION RESOURCE MODIFY REQUEST message, the NG-RAN node may accept the setup of the QoS flow when notification control has been enabled if the requested QoS parameters or at least one of the alternative QoS parameters sets can be fulfilled at the time of setup. In case the NG-RAN node accepts the setup fulfilling one of the alternative QoS parameters it shall indicate the alternative QoS parameters set which it currently fulfils in the Current QoS Parameters Set Index IE within the PDU Session Resource Setup Response Transfer IE of the PDU SESSION RESOURCE MODIFY RESPONSE message. For each PDU session included in the PDU Session Resource Modify Request List IE:

• For each QoS flow included in the QoS Flow Add or Modify Request List IE, based on the QoS Flow Level QoS Parameters IE, the NG-RAN node may establish, modify or release the DRB configuration and may change allocation of resources on NG or Uu accordingly. The NG-RAN node shall associate each QoS flow accepted to setup or modify which is not associated with an MBS QoS flow with a DRB of the PDU session. The associated DRB for the QoS flow accepted to modify may not change. If the PDU Set QoS Parameters IE is received, the NG-RAN node shall, if supported, store the received PDU Set QoS Parameters in the UE context and use it as specified in TS 23.501. If the ECN Marking or Congestion Information Reporting Request IE is included in the PDU Session Resource Setup Request Transfer IE contained in the PDU SESSION RESOURCE SETUP REQUEST message, the NG-RAN node shall, if supported, use it accordingly for the specific QoS flow. If the ECN Marking or Congestion Information Reporting Status IE is included in the PDU Session Resource Modify Response Transfer IE as described in TS 23.501, the AMF shall, if supported, use it to deduce if ECN marking at NG-RAN or ECN marking at UPF or congestion information reporting is active or not active.
• For each QoS flow, if the Redundant QoS Flow Indicator IE is included, the NG-RAN node shall, if supported, store it and consider it for the redundant transmission as specified in TS 23.501.
• For each QoS flow included in the QoS Flow Add or Modify Request List IE, if the QoS Flow Add or Modify Request Item IE is included for an existing QoS Flow Identifier IE, the NG-RAN node shall overwrite the content of the full QoS Flow Add or Modify Request Item IE.
• For each QoS flow included in the QoS Flow to Release List IE, the NG-RAN node shall de-associate the QoS flow with the previously associated DRB.
• For each QoS flow included in the QoS Flow Add or Modify Request List IE, if the UL NG-U UP TNL Information IE is included, the NG-RAN node shall, if supported, include the DL NG-U UP TNL Information IE in the QoS Flow Add or Modify Response Item IE for the QoS flow within the PDU SESSION RESOURCE MODIFY RESPONSE message as specified in TS 23.501.
• For each QoS flow, if the Burst Arrival Time IE is included in the TSC Assistance Information Uplink IE of the TSC Traffic Characteristics IE, the NG-RAN node may include the AN Packet Delay Budget Uplink IE for the same QoS flow within the PDU SESSION RESOURCE MODIFY RESPONSE message as specified in TS 23.501.
• If the NAS-PDU IE is received for the PDU session, the NG-RAN node shall pass it to the UE only if at least one of the requests included in the PDU Session Resource Modify Request Transfer IE is successful (i.e. the PDU session is included in the PDU Session Resource Modify Response Item IE of the PDU SESSION RESOURCE MODIFY RESPONSE message).
• The NG-RAN node may change allocation of resources on NG according to the requested target configuration.
• If the PDU Session Aggregate Maximum Bit Rate IE is included in the PDU Session Resource Modify Request Transfer IE, the NG-RAN node shall store and use the received PDU Session Aggregate Maximum Bit Rate value when enforcing traffic policing for Non-GBR QoS flows for the concerned UE as specified in TS 23.501.
• If the UL NG-U UP TNL Information IE in the UL NG-U UP TNL Modify List IE is included in the PDU Session Resource Modify Request Transfer IE, the NG-RAN node shall update the transport layer information for the uplink data accordingly for the concerned transport bearers identified by the DL NG-U UP TNL Information IE included in the PDU Session Resource Modify Request Transfer IE for the concerned PDU session.
• If the Additional UL NG-U UP TNL Information IE is included in the PDU Session Resource Modify Request Transfer IE, the NG-RAN node may allocate resources for an additional NG-U transport bearer for some or all of the QoS flows present in the QoS Flow Add or Modify Request List IE and it shall indicate these QoS flows in the Additional DL QoS Flow per TNL Information IE in the PDU Session Resource Modify Response Transfer IE. In case the Additional DL QoS Flow per TNL Information IE is not included the SMF shall consider the proposed additional UL NG-U UP TNL information as available again.
• In case more than one NG-U transport bearers have been set up for the PDU session, if all the QoS flows associated to one existing NG-U transport bearer are included in the QoS Flow to Release List IE in the PDU Session Resource Modify Request Transfer IE, the NG-RAN node and 5GC shall consider that the concerned NG-U transport bearer is removed for the PDU session, and both NG-RAN node and 5GC shall therefore consider the related NG-U UP TNL information as available again.
• If the Redundant UL NG-U UP TNL Information IE within the UL NG-U UP TNL Modify List IE is included in the PDU Session Resource Modify Request Transfer IE, the NG-RAN node shall, if supported, update the transport layer information for the uplink data accordingly for the concerned transport bearer identified by the Redundant DL NG-U UP TNL Information IE included in the PDU Session Resource Modify Request Transfer IE for the concerned PDU session.
• If the Additional Redundant UL NG-U UP TNL Information IE is included in the PDU Session Resource Modify Request Transfer IE, the NG-RAN node may allocate resources for an additional redundant NG-U transport bearer for some or all of the QoS flows present in the QoS Flow Add or Modify Request List IE and it shall, if supported, indicate these QoS flows in the Additional Redundant DL QoS Flow per TNL Information IE in the PDU Session Resource Modify Response Transfer IE. In case the Additional Redundant DL QoS Flow per TNL Information IE is not included the SMF shall consider the proposed additional Redundant UL NG-U UP TNL information as available again.
• If the Redundant UL NG-U UP TNL Information IE is included in the PDU Session Resource Modify Request Transfer IE, the NG-RAN node may allocate resources for a redundant NG-U transport bearer for some or all of the QoS flows present in the QoS Flow Add or Modify Request List IE and it shall, if supported, indicate the corresponding NG-RAN endpoint of this NG-U transport bearer in the Redundant DL NG-U UP TNL Information IE in the PDU Session Resource Modify Response Transfer IE.
• If the Security Indication IE is included in the PDU Session Resource Modify Request Transfer IE, the NG-RAN node shall, if supported, only update the maximum integrity protected data rate uplink and/or the maximum integrity protected data rate downlink, and take them into account as defined in the PDU Session Resource Setup procedure.

For each QoS flow which has been successfully added or modified, if the QoS Monitoring Request IE was included in the QoS Flow Level QoS Parameters IE contained in the PDU SESSION RESOURCE MODIFY REQUEST message, the NG-RAN node shall store this information, and, if supported, perform delay measurement and QoS monitoring, as specified in TS 23.501. If the QoS Monitoring Reporting Frequency IE was included in the QoS Flow Level QoS Parameters IE contained in the PDU SESSION RESOURCE MODIFY REQUEST message, the NG-RAN node shall store this information and, if supported, use it for RAN part delay reporting. The NG-RAN node shall report to the AMF, in the PDU SESSION RESOURCE MODIFY RESPONSE message, the result for each PDU session requested to be modified listed in the PDU SESSION RESOURCE MODIFY REQUEST message:

• For each PDU session which is successfully modified, the PDU Session Resource Modify Response Transfer IE shall be included containing:
  1. The list of QoS flows which have been successfully setup or modified, if any, in the QoS Flow Add or Modify Response List IE in case the PDU Session Resource Modify procedure is triggered by QoS flow setup or modification.
  2. The list of QoS flows which have failed to be setup or modified, if any, in the QoS Flow Failed to Add or Modify List IE in case the PDU Session Resource Modify procedure is triggered by QoS flow setup or modification.
• For each PDU session which failed to be modified, the PDU Session Resource Modify Unsuccessful Transfer IE shall be included containing the failure cause.
• For each PDU session, if the DL NG-U UP TNL Information IE is included in the PDU Session Resource Modify Response Transfer IE in the PDU SESSION RESOURCE MODIFY RESPONSE message, it shall be considered by the SMF as the new DL transport layer address for the PDU session. The NG-RAN also may indicate the mapping between each new DL transport layer address and the corresponding UL transport layer address assigned by the 5GC.
• For each PDU session, if the Additional NG-U UP TNL Information IE is included in the PDU Session Resource Modify Response Transfer IE in the PDU SESSION RESOURCE MODIFY RESPONSE message, it shall, if supported, be considered by the SMF as the new DL transport layer address(es) for the PDU session. The NG-RAN also may indicate the mapping between each new DL transport layer address and the corresponding UL transport layer address assigned by the 5GC.
• For each PDU session, if the Additional Redundant NG-U UP TNL Information IE is included in the PDU Session Resource Modify Response Transfer IE in the PDU SESSION RESOURCE MODIFY RESPONSE message, it shall, if supported, be considered by the SMF as the new DL transport layer address(es) for the PDU session for the redundant transmission. The NG-RAN also may indicate the mapping between each new redundant DL transport layer address and the corresponding redundant UL transport layer address assigned by the 5GC.

Upon reception of the PDU SESSION RESOURCE MODIFY RESPONSE message the AMF shall, for each PDU session indicated in the PDU Session ID IE, transfer transparently the PDU Session Resource Modify Response Transfer IE or PDU Session Resource Modify Unsuccessful Transfer IE to each SMF associated with the concerned PDU session. The NG-RAN node shall, if supported, report in the PDU SESSION RESOURCE MODIFY RESPONSE message location information of the UE in the User Location Information IE. For a PDU session or a QoS flow which failed to be modified, the NG-RAN node shall fall back to the configuration of the PDU session or the QoS flow as it was configured prior to the reception of the PDU SESSION RESOURCE MODIFY REQUEST message. Upon reception of the PDU SESSION RESOURCE MODIFY REQUEST message to setup a QoS flow for IMS voice, if the NG-RAN node is not able to support IMS voice, the NG-RAN node shall initiate EPS fallback or RAT fallback for IMS voice procedure as specified in TS 23.501 and report unsuccessful establishment of the QoS flow in the PDU Session Resource Modify Response Transfer IE or in the PDU Session Resource Modify Unsuccessful Transfer IE with cause value "IMS voice EPS fallback or RAT fallback triggered". If the User Location Information IE is included in the PDU SESSION RESOURCE MODIFY RESPONSE message, the AMF shall handle this information as specified in TS 23.501. For each PDU session, if the PDU Session Expected UE Activity Behaviour IE is included in the PDU SESSION RESOURCE MODIFY REQUEST message, the NG-RAN node shall, if supported, handle this information as specified in TS 23.501. For each PDU session for which the Secondary RAT Usage Information IE is included in the PDU Session Resource Modify Response Transfer IE, the SMF shall handle this information as specified in TS 23.502. If the PDU Set QoS Parameters IE is included in the PDU SESSION RESOURCE MODIFY REQUEST message, the NG-RAN node shall, if supported, report in the PDU SESSION RESOURCE MODIFY RESPONSE message the PDU Set based Handling Indicator IE in the PDU Session Resource Modify Response Transfer IE. If the PDU Set based Handling Indicator IE is included in the PDU Session Resource Modify Response Transfer IE in the PDU SESSION RESOURCE MODIFY RESPONSE message, the SMF shall, if supported, handle this information as specified in TS 23.501. Interactions with Handover Preparation procedure:

The unsuccessful operation is specified in the successful operation section.

If the NG-RAN node receives a PDU SESSION RESOURCE MODIFY REQUEST message containing several PDU Session ID IEs (in the PDU Session Resource Modify Request List IE) set to the same value, the NG-RAN node shall report the modification of the corresponding PDU sessions as failed in the PDU SESSION RESOURCE MODIFY RESPONSE message with an appropriate cause value. If the NG-RAN node receives a PDU SESSION RESOURCE MODIFY REQUEST message containing some PDU Session ID IEs (in the PDU Session Resource Modify Request List IE) that the NG-RAN node does not recognize, the NG-RAN node shall report the corresponding invalid PDU sessions as failed in the PDU SESSION RESOURCE MODIFY RESPONSE message with an appropriate cause value. If the NG-RAN node receives a PDU SESSION RESOURCE MODIFY REQUEST message containing a QoS Flow Level QoS Parameters IE in the PDU Session Resource Modify Request Transfer IE for a GBR QoS flow but the GBR QoS Flow Information IE is not present, the NG-RAN node shall report the addition or modification of the corresponding QoS flow as failed in the PDU Session Resource Modify Response Transfer IE of the PDU SESSION RESOURCE MODIFY RESPONSE message with an appropriate cause value. If the NG-RAN node receives a PDU SESSION RESOURCE MODIFY REQUEST message containing the Delay Critical IE in the Dynamic 5QI Descriptor IE of the QoS Flow Level QoS Parameters IE of the PDU Session Resource Modify Request Transfer IE set to the value "delay critical" but the Maximum Data Burst Volume IE is not present, the NG-RAN node shall report the addition or modification of the corresponding QoS flow as failed in the PDU Session Resource Modify Response Transfer IE of the PDU SESSION RESOURCE MODIFY RESPONSE message with an appropriate cause value. If the NG-RAN node receives a PDU SESSION RESOURCE MODIFY REQUEST message containing a PDU session in the PDU Session Resource Modify Request List IE with the same QoS flow included both in the QoS Flow Add or Modify Request List IE and the QoS Flow to Release List IE, the NG-RAN node shall report the corresponding QoS flow as failed in the QoS Flow Failed to Add or Modify List IE in the PDU Session Resource Modify Response Transfer IE of the PDU SESSION RESOURCE MODIFY RESPONSE message with an appropriate cause value if the PDU session is modified successfully. The NG-RAN node shall not release the QoS flow when the corresponding QoS flow already exists.

The purpose of the PDU Session Resource Notify procedure is to notify that the already established QoS flow(s) or PDU session(s) for a given UE are released or not fulfilled anymore or fulfilled again by the NG-RAN node for which notification control is requested. It is also used to notify that the updated QoS parameters during the Path Switch Request procedure are not successfully accepted by the NG-RAN node. The procedure uses UE-associated signalling.

The NG-RAN node initiates the procedure by sending a PDU SESSION RESOURCE NOTIFY message. The PDU SESSION RESOURCE NOTIFY message shall contain the information of PDU session resources or QoS flows which are released or not fulfilled anymore or fulfilled again by the NG-RAN node.

• For each PDU session for which some QoS flows are released or not fulfilled anymore or fulfilled again by the NG-RAN node, the PDU Session Resource Notify Transfer IE shall be included containing:
  1. The list of QoS flows which are released by the NG-RAN node, if any, in the QoS Flow Released List IE.
  2. The list of GBR QoS flows which are not fulfilled anymore or fulfilled again by the NG-RAN node, if any, in the QoS Flow Notify List IE together with the Notification Cause IE. For a QoS flow indicated as not fulfilled anymore the NG-RAN node may also indicate an alternative QoS parameters set which it can currently fulfil in the Current QoS Parameters Set Index IE. For a QoS flow indicated as not fulfilled anymore the NG-RAN node may also indicate the RAN feedback in the TSC Traffic Characteristics Feedback IE.
  3. The list of QoS flows for which the QoS parameters were updated but could not be successfully accepted by the NG-RAN node during the Path Switch Request procedure, if any, in the QoS Flow Feedback List IE which may be associated with a value it could offer.
• For each PDU session resource which is released by the NG-RAN node, the PDU Session Resource Notify Released Transfer IE shall be included containing the release cause in the Cause IE.

The NG-RAN node shall, if supported, report in the PDU SESSION RESOURCE NOTIFY message location information of the UE in the User Location Information IE. Upon reception of the PDU SESSION RESOURCE NOTIFY message, the AMF shall, for each PDU session indicated in the PDU Session ID IE, transfer transparently the PDU Session Resource Notify Transfer IE or PDU Session Resource Notify Released Transfer IE to the SMF associated with the concerned PDU session. Upon reception of PDU Session Resource Notify Transfer IE, the SMF normally initiate the appropriate release or modify procedure on the core network side for the PDU session(s) or QoS flow(s) identified as not fulfilled anymore. For each PDU session for which the Secondary RAT Usage Information IE is included in the PDU Session Resource Notify Transfer IE or the PDU Session Resource Notify Released Transfer IE, the SMF shall handle this information as specified in TS 23.502. If the User Location Information IE is included in the PDU SESSION RESOURCE NOTIFY message, the AMF shall handle this information as specified in TS 23.501.

Void.

The purpose of the PDU Session Resource Modify Indication procedure is for the NG-RAN node to request modification of the established PDU session(s). The procedure uses UE-associated signalling.

The NG-RAN node initiates the procedure by sending a PDU SESSION RESOURCE MODIFY INDICATION message. Upon reception of the PDU SESSION RESOURCE MODIFY INDICATION message, the AMF shall, for each PDU session indicated in the PDU Session ID IE, transparently transfer the PDU Session Resource Modify Indication Transfer IE to the SMF associated with the concerned PDU session. For each PDU session for which the DL QoS Flow per TNL Information IE is included in the PDU Session Resource Modify Indication Transfer IE in the PDU SESSION RESOURCE MODIFY INDICATION message, the SMF shall, if the request is accepted, consider the included DL transport layer address as the DL transport layer address for the included associated QoS flows and provide the associated UL transport layer address in the UL NG-U UP TNL Information IE in the PDU Session Resource Modify Confirm Transfer IE in the PDU SESSION RESOURCE MODIFY CONFIRM message. For each PDU session for which the Additional DL QoS Flow per TNL Information IE is included in the PDU Session Resource Modify Indication Transfer IE in the PDU SESSION RESOURCE MODIFY INDICATION message, the SMF shall, if supported, consider for this split PDU session each included DL transport layer address(es) as the DL transport layer address(s) for the included associated QoS flows and it may provide the associated UL transport layer address(s) in the Additional NG-U UP TNL Information IE in the PDU Session Resource Modify Confirm Transfer IE in the PDU SESSION RESOURCE MODIFY CONFIRM message. In case more than one NG-U transport bearers have been set up for the PDU session, the DL QoS Flow per TNL Information IE and the Additional DL QoS Flow per TNL Information IE in the PDU Session Resource Modify Indication Transfer IE in the PDU SESSION RESOURCE MODIFY INDICATION message shall be included if at least one QoS flow is associated to their respective NG-U transport bearer; if no QoS flow is associated to one existing NG-U transport bearer after the modification, the NG-RAN node and 5GC shall consider that the concerned NG-U transport bearer is removed for the PDU session, and both NG-RAN node and 5GC shall therefore consider the related NG-U UP TNL information as available again. For each PDU session for which the Redundant DL QoS Flow per TNL Information IE is included in the PDU Session Resource Modify Indication Transfer IE in the PDU SESSION RESOURCE MODIFY INDICATION message, the SMF shall, if supported, consider the included DL transport layer address as the new DL transport layer address for the included associated QoS flows for redundant transmission and it may provide the associated UL transport layer address in the Redundant UL NG-U UP TNL Information IE in the PDU Session Resource Modify Confirm Transfer IE in the PDU SESSION RESOURCE MODIFY CONFIRM message. For each PDU session for which the Additional Redundant DL QoS Flow per TNL Information IE is included in the PDU Session Resource Modify Indication Transfer IE in the PDU SESSION RESOURCE MODIFY INDICATION message, the SMF shall, if supported, consider for this split PDU session each included DL transport layer address(es) as the new downlink termination point(s) for the included associated QoS flows and it may provide the associated UL transport layer address(s) in the Additional Redundant NG-U UP TNL Information IE in the PDU Session Resource Modify Confirm Transfer IE in the PDU SESSION RESOURCE MODIFY CONFIRM message for the redundant transmission. For each PDU session for which the Global RAN Node ID of Secondary NG-RAN Node IE is included in the PDU Session Resource Modify Indication Transfer IE of the PDU SESSION RESOURCE MODIFY INDICATION message, the SMF shall, if supported, handle this information as specified in TS 23.501. If the Security Result IE is included in the PDU Session Resource Modify Indication Transfer IE in the PDU SESSION RESOURCE MODIFY INDICATION message, it shall be considered by the SMF as the new security status of the PDU session. For each PDU session for which the Secondary RAT Usage Information IE is included in the PDU Session Resource Modify Indication Transfer IE, the SMF shall handle this information as specified in TS 23.502. The AMF shall report to the NG-RAN node in the PDU SESSION MODIFY RESOURCE CONFIRM message the result for each PDU session listed in PDU SESSION RESOURCE MODIFY INDICATION message:

• For each PDU session which is successfully modified, the PDU Session Resource Modify Confirm Transfer IE shall be included containing:
  1. The list of QoS flows which have been successfully modified in the QoS Flow Modify Confirm List IE.
  2. The list of QoS flows which have failed to be modified, if any, in the QoS Flow Failed to Modify List IE.
• For each PDU session which failed to be modified, the PDU Session Resource Modify Indication Unsuccessful Transfer IE shall be included to report the failure cause.

Upon reception of the PDU Session Resource Modify Confirm Transfer IE for each PDU session listed in the PDU SESSION RESOURCE MODIFY CONFIRM message:

• If the QoS Flow Failed To Modify List IE is included, the NG-RAN node shall either
  1. de-associate the corresponding DRB for the concerned QoS flow, or
  2. keep the previous transport layer information before sending the PDU SESSION RESOURCE MODIFY INDICATION unchanged for the concerned QoS flow.

Upon reception of the PDU Session Resource Modify Indication Unsuccessful Transfer IE for each PDU session listed in the PDU SESSION RESOURCE MODIFY CONFIRM message, the NG-RAN node shall either:

1. release all corresponding NG-RAN configuration and resources for the concerned PDU session, or
2. keep the previous transport layer information before sending the PDU SESSION RESOURCE MODIFY INDICATION unchanged for the concerned PDU session.

The NG-RAN node shall, if supported, report in the PDU SESSION RESOURCE MODIFY INDICATION message location information of the UE in the User Location Information IE. Interactions with PDU Session Resource Setup procedure or PDU Session Resource Modification procedure: If the PDU SESSION RESOURCE MODIFY INDICATION message is received by the AMF during an ongoing PDU Session Resource Setup procedure or an ongoing PDU Session Resource Modification procedure, the AMF shall proceed with the PDU Session Resource Modify Indication procedure. If the PDU Session Resource Modify Indication Transfer IE is received by the SMF during an ongoing PDU Session Resource Setup procedure or an ongoing PDU Session Resource Modification procedure, the SMF shall process the PDU Session Resource Modify Indication Transfer IE.

The unsuccessful operation is specified in the successful operation section.

Void.