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fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.10 CN-initiated selective deactivation of UP connection of an existing PDU Session involving I-SMF | For the CN-initiated selective deactivation of UP connection of an existing PDU Session procedure, if the PDU Session involved I-SMF, the procedure defined in clause 4.3.7 are impacted as following:
- The SMF and UPF in the procedure are replaced by the I-SMF and I-UPF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.11 Xn based handover | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.11.1 General | This clause describes the Xn based handover with the insertion, reallocation and removal of I-SMF.
To support the EAS session continuity upon UL CL relocation (allowing the UE to go on exchanging with the source EAS despite the fact that a new UL CL has been allocated to the PDU Session), the N9 forwarding tunnel between the Source UL CL and Target UL CL is established and released as described in clause 4.23.9.4 or clause 4.23.9.5. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.11.2 Xn based handover with insertion of intermediate SMF | This procedure is used to hand over a UE from a Source NG-RAN to a Target NG-RAN using Xn interface (in this case the AMF is unchanged) and the AMF decides that insertion of a new intermediate I-SMF is needed. This procedure is used for non-roaming or local breakout roaming scenario.
The call flow is shown in figure 4.23.11.2-1.
Figure 4.23.11.2-1: Xn based inter NG-RAN handover with insertion of intermediate SMF
1. Step 1 is the same as described in clause 4.9.1.2.2.
2. For each PDU Session Rejected in the list of PDU Sessions received in the N2 Path Switch Request, the AMF perform same step as step 2 in clause 4.9.1.2.2.
The rest of this procedure applies for each PDU Session To Be Switched.
3a. The AMF checks if an I-SMF needs to be selected as described in clause 5.34.3 of TS 23.501 [2].
3b. If a new I-SMF is selected the AMF sends Nsmf_PDUSession_CreateSMContext Request (SUPI, AMF ID, SMF ID, SM Context ID, PDU Session To Be Switched with N2 SM Information (Secondary RAT usage data), UE Location Information, UE presence in LADN service area) to the new selected I-SMF.
4. The new I-SMF sends Nsmf_PDUSession_Context Request (SM context type, SM Context ID) to SMF to retrieve the SM Context.
The new I-SMF uses SM Context ID received from AMF for this service operation. SM context type indicates that the requested information is all SM context, i.e. PDN Connection Context and 5G SM context. The SM Context ID is used by the recipient of Nsmf_PDUSession_Context Request in order to determine the targeted PDU Session.
5a. I-SMF to I-UPF: N4 Session Establishment Request (Target NG-RAN Tunnel Info).
The I-SMF then selects a I-UPF based on UPF Selection Criteria according to clause 6.3.3 of TS 23.501 [2]. An N4 Session Establishment Request message is sent to the I-UPF. The target NG-RAN Tunnel Info is included in the N4 Session Establishment Request message.
5b. I-UPF to I-SMF: N4 Session Establishment Response.
The I-UPF sends an N4 Session Establishment Response message to the I-SMF. The UL CN Tunnel Info and DL CN Tunnel Info of I-UPF are sent to the I-SMF.
6. I-SMF to SMF: Nsmf_PDUSession_Create Request to the SMF (SUPI, PDU Session ID, Secondary RAT usage data, UE Location Information, UE presence in LADN service area, DL CN Tunnel Info of the I-UPF, DNAI list supported by the I-SMF).
The I-SMF provides the DNAI list it supports to the SMF as defined in Figure 4.23.9.1-1 step 1.
Secondary RAT usage data is extracted from N2 SM Information within PDU Session To Be Switched received from NG RAN.
7a. SMF to UPF (PSA): N4 Session Modification Request (DL CN Tunnel Info of the I-UPF).
The SMF provides the DL CN Tunnel Info of the I-UPF to the UPF(PSA).
If old I-UPF controlled by SMF does not exist and if different CN Tunnel Info need to be used by PSA UPF, i.e. the CN Tunnel Info at the PSA for N3 and N9 are different, the CN Tunnel Info at the PSA for N9 needs to be allocated. The CN Tunnel Info is provided from UPF to SMF in the response.
7b. UPF (PSA) to SMF: N4 Session Modification Response.
The PDU Session Anchor responds with the N4 Session Modification Response message after requested PDU Sessions are switched. At this point, PDU Session Anchor starts sending downlink packets to the Target NG-RAN via I-UPF.
PDU Session Anchor sends one or more "end marker" packets for each N3/N9 tunnel on the old path immediately after switching the path, the source NG-RAN shall forward the "end marker" packets to the target NG-RAN.
8. In order to assist the reordering function in the Target NG-RAN, the PDU Session Anchor sends one or more "end marker" packets for each N3/N9 tunnel on the old path immediately after switching the path, the source NG-RAN shall forward the "end marker" packets to the target NG-RAN.
9. SMF to I-SMF: Nsmf_PDUSession_Create Response(Information for local traffic steering location, CN Tunnel Info at the PSA for N9, updated CN PDB in the QoS parameters for accepted QoS Flows).
The SMF may update the CN PDB in the response or using a separate PDU Session Modification procedure, based on local configuration.
9a. If the CN Tunnel Info at PSA for N9 is allocated, it is included in the response and the I-SMF provides the CN Tunnel Info at the PSA for N9 to I-UPF via N4 Session Modification Request.
In the case of I-SMF insertion and the PDU session corresponds to a LADN, the SMF shall release the PDU session after the handover procedure is completed.
10. I-SMF to AMF: Nsmf_PDUSession_CreateSMContext Response (UL CN Tunnel Info of the I-UPF, updated CN PDB in the QoS parameters for accepted QoS Flows).
The SMF sends an Nsmf_PDUSession_CreateSMContext response to the AMF.
11-13. Steps 11-13 are same as steps 7-9 defined in clause 4.9.1.2.2 with the following addition:
If a Source I-UPF controlled by SMF was serving the PDU Session, the SMF initiates Source I-UPF Release procedure by sending an N4 Session Release Request toward the Source I-UPF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.11.3 Xn based handover with re-allocation of intermediate SMF | This procedure is used to hand over a UE from a Source NG-RAN to a Target NG-RAN using Xn interface (in this case the AMF is unchanged) and the AMF decides that the intermediate SMF(I-SMF) is to be changed. This procedure is used for non-roaming or local breakout roaming scenario. In the case of home routed roaming scenario, this procedure is also used except the I-SMF is replaced by V-SMF.
The call flow is shown in figure 4.23.11.3 -1.
Figure 4.23.11.3-1: Xn based inter NG-RAN handover with intermediate I-SMF re-allocation
1-3. Steps 1-3 are same as steps 1-3 described in clause 4.23.11.2 except that in step 2 the AMF sends Nsmf_PDUSession_UpdateSMContext Request to source I-SMF and then the source I-SMF sends the Nsmf_PDUSession_Update Request to SMF.
4. The target I-SMF sends Nsmf_PDUSession_Context Request to Source I-SMF to retrieve 5G SM Context.
5a-11. Steps 5a-11 are same as steps 5a-11 described in clause 4.23.11.2 with the following difference:
In step 6, the target I-SMF invokes Nsmf_PDUSession_Update Request (Secondary RAT usage data, UE Location Information, UE presence in LADN service area, DL CN Tunnel Info of the I-UPF, DNAI list supported by target I-SMF) toward the SMF;
In step 9, the SMF respond with Nsmf_PDUSession_Update Response. The SMF may provide the DNAI(s) of interest for this PDU Session to I-SMF as described in step 1 of Figure 4.23.9.1-1. The SMF may update the CN PDB in the response or using a separate PDU Session Modification procedure, based on local configuration.
Secondary RAT usage data is extracted from PDU Session To Be Switched with N2 SM Information received from NG RAN.
12a. The AMF sends Nsmf_PDUSession_ReleaseSMContext Request (I-SMF only indication) to source I-SMF. The source I-SMF removes the SM context of this PDU session. An indication is included in this message to avoid invoking resource release in SMF.
12b. The source I-SMF sends N4 Session Release to release the resource in source I-UPF. If the source I-UPF acts as UL CL and is not co-located with local PSA, the source I-SMF also sends N4 Session Release to the local PSA to release the resource for the PDU Session.
13-14. Steps 13-14 are same as steps 12-13 described in clause 4.23.11.2. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.11.4 Xn based handover with removal of intermediate SMF | This procedure is used to hand over a UE from a Source NG-RAN to a Target NG-RAN using Xn interface(in this case the AMF is unchanged) and the AMF decides that removal of intermediate I-SMF is needed. This procedure is used for non-roaming or local breakout roaming scenario.
The call flow is shown in figure 4.23.11.4-1.
Figure 4.23.11.4-1: Xn based inter NG-RAN handover with removal of intermediate SMF
1. Step 1 is the same as described in clause 4.9.1.2.2.
2. For each PDU Session Rejected in the list of PDU Sessions received in the N2 Path Switch Request, the AMF sends Nsmf_PDUSession_UpdateSMContext Request to source I-SMF and then the source I-SMF sends the Nsmf_PDUSession_Update Request to SMF forwarding the failure cause. The SMF decides whether to release the PDU Session.
The rest of this procedure applies for each PDU Session To Be Switched.
3a. The AMF performs I-SMF selection as described in clause 5.34.3 of TS 23.501 [2] and the AMF decides to remove I-SMF in this case.
3b. The AMF sends Nsmf_PDUSession_CreateSMContext Request (SUPI, PDU Session ID, AMF ID, PDU Session To Be Switched with N2 SM Information (Secondary RAT usage data), UE Location Information, UE presence in LADN service area, Target NG-RAN Tunnel Info) to the SMF.
4a. [Conditional] SMF to I-UPF: N4 Session Establishment Request (Target NG-RAN Tunnel Info, UL CN Tunnel Info of the UPF (PSA)).
The SMF may select an I-UPF based on UPF Selection Criteria according to clause 6.3.3 of TS 23.501 [2]. If an I-UPF is selected, an N4 Session Establishment Request message is sent to the I-UPF. The target NG-RAN Tunnel Info is included in the N4 Session Establishment Request message.
4b. I-UPF to SMF: N4 Session Establishment Response.
The I-UPF sends an N4 Session Establishment Response message to the I-SMF. The UL and DL CN Tunnel Info of I-UPF is sent to the I-SMF.
5a. SMF to UPF (PSA): N4 Session Modification Request (DL CN Tunnel Info of the I-UPF if I-UPF is selected, or Target NG-RAN Tunnel Info if I-UPF is not selected).
The SMF provides the DL CN Tunnel Info of the I-UPF to the UPF (PSA) if I-UPF is selected.
If an I-UPF is not selected, the SMF provides the target NG-RAN Tunnel Info to the UPF (PSA). If different CN Tunnel Info need to be used by PSA UPF, i.e. the CN Tunnel Info for N3 and N9 are different, the SMF retrieves the new CN Tunnel Info from UPF.
5b. UPF (PSA) to SMF: N4 Session Modification Response.
If different CN Tunnel Info needs to be used by PSA UPF, i.e. the CN Tunnel Info for N3 and N9 are different, the CN Tunnel Info is allocated by the UPF and provided to the SMF.
The PDU Session Anchor responds with the N4 Session Modification Response message after requested PDU Sessions are switched. PDU Session Anchor sends one or more "end marker" packets for each N3/N9 tunnel on the old path immediately after switching the path, the source NG-RAN shall forward the "end marker" packets to the target NG-RAN. At this point, PDU Session Anchor starts sending downlink packets to the Target NG-RAN via I-UPF.
6a. [Conditional] SMF to I-UPF: N4 Session Modification Request (UL CN Tunnel Info of the UPF (PSA)).
If the UL CN Tunnel Info of the UPF (PSA) has been changed, the SMF provides the UL CN Tunnel Info of the UPF (PSA) to I-UPF.
6b. I-UPF to SMF: N4 Session Modification Response.
The I-UPF responds with the N4 Session Modification Response message.
7. In order to assist the reordering function in the Target NG-RAN, the PDU Session Anchor sends one or more "end marker" packets for each N3/N9 tunnel on the old path immediately after switching the path, the source NG-RAN shall forward the "end marker" packets to the target NG-RAN.
8. SMF to AMF: Nsmf_PDUSession_CreateSMContext Response (UL CN Tunnel Info of the I-UPF if I-UPF is selected, or CN Tunnel Info (on N3) of UPF (PSA) if I-UPF is not selected, updated CN PDB in the QoS parameters for accepted QoS Flows). The SMF may update the CN PDB in the response or using a separate PDU Session Modification procedure, based on local configuration.
The SMF sends an Nsmf_PDUSession_CreateSMContext response to the AMF.
9. Step 9 is same as step 7 defined in clause 4.9.1.2.2.
10a. AMF to source I-SMF: Nsmf_PDUSession_ReleaseSMContext request (I-SMF only Indication).
The AMF sends Nsmf_PDUSession_ReleaseSMContext request to source I-SMF. The I-SMF only indication is included in this message to avoid invoking resource release in SMF.
10b. Source I-SMF to source I-UPF: N4 Session Release Request/Response.
The source I-SMF sends N4 Session Release Request to source I-UPF in order to release resources for the PDU Session.
10c. Source I-SMF to AMF: Nsmf_PDUSession_ReleaseSMContext Response.
The source I-SMF responds to AMF with Nsmf_PDUSession_ReleaseSMContext response.
11-12. Steps 11-12 are same as steps 8-9 defined in clause 4.9.1.2.2. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.11.5 Xn based handover without change of intermediate SMF | When both I-SMF and SMF are available for a PDU Session and no I-SMF change or removal is needed during Xn based handover procedure, compared to the procedure defined in clause 4.9.1.2.2 and clause 4.9.1.2.4 the SMF is replaced with the I-SMF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.12 N26 based Interworking Procedures with I-SMF | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.12.1 General | When UE moves from EPS to 5GS, for a each PDU Session, the AMF determines whether I-SMF needs to be inserted based on UE location and service area of the SMF+PGW-C.
This clause describes the N26 based Interworking Procedures with I-SMF insertion when UE move from EPS to 5GS and removal when UE moves from 5GS to EPS. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.12.2 5GS to EPS Idle mode mobility using N26 interface with I-SMF removal | For 5GS to EPS Idle mode mobility using N26 with I-SMF removal, the procedure "5GS to EPS Idle mode mobility using N26 interface" defined in clause 4.11.1.3.2 for the home routed-roaming case are re-used, with the following change:
- The V-SMF is replaced by I-SMF, H-SMF is replaced by SMF and V-UPF is replaced by I-UPF.
- The V-CN Tunnel Info is replaced by Tunnel Info at I-UPF, H-CN Tunnel Info is replaced by Tunnel Info at UPF (PSA).
4.23.12.2A 5GS to EPS Idle mode mobility using N26 interface with Data forwarding and I-SMF removal
For 5GS to EPS Idle mode mobility using N26 with data forwarding and I-SMF removal, the procedure "5GS to EPS Idle mode mobility using N26 interface with data forwarding" defined in clause 4.11.1.3.2A for the home-routed roaming case is re-used, with the following change:
- The V-SMF is replaced by I-SMF, V-UPF is replaced by I-UPF and H-SMF is replaced by SMF.
- Data forwarding tunnel resource is established and the tunnel information is exchanged through N26 interface. Data buffered in I-SMF/I-UPF is forwarded to UE via Serving GW. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.12.3 EPS to 5GS mobility registration procedure (Idle and Connected State) using N26 interface with I-SMF insertion | For EPS to 5GS Mobility registration procedure using N26 with I-SMF insertion, the procedure "EPS to 5GS Mobility Registration Procedure (Idle and Connected State) using N26 interface" defined in clause 4.11.1.3.3 for the home routed-roaming case are re-used, with the following change:
- The V-SMF is replaced by I-SMF and H-SMF is replaced by SMF, V-UPF is replaced by I-UPF.
- The V-SMF selection is replaced by the I-SMF selection.
- The V-CN Tunnel Info is replaced by Tunnel Info at I-UPF, H-CN Tunnel Info is replaced by Tunnel Info at UPF(PSA).
4.23.12.3A EPS to 5GS Idle mode mobility using N26 interface with Data forwarding and I-SMF insertion
For EPS to 5GS Mobility registration procedure using N26 with data forwarding and I-SMF insertion, the procedure "EPS to 5GS Idle Mobility using N26 interface with data forwarding" defined in clause 4.11.1.3.3A for the home routed-roaming case is re-used, with the following change:
- The V-SMF is replaced by I-SMF and H-SMF is replaced by SMF, V-UPF is replaced by I-UPF.
- The V-SMF selection is replaced by the I-SMF selection.
- The V-CN Tunnel Info is replaced by Tunnel Info at I-UPF, H-CN Tunnel Info is replaced by Tunnel Info at UPF(PSA).
- Data forwarding tunnel resource is established and the tunnel information is exchanged through N26 interface. Data buffered in Serving GW is forwarded to UE via I-SMF/I-UPF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.12.4 Procedures for EPS bearer ID allocation | The EPS Bearer ID allocation procedure, EPS Bearer ID transfer procedure and EPS Bearer ID revocation procedure are perfomed as described for the home-routed roaming case in clause 4.11.1.4, with the following differences:
- H-SMF is replaced by SMF.
- V-SMF is replaced by I-SMF.
- In step 8 of clause 4.11.1.4.1, in addition to home routing roaming scenario, for scenario of deployments topologies with specific SMF Service Areas, if EBI is assigned successfully, the SMF+PGW-C also prepares CN Tunnel Info for each EPS bearer and provides this information to the I-SMF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.12.5 EPS to 5GS mobility registration procedure (Idle) using N26 interface with AMF reallocation and I-SMF insertion | For EPS to 5GS Mobility registration procedure using N26 with AMF reallocation and I-SMF insertion, the procedure "EPS to 5GS Mobility Registration Procedure (Idle) using N26 interface with AMF reallocation" defined in clause 4.11.1.3.4 are re-used, with the following change:
- The V-SMF is replaced by I-SMF and H-SMF is replaced by SMF, V-UPF is replaced by I-UPF.
- The V-SMF selection is replaced by the I-SMF selection.
- The V-CN Tunnel Info is replaced by Tunnel Info at I-UPF, H-CN Tunnel Info is replaced by Tunnel Info at UPF(PSA). |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.12.6 5GS to EPS handover using N26 interface with I-SMF removal | The procedure "5GS to EPS handover using N26 interface" in clause 4.11.1.2.1 for the home routed-roaming case is applied to handover from 5GS to EPS using N26 interface with I-SMF removal with the following changes:
- The V-SMF is replaced by I-SMF and H-SMF is replaced by SMF, V-UPF is replaced by I-UPF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.12.7 EPS to 5GS handover using N26 interface with I-SMF insertion | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.12.7.1 Preparation phase | For handover from EPS to 5GS using N26 interface, if I-SMF needs to be inserted, the preparation procedure defined in clause 4.11.1.2.2.1 for the home routed-roaming case are re-used, with the following changes:
- The V-SMF is replaced by I-SMF and H-SMF is replaced by SMF, V-UPF is replaced by I-UPF.
- The V-SMF selection is replaced by the I-SMF selection.
- The V-CN Tunnel Info is replaced by Tunnel Info at I-UPF, H-CN Tunnel Info is replaced by Tunnel Info at UPF(PSA). |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.12.7.2 Execution phase | For handover from EPS to 5GS using N26 interface, if I-SMF needs to be inserted, the execution procedure defined in clause 4.11.1.2.2.2 for the home routed-roaming case are re-used, with the following change:
- The V-SMF is replaced by I-SMF and H-SMF is replaced by SMF, V-UPF is replaced by I-UPF.
- The V-SMF selection is replaced by the I-SMF selection.
- The V-CN Tunnel Info is replaced by Tunnel Info at I-UPF, H-CN Tunnel Info is replaced by Tunnel Info at UPF(PSA). |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.12.8 Impact to 5GC procedures | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.12.8.1 General | This clause captures impact to 5GC procedures in other clauses of clause 4.23 to support interworking with N26. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.12.8.2 UE Triggered Service Request with I-SMF insertion/change/removal | The following impact is applicable for UE triggered Service Request with I-SMF insertion in clause 4.23.4.3:
- In step 8a, when an I-SMF is inserted, if EBI(s) have been allocated before but the SMF+PGW-C has not prepared the CN Tunnel Info for each EPS bearer, the SMF+PGW-C requests the PGW-U+UPF to allocate the CN Tunnel for each EPS bearer for PDU Session(s). PGW-U+UPF allocates the PGW-U tunnel info for the EPS bearer and sends it to the SMF+PGW-C.
- In step 8c, the SMF+PGW-C provides also CN Tunnel Info for each EPS bearer to the I-SMF.
NOTE: The CN Tunnel Info for each EPS bearer provided to the I-SMF is to prepare for UE mobility to EPC network so that the I-SMF does not need interact with the SMF+PGW-C to get the EPS bearer context(s) at mobility to EPC. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.12.8.3 PDU Session establishment procedure | The following impact is applicable for PDU Session establishment in clause 4.23.5.1:
- If I-SMF is involved in the PDU Session establishment, after EBI has been successfully allocated, the SMF+PGW-C also prepares CN tunnel info for each EPS bearer and provides it to the I-SMF, see clause 4.23.12.4. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.12.8.4 PDU Session modification procedure | The following impact is applicable for PDU Session modification in clause 4.23.5.3:
- If I-SMF is involved in the PDU Session modification, if EBI needs to be allocated and the allocation is successful, the SMF+PGW-C also prepares CN tunnel info for each EPS bearer and provides it to the I-SMF, see clause 4.23.12.4. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.12.8.5 Inter NG-RAN node N2 based handover with I-SMF insertion/change/removal | The following impact is applicable for Inter NG-RAN node N2 based handover with I-SMF insertion in clause 4.23.7.3.2:
- In step 7c, at I-SMF insertion, if EBI(s) have been allocated before but the SMF+PGW-C has not prepared the CN Tunnel Info for each EPS bearer, the SMF+PGW-C requests the PGW-U+UPF to allocate the CN Tunnel for each EPS bearer for PDU Session(s). PGW-U+UPF allocates the PGW-U tunnel info for the EPS bearer and sends it to the SMF+PGW-C.
- In step 7f, the SMF+PGW-C provides also the CN Tunnel Info for each EPS bearer to the I-SMF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.12.8.6 Xn based handover with insertion of I-SMF | The following impact is applicable Xn based handover with insertion of I-SMF in clause 4.23.11.2:
- In step 6, at I-SMF insertion, if EBI(s) have been allocated before but the SMF+PGW-C has not prepared the CN Tunnel Info for each EPS bearer, the SMF+PGW-C requests the PGW-U+UPF to allocate the CN Tunnel for each EPS bearer for PDU Session(s). PGW-U+UPF allocates the PGW-U tunnel info for the EPS bearer and sends it to the SMF+PGW-C.
- In step 9, the SMF+PGW-C provides also the CN Tunnel Info for each EPS bearer to the I-SMF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.13 Non N26 based Interworking Procedures with I-SMF | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.13.1 General | When UE moves a PDU Session from EPS to 5GS, the AMF determines whether I-SMF needs to be inserted based on the UE location and the service area of the SMF+PGW-C.
This clause describes the non N26 based Interworking Procedures with I-SMF insertion when UE move a PDU Session from EPS to 5GS and I-SMF removal when UE moves a PDU Session from 5GS to EPS.
This may happen e.g. when the UE moves a PDU Session between an ePDG (over EPC) and 3GPP access over 5GC; |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.13.2 Mobility procedure without N26 interface from EPS to 5GS | At Mobility procedure from EPS to 5GS without N26 interface the procedure described in Figure 4.11.2.3-1 takes place, with following difference:
- During step 9 of Figure 4.11.2.3-1 "UE requested PDU Session Establishment according to clause 4.3.2.2", the mechanisms described in clause 4.23.5.1 apply |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.13.3 Mobility procedure without N26 interface from EPC/ePDG to 5GS | At Handover from EPC/ePDG to 5GS, the procedure described in Figure 4.11.4.1-1 takes place, with following difference:
- During step 2 of Figure 4.11.4.1-1 "UE requested PDU Session Establishment according to clause 4.3.2.2", the mechanisms described in clause 4.23.5.1 apply |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.13.4 Mobility procedure without N26 interface from 5GS to EPS | At Mobility procedure from 5GS to EPS without N26 interface, the procedure described in Figure 4.11.2.2-1 takes place, with following difference:
- During step 14 of Figure 4.11.2.2-1 (SMF+PGW-C initiates release of the PDU Session(s) in 5GS transferred to EPS), if an I-SMF was involved in the PDU Session, the same mechanisms than in Home Routed roaming apply (release according to Figure 4.3.4.3-1) with the SMF playing the role of the H-SMF and the I-SMF playing the role of the V-SMF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.13.5 Mobility procedure without N26 interface from 5GS to EPC/ePDG | At Handover from 5GS to EPC/ePDG, the procedure described in Figure 4.11.4.2-1 takes place, with following difference:
- During step 3 of Figure 4.11.4.2-1 (5GC and NG-RAN resource release), if an I-SMF was involved in the PDU Session, the same mechanisms than in Home Routed roaming apply (Figure 4.3.4.3-1 steps 3a-16b) with the SMF playing the role of the H-SMF and the I-SMF playing the role of the V-SMF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.14 Pause of charging | When I-SMF is involved for a PDU Session, the procedure for pause of charging in home routed roaming case defined in clause 4.4.4 is applied by replacing the H-SMF with SMF and V-SMF with I-SMF.
When a Local UPF (PSA) is involved, the SMF stops or starts the usage reporting including usage reporting at the Local UPF (PSA) via the I-SMF.
For a PDU Session, if charging has been paused previously, in addition to the conditions for stopping pause of charging as described in clause 4.4.4, the charging is unpaused in the following case:
- When the SMF receives Nsmf_PDUSession_Create Request from a new I-SMF or Nsmf_PDUSession_CreateSMContext request from AMF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.15 PDU Session mobility between 3GPP and non-3GPP access | In this Release of the specification, deployments topologies with specific SMF Service Areas apply only for 3GPP access.
At PDU Session mobility from 3GPP to non-3GPP access, an I-SMF may need to be removed because an I-SMF had been inserted when the PDU Session was served over 3GPP access.
At PDU Session mobility from non-3GPP to 3GPP access, an I-SMF may need to be inserted because the TA associated with the UE location over 3GPP requires the AMF to insert an I-SMF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.16 Handover of a PDU Session procedure between 3GPP and untrusted non-3GPP access | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.16.1 Handover of a PDU Session procedure from untrusted non-3GPP to 3GPP access (non-roaming and roaming with local breakout) | The following impacts are applicable to clause 4.9.2.1 when a PDU Session is handover from untrusted non-3GPP to 3GPP access (non-roaming and roaming with local breakout):
- Step2: The UE performs a PDU Session Establishment procedure with the PDU Session ID of the PDU Session to be moved as specified clause 4.23.5.1 and an I-SMF and an I-UPF may be selected and inserted for this PDU. If I-SMF is selected, in the Nsmf_PDUSession_Create Response the SMF shall include all QoS information for the QoS Flow(s) applicable to the PDU Session for the target access so that when sending the PDU Session Establishment Accept, within the N1 SM container and in the N2 SM information, the I-SMF can include all QoS information (e.g. QoS Rule(s) in N1 SM container, QFI(s) and QoS Profile(s) in N2 SM information) for the QoS Flow(s). |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.16.2 Handover of a PDU Session procedure from 3GPP to untrusted non-3GPP access (non-roaming and roaming with local breakout) | When a PDU Session is handover from 3GPP access with an I-SMF to untrusted non-3GPP access (non-roaming and roaming with local breakout), the following steps take place:
1) Step 1 of clause 4.9.2.2.
2) Step 2 of clause 4.9.2.2.
3) The step 3 in clause 4.9.2.4.2 is executed involving I-SMF instead of V-SMF, with following differences:
- Figure 4.3.4.3-1 step 14 involving I-SMF instead of V-SMF.
- Figure 4.3.4.3-1 step 16a: The SMF invokes Nsmf_PDUSession_StatusNotify (Release) indicating the release is due to a PDU Session Handover out of the I-SMF.
- Figure 4.3.4.3-1 step 16b: the I-SMF invoke the Nsmf_PDUSession_SMContexStatusNotify (Release) indicating the Release is due to a PDU Session Handover out of the I-SMF: the AMF determines that only the SMcontext with the I-SMF is to be released but that the PDU Session is not released.
The steps 2 to 3 above shall be repeated for all PDU Sessions to be moved from 3GPP access to untrusted non-3GPP access. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.16.3 Handover of a PDU Session procedure from untrusted non-3GPP to 3GPP access (home routed roaming) | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.16.3.1 The target AMF is in the PLMN of the N3IWF | The following impacts are applicable to clause 4.9.2.3.1 when a PDU Session is handover from untrusted non-3GPP to 3GPP access (home routed roaming) and target AMF is in the PLMN of the N3IWF:
- Step2: The UE performs a PDU Session Establishment procedure with the PDU Session ID of the PDU Session to be moved as specified clause 4.23.5.1. A different V-SMF and a different V-UPF may be selected for the PDU Session.
If a new V-SMF is selected, in the Nsmf_PDUSession_Create Response the H-SMF shall include all QoS information for the QoS Flow(s) applicable to the PDU Session for the target access so that when sending the PDU Session Establishment Accept, within the N1 SM container and in the N2 SM information, the V-SMF can include all QoS information (e.g. QoS Rule(s) in N1 SM container, QFI(s) and QoS Profile(s) in N2 SM information) for the QoS Flow(s) acceptable according to VPLMN policies.
- (additional) Step 4: If a new V-SMF and a new V-UPF are selected for the PDU Session, the step 3a and 14 in clause 4.3.4.3 are performed to release the resource in the old V-SMF and old V-UPF.
The steps 2 to 4 shall be repeated for all PDU Sessions to be moved from to untrusted non-3GPP access to 3GPP access.
4.23.16a Handover of a PDU Session procedure between 3GPP and trusted non-3GPP access
4.23.16a.1 General
The handover of a PDU Session between 3GPP access and trusted non-3GPP access shall be supported as specified in clause 4.23.16 for all types of handover of a PDU Session between 3GPP access and untrusted non-3GPP access, with the following modifications and clarifications:
- The untrusted non-3GPP access is substituted by a trusted non-3GPP access point (TNAP).
- The N3IWF is substituted by the TNGF.
- The reference to clause 4.9.2 is substituted by clause 4.9.3 specifying handover of a PDU Session procedure between 3GPP and trusted non-3GPP access. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.23.17 Additional considerations for Home-routed roaming | As described in clause 4.23.1, the procedures in clause 4.23 apply for home-routed roaming scenarios with V-SMF insertion/removal/change (i.e. by replacing the I-SMF with V-SMF and SMF with H-SMF). Differences compared to the procedures for I-SMF are described below:
- The Registration procedure as defined in clause 4.23.3 with the following additions:
- Step 8a of clause 4.23.4.3 (for cases d and e): the new V-SMF provides the QoS constraints of the VPLMN to H-SMF.
- Step 8c of clause 4.23.4.3 (for cases d and e): the new V-SMF may apply VPLMN QoS policies as described in TS 23.501 [2], clause 5.7.1.11.
- Inter NG-RAN node N2 based handover with V-SMF insertion/change as defined in clause 4.23.7.3 (i.e. by replacing the I-SMF with V-SMF) with the following additions:
- Preparation phase, step 4b (for case V-SMF change): the target V-SMF may apply VPLMN QoS policies as described in TS 23.501 [2], clause 5.7.1.11.
- Preparation phase, step 5d (for case V-SMF insertion): the target V-SMF may apply VPLMN QoS policies as described in TS 23.501 [2], clause 5.7.1.11.
- Execution phase, step 6 (for case V-SMF change/insertion): the target V-SMF provides the QoS constraints of the VPLMN to H-SMF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.24 Procedures for UPF Anchored Data Transport in Control Plane CIoT 5GS Optimisation | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.24.1 UPF anchored Mobile Originated Data Transport in Control Plane CIoT 5GS Optimisation | This clause describes the procedures for Mobile Originated Transport in Control Plane CIoT 5GS Optimisation where the PDU Session is terminated at a UPF.
Figure 4.24.1-1: UPF anchored Mobile Originated Data Transport in Control Plane CIoT 5GS Optimisation
1. If the UE is CM-CONNECTED it sends a NAS message carrying the ciphered PDU session ID and ciphered uplink data as payload. If the UE is in CM-IDLE, the UE first establishes an RRC connection or sends the RRCEarlyDataRequest message and sends a NAS message as part of this.
The UE may also send NAS Release Assistance Information (NAS RAI) included in the NAS message. NAS RAI indicates that no further Uplink and Downlink Data transmissions are expected, or that only a single Downlink data transmission (e.g. Acknowledgement or response to Uplink data) subsequent to this Uplink Data transmission is expected.
1a. In the NB-IoT case, during step 1 the NG-RAN, based on configuration, may retrieve the NB-IoT UE Priority and the Expected UE Behaviour Parameters from the AMF, if not previously retrieved. Based on such parameters, the NG-RAN may apply prioritisation between requests from different UEs before triggering step 2 and throughout the RRC connection. The NG-RAN may retrieve additional parameters (e.g. UE Radio Capabilities).
2. NG-RAN forwards the NAS message to the AMF using the Initial NAS message procedure (if the UE was in CM-IDLE before step 1) or using the Uplink NAS transport procedure (if the UE was in CM-CONNECTED before step 1). If RRCEarlyDataRequest message was received in step 1, the NG-RAN includes "EDT Session" indication in the N2 Initial UE message.
The RAI signalled by MAC based on the Buffer Status Report (BSR), see TS 36.321 [56], shall not be used when using Control Plane CIoT 5GS Optimisations.
3. AMF checks the integrity of the incoming NAS message and deciphers the PDU session ID and uplink data.
If a NAS RAI is received from the UE and it conflicts with the Expected UE Behaviour, the NAS RAI takes precedence.
3a. If the AMF received "EDT Session" indication from the NG-RAN in step 2, the AMF sends an N2 message to the NG-RAN.
a) In the case of NAS RAI with Uplink data and it indicated that Downlink data was not expected and the AMF does not expect any other signalling with the UE, the AMF shall
- either send a NAS service accept in the N2 Downlink NAS Transport message and include End Indication to indicate that no further data or signalling is expected with the UE; or
- alternatively, the AMF sends an N2 Connection Establishment Indication message including End Indication to indicate that no further data or signalling is expected with the UE.
b) If the AMF determines more data or signalling may be pending, the AMF sends an N2 Downlink NAS Transport message or Initial Context Setup Request message without End Indication.
3b. If 3a was executed, the NG-RAN completes the RRC early data procedure as follows.
a) For the case of 3a.a) the NG-RAN proceeds with RRCEarlyDataComplete message. The procedure is completed in step 5.
b) For the case of 3a.b) the NG-RAN proceeds with RRC connection establishment procedure. In that case, all steps up to step 13 apply.
4. AMF determines the (V-)SMF handling the PDU session based on the PDU session ID contained in the NAS message and passes the PDU Session ID and the data to the (V-)SMF by invoking Nsmf_PDUSession_SendMOData service operation.
If NG-RAN forwarded the NAS message to the AMF using the Initial NAS message procedure in step 2 and the UE is accessing via NB-IoT RAT then the AMF may inform the (H-)SMFs whether the RRC establishment cause is set to "MO exception data", as described in clause 5.31.14.3 of TS 23.501 [2]. The AMF may immediately send the MO Exception Data Counter to the (H-)SMF.
If no Downlink Data is expected based on the NAS RAI from the UE in step 1 and if the AMF is not aware of pending MT traffic, then AMF does not wait for step 7 and continues with step 12.
5. The (V-)SMF decompresses the header if header compression applies to the PDU session and forwards the data to the UPF.
The UPF forwards the data to the DN based on data forwarding rule, e.g. in the case of unstructured data, tunnelling may be applied according to clause 5.6.10.3 of TS 23.501 [2].
6. [Conditional] In the non-roaming and LBO case, the UPF forwards available downlink data to the (V-)SMF, in the home-routed roaming case, the H-UPF forwards the data to the V-UPF then to the V-SMF.
7. [Conditional] The (V-)SMF compresses the header if header compression applies to the PDU session. The (V‑)SMF forwards the downlink data and the PDU session ID to the AMF using the Namf_Communication_N1N2MessageTransfer service operation.
8. [Conditional] The AMF creates a DL NAS transport message with the PDU session ID and the downlink data. The AMF ciphers and integrity protects the NAS transport message
9. [Conditional] The AMF sends the DL NAS transport message to NG-RAN. If NAS RAI indicated for single uplink and single downlink packets (e.g. acknowledgment expected) and AMF has determined the data transmission is for single uplink and single downlink packets, the AMF includes an End Indication in the DL NAS transport message to indicate that no further data or signalling is expected with the UE.
10. [Conditional] NG-RAN delivers the NAS payload over RRC to the UE.
11. If no further data or signalling is pending and AMF received NAS RAI indicating single downlink data transmission, then AMF triggers the AN release procedure (clause 4.2.6) and the procedure stops after this step.
12. [Conditional] If no further activity is detected by NG-RAN, then NG-RAN triggers the AN release procedure.
13. [Conditional] The UE's logical NG-AP signalling connection and RRC signalling connection are released according to clause 4.2.6.
NOTE: The details of the NGAP messages to be used for this procedure are specified in TS 38.413 [10]. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.24.2 UPF anchored Mobile Terminated Data Transport in Control Plane CIoT 5GS Optimisation | This clause describes the procedures for Mobile Terminated Data Transport in Control Plane CIoT 5GS Optimisation where the PDU Session is terminated at a UPF.
Figure 4.24.2-1: Mobile Terminated Data Transport in Control Plane CIoT 5GS Optimisation
1. Downlink data is received by the UPF. If buffering is configured in the UPF, then the flow continues in step 2a, otherwise the flow continues in step 2f.
2a. [conditional] If this is the first downlink packet to be buffered and SMF has instructed the UPF to report the arrival of first downlink packet to be buffered, then the UPF sends a Data Notification to the SMF.
2b. [conditional] The SMF sends a Data Notification ACK to the UPF.
2c. [conditional] The SMF sends a Namf_MT_EnableUEReachability request to the AMF.
The SMF determines whether Extended Buffering applies based on local policy and the capability of the UPF. If Extended Buffering applies, the SMF includes "Extended Buffering support" indication in Namf_MT_EnableUEReachability request.
2d. [conditional] If the UE is considered reachable, step 3 is executed immediately.
If the AMF determines the UE is unreachable (e.g. if the UE is in MICO mode or the UE is configured for extended idle mode DRX), then the AMF rejects the request from the SMF with an indication that the UE is not reachable. If the SMF included Extended Buffering support indication, the AMF indicates the Estimated Maximum Wait time in the response message. Based on the rejection message from the AMF, the SMF should subscribe with the AMF for UE reachability using the Namf_EventExposure service.
If the UE is in MICO mode, the AMF determines the Estimated Maximum Wait time based on the next expected periodic registration timer update expiration or by implementation. The procedure continues in step 8ab when the UE becomes reachable.
If the UE is configured for extended idle mode DRX, the AMF determines the Estimated Maximum Wait time based on the start of next PagingTime Window. The procedure continues in step 3 when the UE becomes reachable.
If the AMF detects that the UE context contains Paging Restriction Information, the AMF may block the paging for this UE based on the stored Paging Restriction Information (see clause 5.38.1 of TS 23.501 [2]). If the AMF blocks paging, the AMF sends MT_EnableUEReachability response to the SMF with an indication that its request has been rejected due to restricted paging.
2e. [conditional] If the SMF receives an "Estimated Maximum Wait time" from the AMF and Extended buffering applies, the SMF sends a failure indication to the UPF with an Extended Buffering time and optionally a DL Buffering Suggested Packet Count. The Extended Buffering time is determined by the SMF and should be larger or equal to the Estimated Maximum Wait time received from the AMF. The DL Buffering Suggested Packet Count parameter is determined by the SMF and if available, the Suggested Number of Downlink Packets parameter may be considered. The procedure stops after this step.
2f. [conditional] If buffering is not configured in the UPF, then the UPF forwards the downlink data to the (V‑)SMF in non-roaming and LBO cases. In the home-routed roaming case, the H-UPF forwards the data to the V-UPF and then to the V-SMF.
2g. [conditional] The SMF determines whether Extended Buffering applies based on local policy and the capability of the SMF.
If user data is received in step 2f and Extended buffering is not configured for the SMF, then (V-)SMF compresses the header if header compression applies to the PDU session and creates the downlink user data PDU that is intended as payload in a NAS message. The (V-)SMF forwards the downlink user data PDU and the PDU session ID to the AMF using the Namf_Communication_N1N2MessageTransfer service operation. If Extended Buffering applies, then (V-)SMF keeps a copy of the downlink data.
If user data is received in step 2f and Extended Buffering applies, the SMF includes "Extended Buffering support" indication in Namf_Communication_N1N2Message Transfer.
2h. [conditional] AMF responds to SMF.
If AMF determines that the UE is reachable for the SMF, then the AMF informs the SMF. Based on this, the SMF deletes the copy of the downlink data.
If the AMF determines the UE is unreachable for the SMF (e.g. if the UE is in MICO mode or the UE is configured for extended idle mode DRX), then the AMF rejects the request from the SMF.
If the SMF included Extended Buffering support indication, the AMF indicates the Estimated Maximum Wait time, in the reject message, for the SMF to determine the Extended Buffering time. Based on the rejection message from the AMF, the SMF should subscribe with the AMF for UE reachability using the Namf_EventExposure service.
If the UE is in MICO mode, the AMF determines the Estimated Maximum Wait time based on the next expected periodic registration timer update expiration or by implementation. The procedure continues in step 8ab when the UE becomes reachable.
If the UE is configured for extended idle mode DRX, the AMF determines the Estimated Maximum Wait time based on the start of next PagingTime Window. The procedure continues in step 3 when the UE becomes reachable.
If the AMF detects that the UE context contains Paging Restriction Information, the AMF may block the paging for this UE, based on the stored Paging Restriction Information (see clause 5.38.1 of TS 23.501 [2]). If the AMF blocks paging, the AMF sends Namf_Communication_N1N2MessageTransfer response to the SMF with an indication that its request has been rejected due to restricted paging.
If the SMF receives an "Estimated Maximum Wait time" from the AMF and Extended Buffering in SMF applies, the SMF store the DL Data for the Extended Buffering time. The Extended Buffering time is determined by the SMF and should be larger or equal to the Estimated Maximum Wait time received from the AMF. The SMF does not send any additional Namf_Communication_N1N2MessageTransfer message if subsequent downlink data packets are received.
3. [Conditional] If the UE is in CM-IDLE, when the AMF determines that the UE is reachable, the AMF sends a paging message to NG-RAN. If available, the AMF may include the WUS Assistance Information in the N2 Paging message(s).
4. [Conditional] If NG-RAN received a paging message from AMF and UE and NG-RAN support WUS, then:
- if the NGAP Paging message contains the Assistance Data for Recommended Cells IE (see TS 38.413 [10]), then NG-RAN shall only broadcast the UE's Wake Up Signal in the last used cell;
- else (i.e. the Assistance Data for Recommended Cells IE is not included in the NGAP Paging message) NG-RAN should not broadcast the UE's Wake Up Signal.
NG-RAN performs paging. If the WUS Assistance Information is included in the N2 Paging message, the NG-eNB takes it into account when paging the UE (see TS 36.300 [46]).
5. [Conditional] If the UE receives paging message, it responds with a NAS message sent over RRC Connection Establishment.
If the UE is in CM-IDLE state in 3GPP access and is using the Multi-USIM Paging Rejection feature (see clause 5.38 of TS 23.501 [2]), upon reception of paging request and if the UE determines not to accept the paging, the UE attempts to send a Reject Paging Indication via the UE Triggered Service Request procedure (clause 4.2.3.2) unless it is unable to do so, e.g. due to UE implementation constraints.
5a. [Conditional] In the NB-IoT case, during Step 5, the NG-RAN, based on configuration, may retrieve the NB-IoT UE Priority and the Expected UE Behaviour Parameters from the AMF, if not previously retrieved. Based on such parameters, the NG-RAN may apply prioritisation between requests from different UEs before triggering step 6 and throughout the RRC connection. The NG-RAN may retrieve additional parameters (e.g. UE Radio Capabilities).
6. [Conditional] The NAS message is forwarded to the AMF. If the AMF receives any Paging Restrictions information in the Control Plane Service Request, the AMF updates the UE context with the received Paging Restrictions information. If no Paging Restriction information is provided, no paging restrictions apply.
7a. [Conditional] AMF to SMF: Namf_MT-EnableUEReachability Response.
If the SMF used the MT_EnableUEReachability request in step 2c and the UE has not responded to paging then the AMF sends a response to the SMF indicating that the request failed.
If the SMF used the MT_EnableUEReachability service operation in step 2c and the UE has responded with a Control Plane Service Request NAS message including Reject Paging Indication in step 5, the AMF notifies the SMF using the MT_EnableUEReachability response that the UE rejected the page and no user plane connection will be established. The UE remains reachable for future paging attempts.
7b. [Conditional] SMF to UPF: If the SMF has received a Namf_MT-EnableUEReachability response from the AMF indicating that the request failed or the UE rejected the paging, the SMF indicates to the UPF to discard the buffered data. . If the AMF indicated that the UE rejected the paging, steps 7c-12 are skipped. Otherwise the procedure stops after this step.
7c. [Conditional] AMF to SMF: Namf_Communication_N1N2Transfer Failure Notification.
If the SMF used the Namf_Communication_N1N2MessageTransfer service operation in step 2g and the UE has not responded to paging, the AMF sends a failure notification to the SMF based on which the SMF discards the buffered data. The procedure stops after this step.
If the SMF used the Namf_Communication_N1N2MessageTransfer service operation in step 2g and the UE has responded with a Control Plane Service Request NAS message including Reject Paging Indication in step 5, the AMF notifies the SMF using the Namf_Communication_N1N2MessageTransfer Failure Notification that the UE rejected the page and no user plane connection will be established. The UE remains reachable for future paging attempts. Steps 9-12 are skipped.
8aa. [Conditional] AMF to SMF: Namf_MT-EnableUEReachability Response.
If the SMF used the MT_EnableUEReachability request in step 2c and steps 2d-2e were skipped, then the AMF indicates to the SMF that the UE is reachable.
8ab. [Conditional] AMF to SMF: If in step 2d or 2h the SMF has subscribed with the AMF for UE reachability event, the AMF uses the Namf_EventExposure Notify service operation indicating to the SMF that the UE is reachable.
8b. [Conditional] SMF to UPF: N4 Session Modification Request.
If the SMF received an indication from the AMF that the UE is reachable, then the SMF indicates to the UPF to deliver buffered data to the SMF.
8c. [Conditional] UPF to SMF: N4 Session Modification Response.
8d. [Conditional] Buffered data is delivered to the SMF.
8e. [Conditional] (V-)SMF compresses the header if header compression applies to the PDU session and creates the downlink user data PDU that is intended as payload in a NAS message. The (V-)SMF forwards the downlink user data PDU and the PDU session ID to the AMF using the Namf_Communication_N1N2MessageTransfer service operation.
When buffering is not configured in the UPF, this step is executed only if in step 2h the SMF has subscribed with the AMF for UE reachability event.
9. The AMF creates a DL NAS transport message with the PDU session ID and the downlink user data PDU received from the SMF. The AMF ciphers and integrity protects the NAS transport message.
10. The AMF sends the DL NAS transport message to NG-RAN.
11. NG-RAN delivers the NAS payload over RRC to the UE.
12. While the RRC connection is established further uplink and downlink data can be exchanged. In order to send uplink data, the procedure continues as per steps 1-10 of the UPF anchored Mobile Originated Data Transport in Control Plane CIoT 5GS Optimisation procedure (clause 4.24.1).
13. If the AMF has paged the UE to trigger the NAS procedure as in step 3-6, the AMF shall initiate the UE configuration update procedure as defined in clause 4.2.4.2 to assign a new 5G-GUTI. If the UE response in the Control Plane Service Request NAS message includes a Reject Paging Indication, the AMF triggers the release of the UE as specified in clause 4.2.3.2.
14. [Conditional] If no further activity is detected by NG-RAN, then NG-RAN triggers the AN release procedure.
15. [Conditional] The UE's logical NG-AP signalling connection and RRC signalling connection are released according to clause 4.2.6.
NOTE: The details of the NGAP messages to be used for this procedure are specified in TS 38.413 [10]. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.25 Procedures for NEF based Non-IP Data Delivery | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.25.1 General | Non-IP Data Delivery (NIDD) it is a means for delivering data via a PDU Sessions of type "Unstructured". The subsequent clauses describe the procedures necessary to support NEF based NIDD. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.25.2 SMF-NEF Connection Establishment | When the UE performs the PDU Session establishment with PDU Session type of "Unstructured" and the subscription information corresponding to the UE requested DNN includes the "NEF Identity for NIDD" (NEF ID), then the SMF initiates a SMF-NEF Connection establishment procedure towards the NEF corresponding to the "NEF ID" for that DNN / S-NSSAI Combination.
Figure 4.25.2-1: SMF-NEF Connection procedure
1. Steps 1-7 and step 9 of clause 4.3.2.2.1 for UE-requested PDU Session Establishment Procedure for non-roaming scenarios or steps 1-9 of clause 4.3.2.2.2 for UE-requested PDU Session Establishment Procedure for home-routed roaming scenarios. The (H-)SMF receives the Session Management Subscription data for the corresponding SUPI, DNN and S-NSSAI that is associated with NEF Identity for NIDD and NIDD information such GPSI and AF Identifier.
2. If the subscription information corresponding to DNN and S-NSSAI includes the "NEF Identity for NIDD" (NEF ID), the SMF shall create a PDU session towards the NEF. The SMF invokes Nnef_SMContext_Create Request (User Identity, PDU Session ID, SMF ID, NIDD information, S-NSSAI, DNN, [RDS support indication], [Small Data Rate Control parameters], [Small Data Rate Control Status], [Serving PLMN Rate Control parameters]) message towards the NEF. The RDS support indication is included if the UE capability to support Reliable Data Service (RDS) is included in the PCO in the PDU Session Establishment Request message. The SMF provides Small Data Rate Control parameters to the NEF for PDU Session, if required. The SMF provides the Small Data Rate Control Status to the NEF, if received from the AMF. If the Serving PLMN intends to enforce Serving PLMN Rate Control (see clause 5.31.14.2 of TS 23.501 [2]) for this PDU session then the SMF shall provide Serving PLMN Rate Control parameters to NEF for limiting the rate of downlink control plane data packets.
If no AF has previously performed the NIDD Configuration procedure with the NEF for the User Identity received in step 2, then the NEF initiates the NIDD Configuration procedure (see clause 4.25.3) before step 3.
3. The NEF creates an NEF PDU session Context and associates it with User Identity and PDU session ID. The NEF invokes Nnef_SMContext_Create Response (Cause, [RDS support indication], [Extended Buffering Support indication], [NIDD parameters]) towards the SMF confirming establishment of the PDU session to the NEF for the UE. If NEF supports and allows use of RDS, it includes the RDS support indication to SMF and the SMF includes it in the PCO. If NEF supports Extended Buffering, NEF includes Extended Buffering Support indication in the response and subscribes for mobility-related events with the AMF to receive an indication when the UE becomes reachable. The NIDD parameters (e.g. maximum packet size) are sent to the SMF, if available.
4. Steps 11-13 of clause 4.3.2.2.1 for UE-requested PDU Session Establishment Procedure for non-roaming scenarios or steps 13-16 of clause 4.3.2.2.2 for UE requested PDU Session Establishment Procedure for home-routed roaming scenarios. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.25.3 NIDD Configuration | Figure 4.25.3-1 illustrates the procedure for configuring necessary information for data delivery via the NIDD API.
The NIDD Configuration procedure can be NEF initiated or AF triggered: in the former case the procedure starts at step 1, in the latter case it starts at step 2.
Figure 4.25.3-1: NIDD Configuration procedure
1. [Optional] If the NEF requires a NIDD configuration with a given AF, then the NEF sends a Nnef_NIDDConfiguration_TriggerNotify (GPSI, AF Identifier, NEF ID) message to the AF for asking the Nnef_NIDDConfiguration_Create Request for the UE identified by the GPSI.
2. The AF sends a Nnef_NIDDConfiguration_Create Request message (GPSI or External Group Identifier, AF Identifier, NIDD Duration, T8 Destination Address, Requested Action, TLTRI, Reliable Data Service Configuration, MTC Provider Information) to the NEF.
Reliable Data Service Configuration is an optional parameter that is used to configure the Reliable Data Service (as defined in clause 5.31.6 of TS 23.501 [2]) including port numbers for originator application(s) and receiver application(s). TLTRI is included in the request if the Requested Action is set to "Update" or "Cancel", otherwise TLTRI is not included in the request and the NEF assigns a TLTRI to the NIDD Configuration. If Reliable Data Service Configuration is present, the Reliable Data Service Configuration may include the mobile terminated and mobile originated serialization format(s) that are supported by the AF for each port number.
NOTE 1: It is up to the AF to determine whether and if NIDD Duration can be set to never expire.
NOTE 2: The AF is expected to be configured to use the same NEF as the one selected by the SMF during the UE's establishment of the PDU Session used for NEF based NIDD.
NOTE 3: When more than one AF is associated with a PDU Session, the parameters that are provided in step 2 can be provisioned in the NEF based on operator policy or configuration. In which case, any parameters that are provided in step 2 that conflict with the provisioned values are ignored.
NOTE 4: If the AF does not indicate a serialization format, it is assumed that the UE application is provisioned to know what serialization format will be used for MT traffic or that the AF will use the same format that is used by the associated MO traffic.
3. If the Requested Action is set to "Cancel" it indicates that the purpose of the request is to cancel the transaction identified by TLTRI and the flow proceeds to step 7. If the Requested Action is set to "Update", the purpose of the transaction is to update the parameters associated with the configuration (i.e. Reliable Data Service). Otherwise, the request is for a new NIDD configuration and the NEF stores the received GPSI or External Group Identifier, AF Identifier, T8 Destination Address and NIDD Duration. If either the AF is not authorised to perform this request (e.g. based on policies, if the SLA does not allow for it) or the Nnef_NIDDConfiguration_Create Request is malformed, the NEF performs step 7 and provides a Cause value appropriately indicating the error. Depending on the configuration, the NEF may change the NIDD Duration.
4. The NEF sends an Nudm_NIDDAuthorisation_Get Request (GPSI or External Group Identifier, S-NSSAI, DNN, AF Identifier, MTC Provider Information, NIDD Duration, Update Notification Address) message to the UDM to authorise the NIDD configuration request for the received External Group Identifier or GPSI.
NOTE 5: The NEF uses the AF Identifier, External Group Identifier or GPSI that was obtained in step 2 to determine what DNN will be used to enable transfer of unstructured data between the UE and the AF. This determination is based on local policies.
NOTE 6: The MTC Provider Information in step 2 is an optional parameter. The NEF should validate the provided MTC Provider Information and may override it to a NEF selected MTC Provider Information based on configuration. How the NEF determines the MTC Provider Information, if not present in step 2, is left to implementation (e.g. based on the requesting AF).
5. The UDM examines the Nudm_NIDDAuthorisation_Get Request message.
If the authorisation is successful and if an External Group Identifier was included in step 4, the UDM maps the External Group Identifier to an Internal-Group Identifier and a list of GPSIs and maps GPSIs to SUPIs.
NOTE 7: If External Group Identifier was included in step 4, how the UDM selects a GPSI when multiple GPSIs are associated with the same SUPI is left to implementation, e.g. based on the MTC Provider Information (if received) or the default GPSI (if not received).
6. The UDM sends an Nudm_NIDDAuthorisation_Get Response (single value or list of (SUPI and GPSI), Result) message to the NEF to acknowledge acceptance of the Nudm_NIDDAuthorisation_Get Request. If the UDM determines that the list size exceeds the message capacity, the UDM shall segment the list and send it in multiple messages (for details on segmentation, see TS 29.503 [52]). The SUPI(s) and if available, the GPSI(s) (when Nnef_NIDDConfiguration_Create Request contains an GPSI) are returned by the UDM in this response. This allows the NEF to correlate the AF request received in step 2 of this procedure with the SMF-NEF Connection to be established for each UE or each group member UE. Depending on the configuration (e.g. based on DNN), the UDM may change the NIDD Duration and include the updated value of the NIDD Duration in the response to the NEF.
7. The NEF sends a Nnef_NIDDConfiguration_Create Response (TLTRI, Maximum Packet Size, Reliable Data Service Indication and Cause) message to the AF to acknowledge acceptance of the Nnef_NIDDConfiguration_Create Request. If the NIDD Configuration was accepted, the NEF assigns a TLTRI to the NIDD Configuration and sends it to the AF. The NEF creates an association between the TLTRI, GPSI or External Group Identifier, SUPI and PDU session ID which is received from the SMF in step 2 of the SMF-NEF Connection procedure in clause 4.25.1. In the MT NIDD procedure, the NEF will use TLTRI and either GPSI or External Group Identifier to determine the SUPI(s) and PDU session ID(s) of PDU Session(s) for delivering unstructured data. In the MO NIDD procedure, the NEF will use the SUPI(s) and PDU session ID(s) to obtain the TLTRI, GPSI. The Reliable Data Service Indication indicates if the Reliable Data Service is enabled in the NIDD configuration. The Maximum Packet Size is the maximum NIDD packet size. The response may include an updated value of the NIDD Duration. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.25.4 NEF Anchored Mobile Originated Data Transport | Figure 4.25.4-1 illustrates the NEF Anchored Mobile Originated Data Transport procedure.
Figure 4.25.4-1: NEF Anchored Mobile Originated Data Transport procedure
1. The UE sends a NAS message with unstructured data according to steps 1-4 of the procedure for UPF anchored Mobile Originated Data Transport in Control Plane CIoT 5GS Optimisation (see clause 4.24.1). The Reliable Data Service header is included if the Reliable Data Service is enabled.
2. [Conditional] In the case of home-routed roaming the V-SMF sends the Nsmf_PDUSession_TransferMOData request to the H-SMF including MO small data.
3. The (H-)SMF sends the Nnef_SMContext_Delivery Request (User Identity, PDU session ID, unstructured data) message to the NEF.
4. When the NEF receives the unstructured data and finds an NEF PDU Session context and the related T8 Destination Address, then it sends the unstructured data to the AF that is identified by the T8 Destination address in a Nnef_NIDD_DeliveryNotify Request (GPSI, unstructured data, Reliable Data Service Configuration). If no T8 Destination address is associated with the UE's PDN connection, the data is discarded, the Nnef_NIDD_DeliveryNotify Request is not sent and the flow continues at step 6. The Reliable Data Service Configuration is used to provide the AF with additional information such as indicate if an acknowledgement was requested and port numbers for originator application and receiver application, when the Reliable Data Service is enabled.
Editor's note: It is left to Stage 3 whether or not the NEF aggregates Nnef_NIDD_DeliveryNotify Request messages to the AF.
5. The AF responds to the NEF with a Nnef_NIDD_DeliveryNotify Response (Cause).
6. The NEF sends Nnef_SMContext_Delivery Response to the SMF. If the NEF cannot deliver the data, e.g. due to missing AF configuration, the NEF sends an appropriate error code to the SMF.
7. [Conditional] In the case of home-routed roaming, the H-SMF responds to the V-SMF with a Nsmf_PDUSession_TransferMOData (Result Indication) Response. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.25.5 NEF Anchored Mobile Terminated Data Transport | Figure 4.25.5-1 illustrates the procedure using which the AF sends unstructured data to a given user as identified via External Identifier or MSISDN.
Figure 4.25.5-1: NEF Anchored Mobile Terminated Data Transport
1a. If AF has already activated the NIDD service for a given UE and has downlink unstructured data to send to the UE, the AF sends a Nnef_NIDD_Delivery Request (GPSI, TLTRI, unstructured data, Reliable Data Service Configuration) message to the NEF. Reliable Data Service Configuration is an optional parameter that is used to configure the Reliable Data Service, it may be used to indicate if a Reliable Data Service acknowledgement is requested and port numbers for originator application and receiver application.
1b. AMF indicates to NEF that the UE has become reachable. Based on this the NEF re-starts delivering buffered unstructured data to the UE.
2. The NEF determines the 5GS QoS Flow Context based on the DNN associated with the NIDD configuration and the User Identity. If an NEF 5GS QoS Flow Context corresponding to the GPSI included in step 1 is found, then the NEF checks if the AF is authorised to send data and if it does not exceed its quota or rate. If these checks fail, then steps 3-15 are skipped and an appropriate error code is returned in step 17.
3. The NEF forwards the unstructured data to the (H-)SMF using Nsmf_NIDD_Delivery Request. If NEF has indicated support of Extended Buffering in Nnef_SMContext_Create Response during SMF-NEF connection establishment, then NEF keeps a copy of the data.
4. In the roaming case, the H-SMF sends the Nsmf_PDUSession_TransferMTData to the V-SMF including MT small data.
5. The (V-)SMF determines whether Extended Buffering applies based on local policy and based on whether NEF has indicated support of Extended Buffering in Nnef_SMContext_Create Response during SMF-NEF connection establishment. (V-)SMF compresses the header if header compression applies and forwards the data and the PDU session ID to the AMF using the Namf_Communication_N1N2MessageTransfer service operation. If Extended Buffering applies, then (V-SMF) includes "Extended Buffering support" indication in Namf_Communication_N1N2Message Transfer.
6. If AMF determines the UE is unreachable for the SMF (e.g. if the UE is in MICO mode or the UE is configured for extended idle mode DRX), then the AMF rejects the request from the SMF. The AMF may include in the reject message an indication that the SMF need not trigger the Namf_Communication_N1N2MessageTransfer Request to the AMF, if the SMF has not subscribed to the event of UE reachability.
If the SMF included Extended Buffering support indication, the AMF indicates the Estimated Maximum Wait time, in the reject message, for the SMF to determine the Extended Buffering time. If the UE is in MICO mode, the AMF determines the Estimated Maximum Wait time based on the next expected periodic registration timer update expiration or by implementation. If the UE is configured for extended idle mode DRX, the AMF determines the Estimated Maximum Wait time based on the start of next PagingTime Window. The AMF stores an indication that the SMF has been informed that the UE is unreachable.
7. In the roaming case V-SMF sends Nsmf_PDUSession_TransferMTData (Result Indication) response to H-SMF. If the V-SMF receives an "Estimated Maximum Wait time" from the AMF and Extended Buffering applies, the V-SMF also passes the "Estimated Maximum Wait time" to the H-SMF.
8. If the (H-)SMF receives a failure indication, (H-)SMF also sends a failure indication to NEF. If (H-)SMF has received the "Estimated Maximum Wait time" and Extended Buffering applies, the (H-)SMF includes Extended Buffering time in the failure indication. The Extended Buffering time is determined by the (H-)SMF and should be larger or equal to the Estimated Maximum Wait time. The NEF stores the DL data for the Extended Buffering time. The NEF does not send any additional Nsmf_NIDD_Delivery Request message if subsequent downlink data packets are received. The procedures stop at this step.
9. If the AMF determines the UE to be reachable in Step 5, then Steps 3 to 6 of the UPF anchored Mobile Terminated Data Transport in Control Plane CIoT 5GS Optimisation procedure (clause 4.24.2) apply.
If the Reliable Data Service header indicates that the acknowledgement is requested, then the UE shall respond with an acknowledgement to the DL data that was received.
10. If the AMF has paged the UE to trigger the NAS procedure in step 9, the AMF shall initiate the UE configuration update procedure as defined in clause 4.2.4.2 to assign a new 5G-GUTI.
11. If the UE has not responded to paging, the AMF sends a failure notification to the (V-)SMF. Otherwise the procedure continues at step 13.
12. In the roaming case, if V-SMF has received a failure notification from AMF, then V-SMF sends Nsmf_PDUSession_TransferMTData (Result Indication) response to H-SMF.
13. If (H-)SMF receives a failure notification, then SMF indicates to the NEF that the requested Nsmf_NIDD_Delivery has failed. If Extended Buffering applies, then NEF purges the copy of the data. The procedure continues at step 17.
14. Steps 9 to 11 of the UPF anchored Mobile Terminated Data Transport in Control Plane CIoT 5GS Optimisation procedure (clause 4.24.2) apply.
15. AMF informs (V-)SMF that data has been forwarded.
16. In the roaming case, V-SMF sends Nsmf_PDUSession_TransferMTData (Result Indication) response to H-SMF that the data has been forwarded.
17. (H-)SMF indicates to NEF that the data has been forwarded. If Extended Buffering applies then NEF purges the copy of the data.
18. The NEF sends a Nnef_NIDD_Delivery Response (cause) to the AF.
The Reliable Data Service Acknowledgement Indication is used to indicate if an acknowledgement was received from the UE for the MT NIDD. If the Reliable Data Service was requested in step 1, then the Nnef_NIDD_Delivery Response is sent to the AF after the acknowledgement is received from the UE or, if no acknowledgment is received, then the Nnef_NIDD_Delivery Response is sent to the AF with a cause value indicating that no acknowledgement was received. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.25.6 NIDD Authorization Update | Figure 4.25.6-1 illustrates the procedure for updating or revoking an existing NIDD Authorization.
The UDM may initiate the NIDD Authorization Update procedure with the NEF to send updated Authorization information to the NEF.
Figure 4.25.6-1: NIDD Authorization Update procedure
0. UDM provided a successful authorization for a NIDD configuration request as defined in clause 4.25.3. The NIDD authorization is modified in UDM (e.g. subscription withdrawal, DNN used for NIDD service is removed from the UE subscription) before expiration of the NIDD Duration previously authorized.
1. The UDM sends an NIDD Authorization Update information using Nudm_NIDDAuthorisation_UpdateNotify Request (SUPI, GPSI, S-NSSAI, DNN, Result, Cause, NIDD Duration) message to the NEF to update an user's NIDD authorization.
2. The NEF sends Nudm_NIDDAuthorisation_UpdateNotify Response message to the UDM to acknowledge the authorization update.
3. If the authorization is removed, the NEF should initiate the SMF-NEF Connection release procedure as specified in clause 4.25.8.
4. The NEF informs the AF that the user's authorisation status has changed by sending Nnef_NIDDConfiguration_UpdateNotify Request (GPSI, TLTRI, Result, Cause, NIDD Duration) message to the AF to update a user's NIDD authorization.
5. The AF responds to the NEF with Nnef_NIDDConfiguration_UpdateNotify Response message. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.25.7 SMF Initiated SMF-NEF Connection Release procedure | When the PDU Session Release is initiated and if a NEF has been selected as anchor of the Control Plane CIoT 5GS Optimisation enabled PDU session which is Unstructured PDU Session Type as described in clause 4.3.4.2, then the SMF initiates a SMF-NEF Connection Release procedure towards the NEF corresponding to the "NEF ID" for that DNN / S-NSSAI Combination.
Figure 4.25.7-1: SMF Initiated SMF-NEF Connection Release procedure
1. The SMF performs Step 1 of PDU Session Release Procedure as described in clause 4.3.4.2.
2. If a NEF has been selected as anchor of the Control Plane CIoT 5GS Optimisation enabled PDU session which is Unstructured PDU Session Type as described in clause 4.3.2.2, the SMF initiates the SMF-NEF Connection release for this PDU Session by sending Nnef_SMContext_Delete Request (User Identity, PDU Session ID, S-NSSAI, DNN, Release Cause) message to the NEF.
3. The NEF deletes the NEF PDU Session Context associated with the User Identity and the PDU session ID. The NEF sends Nnef_SMContext_Delete Response (Cause, [Small Data Control Rate Status], [APN Rate Control Status]) to the SMF confirming release of the SMF-NEF session for the UE. The NEF includes Small Data Rate Control Status if PDU Session used Small Data Rate Control.
4. Steps 3-15 of PDU Session Release Procedure as described in clause 4.3.4.2. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.25.8 NEF Initiated SMF-NEF Connection Release procedure | NEF initiates a SMF-NEF connection release procedure in the following cases:
- when a NIDD Authorization Update Request from the UDM indicates that the User is no longer authorized for NIDD, or
- failure of AF or failure of AF connection, or
- based on a request from the AF.
Figure 4.25.8-1 illustrates the NEF Initiated SMF-NEF Connection Release procedure based on a request from AF.
Figure 4.25.8-1: NEF Initiated SMF-NEF Connection Release procedure on the AF request
1. AF may indicate that a User's NIDD SMF-NEF connection is no longer needed by invoking Nnef_NIDDConfiguration_Delete Request (TLTRI) toward NEF.
2. The NEF deletes the NEF PDU session Context associated with the TLTRI and acknowledges the deletion of the NIDD configuration by invoking Nnef_NIDDConfiguration_Delete Response to the AF.
3. The NEF notifies the deletion of the SM context information by invoking Nnef_SMContext_DeleteNotify Request toward the SMF.
4. The SMF acknowledges the notification by invoking Nnef_SMContext_DeleteNotify Response to the NEF.
5. If the PDU session is not longer needed, the SMF performs steps 2-11 of PDU Session Release Procedure (see clause 4.3.4.2).
Figure 4.25.8-2 illustrates the NEF Initiated SMF-NEF Connection Release procedure based on the NIDD Authorization Update.
Figure 4.25.8-2: NEF Initiated SMF-NEF Connection Release procedure on the NIDD Authorization Update
1. On NIDD Authorization Update by UDM, NEF may determine that it needs to release the corresponding SMF-NEF Connection.
2. The NEF deletes the corresponding NEF PDU session Context and notifies the deletion of the SM context information by invoking Nnef_SMContext_DeleteNotify Request toward the SMF.
3. The SMF acknowledges the notification by invoking Nnef_SMContext_DeleteNotify Response to the NEF.
4. If the PDU session is not longer needed, the SMF performs steps 2-11 of PDU Session Release Procedure (see clause 4.3.4.2). |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.25.9 NEF Anchored Group NIDD via NEF anchored unicast MT data | Figure 4.25.9-1 illustrates the procedure by which the AF can send a Group NIDD addressed to External Group Identifier. It is a pre-requisite assumption that the NEF has already resolved the mapping of External Group Identifier to individual SUPIs with the help of UDM during NIDD Configuration procedure as specified in clause 4.25.3. Standalone MT NIDD procedure specified in clause 4.25.5 is re-used by NEF to unicast the MT data to each UE.
Figure 4.25.9-1: NEF Anchored Group NIDD via NEF anchored unicast data
1. If AF has already used the NIDD Configuration procedure of clause 4.25.3 to activate the NIDD service for a group of UEs and has unstructured data to send to the group identified by an External Group Identifier, the AF sends a Nnef_NIDD_Delivery Request (External Group Identifier, TLTRI, unstructured data, Reliable Data Service Configuration) message to the NEF. Reliable Data Service Configuration is an optional parameter that is used to configure the Reliable Data Service. When unstructured data is sent to an External Group Identifier, the AF shall not request acknowledgement in the Reliable Data Service Configuration.
2. Based on the existing NIDD configuration of the UE Group (see clause 4.25.3), the NEF sends a single Nnef_NIDD_Delivery Response to AF to acknowledge the acceptance of the Group NIDD delivery request in step 1.
3. The NEF uses the NEF anchored Mobile Terminated Data Transport procedure that is specified in steps 2-16 in clause 4.25.5 to send the same MT NIDD to each UE in the group.
4. After executing step 3 for all UEs in the group, the NEF sends aggregated response in Nnef_NIDD_GroupDeliveryNotify message. If some target UEs were not reachable due to UE power saving, then the NEF does not buffer the MT NIDD, but it may include indication on the expected reachability of those UEs in its response to AF in this step. If the delivery towards certain UE failed, the NEF may include the cause value. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.26 Network Function/NF Service Context Transfer Procedures | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.26.1 General | Network Function/NF Service Context Transfer Procedures allow transfer of Service Context of a NF/NF Service from a Source NF/NF Service Instance to the Target NF/NF Service Instance, e.g. before the Source NF/NF Service can gracefully close its NF/NF Service. If SMF sets are deployed this applies from an SMF instance within an SMF set to an SMF instance of another SMF set.
A request (push procedure, see clause 4.26.2) or response (pull procedure, see clause 4.26.3) from a Source NF/NF Service Instance to a Target NF/NF Service Instance contains either
- the context being transferred, e.g. SM context (direct mode); or
- optionally, an endpoint address from which Target NF/NF Service Instance can retrieve the context, see TS 29.501 [62] (indirect mode).
It assumes that access to a given context endpoint address can be restricted to single Target NF/NF Service Instance.
NOTE: Which procedures need to be executed for indirect mode is part of the specific context transfer procedures as specified in clause 4.26.5. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.26.2 NF/NF Service Context Transfer Push Procedure | Figure 4.26.2-1: NF/NF Service Context Push procedure
1. When triggered, the Source NF/NF Service acting as NF Service Consumer sends its Context (e.g. UE Context or SM context) to the Target NF/NF Service acting as NF Service producer. This may trigger several other procedures that ensure all necessary NF/NF Services are being updated and set up with necessary information about the new context location.
2. The NF Service Consumer receives the response indicating the result of the operation (successful or not successful). When all procedures have been executed successfully the Target NF/NF Service can continue to serve the original NF Service Consumers of the Source NF/NF Service, which e.g. can be shut down gracefully.
NOTE: After resumption of a new service transaction, it may be necessary to contact the UE using existing procedures. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.26.3 NF/NF Service Context Transfer Pull procedure | Figure 4.26.3-1: NF/NF Service Context Pull procedure
1. When triggered, the Target NF/NF Service as an NF Service Consumer requests a Context (e.g. UE context or SM context) from the Source NF as a NF Service Producer. This may trigger several other procedures that ensure all necessary NF/NF services are being updated and set up with necessary information about the new context location.
NOTE 1: Which procedures need to be executed and what information needs to be updated is part of the specific context transfer procedures as specified in clause 4.26.5.
2. The NF Service Consumer receives the Context and the operation was successful. When all procedures have been executed successfully the Target NF/NF Service can continue to serve the original NF Service Consumers of the Source NF/NF Service, which e.g. can be shut down gracefully.
NOTE 2: After resumption of a new service transaction, it may be necessary to contact the UE using existing procedures. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.26.4 Context Transfer due to decommissioning | In the case of decommissioning, the Old NF may inform NRF that it is about to be decommissioned. NRF will in this case not include the NF profile of the Old NF in any discovery result from the NF/NF service discovery procedure. The NRF will also notify any consumers subscribed to changes to this resource. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.26.5 SMF Service Context Transfer procedures | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.26.5.1 General | This clause lists the context-specific transfer procedures between different SMF Sets supporting the same DNN/S-NSSAI pair supported for SM Contexts (i.e. SMF contexts). |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.26.5.2 I-SMF Context Transfer procedure | Old I-SMF triggered from O&M procedure sends Nsmf_PDUSession_SMContextStatusNotify (I-SMF transfer indication, New SMF ID or SMF set ID) to AMF.
Steps 2-25 in clause 4.23.4.3 follows, where in step 2 AMF selects the indicated I-SMF, or selects the I-SMF from the indicated SMF set. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.26.5.3 SMF Context Transfer procedure, LBO or no Roaming, no I-SMF | In the case of dynamic IP address assignment (IPv4 address and/or IPv6 prefix), the procedure in figure 4.26.4.1.1-1 assumes that, if the UE IP address is received from Old SMF, the control of the IP address(es) assigned by Old SMF is moved to New SMF by O&M procedures. New SMF is in full control of the concerned IP address(es) when the transfer is complete.
NOTE 1: If UPF has the IP point of presence from the DNN, the same UPF is used.
Figure 4.26.4.1.1-1: Context transfer of a PDU session
1. SM context transfer is triggered, e.g. by OAM to Old SMF including SUPI, PDU session ID and New SMF ID or SMF set ID. The SMF selection by using SMF set ID not applicable when the IP range is managed by SMF.
2. [Conditional - depending on current subscription] Old SMF subscribes to events when UE status becomes CM-IDLE or CM-CONNECTED with RRC_INACTIVE state (Namf_EventExposure_Subscribe).
3. [Conditional - depending on the event] The AMF detects the monitored event occurs and sends the event report by means of Namf_EventExposure_Notify message, to Old SMF.
4. From Old SMF to AMF Nsmf_PDUSession_SMContextStatusNotify (SMF transfer indication, Old SMF ID, New SMF ID or SMF set ID from Step 1, PDU Session ID, SUPI, SM Context ID).
5. AMF, or SCP if delegated discovery is used, uses New SMF ID or SMF set ID to select New SMF and sends Nsmf_PDUSession_CreateSMContext request (PDU Session ID, Old SMF ID, SM Context ID in Old SMF, UE location info, Access Type, RAT Type, Operation Type, SMF transfer indication). The same PDU Session ID as received in step 4 is used. If the AMF receives the service request from the UE for the PDU session(s) affected by this procedure the AMF delays the transaction with the SMF until the step 13 completes. If the AMF receives the UE context transfer request from the other AMF due to the UE mobility, the AMF defers the response until the step 13 completes. Also, to avoid infinite waiting time, the AMF starts a locally configured guard timer upon sending the request to the SMF and the AMF decides the procedure has failed at expiry of the guard timer.
NOTE 2: Either delay or failure of the SM Context transfer may incur timeout or failure in UE procedure(s).
6. From New SMF to Old SMF Nsmf_PDUSession_ContextRequest request (SM Context type, SM Context ID, SMF transfer indication). If New SMF is not capable to transfer this SM Context (e.g. it is not responsible for the IP range), steps 9 to 12 are skipped.
7. Old SMF releases the N4 session with the UPF by sending a flag notifying the UPF about the expected re-establishment of the N4 session for the same PDU session. Based on this, if supported, the UPF should delay the release of the N4 session up to step 10.2 to allow for uninterrupted packet handling until the N4 session is re-established by New SMF.
8. From Old SMF to New SMF Nsmf_PDUSession_ContextRequest response (SM Context or endpoint address where New SMF can retrieve SM Context). The SM Context includes the IP address(es) if the PDU session is of type IPv4, IPv6 or IPv4v6, or the Ethernet MAC address(es) if the PDU session if of type Ethernet as well as the UPF to be selected by New SMF. Old SMF starts a timer to monitor the SMF context transferring process.
9. [Conditional] If dynamic PCC is used for the PDU Session, New SMF sets up a new policy association towards PCF.
10.1. UPF receives a N4 session establishment request for the same PDU session from step 7. The parameters from step 8 and if applies, step 9 are used.
10.2. New SMF performs a full re-establishment of the N4 session, establishing a new N4 session. All information related to the N4 session of Old SMF that is not used by the N4 session of New SMF is removed from UPF if not already done.
11. New SMF registers to UDM. The information stored at the UDM includes SUPI, SMF identity and the associated DNN and PDU Session ID.
12. New SMF subscribes to subscription changes for the UE.
13. From New SMF to AMF: Nsmf_PDUSession_CreateSMContext response. If this response indicates a redirect (e.g. another SMF in the set), the procedure moves to step 5 with the indicated endpoint address as target.
14. UDM notifies Old SMF that it is deregistered for the PDU Session by sending Nudm_UECM_DeregistrationNotification, optionally including New SMF ID
15. [Conditional] If 14 was not received and the timer from step 8 expires, Old SMF re-establishes the N4 session. The UPF may for the purpose use the information stored in step 7. In this case, the procedure ends here.
16. [Conditional] If Nudm_UECM_DeregistrationNotification in step 14 was received, Old SMF removes its policy association with PCF. Any changes to the QoS rules need to be sent to the UE when it becomes active.
17. Old SMF releases any internal resources corresponding to the indicated PDU session. Subscribers to SMContextStatusNotify for the transferred SM context are notified of the context transfer and optionally of the new location of the transferred SM context. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.27 Procedures for Enhanced Coverage Restriction Control via NEF | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.27.1 General | The support for Enhanced Coverage Restriction Control via NEF enables AF to query status of Enhanced Coverage Restriction or enable/disable Enhanced Coverage Restriction per individual UEs. Figure 4.27.1-1 shows the procedure for Enhanced Coverage Restriction Control via NEF.
Figure 4.27.1-1: Enhanced Coverage Restriction Control via NEF
1. The AF may enable or disable Enhanced Coverage Restriction or query the status of Enhanced Coverage Restriction by sending the Nnef_ECRestriction_Update Request or Nnef_ECRestriction_Get Request respectively. Both the service operations require GPSI and AF Identifier as required input and optionally MTC Provider Information.
2. Based on operator policies, if the AF is not authorized to perform the request (e.g. if the SLA does not allow for it) or if the AF has exceeded its quota or rate of submitting Enhanced Coverage Requests, the NEF performs Step 8 and provides a cause value appropriately indicating the failure result.
3. The NEF sends the Nudm_ParameterProvision_Update Request to update the subscription data for Enhanced Coverage Restriction. The NEF sends the Nudm_SDM_Get Request service operation to query the status of Enhanced Coverage Restriction.
4. The UDM checks the GPSI and examines whether any included parameters are in the range acceptable by the operator, whether Enhanced Coverage Restriction is supported by the serving NF (i.e. AMF in this case). If this check fails, the UDM provides a cause value indicating the reason for failure condition to the NEF in step 7
In the case of Nudm_ParameterProvision_Update Request, the UDM sets the Enhanced Coverage Restriction information to the appropriate value and procedure continues to step 5.
In the case of Nudm_SDM_Get Request, the UDM may retrieve the status of Enhanced Coverage Restriction information from UDR using Nudr_DM_Query Request and skip steps 5 and 6.
5. The UDM sends Nudm_SDM_Notification and provide AMF with updates Enhanced Coverage Restriction information.
6. The AMF updates the Enhanced Coverage Restriction information stored in the UE context. The AMF will transfer Enhanced Coverage Restriction information stored as part of its UE context during AMF change.
NOTE: UE is informed of the updated Enhanced Coverage Restriction information at the next Registration procedure or based on the local policy the network can de-register the UE indicating re-registration is required.
7. The UDM sends the Nudm_ParameterProvision_Update Response or Nudm_SDM_Get Response to the NEF.
8. The NEF sends the Nnef_ECRestriction_Update Response or Nnef_ECRestriction_Get Response to the AF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.28 Subscription-based distribution of timing information | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.28.1 General | The distribution of 5G Clock (5G Access Stratum-based Time Distribution) and the (g)PTP domain synchronization ((g)PTP-based Time Distribution) may be controlled based on subscription data. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.28.2 5G Access Stratum-based Time Distribution | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.28.2.1 Control of access stratum time synchronization service without AF request | The control of 5G Access Stratum-based Time Distribution for a UE is performed by the AMF according to parameters retrieved in the Access and Mobility Subscription data.
Figure 4.28.2.1-1: Subscription-based control of 5G access stratum-based time distribution
1. The UE performs the registration procedure as described in clause 4.2.2.2.2. The AMF retrieves the Access and Mobility Subscription data including the Access Stratum Time Synchronization Service Authorization. The Access and Mobility Subscription data may further include the Uu time synchronization error budget, one or more periods of start and stop times defining active times, a coverage area, clock quality detail level, and the acceptance criteria for the UE, as described in clause 5.27.1.11 of TS 23.501 [2].
As part of this, the AMF shall, if supported, store the 5G access stratum time distribution indication (enable, disable), the Uu time synchronization error budget, clock quality detail level and clock quality acceptance criteria, and the UE reconnection indication in the UE context in AMF.
2. The AMF performs the control according to the subscription data as follows.
If the AMF receives start and stop times then the AMF sends the message to the NG-RAN to enable or disable the 5G access stratum time distribution according to the expiry of start and stop times if the UE is in CM-CONNECTED state. If the UE is in CM-IDLE state when a Start time condition is met, then the AMF pages the UE and provides the 5G access stratum distribution indication to NG-RAN as part of the subsequent service request procedure initiated by the UE in the response to the paging.
If the AMF received Time Synchronization Coverage Area information as part of the Access and Mobility Subscription data including the Access Stratum Time Synchronization Service Authorization, the AMF determines if the Coverage Area information shall trigger an activation or deactivation of the access stratum time distribution:
- If the UE has moved inside the Coverage Area, then the AMF determines to enable access stratum time distribution for the UE.
- If the UE has moved outside the Coverage Area, then the AMF determines to disable access stratum time distribution for the UE.
The AMF determines whether the UE moves inside/outside of the Coverage Area specified in the clause 5.27.1.11 of TS 23.501 [2]
The AMF shall send the UE reconnection indication to the UE updating the UE configuration as defined in clause 4.2.2 or clause 4.2.4.2.
3. The AMF sends N2 message (UE Context Modification Request) to the NG-RAN. The AMF sends the 5G access stratum time distribution indication (enable, disable), the Uu time synchronization error budget, clock quality detail level and clock quality acceptance criteria when they are available, to NG-RAN during mobility registration, AM policy modification, Service Request, N2 Handover and Xn handover as specified in TS 38.413 [10]. The NG-RAN node shall, if supported, store the information in the UE Context. Based on this information, the NG-RAN node provides the 5GS access stratum time to the UE according to the Uu time synchronization error budget as provided by the TSCTSF (if supported by UE and NG-RAN) and NG-RAN provides timing synchronization status reports to the UE (as described in clause 4.15.9.5.2). |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.28.3 (g)PTP-based Time Distribution | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.28.3.1 Control of (g)PTP time synchronization service without AF request | The TSCTSF may use the subscription data to control the (g)PTP-based time distribution without AF request.
Figure 4.28.3.1-1: Subscription based control of (g)PTP time synchronization service without AF request
1. The UE performs the UE-requested PDU Session Establishment.
2. The PCF determines if the PDU Session is potentially impacted by time synchronization service and invokes Npcf_PolicyAuthorization_Notify service operation to the TSCTSF discovered and selected for time synchronization to indicate there is a UE connected to a specific DNN/S-NSSAI configured for (g)PTP-based time distribution. The TSCTSF retrieves the UE SUPI using IP address and /or DNN/S-NSSAI from BSF as specified in the clause 4.15.10.
3. The TSCSTF uses the SUPI to retrieve the Time Synchronization Subscription Data available at the UDM.
4. The TSCTSF controls the (g)PTP-based time synchronization service based on the Time Synchronization Subscription Data as defined in clause 5.27.1.11 of TS 23.501 [2]. If the Time Synchronization Subscription Data contains:
a) one or more Subscribed Time Synchronization Service ID(s) that can be mapped to PTP instance configuration(s), the TSCTSF determines if one or more of the PTP instance configurations match with the DNN/S-NSSAI of the given PDU Session. The TSCTSF stores information that the time-synchronization service cannot be controlled by an AF for the DNN/S-NSSAI of given SUPI.
b) An indication whether an AF-requested (g)PTP time synchronization service is allowed for the given UE and DNN/S-NSSAI. If it is allowed, the TSCTSF determines that the time-synchronization service can be controlled by an AF for the DNN/S-NSSAI of given SUPI.
c) If TSCTSF receives neither a) nor b), the TSCTSF assumes that the time-synchronization service cannot be applied for the given PDU session. The TSCTSF does not initiate the AF-session establishment with the PCF.
d) If TSCTSF receives both a) and b) and both a) and b) contain the same DNN/S-NSSAI, TSCTSF determines that the time-synchronization service cannot be controlled by an AF for the DNN/S-NSSAI of given SUPI.
5. For each matching PTP instance configuration determined in step 4, if no PTP instance exists for the given PTP instance configuration, the TSCTSF initializes the PTP instance in 5GS as described in clause K.2.2 of TS 23.501 [2]. The TSCTSF configures a PTP port in DS-TT and adds it to the corresponding PTP instance in NW-TT as described in clause K.2.2 of TS 23.501 [2]. The TSCTSF uses the procedure in clause 4.15.9.4 to activate or modify the 5G access stratum time distribution for the UE.
If the PTP instance configuration referenced by the Time Synchronization Subscription data for the UE contains start and stop times or a coverage area, the TSCTSF updates the PTP port for the corresponding PTP instance as defined in clause 5.27.1.11 of TS 23.501 [2]. The TSCTSF uses the procedure in clause 4.15.9.4 to activate or deactivate the 5G access stratum time distribution for the UEs that are part of the impacted PTP instance.
6. If a coverage area is included in the subscription data for UE related to the PTP instance, TSCTSF discovers the AMF(s) serving the TA(s) defined for the time synchronization coverage area (Area of Interest) and subscribe to receive notifications in UEs presence in the Area of Interest. Based on the outcome the TSCTSF determines whether to activate or deactivate the time synchronization service for the impacted PTP instance. The TSCTSF will activate/deactivate the service by modifying the PTP instance configuration as described in clause K.2.2 of TS 23.501 [2]. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.29 Energy consumption information collection and exposure | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.29.0 General | This clause describes how EIF collects the energy consumption information and exposes the energy consumption information to the Consumer NF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.29.1 Energy Consumption information exposure | The procedure is used by the AF to subscribe to notifications and to explicitly cancel a previous subscription for Energy Consumption information exposure.
Figure 4.29.1-1: Energy consumption information exposure
1a. The untrusted AF (un)subscribes energy consumption event by invoking the Nnef_EventExposure_(Un)Subscribe service operation. If the energy consumption information (un)subscription request is authorized by the NEF, the NEF proceeds with the steps below.
1b. Based on the request from the untrusted AF, the NEF (un)subscribes energy consumption event by invoking the Neif_EventExposure_(Un)Subscribe/ service operation.
1c. The trusted AF (un)subscribes to energy consumption event directly to EIF by invoking Neif_EventExposure_(Un)Subscribe service operation.
2a. The EIF acknowledges the (un)subscription for the energy consumption event .
2b. The NEF acknowledges the (un)subscription for the energy consumption event from untrusted AF.
2c. The EIF acknowledges the (un)subscription for energy consumption event from trusted AF.
3a. The EIF notifies the NEF with the energy consumption information by invoking Neif_EventExposure_Notify service operation.
3b. If the NEF receives the notification from the EIF, the NEF notifies the untrusted AF with the energy consumption information by invoking Nnef_EventExposure_Notify service operation.
3c. The EIF notifies the trusted AF with the energy consumption information by invoking Neif_EventExposure_Notify service operation. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.29.2 Energy Consumption information collection | Figure 4.29.2-1 shows the procedure for EIF to collect the Energy consumption information.
Figure 4.29.2-1: Energy Consumption information collection
1. The Consumer NF (i.e. trusted AF or 5GC NF) subscribes to the energy consumption event with the EIF by using Neif_EventExposure_Subscribe service for the required granularities (UE, PDU Session and/or QoS flow) as described in clause 5.51.2.3 of TS 23.501 [2].
If the Consumer is untrusted AF, the subscription is sent via NEF. If the event subscription is authorized by the NEF, then the NEF sends the event subscription to the EIF via Neif_EventExposure_Subscribe.
2. The EIF invokes Nudm_UECM_Get service operation to retrieve the SMF ID for the required granularity.
3. The EIF invokes the Nsmf_EventExposure_Subscribe request to the SMF to request the information as defined in clause 5.51.2 of TS 23.501 [2].
4. The SMF informs the UPF with requesting the PSA UPF to report the data volume of the required granularity.
5. The SMF provides the information for energy consumption calculation (defined 5.51.2 of TS 23.501 [2]) to EIF by invoking Nsmf_EventExposure_Notify service operation for the required granularity.
NOTE: The SMF can derive gNB ID(s) according to the AMF provided ULI as described in clause 4.3.2.
6. If there is no related Node-level energy consumption information and Node-level data volume, the EIF obtains the Node-level energy consumption information and Node-level data volume from OAM with providing gNB ID(s) and UPF ID(s).
7. The EIF performs the energy consumption information calculation as described in clause 5.51.2.3 of TS 23.501 [2] and then reports the energy consumption information of the required granularity to the Consumer NF via Neif_EventExposure_Notify. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5 Network Function Service procedures | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.1 Network Function Service framework procedures | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.1.1 Network Function Service Discovery | The network function (NF) within the core network may expose its capability as service via its service based interfaces, which can be re-used by other NFs. Unless the expected NF information is locally configured on requester NF, e.g. the expected NF is in the same PLMN, the NF service discovery is implemented via the NF discovery. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2 Network Function services | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.1 General | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2 AMF Services | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.1 General | The following table shows the AMF Services and AMF Service Operations.
Table 5.2.2.1-1: List of AMF Services
Service Name
Service Operations
Operation
Semantic
Known Consumer(s)
Namf_Communication
UEContextTransfer
Request/Response
Peer AMF
CreateUEContext
Request/Response
Peer AMF
RelocateUEContext
Request/Response
Peer AMF
CancelRelocationUEContext
Request/Response
Peer AMF
ReleaseUEContext
Request/Response
Peer AMF
RegistrationStatusUpdate
Request/Response
Peer AMF
N1MessageNotify
Subscribe/Notify
PCF, LMF, Peer AMF
N1N2MessageSubscribe
PCF
N1N2MessageUnSubscribe
PCF
N1N2MessageTransfer
Request/Response
SMF, SMSF, PCF, LMF
N1N2TransferFailureNotification
Subscribe/Notify
SMF, SMSF, PCF, LMF
N2InfoSubscribe
Subscribe/Notify
NOTE 1
N2InfoUnSubscribe
NOTE 1
N2InfoNotify
AMF, LMF
EBIAssignment
Request/Response
SMF
AMFStatusChangeSubscribe
Subscribe/Notify
SMF, PCF, NEF, SMSF, UDM
AMFStatusChangeUnSubscribe
Subscribe/Notify
SMF, PCF, NEF, SMSF, UDM
AMFStatusChangeNotify
Subscribe/Notify
SMF, PCF, NEF, SMSF, UDM
NonUeN2MessageTransfer
Request/Response
Peer AMF, CBCF, PWS-IWF, LMF, TSCTSF
NonUeN2InfoSubscribe
Subscribe/Notify
CBCF, PWS-IWF, TSCTSF
NonUeN2InfoUnSubscribe
CBCF, PWS-IWF, TSCTSF
NonUeN2InfoNotify
CBCF, PWS-IWF, LMF, TSCTSF
Namf_EventExposure
Subscribe
Subscribe/Notify
NEF, SMF, UDM, NWDAF, LMF, GMLC, TSCTSF
Unsubscribe
Subscribe/Notify
NEF, SMF, UDM, NWDAF, LMF, GMLC, TSCTSF
Notify
Subscribe/Notify
NEF, SMF, UDM, NWDAF, LMF, GMLC, TSCTSF
Namf_MT
EnableUEReachability
Request/Response
SMSF, SMF
ProvideDomainSelectionInfo
Request/Response
UDM
EnableGroupReachability
Request/Response
SMF
UEReachabilityInfoNotify
Subscribe/Notify
SMF
Namf_Location
ProvidePositioningInfo
Request/Response
GMLC
EventNotify
Subscribe/Notify
GMLC
ProvideLocationInfo
Request/Response
UDM
CancelLocation
Request/Response
GMLC
NOTE 1: In this Release of the specification no known consumer is identified to use this service operation. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2 Namf_Communication service | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.1 General | Service description: This service enables an NF to communicate with the UE through N1 NAS messages or with the AN (both UE and non UE specific). The service operations defined below allow the NF to communicate with the UE and the AN. The following are the key functionalities of this NF service.
- Provide service operations for transporting N1 messages to the UE;
- Allow NFs to subscribe and unsubscribe for notifications of specific N1 messages from the UE;
- Allow NFs to subscribe and unsubscribe for notifications about specific information from AN;
- Provide service operations for initiating N2 messages towards the AN;
- Security Context Management; and
- UE information management and transfer (including its security context). |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.2 Namf_Communication_UEContextTransfer service operation | Service operation name: Namf_Communication_UEContextTransfer
Description: Provides the UE context to the consumer NF.
Input, Required: 5G-GUTI or SUPI, Access Type, Reason.
Input, Optional: Integrity protected message from the UE that triggers the context transfer.
Output, Required: The UE context of the identified UE or only the SUPI and an indication that the Registration Request has been validated. The UE context is detailed in table 5.2.2.2.2-1.
Output, Optional: Mobile Equipment Identifier (if available), Allowed NSSAI, Mapping Of Allowed NSSAI.
See clause 4.2.2.2.2 for example of usage of this service operation. If the consumer NF sent an integrity protected message from the UE, the AMF uses it to verify whether this request is permitted to retrieve the UE context of the UE. If it is permitted, the AMF provides UE context to the consumer NF in the Namf_Communication_UEContextTransfer response. The following table illustrates the UE Context:
Table 5.2.2.2.2-1: UE Context in AMF
Field
Description
SUPI
SUPI (Subscription Permanent Identifier) is the subscriber's permanent identity in 5GS.
Routing Indicator
UE's Routing Indicator that allows together with SUCI/SUPI Home Network Identifier to route network signalling to AUSF and UDM instances capable to serve the subscriber.
Home Network Public Key identifier
UE's Network Public Key identifier that may be used together with SUCI/SUPI Home Network Identifier and Routing Indicator to route network signalling to AUSF and UDM instances capable to serve the subscriber.
AUSF Group ID
The AUSF Group ID for the given UE.
UDM Group ID
The UDM Group ID for the UE.
PCF Group ID
The PCF Group ID for the UE.
SUPI-unauthenticated-indicator
This indicates whether the SUPI is unauthenticated.
GPSI
The GPSI(s) of the UE. The presence is dictated by its storage in the UDM.
5G-GUTI
5G Globally Unique Temporary Identifier.
PEI
Mobile Equipment Identity.
Internal Group ID-list
List of the subscribed internal group(s) that the UE belongs to.
UE Specific DRX Parameters
UE specific DRX parameters for E-UTRA and NR.
UE Specific DRX Parameters for NB-IoT
UE Specific DRX Parameters for NB-IoT.
UE MM Network Capability
Indicates the UE MM network capabilities.
5GMM Capability
Includes other UE capabilities related to 5GCN or interworking with EPS. See details in clause 5.4.4a of TS 23.501 [2].
Events Subscription
List of the event subscriptions by other CP NFs. Indicating the events being subscribed as well as any information on how to send the corresponding notifications.
LTE-M Indication
Indicates if the UE is a Category M UE. This is based on indication provided by the NG-RAN or by the MME at EPS to 5GS handover.
NR RedCap Indication
Indicates if the UE is a NR RedCap UE. This is based on indication provided by the NG-RAN as specified in TS 23.501 [2].
MO Exception Data Counter
MO Exception Data Counter used for Small Data Rate Control purposes, see clause 5.31.14.3 of TS 23.501 [2].
AMF-Associated Expected UE Behaviour parameters
Indicates per UE the Expected UE Behaviour Parameters and their corresponding validity times as specified in clause 4.15.6.3.
Disaster Roaming
Indicates the UE is registered for Disaster Roaming service.
PLMN with disaster condition
This is the PLMN of the UE which has faced disaster condition.
SNPN Onboarding indication
Indicates that the UE is registered for onboarding in an SNPN.
For the AM Policy Association:
AM Policy Information
Information on AM policy provided by PCF. It includes the Policy Control Request Triggers and Access and mobility related policy information as described in clauses 6.1.2.5 and 6.5 of TS 23.503 [20] except RFSP Index in Use Validity Time.
PCF ID
The identifier of the PCF for AM Policy. In roaming, the identifier of V-PCF (NOTE 2).
AM Policy Association indicator
Indicates whether AM Policy Association is "enabled" or "disabled"
For the UE Policy Association:
Trigger Information
The Policy Control Request Triggers on UE policy provided by PCF.
PCF ID(s)
The identifier of the PCF for UE Policy. In roaming, the identifiers of both V-PCF and H-PCF (NOTE 1) (NOTE 2).
UE Policy Container
The UE Policy Container received from the UE
UE Policy Association indicator
Indicates whether UE Policy Associations is "enabled" or "disabled"
For the UE NWDAF association:
NWDAF ID(s)
Indicating the NWDAF ID(s) (instance ID(s) or Set ID(s)) used for the UE specific Analytics.
Subscription Correlation ID(s)
Active UE-related analytics subscription(s) for each given NWDAF ID.
Analytics ID(s)
Analytics ID(s) per NWDAF ID.
Analytics specific data
Additional information on the Analytics ID(s) the AMF is subscribed related to the UE specific Analytics, i.e. per Analytics ID it contains the following parameters: Analytics Filter Information, Target of Analytics reporting, Analytics Reporting Info.
Other information
Subscribed RFSP Index
An index to specific RRM configuration in the NG-RAN that is received from the UDM.
RFSP Index in Use
An index to specific RRM configuration in the NG-RAN that is currently in use.
5G access stratum time distribution indication
The 5G access stratum time distribution indication to be provided to RAN based on the 5G access stratum time distribution indication received from the PCF.
Uu time synchronization error budget
The Uu time synchronization error budget to be provided to RAN based on the Uu time synchronization error budget received from the PCF.
Clock quality detail level
It indicates whether and which clock quality information to provide to the UE and can take one of the following values "clock quality metrics" or "acceptable/not acceptable indication".
Clock quality acceptance criteria
Indicates acceptable criteria for the UE based on the attributes defined in Table 5.27.1.12-1 of TS 23.501 [2].
UE reconnection indication
Indicates to the UE to reconnect to the network in the case the UE determines that the reference report ID has changed as described in clause 5.27.1.12 of TS 23.501 [2].
UE-AMBR in serving network
The UE-AMBR that has been sent to RAN (e.g. based on subscribed UE-AMBR from UDM or UE-AMBR received from PCF)
List of UE-Slice-MBR(s)
The list of UE-Slice-MBR if applicable. There is a single uplink and a single downlink value per S-NSSAI.
MICO Mode Indication
Indicates the MICO Mode for the UE.
Extended idle mode DRX Parameters
Negotiated extended idle mode DRX parameters.
Active Time Value for MICO mode
UE specific Active Time value allocated by AMF for MICO mode handling.
Strictly Periodic Registration Timer Indication
An indication that UE shall perform the Periodic Registration Update in a strictly periodic time, see clause 5.31.7.5 of TS 23.501 [2].
Voice Support Match Indicator
An indication whether the UE radio capabilities are compatible with the network configuration. The AMF uses it as an input for setting the IMS voice over PS Session Supported Indication over 3GPP access.
Homogenous Support of IMS Voice over PS Sessions
Indicates per UE if "IMS Voice over PS Sessions" is homogeneously supported in all TAs in the serving AMF or homogeneously not supported, or, support is non-homogeneous/unknown, see clause 5.16.3.3 of TS 23.501 [2].
UE Radio Capability for Paging Information
Information used by the NG-RAN to enhance the paging towards the UE (see clause 5.4.4.1 of TS 23.501 [2]).
Information On Recommended Cells And RAN nodes For Paging
Information sent by the NG-RAN and used by the AMF when paging the UE to help determining the NG-RAN nodes to be paged as well as to provide the information on recommended cells to each of these NG-RAN nodes, in order to optimize the probability of successful paging while minimizing the signalling load on the radio path.
UE Radio Capability Information
Information sent by the NG-RAN node and stored in the AMF. The AMF sends this information to the NG-RAN node within the UE context during transition to CM-CONNECTED state, except for NB-IoT when NB-IoT specific UE Radio Access Capability are sent instead.
UE Radio Capability ID
Pointer that uniquely identifies a set of UE Radio Capabilities in UCMF as defined in TS 23.501 [2].
NB-IoT specific UE Radio Access Capability Information
NB-IoT specific UE radio access capabilities.
WUS Assistance Information
Assistance information for determining the WUS group (see TS 23.501 [2]).
AMF PEIPS Assistance Information
AMF assigned NR paging subgroup information for use in NR paging subgrouping related to PEIPS support (see TS 23.501 [2]).
AMF LP-WUSPS Assistance Information
AMF assigned NR paging subgroup information for use in NR paging subgrouping related to LP-WUSPS support (see TS 23.501 [2]).
SMSF Identifier
The Identifier of the SMSF serving the UE in RM‑REGISTERED state.
SMSF Address
The Address of the SMSF serving the UE in RM-REGISTERED state. (see clause 4.13.3.1).
SMS Subscription
Indicates subscription to any SMS delivery service over NAS irrespective of access type.
SEAF data
Master security information received from AUSF.
Last used EPS PLMN ID
The identifier of the last used EPS PLMN.
Paging Assistance Data for CE capable UE
Paging Assistance Data for Enhanced Coverage level and cell ID provided by the last NG-RAN the UE was connected to.
Enhanced Coverage Restricted Information
Specifies per PLMN whether CE mode B is restricted for the UE, or both CE mode A and CE mode B are restricted for the UE, or both CE mode A and CE mode B are not restricted for the UE.
NB-IoT Enhanced Coverage Restricted Information
Specifies per PLMN whether the Enhanced Coverage is restricted or not for the UE.
Service Gap Time
Used to set the Service Gap timer for Service Gap Control (see clause 5.31.16 of TS 23.501 [2]).
Running Service Gap expiry time
The time of expiry of a currently running Service Gap Timer (see clause 5.31.16 of TS 23.501 [2]).
NB-IoT UE Priority
Numerical value used by the NG-RAN to prioritise between UEs accessing via NB-IoT.
List of Small Data Rate Control Statuses
List of Small Data Rate Control Statuses by DNN and S-NSSAI for the released PDU Sessions, see clause 5.31.14.3 of TS 23.501 [2].
List of APN Rate Control Statuses
Indicates for each APN, the APN Rate Control Status (see clause 4.7.7.3 of TS 23.401 [13]) received from an MME when mobility from EPC to 5GC occurs. This information is provided to the MME during 5GC to EPC mobility.
UE positioning capability
Information sent by the LMF and stored in the AMF. The AMF sends this information along with the location request to the LMF.
UE LCS User plane connection information
Information of UE LCS-UP connection indicating the UE has a maintained LCS User Plane connection with certain LMFs.
Energy Saving Indicator
The Energy Saving indicator defined in clause 5.51.5 of TS 23.501 [2].
For each access type level context within the UE access and mobility context:
Access Type
Indicates the access type for this context.
RM State
Registration management state.
UUAA-MM Status
Indicates the status of UUAA-MM if the AMF is configured to perform the UAV authentication/authorization at 5GS registration as described in clause 5.2.2 of TS 23.256 [80]. Possible states are "PENDING", "SUCCESS", "FAILED".
For status "PENDING" and "FAILED" the AMF rejects any PDU session establishment request from the UE for DNN and S-NSSAI that are used for UAS services.
Registration Area
Current Registration Area (a set of tracking areas in TAI List).
TAI of last Registration
TAI of the TA in which the last Registration Request was initiated.
User Location Information
Information on user location.
Mobility Restrictions
Mobility Restrictions restrict mobility handling or service access of a UE. It consists of RAT restriction, Forbidden area, Service area restrictions and Core Network type restriction. It may also contain an Allowed CAG list and optionally an indication whether the UE is only allowed to access 5GS via CAG cells. Each entry in the Allowed CAG list may also be associated with validity conditions (NOTE 4).
Security Information for CP
As defined in TS 33.501 [15].
Security Information for UP
As defined in TS 33.501 [15].
Allowed NSSAI
Allowed NSSAI consisting of one or more S-NSSAIs for serving PLMN in the present Registration Area.
Mapping Of Allowed NSSAI
Mapping Of Allowed NSSAI is the mapping of each S-NSSAI of the Allowed NSSAI to the S-NSSAIs of the Subscribed S-NSSAIs.
Partially Allowed NSSAI
Partially Allowed NSSAI consisting of one or more S-NSSAIs for serving PLMN.
An associated TA-list for each of the S-NSSAIs in the Partially Allowed NSSAI defines in which TAs the S-NSSAI may be used.
Mapping Of Partially Allowed NSSAI
Mapping Of Partially Allowed NSSAI is the mapping of each S-NSSAI of the Partially Allowed NSSAI to the S-NSSAIs of the Subscribed S-NSSAIs.
S-NSSAIs subject to Network Slice-Specific Authentication and Authorization
Subscribed S-NSSAIs which are subject to NSSAA procedure.
Also including the status, i.e. result, of the NSSAA if already executed or whether the S-NSSAI is pending the completion of an NSSAA procedure.
Inclusion of NSSAI in RRC Connection Establishment Allowed by HPLMN
[Only for 3GPP access] it defines whether the UDM has indicated that the UE is allowed to include NSSAI in the RRC connection Establishment in clear text.
Access Stratum Connection Establishment NSSAI Inclusion Mode
Defines what NSSAI, if any, to include in the Access Stratum connection establishment as specified in clause 5.15.9 of TS 23.501 [2].
List of mapping of the S-NSSAI to the Alternative S-NSSAI
Defines the mapping of the replaced S-NSSAIs to the Alternative S-NSSAIs configured to the UE, see clause 5.15.19 of TS 23.501 [2].
Slice Deregistration Inactivity Timer Information
It includes following information per on demand slice:
- On demand S-NSSAI.
- Ongoing slice deregistration inactivity timer information, if the slice deregistration inactivity timer is started.
If the Configured slice deregistration inactivity timer value is received from PCF, it is transferred between AMF(s) within the AM Policy information.
For more detail see clause 5.15.15.2 of TS 23.501 [2].
CM state for UE connected via N3IWF/TNGF
Identifies the UE CM state (CM-IDLE, CM-CONNECTED) for UE connected via N3IWF/TNGF
N2 address information for N3IWF/TNGF
Identifies the N3IWF/TNGF to which UE is connected. Exists only if CM state for UE connected via N3IWF/TNGF is CM-CONNECTED.
AMF UE NGAP ID
Identifies the UE association over the NG interface within the AMF as defined in TS 38.413 [10]. This parameter exists only if CM state for the respective Access Type is CM-CONNECTED.
RAN UE NGAP ID
Identifies the UE association over the NG interface within the NG-RAN node as defined in TS 38.413 [10]. This parameter exists only if CM state for the respective Access Type is CM-CONNECTED.
Network Slice Instance(s)
The Network Slice Instances selected by 5GC for this UE.
URRP-AMF information
UE Reachability Request Parameter contains a list of URRP-AMF flags and associated authorised NF IDs. Each URRP-AMF flag indicates whether direct UE reachability notification has been authorised by the HPLMN towards the associated NF ID or not.
SoR Update Indicator for Initial Registration
An indication whether the UDM requests the AMF to retrieve SoR information when the UE performs NAS Registration Type "Initial Registration".
SoR Update Indicator for Emergency Registration
An indication whether the UDM requests the AMF to retrieve SoR information when the UE performs NAS Registration Type "Emergency Registration".
Charging Characteristics
The Charging Characteristics as defined in Annex A of TS 32.256 [71].
For each PDU Session level context:
S-NSSAI(s)
The S-NSSAI(s) associated to the PDU Session.
Alternative S-NSSAI(s)
The Alternative S-NSSAI(s) for one or more of the S-NSSAI(s) may be present in case of Network Slice replacement, see clause 5.15.19 of TS 23.501 [2].
DNN
The associated DNN for the PDU Session.
Network Slice Instance id
The network Slice Instance information for the PDU Session
PDU Session ID
The identifier of the PDU Session.
SMF Information
The associated SMF identifier and SMF address for the PDU Session.
When an I-SMF is used, this additionally include the information correspond to an I-SMF.
Access Type
The current access type for this PDU Session (for a MA PDU Session this may correspond to information indicating 2 Access Type).
EBI-ARP list
The allocated EBI and associated ARP pairs for this PDU session.
5GSM Core Network Capability
The UEs 5GSM Core Network Capability as defined in clause 5.4.4b of TS 23.501 [2].
SMF derived CN assisted RAN parameters tuning
These are PDU Session specific parameters received from the SMF and used by the AMF to derive the Core Network assisted RAN parameters tuning.
PDU Session Priority
The PDU Session Priority value of the PDU session, if it is received from SMF as specified in TS 23.501 [2].
Local Offloading Management Allowed indication
Indicates whether Local Offloading Management is allowed for the PDU Session, as specified in TS 23.548 [74].
HR-SBO allowed indication
During intra-PLMN handover, indicates whether HR-SBO is allowed for the PDU session, see clause 6.7.2.6 of TS 23.548 [74].
NOTE 1: The AMF transfers the PCF ID to the SMF during PDU Session Establishment. The SMF may select the PCF identified by the PCF ID as described in clause 6.3.7.1 of TS 23.501 [2]. In HR roaming case, the AMF transfers the identifier of H-PCF as described in clause 4.3.2.2.2. In LBO roaming case, the AMF transfers the identifier of V-PCF as described in clause 4.3.2.2.1.
NOTE 2: The PCF ID in AM Policy Association information and the PCF ID in UE Policy Association Information should be the same in non-roaming case. The V-PCF ID in AM Policy Association information and the V-PCF ID in UE Policy Association Information should be the same in roaming case.
NOTE 3: Not all the parameters stored at AMF are required to be transferred between AMFs during the inter-AMF mobility. The parameters which are required to be transferred between AMFs are defined in TS 29.518 [18].
NOTE 4: The validity information is not provided to the NG-RAN. The AMF shall determine the CAG Identifier(s) to be provided to the NG-RAN in Allowed CAG list, by taking into consideration the validity information associated with the CAG Identifier(s), as described in clause 5.30.3 of TS 23.501 [2]. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.3 Namf_Communication_RegistrationStatusUpdate service operation | Service operation name: Namf_Communication_RegistrationStatusUpdate
Description: This service operation is used by the consumer NF to inform the AMF that a prior UE context transfer has resulted in the UE successfully registering with it. The UE context is marked inactive in the AMF.
Input, Required: 5G-GUTI, Status.
Input, Optional: PDU Session ID(s) (indicates the PDU Session(s) to be released), PCF reselected indicator (indicates that new AMF has selected a new PCF to handle the AM Policy association and/or the UE Policy association).
Output, Required: None.
Output, Optional: None.
See clause 4.2.2.2.2 step 10 for example usage of this service operation. When the AMF receives this request, it marks the UE context information as inactive since the UE context has been successfully transferred to the peer NF and the UE has successfully registered there. The AMF receives information about whether the AM Policy Association Information and/or the UE Policy Association Information in the UE context will be used or not (i.e. new AMF may select a different PCF and then create a new AM Policy Association and/or a new UE Policy Association). The AMF sends a Namf_Communication_RegistrationStatusUpdate response to the consumer NF.
NOTE 2: Whether notification Ack need a separate message or be realized in the transport layer will be determined in TS 29.518 [18]. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.4 Namf_Communication_N1MessageNotify service operation | Service operation name: Namf_Communication_N1MessageNotify
Description: AMF notifies the N1 message received from the UE to a destination CN NF.
Input, Required: AMF ID (GUAMI), N1 Message(s)
Input, Optional: local time zone, UE's current location, AN access information (e.g. AN type AN N2 terminating point, CAG Identifier(s) of the CAG cell), Allowed NSSAI, Mapping Of Allowed NSSAI, SUPI, MM Context, LMF identification, PRU subscription verification result.
Output, Required: None.
Output, Optional: None.
The destination NF type to be notified is determined based on one of the following:
- The N1 message type is always known to be consumed by one particular NF type; or
- An NF had explicitly subscribed for the particular N1 message type to be notified towards it.
NOTE: Whether notification Ack need a separate message or be realized in the transport layer will be determined in TS 29.518 [18].
The optional AN access information (if available), SUPI, MM Context, Allowed NSSAI and Mapping Of Allowed NSSAI parameters are included if the service operation is invoked towards a peer AMF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.5 Namf_Communication_N1N2MessageSubscribe service operation | Service operation name: Namf_Communication_N1N2MessageSubscribe.
Description: An NF can subscribe with the AMF to get notified of a particular N1 message type or a specific N2 information type about the UE.
Input, Required: CN NF ID, N1 Message Type
Input, Optional: SUPI.
Output, Required: None.
Output, Optional: None.
The consumer NF invokes the Namf_Communication_N1MessageSubscribe service operation (NF ID, N1 message type or N2 information type to subscribe) on the AMF. The consumer NF shall provide a SUPI for UE associated N1 message subscriptions. If the consumer NF is allowed to subscribe for the type of N1/N2 message requested, the AMF creates a binding for the consumer NF to deliver subsequent Namf_Communication_N1MessageNotify or Namf_Communication_N2InfoNotify towards that NF.
NOTE: Whether Subscription Ack need a separate message or be realized in the transport layer will be determined in TS 29.518 [18]. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.6 Namf_Communication_N1N2MessageUnSubscribe service operation | Service operation name: Namf_Communication_N1N2MessageUnSubscribe.
Description: An NF can unsubscribe with the AMF to stop notifying a particular N1 message type or a specific N2 information type about the UE.
Input, Required: CN NF ID, N1 Message Type
Input, Optional: None.
Output, Required: None.
Output, Optional: None.
The consumer NF invokes the Namf_Communication_N1MessageUnSubscribe service operation (NF ID, N1 message type or N2 information type to subscribe) on the AMF. The AMF deletes the binding for the consumer NF for the requested N1 message type.
NOTE: Whether UnSubscribe Ack need a separate message or be realized in the transport layer will be determined in TS 29.518 [18]. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.7 Namf_Communication_N1N2MessageTransfer service operation | Service operation name: Namf_Communication_N1N2MessageTransfer.
Description: CN NF request to transfer downlink N1 and/or N2 message to the UE and/or AN through the AMF.
Input, Required: CN NF ID, Message type (N1 or N2 or both), Message Container (s) where at least one of the message containers (N1 or N2) is required.
Input, Optional: last message indication, Session ID, Paging Policy Indicator, ARP, Area of validity for the N2 SM information, 5QI, N1N2TransferFailure Notification Target Address, type of N2 SM information, type of N2 NRPPa information, Extended Buffering Support. MA PDU session Accepted indication, target access type (3GPP access or non-3GPP access), selected alternative H-SMF ID, PDU Session Priority.
Namf_Communication_N1N2MessageTransfer supports the transfer of only one N2 message. N2 SM information and N2 NRPPa information are mutually exclusive.
Output, Required: Result indication.
Output, Optional: Redirection information, Estimated Maximum wait time.
If the UE is in CM-IDLE state, the AMF initiates the network triggered Service Request procedure as specified in clause 4.2.3.3 and responds to the consumer NF with a result indication, "attempting to reach UE". Otherwise, the AMF responds to the consumer NF, with a Namf_Communication_N1N2MessageTransfer response, providing a result indication of whether the AMF was able to successfully transfer the N1 and/or the N2 message towards the UE and/or the AN. A result indication of "N1/N2 transfer success" does not mean that N1 message is successfully received by the UE. It only means that the AMF is able to successfully send the N1 or N2 message towards the AN.
The "Area of validity for the N2 SM information", if included is used by the AMF to determine whether the N2 SM information provided by the consumer NF can be used towards the AN based on the current location of the UE. If the location of the UE is outside the "Area of validity for the N2 SM information" indicated, the AMF shall not send the N2 SM information to the AN.
If the consumer NF knows that a specific downlink N1 message is the last message to be transferred in this transaction, the consumer NF shall include the last message indication in the Namf_Communication_N1N2MessageTransfer service operation so that the AMF knows that the no more downlink N1 message need to be transferred for this transaction.
The CN NF is implicitly subscribed to be notified of N1N2TransferFailure by providing the N1N2TransferFailure Notification Target Address. When AMF detects that the UE fails to respond to paging, or the UE responds to paging with a Reject Paging Indication, or the AMF determines the UE is temporarily unreachable e.g. due to extended idle mode DRX or MICO mode, the AMF invokes the Namf_Communication_N1N2TransferFailureNotification to provide the failure notification to the location addressed by N1N2TransferFailure Notification Target Address.
The "Extended Buffering applies" indication, if included, is used by the AMF to include "Estimated Maximum Wait time" in Namf_Communication_N1N2 TransferFailureNotification if invoked due to the UE being unreachable.
If the result of the service operation fails, the AMF shall set the corresponding cause value in the result indication which can be used by the NF consumer for further action. If the related UE is not served by AMF and the AMF knows which AMF is serving the UE, the AMF provides redirection information which can be used by the consumer NF to resend UE related message to the AMF that serves the UE.
If the consumer NF is a SMF and he request includes N2 SM information, the SMF indicates the type of N2 SM information. If the consumer NF is a LMF and the request includes N2 NRPPa information, the LMF indicates the type of N2 NRPPa information.
NOTE: The actual N2 SM information or N2 NRPPa information is not interpreted by the AMF.
The selected alternative H-SMF ID information may be provided as described in clause 4.3.2.2.2.
The Small Data Rate Control Status is included if a PDU Session is being released and the UPF or NEF provided Small Data Rate Control Status when the PDU Session was released for the AMF to store.
For the usage of MA PDU session Accepted indication and target access type (3GPP access or non-3GPP access) see clauses 4.22.2, 4.22.3, 4.22.6.3 and 4.22.9.4.
5.2.2.2.7A Namf_Communication_N1N2TransferFailureNotification service operation
Service operation name: Namf_Communication_N1N2TransferFailureNotification.
Description: The AMF uses this notification to inform the NF service consumer that initiated an earlier Namf_Communication_N1N2MessageTransfer, that the AMF failed to deliver the N1 message to the UE as the UE failed to respond to paging, or the UE responded with a Reject Paging Indication.
Input, Required: Cause, N1N2MessageTransfer Notification Target Address.
Input, Optional: Estimated Maximum wait time.
Output, Required: None.
Output, Optional: None. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.8 Namf_Communication_N2InfoSubscribe service operation | Service operation name: Namf_Communication_N2InfoSubscribe.
Description: An NF invokes this service operation to subscribe for the delivery of information contained in a specific N2 message type.
Input, Required: CN NF ID, N2 information type to be subscribed.
Input, Optional: None.
Output, Required: None.
Output, Optional: None. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.9 Namf_Communication_N2InfoUnsubscribe service operation | Service operation name: Namf_Communication_N2InfoUnSubscribe.
Description: An NF can invoke this service operation to unsubscribe for the delivery of information contained in a specific N2 message type.
Input, Required: CN NF ID, N2 information type to unsubscribe.
Input, Optional: None.
Output, Required: None.
Output, Optional: None.
The consumer NF invokes the Namf_Communication_N2InfoUnSubscribe service operation (CN NF ID, N2 information type to unsubscribe) on the AMF. The AMF deletes the binding for the consumer NF to for the requested information to unsubscribe. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.10 Namf_Communication_N2InfoNotify service operation | Service operation name: Namf_Communication_N2InfoNotify.
Description: The AMF uses this service operation to notify a particular N2 message information towards the NFs that have subscribed (implicitly or explicitly) for the specific information. This service operation is also used to redirect the N2 message to the AMF that are serving the UE.
Input, Required: AMF ID (GUAMI), N2 information.
Input, Optional: Indication of the I-SMF change/removal.
Output, Required: None.
Output, Optional: None. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.11 Namf_Communication_CreateUEContext service operation | Service operation name: Namf_Communication_CreateUEContext
Description: This service operation is used by a source AMF to create the UE context in a target AMF during handover procedures or an initial AMF to relocate the UE context to a target AMF during inter PLMN handover procedure.
Input, Required: 5G-GUTI, UE context of the identified UE. As described in Table 5.2.2.2.2-1, the UE context may include the SUPI, DRX parameters, AM policy information, UE Radio Capability ID, PCF ID, UE network capability, used N1 security context information, event subscriptions by other consumer NF and the list of SM PDU Session IDs along with the SMF handling the PDU Session, N2 information including source to target RAN transparent container, Endpoint information of S-AMF to receive N2 information notification about handover complete (i.e. N2 notify URI).
Input, Optional: allocated EBI information, PCF ID, MS Classmark 2, STN-SR, C MSISDN, the Supported Codec IE, NWDAF ID(s) (i.e. Instance ID or Set ID)with the corresponding Subscription Correlation ID(s), Analytics ID (s) and Analytics specific data as defined in Table 5.2.2.2.2-1.
Output, Required: Cause, N2 information including Target to Source transparent container, N2 SM information (PDU Sessions failed to be setup list and the N3 DL forwarding information), handle for the UE context created, PCF ID.
Output, Optional: Target AMF ID. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.12 Namf_Communication_ReleaseUEContext service operation | Service operation name: Namf_Communication_ReleaseUEContext
Description: This service operation is used by a source AMF to release the UE context in a target AMF during handover cancel procedures.
Input, Required: Handle of the UE context.
Input, Optional: None.
Output, Required: Cause.
Output, Optional: None. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.13 Namf_Communication_EBIAssignment service operation | Service operation name: Namf_Communication_EBIAssignment.
Description: The consumer NF uses this service operation to request a bunch of EPS Bearer IDs for a PDU Session and optionally indicate to the AMF the list of EBI(s) to be released.
Inputs, Required: SUPI, PDU Session ID, ARP list.
Input, Optional: Released EBI list.
Outputs, Required: None.
Outputs, Optional: a list of <ARP, EBI> pair, <ARP, Cause> pair.
The consumer NF invokes the Namf_Communication_EBIAssignment service operation when it determines that one or more EPS Bearer IDs are required for EPS QoS mapping for a PDU Session. The ARP list indicates the number of the requested EBIs and the corresponding ARP. The AMF uses the ARP list (including ARP priority level, the pre-emption capability and the pre-emption vulnerability) and the S-NSSAI to prioritize the EBI request, AMF can revoke the EBI from an ongoing lower priority PDU Session, if the maximum number of EBIs have been reached and a session with a higher priority requests an EBI. The AMF responds the consumer NF with a cause which indicates whether the assignment is successful or not. If the assignment is successful, the AMF provides a list of <ARP, EBI> pair to the consumer NF.
If the consumer NF determines that some EBIs are not needed, the consumer NF indicates the EBI(s) that can be released in the Released EBI list. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.14 Namf_Communication_AMFStatusChangeSubscribe service operation | Service operation name: Namf_Communication_AMFStatusChangeSubscribe
Description: This service operation is used by an NF to subscribe for AMF Status Change notification.
Input, Required: GUAMI(s).
Input, Optional: None.
Output, Required: None.
Output, Optional: None.
See clause 5.21.2.2 of TS 23.501 [2] for the example usage of this service operation. The GUAMI(s) is used to identify the AMF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.15 Namf_Communication_AMFStatusChangeUnSubscribe service operation | Service operation name: Namf_Communication_AMFStatusChangeUnSubscribe
Description: This service operation is used by an NF to unsubscribe for AMF Status Change notification.
Input, Required: GUAMI(s).
Input, Optional: None.
Output, Required: None.
Output, Optional: None.
See clause 5.21.2.2 of TS 23.501 [2] for the example usage of this service operation. The GUAMI(s) is used to identify the AMF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.16 Namf_Communication_AMFStatusChangeNotify service operation | Service operation name: Namf_Communication_AMFStatusChangeNotify
Description: Report AMF Status change (e.g. AMF unavailable) notification to subscribed NFs.
Input, Required: GUAMI(s).
Input, Optional: Target AMF(s) Name associated with the indicated GUAMI.
Output, Required: None.
Output, Optional: None.
See clause 5.21.2.2 of TS 23.501 [2] for the example usage of this service operation. The GUAMI(s) is used to identify the AMF. For network deployment without UDSF case, the target AMF Name which is to serve the user of the indicated GUAMI is also included. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.17 Namf_Communication_NonUeN2MessageTransfer service operation | Service operation name: Namf_Communication_NonUeN2MessageTransfer
Description: NF Service Consumer requests to transfer a non-UE specific message to NG-RAN node(s) via N2.
Input, Required: N2 Message Container.
Input, Optional: TAI List, RAT Selector (ng-eNB or gNB), Global RAN Node List, Send Write-Replace-Warning-Indication, Send Stop-Warning-Indication, Timing synchronization status reporting indication.
Output, Required: N2 Information Transfer Result.
Output, Optional: PWS Result Data.
PWS Result Data is included when parts of a PWS received message have not been comprehended or were missing, or if the message contained logical errors. It may contain the Unknown Tracking Area List which may be present in the associated PWS response message. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.18 Namf_Communication_NonUeN2InfoSubscribe service operation | Service operation name: Namf_Communication_NonUeN2InfoSubscribe
Description: The NF Service Consumer invokes this service operation to subscribe to the delivery of non-UE specific information from the NG-RAN node sent via N2 to the AMF.
Input, Required: Notification Target Address, Notification Correlation ID, N2 information type to be subscribed.
Input, Optional: NG-RAN node identifier(s).
Output, Required: Subscription Correlation ID.
Output, Optional: None. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.19 Namf_Communication_NonUeN2InfoUnSubscribe service operation | Service operation name: Namf_Communication_NonUeN2InfoUnSubscribe
Description: The NF Service Consumer invokes this service operation to unsubscribe to stop notifying non-UE specific N2 information.
Input, Required: Subscription Correlation Id.
Input, Optional: None.
Output, Required: None.
Output, Optional: None. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 5.2.2.2.20 Namf_Communication_NonUeN2InfoNotify service operation | Service operation name: Namf_Communication_NonUeN2InfoNotify
Description: The AMF uses this service operation to notify a particular event towards the NF Service Consumer that has subscribed for the specific information. The AMF receives messages for such events from NG-RAN via N2.
Input, Required: Notification Correlation Information, N2 information.
Input, Optional: None.
Output, Required: None.
Output, Optional: None. |
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