5.2.2 Message flows

32.2563GPP5G connection and mobility domain chargingCharging managementRelease 16Stage 2TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

5.2.2.1 General

The flows in the present document specify the interaction between the AMF and the CHF for 5G connection and mobility converged charging functionality, in different scenarios, based on TS 23.501 [200] and TS 23.502 [201] procedures and flows.

This interaction is based on Charging Data Request /Response specified in TS 32.290 [57], exchanged between the AMF embedding the CTF and the CHF.

As a general principle, the steps in the figures for the message flows below correspond to the steps of figures in TS 23.502 [202], which is the reference. The present document specifies the charging specific extension part.

5.2.2.2 Registration management charging from AMF

5.2.2.2.1 General

The subclause below describes registration management charging.

For registration procedures, the following scenarios specified in TS 32.290 [57] are supported:

– PEC;

– IEC;

– ECUR.

For deregistration procedures, only PEC scenario is supported.

5.2.2.2.2 General Registration – PEC charging

The following figure 5.2.2.2.2.1 describes a Registration charging message flow in PEC charging, based on figure 4.2.2.2.2-1 of TS 23.502 [202] description and, applicable to:

– Initial Registration in 5GS;

– Mobility Registration Update; or

– Periodic Registration Update; or

– Emergency Registration.

Figure 5.2.2.2.2.1: Registration – PEC charging

1-14c. Registration procedure initiated by UE.

10: The new AMF notifies the old AMF that the registration of the UE in the new AMF is completed.

14d: If necessary, the old AMF is requested by UDM to delete Registration Management contexts and PDU Sessions.

14dCh: The old AMF interacts with the CHF as per deregistration procedure described in figure 5.2.2.2.8.1.

21. Upon successful procedure, Registration Accept sent to the UE.

21ch-a. The AMF sends Charging Data Request [Event] to CHF for the UE successful registration.

21ch-b. The CHF creates the CDR for this registration.

21ch-c. The CHF acknowledges by sending Charging Data Response [Event] to the AMF.

5.2.2.2.3 General Registration – IEC

The following figure 5.2.2.2.3.1 describes a Registration charging message flows in IEC, based on the clause 5.2.2.2.2 Registration description:

Figure 5.2.2.2.3.1: Registration – IEC

1-14c. Registration procedure initiated by UE.

15-16: AM policy association procedure.

16ch-a. The AMF sends Charging Data Request [Event] to CHF for the UE registration to be granted authorization, rated and accounted.

16ch-b. Account and Rating control by the CHF for the registration and CDR creation.

16ch-c. The CHF acknowledges by sending Charging Data Response [Event] and the AMF, granting authorization to the registration.

17 to 24. Same steps as in Figure 5.2.2.2.2.1.

5.2.2.2.4 General Registration – ECUR

The following figure 5.2.2.2.4.1 describes a Registration charging message flows in ECUR, based on the clause 5.2.2.2.2 Registration description:

Figure 5.2.2.2.4.1: Registration – ECUR

1-14c. Registration procedure initiated by UE.

15-16: AM policy association procedure.

16ch-a. The AMF sends Charging Data Request [Initial] to CHF for the UE registration to be granted authorization.

16ch-b. Account and Rating control by the CHF for the registration and open a CDR.

16ch-c. The CHF acknowledges by sending Charging Data Response [Initial] and the AMF, granting authorization to the registration.

17 to 21. Same steps as in Figure 5.2.2.2.2.1.

21ch-a. The AMF sends Charging Data Request [Termination] to CHF for the UE successful registration.

21ch-b. The CHF closes the CDR for this registration.

21ch-c. The CHF acknowledges by sending Charging Data Response [Termination] to the AMF.

5.2.2.2.5 Registration with AMF re-allocation – PEC charging

The following figure 5.2.2.2.5.1 describes a registration with AMF re-allocation PEC charging, based on figure 4.2.2.2.3-1 TS 23.502 [202] description:

Figure 5.2.2.2.5.1: Registration with AMF re-allocation– PEC charging

1-7b. Registration with AMF re-allocation procedure.

21ch-a to 21ch-c: same steps as per Figure 5.2.2.2.2.1.

4-24b. Registration procedure in PEC charging in clause 5.2.2.2.2.

5.2.2.2.6 Registration with AMF re-allocation – IEC

AMF re-allocation IEC charging is described by the figure 5.2.2.2.5.1 with the Registration procedure in steps 4-24b. referring to IEC charging in clause 5.2.2.2.3.

5.2.2.2.7 Registration with AMF re-allocation – ECUR

AMF re-allocation IEC charging is described by the figure 5.2.2.2.5.1 with the Registration procedure in steps 4-24b. referring to ECUR charging in clause 5.2.2.2.4.

5.2.2.2.8 Deregistration – PEC charging

The Deregistration message flows are applicable to:

– UE-initiated deregistration

– Network-initiated Deregistration.

The following figure 5.2.2.2.8.1 describes a UE-initiated deregistration in PEC charging, based on figure 4.2.2.3.2-1 of TS 23.502 [202] description:

Figure 5.2.2.2.8.1: UE-initiated Deregistration – PEC charging

1. Deregistration procedure initiated by UE.

1ch-a. The AMF sends Charging Data Request [Event] to CHF for the UE deregistration.

1ch-b. The CHF creates the CDR for this deregistration.

1ch-c. The CHF acknowledges by sending Charging Data Response [Event] to the AMF.

7: The AMF sends NAS message Deregistration Accept to UE. In case of Deregistration type is switch-off, the Deregistration Accept message is not sent.

The following figure 5.2.2.2.8.2 describes a Network-initiated Deregistration in PEC charging, based on figure 4.2.2.3.3-1 of TS 23.502 [202] description:

Figure 5.2.2.2.8.2: Network-initiated Deregistration – PEC charging

1. AMF receives Nudm_UECM_DeregistrationNotification from UDM.

2. Deregistration Request sent towards the UE. In case of Implicit Deregistration, the Deregistration Request message is not sent.

2ch-a. The AMF sends Charging Data Request [Event] to CHF for the UE successful deregistration.

2ch-b. The CHF creates the CDR for this deregistration.

2ch-c. The CHF acknowledges by sending Charging Data Response [Event] to the AMF.

[3-8]. Deregistration procedure steps.

5.2.2.2.9 Registration – Untrusted non-3GPP access – PEC charging

The following figure 5.2.2.2.9.1 describes UE Registration via Untrusted non-3GPP Access, in PEC charging, based on figure 4.12.2.2-1 of TS 23.502 [202] description.

Figure 5.2.2.2.9.1: Registration via Untrusted non-3GPP Access – PEC

1-11b. UE registration procedure via N3IWF.

12. Upon successful procedure, NAS Registration Accept sent to N3IWF by AMF.

12ch-a. The AMF sends Charging Data Request [Event] to CHF for the UE successful registration.

12ch-b. The CHF creates the CDR for this registration.

12ch-c. The CHF acknowledges by sending Charging Data Response [Event] to the AMF.

5.2.2.2.10 Registration – Untrusted non-3GPP access – IEC

The following figure 5.2.2.2.10.1 describes UE Registration via Untrusted non-3GPP Access in IEC, based on figure 4.12.2.2-1 of TS 23.502 [202] description.

Figure 5.2.2.2.10.1: Registration via Untrusted non-3GPP Access – IEC

1-11b. UE registration procedure via N3IWF.

11c. Registration procedure in IEC with AMF interactions with PCF, UDM, as specified in clause 5.2.2.2.3.

11cch-a. to 11cch-c. Same steps as 16ch-a to 16ch-c of Figure 5.2.2.2.3.1.

5.2.2.2.11 Registration – Untrusted non-3GPP access – ECUR

The following figure 5.2.2.2.11.1 describes UE Registration via Untrusted non-3GPP Access in ECUR, based on figure 4.12.2.2-1 of TS 23.502 [202] description.

Figure 5.2.2.2.11.1: Registration via Untrusted non-3GPP Access – ECUR

1-11b. UE registration procedure via N3IWF.

11c. Registration procedure with AMF interactions with PCF, UDM, as specified in clause 5.2.2.2.3.

11cch-a. to 11cch-c. Same steps as 16ch-a to 16ch-c of Figure 5.2.2.2.4.1.

12ch-a. to 12ch-c. Same steps as 21ch-a to 21ch-c of Figure 5.2.2.2.4.1.

5.2.2.2.12 Registration for SMS over NAS – PEC charging

The following figure 5.2.2.2.12.1 describes a registration in 5GS for SMS over NAS in PEC charging, based on figure 4.13.3.1-1 TS 23.502 [202], where the "SMS supported" indication is included in Registration Request from the UE.

Figure 5.2.2.2.12.1: Registration for SMS over NAS – PEC charging

Steps 1-7: SMS service activation in the SMSF

Step 8: SMSF answers to the AMF with Nsmsf_SMService_Activate service

9ch-a to 9ch-c: Same steps as 21ch-a to 21ch-c of Figure 5.2.2.2.2.1. The "SMS allowed" indication is included in addition.

5.2.2.2.13 Registration for SMS over NAS – IEC

The following figure 5.2.2.2.13.1 describes a registration in 5GS for SMS over NAS in IEC, based on clause 5.2.2.2.12.

Figure 5.2.2.2.13.1: Registration for SMS over NAS – IEC

Steps 1-4: UE Registration for SMS.

4ch-a to 4ch-c: Same steps as 16ch-a to 16ch-c of Figure 5.2.2.2.2.1. The "SMS allowed" indication is included.

Step 5-9: Registration for SMS procedure

5.2.2.2.14 Registration for SMS over NAS – ECUR

The following figure 5.2.2.2.14.1 describes a registration in 5GS for SMS over NAS in ECUR, based on clause 5.2.2.2.12.

Figure 5.2.2.2.14.1: Registration for SMS over NAS – ECUR

Steps 1-4: UE Registration for SMS.

4ch-a to 4ch-c: Same steps as 16ch-a to 16ch-c of Figure 5.2.2.2.4.1. The "SMS allowed" indication is included.

Step 5-9: Registration for SMS procedure

9ch-a to 9ch-c: Same steps as 21ch-a to 21ch-c of Figure 5.2.2.2.4.1.

5.2.2.2.15 Deregistration for SMS over NAS – PEC charging

Deregistration procedures for SMS over NAS are specified in TS 23.502 [202] clause 4.13.3.2:

– When based on subsequent Registration Request message from the UE, the registration charging scenario in clause 5.2.2.2.2 or 5.2.2.2.3 applies.

– When based on procedures in which UE is determined as deregistered by the AMF, the Network-initiated deregistration charging scenario in clause 5.2.2.2.8 applies.

5.2.2.3 Connection management charging from AMF

5.2.2.3.1 General

The clause below describes connection management charging, which includes:

– N2 connection for this UE between the AN and the AMF for 3GPP access and untrusted non-3GPP access.

The TS 23.502 [201] service request procedures and flows are used to describe one of the N2 connection establishment cases. The procedures for N2 connection establishment are specified in TS 38.413 [203] for 3GPP access and exceptions in TS 29.413 [204] for untrusted non-3GPP, under the establishment of UE-associated logical NG-connection.

5.2.2.3.2 UE Triggered Service Request

The following figure 5.2.2.3.2.1 describes UE N2 connection during UE Triggered Service Request, in event based offline charging, based on figure 4.2.3.2-1 of TS 23.502 [202] description.

Figure 5.2.2.3.2.1: UE Triggered Service Request –PEC charging

1-13. Service request procedure initiated by UE.

14. The (R)AN sends N2 Request ACK to AMF.

14ch-a. The AMF sends Charging Data Request [Event] to CHF for the N2 connection established for the UE.

14ch-b. The CHF creates the CDR for this N2 connectionestablishment.

14ch-c. The CHF acknowledges by sending Charging Data Response [Event] to the AMF.

15-22. Service request procedure continuation.

In case of untrusted non-3GPP, the (R)AN corresponds to an N3IWF, and the figure 4.2.3.2-1 of TS 23.502 [202] description applies with the exceptions specified in clause 4.12.4.1 of TS 23.502 [202].

5.2.2.3.3 Network Triggered Service Request

Based on figure 4.2.3.3-1 of TS 23.502 [202] description, a Service Request procedure from the UE is triggered from the Network, and corresponding N2 connection event offline charging in clause 5.2.2.3.2 applies.

5.2.2.3.4 AN release

The following figure 5.2.2.3.4.1 describes UE N2 connection release in event based offline charging, based on figure 4.2.6-1 of TS 23.502 [202] description.

Figure 5.2.2.3.4.1: AN release –PEC charging

1a-3. Release initiated by the (R)AN.

4. The AMF receives an N2 UE Context Release Complete.

4ch-a. The AMF sends Charging Data Request [Event] to CHF for the UE N2 connection release.

4ch-b. The CHF creates the CDR for this N2 connection release.

4ch-c. The CHF acknowledges by sending Charging Data Response [Event] to the AMF.

5-7. AN release procedure continuation.

In case of untrusted non-3GPP, the procedure is specified in figure 4.12.4.2-1 of TS 23.502 [202], and the figure 5.2.2.3.4.1 applies with following differences:

– (R)AN corresponds to an N3IWF.

– step 1a is replaced by conditions in figure 4.12.4.2-1 of TS 23.502 [202]

5.2.2.4 Location reporting charging

5.2.2.4.1 General

The clause below describes location reporting charging.

5.2.2.4.2 Location reporting

The following figure 5.2.2.4.2.1 describes Location reporting charging, in Post Event Charging.

Figure 5.2.2.4.2.1: Location reporting – Post Event Charging

1. A New N2 connection is established between NG-RAN and AMF and Location Reporting charging is activated in the AMF charging profile, potentially with a list of Presence Reporting Area(s).

2. The AMF starts the procedure based on figure 4.10-1 of TS 23.502 [202] description and sends "Location Reporting Control" to NG-RAN indicating UE changes of location or presence in Presence Reporting Area(s) need to be reported.

3. Location Report received by AMF includes the UE current location, and potentially presence in Presence Reporting Area(s).

3ch-a. The AMF sends Charging Data Request [Event, location reporting] to CHF with the current user location, and initial status(es) of presence in subscribed PRA(s) if requested in step 1.

3ch-b. The CHF creates the CDR for this location reporting.

3ch-c. The CHF acknowledges by sending Charging Data Response [Event, location reporting] to the AMF.

4. Change in UE Location or presence in Presence Reporting Area(s) occur per AMF criteria provided in step 2.

5. Location Report is received by AMF.

5ch-a. The AMF sends Charging Data Request [Event, location reporting] to CHF with the new user location, and PRA Identifier(s) and indication(s) whether the UE is inside or outside the Presence Reporting Area(s) if any.

5ch-b. The CHF creates the CDR for this location reporting.

5ch-c. The CHF acknowledges by sending Charging Data Response [Event, location reporting] to the AMF.

5.2.2.5 Roaming – Registration management charging from AMF

5.2.2.5.1 General

In roaming, for registration management charging, the AMF in VPLMN:

– may support PEC, IEC or ECUR scenario with H-CHF in HPLMN;

– shall support PEC scenario with V-CHF in VPLMN.

5.2.2.5.2 Registration – PEC to HPLMN

The following figure 5.2.2.5.2.1 describes a Registration charging message flow in PEC to HPLMN scenario for roaming, based on figure 4.2.2.2.2-1 of TS 23.502 [202] description

Figure 5.2.2.5.2.1: Roaming Registration – PEC to HPLMN

1-20a. Registration procedure initiated by UE per steps 1 to 20a of figure 4.2.2.2.2-1 of TS 23.502, with PCF, AUSF and UDM in HPLMN.

21. Upon successful procedure, Registration Accept sent to the UE.

21ch-a. Upon Registration completed trigger, the AMF in VPLMN may send Charging Data Request [Event] to H-CHF for the UE successful registration, indicating "roamer out".

21ch-b. The H-CHF creates the CDR for this registration.

21ch-c. The H-CHF acknowledges by sending Charging Data Response [Event] to the AMF in VPLMN.

21ch-d. The AMF in VPLMN sends Charging Data Request [Event] to the V-CHF for the UE successful registration, indicating "roamer in".

21ch-e. The V-CHF creates the CDR for this registration.

21ch-f. The V-CHF acknowledges by sending Charging Data Response [Event] to the AMF in VPLMN.

5.2.2.5.3 Registration – IEC to HPLMN

The following figure 5.2.2.5.3.1 describes a Registration charging message flows in IEC to HPLMN scenario for roaming, based on the clause 5.2.2.2.2 Registration description:

Figure 5.2.2.5.3.1: Roaming Registration – IEC to HPLMN

1-16. Registration procedure initiated by UE per steps 1 to 16 of figure 4.2.2.2.2-1 of TS 23.502, with PCF, AUSF and UDM in HPLMN.

16ch-a. Upon Registration checked trigger, the AMF in VPLMN sends Charging Data Request [Event] to H-CHF for the UE registration to be granted authorization, rated and accounted, indicating "roamer out".

16ch-b. Accounting and Rating control by the H-CHF for the registration and CDR creation.

16ch-c. The H-CHF acknowledges by sending Charging Data Response [Event] to the AMF in VPLMN, granting authorization to the registration.

21ch-a. Upon Registration completed trigger, the AMF in VPLMN sends Charging Data Request [Event] to V-CHF for the UE successful registration, indicating "roamer in".

21ch-b. The V-CHF creates the CDR for this registration.

21ch-c. The V-CHF acknowledges by sending Charging Data Response [Event] to the AMF in VPLMN.

17 to 24. Same steps as in Figure 5.2.2.2.2.1.

5.2.2.5.4 Registration – ECUR to HPLMN

The following figure 5.2.2.5.4.1 describes a Registration charging message flows in ECUR to HPLMN scenario for roaming, based on the clause 5.2.2.2.2 Registration description:

Figure 5.2.2.5.4.1: Roaming Registration – ECUR to HPLMN

1-16. Registration procedure initiated by UE per steps 1 to 16 of figure 4.2.2.2.2-1 of TS 23.502, with PCF, AUSF and UDM in HPLMN.

16ch-a. Upon Registration checked trigger, the AMF sends Charging Data Request [Initial] to H-CHF for the UE registration to be granted authorization, indicating "roamer out".

16ch-b. Account and Rating control by the H-CHF for the registration and open a CDR.

16ch-c. The H-CHF acknowledges by sending Charging Data Response [Initial] to the AMF in VPLMN, granting authorization to the registration.

17 to 21. Same steps as in Figure 5.2.2.2.2.1.

21ch-a. The AMF in VPLMN sends Charging Data Request [Termination] to H-CHF for the UE successful registration.

21ch-b. The H-CHF closes the CDR for this registration.

21ch-c. The H-CHF acknowledges by sending Charging Data Response [Termination] to the AMF in VPLMN.

21ch-d. The AMF in VPLMN sends Charging Data Request [Event] to V-CHF for the UE successful registration, indicating "roamer in".

21ch-e. The V-CHF creates the CDR for this registration.

21ch-f. The V-CHF acknowledges by sending Charging Data Response [Event] to the AMF in VPLMN.

5.2.2.5.5 Deregistration – PEC to HPLMN

The following figure 5.2.2.5.5.1 describes a deregistration UE-initiated or Network-initiated in PEC to HPLMN for roaming, based on figure 4.2.2.3.2-1 and figure 4.2.2.3.3-1 of TS 23.502 [202] description:

Figure 5.2.2.5.5.1: Roaming Deregistration – PEC to HPLMN

1. Deregistration Request from the UE or towards the UE.

1ch-a. Upon Deregistration trigger, the AMF in VPLMN sends Charging Data Request [Event] to H-CHF for the UE successful deregistration, indicating "roamer out".

1ch-b. The H-CHF creates the CDR for this deregistration.

1ch-c. The H-CHF acknowledges by sending Charging Data Response [Event] to the AMF in VPLMN.

1ch-d. The AMF in VPLMN sends Charging Data Request [Event] to V-CHF for the UE successful deregistration, indicating "roamer in".

1ch-e. The V-CHF creates the CDR for this deregistration.

1ch-f. The V-CHF acknowledges by sending Charging Data Response [Event] to the AMF in VPLMN

[6-8]. Deregistration procedure steps.