4.3.1 Network-Initiated IP-CAN Session Modification

29.2133GPPPolicy and charging control signalling flows and Quality of Service (QoS) parameter mappingRelease 17TS

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4.3.1.1 Interactions between BBERF, PCEF, TDF, OCS, TSSF and PCRF(PCC/QoS/ADC Rule Provisioning in PUSH mode)

This flow shows the provisioning of PCC/QoS/ADC Rules and/or authorized QoS triggered by an event in the PCRF.

Figure 4.3.1.1.1: Interactions between BBERF, PCEF, TDF, OCS, TSSF and PCRF for PCRF-Initiated IP-CAN Session Modification

1. The H-PCRF receives an internal or external trigger to re-evaluate PCC Rules and policy decision for an IP-CAN Session. Possible external trigger events are described in clause 4.3.1.2. In addition, this procedure is triggered by

– PCEF subscribed event

– SPR subscription data modification (e.g. change in MPS EPS Priority, MPS Priority Level and/or IMS Signalling Priority, or change in user profile configuration indicating whether supporting application detection and control).

– OCS status of a policy counter identifier(s) has changed and the PCRF requested notification for spending limits apply.

– Application detection information report from TDF.

2. The H-PCRF selects the PCC Rule(s) to be installed, modified or removed for the IP-CAN Session. In case of PCEF supporting Application Detection and Control feature, some of those PCC rules may be used for application detection and control. The H-PCRF may also update the policy decision by defining an authorized QoS and enable or disable the service flow(s) of PCC Rules. If the PCEF controls the binding of IP-CAN bearers, the H-PCRF may add or change QoS information per QCI applicable to that IP-CAN session. In case of TDF, the H-PCRF selects the applicable ADC rules for the solicited application reporting with a TDF. If NBIFOM applies to the IP-CAN session and Network-initiated mode is selected, the H-PCRF determines the access that is to be used for the transfer of traffic and include the allowed access type in the PCC rules. If NBIFOM applies to the IP-CAN session, the H-PCRF determines one access is to be removed from multi access IP-CAN session.

3. The H-PCRF stores the updated PCC Rules, and ADC rules if available.

4. Step 4 is only applicable if the Bearer Control Mode (BCM) selected is UE-only or, for UE/NW the H-PCRF determines that UE mode applies for the affected PCC Rules, and the PCRF receives an external trigger from the AF.
The PCRF may start a timer to wait for a UE requested bearer resource initiation, modification or removal procedure initiated by the UE, as depicted in figure 4.3.2.1.1.

If a UE requested bearer resource initiation, modification or termination procedure initiated by the terminal is received for the affected PCC rules while the timer is running, all subsequent steps in the present figure shall not be executed and, for case 1, the steps in figure 4.3.2.1.1 (on provisioning based on PULL procedure at PCEF –initiated IP-CAN session modification when the AF is located in the HPLMN), 4.3.2.2.1 (on provisioning based on PULL procedure at PCEF-initiated IP-CAN session modification when the AF is located in the VPLMN) and for cases 2a and 2b, the steps in figure 4.4.2.1.1 (Home Routed case) or 4.4.2.2.1 (Visited Access case) shall be executed instead.

Otherwise, if the BCM selected is UE/NW, the PCRF shall proceed with the subsequent steps (provisioning based on PUSH procedure) in the present figure after timer expiry.

NOTE 1: For IMS Emergency session and RLOS session step 4 is not applicable.

5. For case 2a and 2b, if Gxx applies for the IP-CAN session and the user is not roaming, or the user is roaming in a Home Routed scenario or a Visited Access scenario for case 2a when the available QoS rule are not related to any IP-CAN session, the H-PCRF may initiate Gateway Control and QoS rules provisioning procedures described in clause 4.4.3.

NOTE 2: This step is not executed if this procedure is triggered by PCEF subscribed events and/or credit re-authorisation triggers reported by the BBERF.

6. The H-PCRF sends a Diameter RAR to request that the PCEF installs, modifies or removes PCC Rules and updates the policy decision, or to report PCEF subscribed events reported by the BBERF. The report includes the User Location Information and the User CSG Information (If received from the BBERF). If the provided PCC rules are related to an AF session associated with a sponsor that has requested sponsoring the service, the H-PCRF includes, in the Charging-Rule-Definition AVP, the Sponsor-Identity AVP and the Application-Service-Provider-Identity AVP that it received from the AF if the Reporting-Level AVP is set to the value SPONSORED_CONNECTIVITY_LEVEL and, if AF provided the application usage thresholds, the Usage-Monitoring-Information AVP. If the AF requests the access network information, the H-PCRF includes Required-Access-Info AVP in the Charging-Rule-Definition AVP and/or Charging-Rule-Remove AVP. In addition, the H-PCRF includes the Event-Trigger set to the value "ACCESS_NETWORK_INFO_REPORT" if not provided yet. If the Sharing-Key-UL AVP and/or Sharing-Key-DL AVP are provided within the Media-Component-Description AVP, the PCRF may apply the mechanisms for resource sharing as specified at 3GPP TS 29.212 [9]. The PCRF includes the Removal-Of-Access AVP set to the value REMOVAL_OF_ACCESS (0) and the IP-CAN-Type AVP set to the value of removed access to remove one access from the multi access IP-CAN session. If the H-PCRF subscribes the change of UE presence in Presence Reporting Area, the H-PCRF may provide the Presence Reporting Area Information to the PCEF. If the RAN-Support-Info feature is enabled and local policy allows, for PCC rules with QCI of 1, the PCRF can provide the Charging-Rule-Definition AVP including the maximum packet loss rate(s) for uplink and/or downlink direction(s) in the Max-PLR-UL/DL AVP(s) respectively.

When the UE is roaming in a Visited Access scenario, steps 6a ~ 6e are executed instead of step 6:

6a. The H-PCRF sends a Diameter RAR to the V-PCRF to request that the PCEF installs, modifies or removes PCC Rules and updates the policy decision. In the case of VPLMN supporting Application Detection and Control feature for solicited application reporting, some of those PCC Rules may be used for application detection and control. If the provided PCC rules are related to an AF session associated with a sponsor that has requested sponsoring the service, the H-PCRF includes, in the Charging-Rule-Definition AVP, the Sponsor-Identity AVP and the Application-Service-Provider-Identity AVP that it received from the AF if the Reporting-Level AVP is set to the value SPONSORED_CONNECTIVITY_LEVEL and, if AF provided the application usage thresholds, the Usage-Monitoring-Information AVP. If the AF requests the access network information, the H-PCRF includes Required-Access-Info AVP in the Charging-Rule-Definition AVP and/or Charging-Rule-Remove AVP. In addition, the H-PCRF includes the Event-Trigger set to the value "ACCESS_NETWORK_INFO_REPORT" if not provided yet.

6b. The V-PCRF enforces visited operator policies regarding PCC rules requested by the H-PCRF based on roaming agreements or locally configured policy. In case of TDF, V-PCRF extracts the ADC rules from the PCC Rules received from the H-PCRF and stores them.

NOTE 3: If the V-PCRF rejects provisioned PCC rules received from the H-PCRF, the remaining steps in this call flow are not followed. Instead, the V-PCRF shall notify the H-PCRF by sending a Diameter RAA, including the Experimental-Result-Code AVP set to the value PCC_RULE_EVENT, identify the failed PCC rules as specified in 3GPP TS 29.212 [9], and additionally may provide the acceptable QoS Information for the service.

6c. In case of TDF, solicited application reporting, for roaming UE with visited access, the V-PCRF initiates the TDF session establishment, modification, or termination. If the provided ADC rules are related to an AF session associated with a sponsor that has requested sponsoring the service, the H-PCRF includes, in the ADC-Rule-Definition AVP, the Sponsor-Identity AVP and the Application-Service-Provider-Identity AVP that are received from the AF if the Reporting-Level AVP is set to the value SPONSORED_CONNECTIVITY_LEVEL. Additionally, if the AF provided the application usage thresholds, the H-PCRF includes the Usage-Monitoring-Information AVP. If the last ADC rule is deactivated, the V-PCRF requests the TDF to terminate the TDF session toward the V-PCRF as defined in clause 4.6.2. If there is no active TDF session between the TDF and the V-PCRF, the V-PCRF requests the TDF to establish the TDF session towards V-PCRF and provides ADC Rules to the TDF as defined in clause 4.6.1. If there is already an active TDF session between the TDF and the V-PCRF, the V-PCRF provides the ADC rules to the TDF as defined in clause 4.6.3.2.

6d. For case 2a and 2b, V-PCRF will derive the QoS rules from the PCC rules. The V-PCRF will initiate a Gateway Control and QoS Rule procedure as described in clause 4.4.3 to install, modify or remove QoS rules and optionally subscribe to new events in the BBERF.

6e. The BBERF installs, modifies or removes the identified QoS Rules. The BBERF also enforces the authorized QoS of the corresponding QoS Rules.

6f. The V-PCRF sends a Diameter RAR to request that the PCEF installs, modifies or removes PCC Rules.

7. The PCEF installs, modifies or removes the identified PCC Rules. The PCEF also enforces the authorized QoS and enables or disables service flow according to the flow status of the corresponding PCC Rules. If QoS information is received per QCI, PCEF shall set/update the upper limit for the MBR that the PCEF assigns to the non-GBR bearer for that QCI. In the case of PCEF supporting Application Detection and Control feature, the PCEF may also enforce application detection and control. The PCEF may perform resource sharing among PCC rules if requested from the PCRF. If allowed access type information is included in the PCC rules, the PCEF generates the NBIFOM routing rules based on the PCC rules. If the RAN-Support-Info feature is supported, the PCEF sets the UL/DL maximum packet loss rate value(s) as described in subclause B.3.18 of 3GPP TS 29.212 [9].

The following applies for emergency sessions only:

When the PCEF receives an IP-CAN Session Modification Request from the PCRF requesting the removal of the PCC rules of an emergency session, the PCEF starts an inactivity timer to enable the PSAP to request a callback session with the UE.

When the timer expires, the PCEF initiates an IP-CAN Session Termination Request (per clause 4.2.2.1) to terminate the emergency session.

If, before the timer expires, the PCEF receives an IP-CAN Session Modification Request from the PCRF with PCC rules for an emergency session the PCEF cancels the timer.

8. The PCEF sends a Diameter RAA to acknowledge the RAR. The PCEF informs the H-PCRF about the outcome of the PCC rule operation

When the UE is roaming in a Visited Access scenario, steps 8a ~ 8d are executed instead of step 8:

8a. The BBERF informs the V-PCRF about the outcome of the operation by sending a Diameter RAA command.

8b. The PCEF informs the V-PCRF about the outcome of the PCC rule operation by sending a Diameter RAA command.

8c. The V-PCRF stores the received information.

8d. The V-PCRF informs the H-PCRF about the outcome of the operation by sending a Diameter RAA command.

9. In case of TDF, solicited application reporting, for non-roaming UE/roaming UE with home routed access, H-PCRF initiates the TDF session establishment, modification, or termination. If the provided ADC rules are related to an AF session associated with a sponsor that has requested sponsoring the service, the H-PCRF includes, in the ADC-Rule-Definition AVP, the Sponsor-Identity AVP and the Application-Service-Provider-Identity AVP that are received from the AF if the Reporting-Level AVP is set to the value SPONSORED_CONNECTIVITY_LEVEL. Additionally, if the AF provided the application usage thresholds, the H-PCRF includes the Usage-Monitoring-Information AVP. If the last ADC rule is deactivated, the H-PCRF requests the TDF to terminate the TDF session toward the H-PCRF as defined in clause 4.6.2. If there is no active TDF session between the TDF and the H-PCRF, the H-PCRF requests the TDF to establish the TDF session towards H-PCRF and provides ADC Rules to the TDF as defined in clause 4.6.1. If there is already an active TDF session between the TDF and the H-PCRF, H-PCRF provides the ADC rules to the TDF as defined in clause 4.6.3.2.

NOTE 4: Step 9 can occur anytime after step 6.

10. If traffic steering control over St applies, if the PCRF determines that the traffic steering control information needs to be provisioned for the IP-CAN session; the PCRF initiates the St session establishment procedure according to the subclause 4.9.1. If the PCRF determines that the traffic steering control information provisioned to the TSSF needs to be updated, the PCRF initiates the St session modification procedure according to the subclause 4.9.2. If the PCRF determines that the traffic steering control information is not needed for the IP-CAN session any more, the PCRF initiates the St session termination procedure according to the subclause 4.9.3.

11. In case of spending limits, for non-roaming/roaming UE with both home routed and visited access, H-PCRFinitiates Initial/ Intermediate/ Final Spending Limit Report Request. The H-PCRF sends an Initial Spending Limit Report Request if this is the first time a status notification of policy counter is requested for the user as defined in clause 4.7.1. If the H-PCRF decides to modify the list of subscribed policy counters the H-PCRF sends an Intermediate Spending Limit Report Request as defined in clause 4.7.2. If the H-PCRF decides to unsubscribe any future status notification of policy counters, it sends a Final Spending Limit Report Request to cancels the request for reporting the change of the status of the policy counters available at the OCS as defined in clause 4.7.3.

NOTE 5: Step 11 can occur anytime after step 2.

12. If usage monitoring is enabled and the H-PCRF either removed the last PCC rule applicable for certain monitoring key, or disabled usage monitoring or requested usage report, the PCEF shall initiate an IP-CAN session modification procedure.

13. When Gxx does not apply for the IP-CAN session, IP-CAN bearer signalling is executed separately for each IP-CAN bearer under the following conditions:

– If all PCC rules bound to a bearer have been removed or deactivated (bearer deactivation is applicable)

– If one or more bearers have to be modified

– If the PCEF needs to establish a new bearer (bearer establishment is applicable).

– If the PCEF needs to request access network information.

– if the PCEF needs to send the NBIFOM routing rules to the UE in the corresponding access.

14. If the AF, in step 1, has requested notifications from the PCRF, e.g. in the case of access network information the PCEF initiates an IP-CAN session modification procedure to provide the requested information as described in clause 4.3.2.

NOTE 6: If the conditions of both step 14 and step 12 apply the PCEF can make use of only one IP-CAN session modification procedure in step 14.

4.3.1.2 Interactions between PCRF, AF and SPR

4.3.1.2.1 AF Session Establishment

4.3.1.2.1.1 AF located in HPLMN

Figure 4.3.1.2.1.1.1: AF session establishment triggers PCRF-Initiated IP-CAN Session Modification (AF in HPLMN)

1. The AF receives an internal or external trigger to set-up a new AF session and provides Service Information. The AF identifies the Service Information needed (e.g. IP address of the IP flow (s), port numbers to be used, information on media types, etc).

2. The AF provides the Service Information to the H-PCRF by sending a Diameter AAR for a new Rx Diameter session. If this AF session is associated with a sponsor, Sponsor-Identity AVP, optionally the Sponsoring-Action AVP set to applicable value and the Application-Service-Provider-Identity AVP are included in Sponsored-Connectivity-Data AVP. If usage thresholds are to be associated with this sponsored AF session, then Granted-Service-Unit AVP is included in Sponsored-Connectivity-Data AVP. The AF can request access network information within the AAR by adding Required-Access-Info AVP(s) and Specific-Action AVP set to the value "ACCESS_NETWORK_INFO_REPORT". If the Service can be subject to resource sharing, the AF includes the Sharing-Key-UL AVP and/or Sharing-Key-DL AVP within the Media-Component-Description AVP. If PrioritySharing feature is supported and the service is allowed to use the same Allocation and Retention Priority (ARP) as media flows belonging to other AF sessions, the AF includes the Priority-Sharing-Indicator AVP set to PRIORITY_SHARING_ENABLED within the Media-Component-Description AVP. If the CHEM feature is supported, the AF may also include the maximum packet loss rate(s) for uplink and/or downlink direction(s) in the Max-PLR-UL/DL AVP(s) respectively within the Media-Component-Description AVP. If the service has negotiated the background data transfer policy, the AF includes the reference id of the transfer policy within the Reference-Id AVP. To invoke MPS for DTS, the AF includes the MPS-Action AVP within the AAR, as specified in clause 5.3.

3. The H-PCRF stores the received Service Information.

4. If the H-PCRF requires subscription related information and does not have it, the PCRF sends a request to the SPR in order to receive the information. If the Reference-Id AVP is received, the PCRF retrieves the corresponding transfer policy from the SPR and derives the PCC rules for the background data transfer according to the transfer policy.

If the AF session is for MPS for DTS invocation, the PCRF performs MPS subscription checks if and only if requested by the AF, as described in subclause 4.4.11 of 3GPP TS 29.214 [10].

5. The SPR replies with the subscription related information containing the information about the allowed service(s), QoS information and PCC Rules information.

NOTE: For steps 4 and 5: The details associated with the Sp reference point are not specified in this Release. The SPR’s relation to existing subscriber databases is not specified in this Release.

6. If the AF session is associated with a sponsor and sponsored service is enabled,

– if the UE is in the non-roaming case or UE is roaming with the home routed case and operator policies allow accessing the sponsored data connectivity with this roaming case, the H-PCRF authorizes the request based on sponsored data connectivity profile obtained from the SPR;

– if the UE is roaming with the home routed case and operator policies do not allow accessing the sponsored data connectivity with this roaming case or the UE is roaming with the visited access case, the H-PCRF rejects the request.

The H-PCRF identifies the affected established IP-CAN Session(s) using the information previously received from the PCEF/V-PCRF and the Service Information received from the AF.

7. The H-PCRF sends a Diameter AAA to the AF. The PCRF indicates whether the support for UE IP address/mask in the TFT filter is available in the IP-CAN session.

8. The H-PCRF interacts with the PCEF/BBERF/V-PCRF according to figure 4.3.1.1.1 (Interactions between BBERF/PCEF and PCRF for PCRF-Initiated IP-CAN Session Modification).

4.3.1.2.1.2 AF located in VPLMN

Figure 4.3.1.2.1.2.1: AF session establishment triggers PCRF-Initiated IP-CAN Session Modification (AF in VPLMN)

2. The AF provides the Service Information to the V-PCRF by sending a Diameter AAR for a new Rx Diameter session. If the AF session is associated with a sponsor, Sponsor-Identity AVP and Application-Service-Provider-Identity are included in Sponsored-Connectivity-Data AVP. If usage thresholds are to be associated with this sponsored AF session, then Granted-Service-Unit AVP is included in Sponsored-Connectivity-Data AVP. The AF can request access network information within the AAR by adding Required-Access-Info AVP(s) and Specific-Action AVP set to the value "ACCESS_NETWORK_INFO_REPORT". If the Service can be subject to resource sharing, the AF includes the Sharing-Key-UL AVP and/or Sharing-Key-DL AVP within the Media-Component-Description AVP. If PrioritySharing feature is supported and the service is allowed to use the same Allocation and Retention Priority (ARP) as media flows belonging to other AF sessions, the AF includes the Priority-Sharing-Indicator AVP set to PRIORITY_SHARING_ENABLED within the Media-Component-Description AVP. To invoke MPS for DTS, the AF includes the MPS-Action AVP within the AAR, as specified in clause 5.3.

3. The V-PCRF stores the Service Information.

NOTE 1: The V-PCRF may employ operator policies and reject the AAR from the AF if the provided Service Information is not acceptable. If this happens, the V-PCRF replies immediately to the AF, includes an unsuccessful Result-Code or Experimental-Result-Code in the AAA, and the remaining steps of this call flow are not carried out.

4. The V-PCRF forwards the Diameter AAR to the H-PCRF.

5. The H-PCRF stores the received Service Information.

6. If the H-PCRF requires subscription-related information and does not have it, the H-PCRF sends a request to the SPR in order to receive the information.

If the AF session is for MPS for DTS invocation, the PCRF performs MPS subscription checks if and only if requested by the AF, as described in subclause 4.4.11 of 3GPP TS 29.214 [10].

7. The SPR replies with the subscription related information containing the information about the allowed service(s), QoS information and PCC Rules information.

NOTE 2: For steps 6 and 7: The details associated with the Sp reference point are not specified in this Release. The SPR’s relation to existing subscriber databases is not specified in this Release.

8. If the AF session is associated with a sponsor, the H-PCRFrejects the request. Otherwise, the H-PCRF stores the Service Information and identifies the affected established IP-CAN Session (s) using the information previously received from the PCEF via the V-PCRF and the Service Information received from the AF.

9. The H-PCRF responds to the V-PCRF with a Diameter AAA. The H- PCRF indicates whether the support for UE IP address/mask in the TFT filter is available in the IP-CAN session.

10. The V-PCRF forwards the Diameter AAA to the AF.

11. The H-PCRF interacts with the PCEF/BBERF via the V-PCRF according to figure 4.3.1.1.1 (Interactions between BBERF/PCEF and PCRF for PCRF-Initiated IP-CAN Session Modification).

4.3.1.2.2 AF session modification

4.3.1.2.2.1 AF located in the HPLMN

Figure 4.3.1.2.2.1.1: AF session modification triggers PCRF-Initiated IP-CAN Session Modification (AF in HPLMN)

1. The AF receives an internal or external trigger to modify an existing AF session and provide related Service Information.

2. The AF identifies the Service Information needed (e.g. IP address of the IP flow(s), port numbers to be used, information on media types, etc.).

3. The AF provides the Service Information to the H-PCRF by sending a Diameter AAR for the existing Rx Diameter session corresponding to the modified AF session. If this AF session is associated with a sponsor, Sponsor-Identity AVP, optionally if the AF wants to enable sponsored dataconnectivity the Sponsoring-Action AVP set to the value "ENABLE_SPONSORING" and Application-Service-Provider-Identity are included in Sponsored-Connectivity-Data AVP. If application usage thresholds are to be associated with this sponsored AF session, then Granted-Service-Unit AVP is included in Sponsored-Connectivity-Data AVP. If this AF session is associated with a sponsor and the AF wants to disable sponsored data connectivity the AF includes the Sponsoring-Action AVP set to the value "DISABLE_SPONSORING" within the Sponsored-Connectivity-Data AVP. The AF can request access network information within the AAR by adding Required-Access-Info AVP(s) and Specific-Action AVP set to the value "ACCESS_NETWORK_INFO_REPORT". If resource sharing conditions have been changed, the AF includes the Sharing-Key-UL AVP and/or Sharing-Key-DL AVP within the Media-Component-Description AVP. If the service has negotiated the background data transfer policy, the AF includes the reference id of the transfer policy within the Reference-Id AVP. If PrioritySharing feature is supported and the service is allowed to use the same Allocation and Retention Priority (ARP) as media flows belonging to other AF sessions, the AF includes the Priority-Sharing-Indicator AVP within the Media-Component-Description AVP to indicate if priority sharing is enabled or disabled. The AF may also include the Pre-emption-Capability AVP and the Pre-emption-Vulnerability AVP within the Media-Component-Description AVP for the PCRF to determine the ARP values and include the Pre-emption-Control-Info AVP at the command level for the PCRF to perform the pre-emption control. If the CHEM feature is supported, the AF may also include the maximum packet loss rate(s) for uplink and/or downlink direction(s) in the Max-PLR-UL/DL AVP(s) respectively within the Media-Component-Description AVP. To invoke/revoke MPS for DTS, the AF includes the MPS-Action AVP within the AAR as specified in clause 5.3.

4. The H-PCRF stores the received Service Information. If the Reference-Id AVP is received, the PCRF retrieves the corresponding transfer policy from the SPR and derives the PCC rules for the background data transfer according to the transfer policy.

If the AF session is for MPS for DTS invocation, the PCRF performs MPS subscription checks if and only if requested by the AF, as described in subclause 4.4.11 of 3GPP TS 29.214 [10].

5. If the AF session is associated with a sponsor and sponsored service is enabled,

The H-PCRF identifies the affected established IP-CAN Session(s) using the information previously received from the PCEF/V-PCRF and the Service Information received from the AF.

6. The H-PCRF sends a Diameter AAA to the AF.

7. The H-PCRF interacts with the BBERF/PCEF/V-PCRF according to figure 4.3.1.1.1.

4.3.1.2.2.2 AF located in the VPLMN

Figure 4.3.1.2.2.2.1 AF session modification triggers PCRF-Initiated IP-CAN Session Modification (AF in VPLMN)

1. The AF receives an internal or external trigger to modify an existing AF session and provide related Service Information.

2. The AF identifies the Service Information needed (e.g. IP address of the IP flow(s), port numbers to be used, information on media types, etc.). If resource sharing conditions have been changed, the AF includes the Sharing-Key-UL AVP and/or Sharing-Key-DL AVP within the Media-Component-Description AVP. If PrioritySharing feature is supported and the service is allowed to use the same Allocation and Retention Priority (ARP) as media flows belonging to other AF sessions, the AF may include the Priority-Sharing-Indicator AVP within the Media-Component-Description AVP to indicate if priority sharing is enabled or disabled.

3. The AF provides the Service Information to the V-PCRF by sending a Diameter AAR for the existing Rx Diameter session corresponding to the modified AF session. If this AF session is associated with a sponsor, Sponsor-Identity AVP and Application-Service-Provider-Identity AVP are included in Sponsored-Connectivity-Data AVP. If usage thresholds are to be associated with this sponsored AF session, then Granted-Service-Unit AVP is included in Sponsored-Connectivity-Data AVP. The AF can request access network information within the AAR by adding Required-Access-Info AVP(s) and Specific-Action AVP set to the value "ACCESS_NETWORK_INFO_REPORT". To invoke/revoke MPS for DTS, the AF includes the MPS-Action AVP within the AAR, as specified in clause 5.3.

4. The V-PCRF stores the received Service Information.

NOTE: The V-PCRF may employ operator policies and reject the AAR from the AF if the provided Service Information is not acceptable. If this happens, the V-PCRF replies immediately to the AF, includes an unsuccessful Result-Code or Experimental-Result-Code in the AAA, and the remaining steps of this call flow are not carried out.

5. The V-PCRF forwards the Diameter AAR to the H-PCRF.

6. The H-PCRF stores the received Service Information.

If the AF session is for MPS for DTS invocation, the PCRF performs MPS subscription checks if and only if requested by the AF, as described in subclause 4.4.11 of 3GPP TS 29.214 [10].

7. The H-PCRF identifies the affected established IP-CAN Session(s) using the information previously received from the PCEF/V-PCRF and the Service Information received from the AF.

8. The H-PCRF responds with a Diameter AAA.

9. The V-PCRF forwards the Diameter AAA to the AF.

10. The H-PCRF interacts with the BBERF/PCEF via the V-PCRF according to figure 4.3.1.1.1.

4.3.1.2.3 AF session termination

4.3.1.2.3.1 AF located in the HPLMN

Figure 4.3.1.2.3.1.1: Removal of PCC/QoS Rules at AF session release (AF in HPLMN)

1. The AF receives an internal or external trigger for a session release.

2. The AF sends a session termination request, Diameter STR, to the H-PCRF to request the removal of the session. The AF can request access network information within the STR by adding a Required-Access-Info AVP.

3. The H-PCRF identifies the affected IP-CAN Session where PCC Rules and, if available, QoS Rules for the IP flow(s) of this AF session are installed. These PCC/QoS Rules need to be removed.

If the AF session being terminated corresponds to a session that included the Priority-Sharing-Indicator AVP set to PRIORITY_SHARING_ENABLED within the Media-Component-Description AVP, if the related media flow(s) was in priority sharing with other media flows, the PCRF should readjust the Allocation and Retention Priority for the remaining services sharing priority. These PCC/QoS Rules may need to be modified.

If the AF did not request access network information, and if no usage thresholds due to an AF session associated with a sponsor were provided that relate to the installed PCC rules and RAN-NAS-Cause feature is not supported, step 4a applies. If AF requested access network information, or usage thresholds due to an AF associated with a sponsor were provided that relate to the installed PCC rules,step 4b applies. If RAN-NAS-Cause is supported but Enh-RAN-NAS-Cause is not supported over Gx and the previous conditions do not apply , step 4a applies.. Otherwise step 4b applies.

4a. The H-PCRF sends Diameter STA, session termination answer, to the AF.

4b. The H-PCRF sends Diameter STA, session termination answer, to the AF and includes access network information and/or information about the resources that have been consumed by the user since the last report or RAN/NAS/TWAN/Untrusted WLAN release cause(s) if available obtained in step 5.

5. The H-PCRF interacts with the BBERF/PCEF/V-PCRF according to figure 4.3.1.1.1.

4.3.1.2.3.2 AF located in the VPLMN

Figure 4.3.1.2.3.2.1: Removal of PCC/QoS Rules at AF session release (AF in VPLMN)

1. The AF receives an internal or external trigger for a session release.

2. The AF sends a session termination request, Diameter STR, to the V-PCRF to request the removal of the session. The AF can request access network information within the STR by adding a Required-Access-Info AVP.

3. The V-PCRF forwards the Diameter STR to the H-PCRF.

4. The H-PCRF identifies the affected IP-CAN Session where PCC Rules and, if available, QoS Rules for the IP flow(s) of this AF session are installed. These PCC/QoS Rules need to be removed.

Steps 5a and 6a apply if the AF did not request access network information

5a. The H-PCRF sends Diameter STA, session termination answer, to the V-PCRF.

6a. The V-PCRF forwards the Diameter STA to the AF.

7. The H-PCRF interacts with the BBERF/PCEF via the V-PCRF according to figure 4.3.1.1.1.

Steps 5b and 6b apply if the AF requested access network information

5b. The H-PCRF sends Diameter STA, session termination answer, to the V-PCRF and includes access network information obtained in step 7.

6b. The V-PCRF forwards the Diameter STA to the AF.