Content for  TS 23.203  Word version:  17.2.0

The BBF access network may become aware of the IMSI of the 3GPP UE if 3GPP-based access authentication (EAP-AKA/AKA') is performed. The BPCF also becomes aware of the UE local IP address.

The BPCF Initiates a IP-CAN session establishment over S9a to the PCRF for non-roaming and to the V-PCRF for roaming cases, the information contained in the request message includes IMSI, IP-CAN type, local UE IP address and the NSWO-APN. Triggered by the IP-CAN session establishment over S9 the V-PCRF triggers the S9 session establishment to the H-PCRF.

The PCRF retrieves user profile from SPR as described in clause 7.2. As part of the user profile, the PCRF may receive an indication on whether policy control for NSWO traffic should be performed for that UE.

The PCRF enables policy control for NSWO traffic for that UE based on operator policies and user profile information that may depend on e.g. network where the UE is offloading. The PCRF sends a reply message containing PCC Rules if policy control is enabled .

Triggered by the successful establishment of the IP-CAN session for the UE local IP address in step 3, the V-PCRF (roaming) and the PCRF (non-roaming) may establish a session with the TDF to provision ADC Rules for that UE local IP address (if applicable, when solicited application reporting applies and when policy control for offloaded traffic is to be performed). The PCRF provides the TDF with the UE local IP address, the IMSI, the IP-CAN type and the NSWO-APN.

The TDF replies as described in the clause 7.2.

IP-CAN session establishment as specified in clause 7.2 is performed, including the establishment of a Gateway Control session (if applicable), as specified below with the following additional information: In case 2a and case 2b, the ePDG (BBERF) initiates a Gateway Control Session Establishment procedure to provide the UE local IP address and UDP port (if available) as defined in clause P.7.5.1. For case 1, step 3 of clause 7.2 for WLAN scenario the PCEF includes the UE local IP address and the UDP port number (if available), while for the H(e)NB scenario the PCEF includes the H(e)NB Local IP address and the UDP port number (if available) in the Fixed Broadband Access at which the H(e)NB is connected to. In case 2b, S-GW (BBERF) initiates a Gateway Control Session Establishment procedure to request QoS Rules for the H(e)NB local IP address as defined in clause P.7.5.1. The PCRF determines, based on information (UE local IP address information or H(e)NB local IP address information) provided in the IP-CAN session establishment indication or Gateway Control Session establishment indication (if applicable), whether or not the user is connecting via a Fixed Broadband Access Network.

Triggered by the IP-CAN session establishment indication, or triggered by Gateway control session establishment over Gxb*, the PCRF (non-roaming case) or the V-PCRF (visited access roaming case) initiates Gateway Control Session establishment with the BPCF over S9a, if no Gateway Control Session exists for the same IMSI for WLAN scenario. The PCRF includes in the request message to BPCF the IMSI, the UE local IP address and the UDP port number (if available), QoS Rules, and the ePDG IP address (for S2b-GTP access) or PDN GW IP address (for trusted S2c access), while for the H(e)NB scenario, the PCRF (Non-roaming case) or the V-PCRF (visited access roaming case) initiates Gateway Control Session establishment with the BPCF over S9a, if no Gateway Control Session exists for the same H(e)NB including the IMSI, H(e)NB Local IP address, the UDP port number (if available) and QoS Rules. For home routed, the H-PCRF initiates a Gateway Control Session over S9 to trigger the V-PCRF to establish a Gateway Control Session over S9a, for visited access, the V-PCRF initiates a Gateway Control Session over S9 to H-PCRF and the Gateway Control Session over S9a to BPCF.

For WLAN scenario the BPCF Initiates the Gateway Control session establishment on S9a including in the request message the IMSI, UE Local IP address and the UDP port (if available), while for the H(e)NB scenario it includes the IMSI, H(e)NB Local IP address and the UDP port number (if available) to the PCRF.

The PCRF reply message contains the result code.

Triggered by the IP-CAN session establishment indication, or triggered by Gateway control session establishment over Gxb*, the PCRF (non-roaming case) or the V-PCRF (visited access roaming case) initiates Gateway Control and QoS Rule provisioning including QoS Rules and the PDN GW IP address (for trusted S2c access and if this PDN GW IP address has not been provided before), if a Gateway Control Session exists for the same IMSI for WLAN scenario while for the H(e)NB scenario the PCRF (Non-roaming case) or the V-PCRF (visited access roaming case) initiates Gateway Control and QoS Rule provisioning, if Gateway Control Session exists for the same H(e)NB including QoS Rules.

The PCRF reply message contains the result code.

Remaining steps of IP-CAN session establishment procedure as defined in clause 7.2 from step 6 onwards.

The PCEF initiates the IP-CAN session termination over Gx, as defined in the clauses 7.3.1 and 7.3.2.

This step is triggered by the IP-CAN session termination indication in step 3 in clauses 7.3.1 and 7.3.2, the PCRF (non-roaming case) or the H-PCRF (roaming case) initiates Gateway Control Session Termination over S9a with the BPCF if this is the last IP-CAN session corresponding to this Gateway Control Session over S9a, or initiates Gateway Control and QoS Rule Provisioning over S9a to remove QoS Rules for the purpose to release resources in the Fixed Broadband Access. For case 2a, the description of the Gateway Control Session Termination procedure over Gxb* when triggered by the PCRF is described in clause P.7.5.4.

The BPCF reply message contains the result code.

Remaining steps of IP-CAN session termination as described in clause 7.3 from step 4 onwards, with the additions that in .case 2a and roaming scenario, triggered by step2, the vPCRF initiates the Gateway control session termination with the ePDG over Gxb* if the Gateway control session over S9a bound to that IMSI has been terminated.

If the BBF access network is aware of the UE is detached from the BBF access network, the BPCF Initiates IP-CAN session termination to the PCRF (non-roaming) and the V-PCRF (for roaming cases). Triggered by the IP-CAN session termination over S9a, the V-PCRF triggers the IP-CAN session termination over S9.

The PCRF reply message contains the result code for the IP-CAN session terminated.

Triggered by step 6, the PCRF (for non-roaming case) and the V-PCRF (for roaming cases) terminates the TDF session, if exists for the UE local IP address as described in the clause 7.3.

The TDF replies as described in the clause 7.3.

The PCRF (non-roaming case) initiates Gateway Control and QoS Rule Provisioning with the BPCF to provide either:

1. QoS-Rule with the QoS control information (i.e. QCI, GBR, MBR, ARP) and SDF information; and/or
2. UE local IP address and/or the UDP port number, the H(e)NB Local IP address may be provided in the request;
3. Information (e.g. Session ID) that allows the BPCF to associate the request with the existing Gateway Control Session on S9a so that the fixed access can identify the traffic plane resources that are affected.

The H-PCRF (home routed roaming case) provisions for WLAN case the UE local IP address and UDP port number (if available) and for H(e)NB case the H(e)NB local IP address and UDP port number (if available) to the V-PCRF to trigger the provisioning over S9a.

The BPCF translates the QoS rule as received of the S9a interface (i.e. SDF information, QCI, GBR, MBR and ARP) into access specific QoS parameters applicable in the BBF domain (the details of the mapping from 3GPP QoS parameters on S9a to QoS parameters applicable in the BBF domain is out of 3GPP scope). The BPCF may respond with a "counter-offer" in form of acceptable bandwidth and/or QoS for one or more SDFs if it cannot provide the requested QoS from the PCRF. The BPCF provides the acceptable QoS in the BBF access using 3GPP QoS parameters (i.e. QCI, GBR, MBR and ARP) and SDF information on S9a interface in the reply if the QoS validation for admission control fails. The PCRF may make a new policy decision, e.g. decide to modify or remove the affected QoS rules.

The AF or the TDF provides/revokes service information to the PCRF and detected event triggers if applicable as described in steps 1a, 2a and 1b in clause 7.4.2. For roaming case and for NS-WLAN offloaded traffic, the TDF provides service information and event triggers detected to the V-PCRF.

The PCRF for non-roaming cases or the H-PCRF for roaming cases, makes the authorization and policy decision.

The PCRF acknowledges to the TDF as described in clause 7.4.2.

The steps in (A) show PCC signalling to provision QoS Rules for EPC routed traffic. Step A.1. Step A.2. Step A.3.

The steps in (B) show PCC signalling to provision PCC Rules for NS-WLAN offloaded traffic. Step B.1. Step B.2. Step B.3.

The AF acknowledges the notification from the PCRF.

The steps in (A) show PCC signalling to report QoS Rule failure to PCRF for the EPC routed traffic. Step A.1. Step A.2. Step A.3. Step A.4. Step A.5.

The steps in (B) show PCC signalling to report PCC Rule failure to PCRF for NSWO traffic. Step B.1. Step B.2. Step B.3. Step B.4.