S.4 Architecture model and reference points
23.2033GPPPolicy and charging control architectureRelease 17TS
S.4.1 Reference architecture
S.4.1.1 General
The reference architecture described in clause 5.1 and shown in figures S.4.1.2-1 and S.4.1.3-1 applies with the exception and addition listed in the following:
– PCEF resides in the IP-Edge in the Broadband Forum access network;
– Gxx reference point is not used.
NOTE 1: Either SPR or UDR is used in this architecture.
NOTE 2: The roaming scenario is not applicable to fixed device and RG.
S.4.1.2 Reference architecture – Non-Roaming
Figure S.4.1.2-1: PCC Reference architecture for Fixed Broadband Access convergence when SPR is used
S.4.1.3 Reference architecture – Roaming
Figure S.4.1.3-1: PCC Reference architecture for Fixed Broadband Access convergence (roaming) when SPR is used
S.4.2 Reference points
S.4.2.1 Gx Reference Point
This reference point corresponds to the Gx which resides between the PCEF in the IP-Edge and the PCRF.
The same functionality as defined in clause 5.2.2 with the following exceptions:
– No provisioning of IP flow mobility routing information from PCEF to PCRF is performed.
– Negotiation of IP‑CAN bearer establishment mode (UE-only or UE/NW) does not apply.
In addition, for the purpose of convergence between 3GPP access and Broadband Forum access network, the Gx reference point enables the transfer of PCC rules for an IP-CAN session that exists in the PCEF for a fixed device or for a 3GPP UE.
S.4.2.2 Sp Reference Point
For the purpose of policy and charging control convergence between 3GPP and Broadband Forum access network, the Sp reference point allows the PCRF to request subscription information from the SPR based on a subscriber ID that is defined in clause S.5.2.1. When the subscriber Id is an IMSI, the PDN identifier is the NSWO-APN. When the subscriber Id is used to identify a fixed device no PDN identifier is applicable.
NOTE 1: The naming convention of NSWO-APN is left to operator’s implementation decision.
S.4.2.3 Ud Reference Point
For the purpose of convergence between 3GPP access and Broadband Forum access network, the Ud reference point provides the same functionality as the Sp reference point described in clause S.4.2.2.
S.4.2.4 Gy/Gz Reference Point
These reference points provide the same functionality as defined in the clauses 5.2.4 and 5.2.5 respectively.
For the purpose of convergence between 3GPP access and BBF access network, the functions of credit management and reporting is defined in clause S.5.1.6.
The Gz and Gy interfaces are specified in TS 32.240 [3] and the functionalities required across the Gz and Gy reference point are defined in TS 32.251 [9].
S.4.2.5 Gyn/Gzn Reference Point
These reference points provide the same functionality as defined in the clause 5.2.10 and 5.2.11 respectively.
In addition for the purpose of convergence between 3GPP and BBF access network, the functions of credit management and reporting are defined in clause S.5.1.6.
The Gzn and Gyn interfaces are specified in TS 32.240 [3] and the functionalities required across the Gzn and Gyn reference point are defined in TS 32.251 [9].
S.4.2.6 Sd Reference Point
For the purpose of convergence between 3GPP and Broadband Forum access network, the Sd reference point allows PCRF to have dynamic control over the application detection and control behaviour at a TDF for a fixed device or for a 3GPP UE. The Sd reference point enables the signalling of ADC decision, which governs the ADC behaviour. The Sd reference point provides the same functionality as the Sd described in clause 5.2.8.