6.4b APN related policy information

23.2033GPPPolicy and charging control architectureRelease 17TS

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

The purpose of the APN related policy information is to provide policy and charging control related information that is applicable to all IP‑CAN sessions of a UE to the same APN. The PCRF provides APN related policy information to the PCEF using the PCC provision procedure together with PCC rules or separately.

Table 6.4b-1 lists the applicable PCC specific APN related policy information.

Table 6.4b-1: PCC specific APN related policy information

Attribute	Description	PCRF permitted to modify the attribute	Scope
Authorized APN-AMBR	Defines the APN-AMBR for the total bandwidth usage of non-GBR QCI traffic at the APN.	Yes	All IP‑CAN sessions for the same UE within the same APN
Subsequent APN-AMBR (NOTE 1)	Defines the APN-AMBR for the total bandwidth usage of non-GBR QCI traffic at the APN to be applied by the PCEF when the APN-AMBR change time is reached.	No (NOTE 2)	All IP‑CAN sessions for the same UE within the same APN
APN-AMBR change time (NOTE 1)	Defines the time at which the PCEF shall apply the Subsequent APN-AMBR for the total bandwidth usage of non-GBR QCI traffic at the APN.	No (NOTE 2)	All IP‑CAN sessions for the same UE within the same APN
NOTE 1: Both parameters shall be provided together. The PCRF may provide up to four instances of them. If multiple instances are provided, the values of the APN-AMBR change time have to be different and should not be too close to each other in order to reduce the risk for signalling overload. NOTE 2: The PCRF may replace all instances that have been provided previously with a new instruction. A previously provided Subsequent APN-AMBR or APN-AMBR change time cannot be individually modified.

The PCRF may provide the (unconditional) Authorized APN-AMBR in every interaction with the PCEF. The PCEF shall apply the Authorized APN-AMBR as APN-AMBR for all IP‑CAN sessions of the UE to the same APN and shall communicate the changed APN-AMBR to the UE.

NOTE 1: There is always an unconditional value for the APN-AM BR available at the PCEF. The initial value is received as Subscribed APN-AMBR in an access specific manner and the PCRF can overwrite it by providing an Authorized APN-AMBR.

NOTE 2: In order to reduce the risk for signalling overload, the PCRF should avoid simultaneous provisioning of Authorized APN-AMBR for many UEs (e.g. by spreading over time).

The Authorized APN-AMBR may be provided together with conditions, i.e. a list of RAT types and/or a list of IP-CAN types. One or multiple instances of conditional APN-AMBR, with different conditions, may be provided by the PCRF. The PCEF shall apply a conditional Authorized APN-AMBR as APN-AMBR only if the current RAT type and IP-CAN type match one of the RAT types and IP-CAN types specified in the conditions, respectively. Otherwise the PCEF shall apply the unconditional Authorized APN-AMBR as APN-AMBR. A changed APN-AMBR shall be communicated to the UE.

NOTE 3: Guidance what conditional Authorized APN-AMBR value to use in case the current RAT type and IP-CAN type match multiple conditional Authorized APN-AMBRs is specified in stage 3.

Conditional Authorized APN-AMBR(s) are not applied for a PDN connection supporting NBIFOM.

Upon PCRF changing the unconditional Authorized APN-AMBR or providing a conditional Authorized APN-AMBR, the PCEF shall discard any previously received conditional Authorized APN-AMBR.

The PCRF may provide the unconditional and/or one or multiple instances of conditional Authorized APN-AMBR together with an APN-AMBR change time, referred to as Subsequent APN-AMBR. When the APN-AMBR change time is reached, the PCEF shall apply the unconditional and/or conditional Subsequent APN-AMBR as unconditional and/or conditional Authorized APN-AMBR and discard any previously applied conditional Authorized APN-AMBRs.

NOTE 4: The modification is made in the same way as if the PCRF had modified the Authorized APN-AMBR at that point in time.

Up to four instances of Subsequent APN-AMBR may be provided by the PCRF. The PCEF shall discard any previously received Subsequent APN-AMBR instances on explicit instruction as well as whenever the PCRF provides a new instruction for one or more subsequent changes to the APN-AMBR or any other subsequent parameter.

NOTE 5: In order to provide further Subsequent APN-AMBRs in a timely fashion the PCRF can use its own clock to issue the desired changes or use the Revalidation time limit parameter (clause 6.4) to trigger a PCEF request for a policy decision.