5.2.13 BSF Services

23.5023GPPProcedures for the 5G System (5GS)Release 18TS

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

5.2.13.1 General

The following table shows the BSF Services and Service Operations:

Table 5.2.13.1-1: NF services provided by the BSF

Service Name	Service Operations	Operation Semantics	Example Consumer(s)
Nbsf_Management	Register	Request/Response	PCF
	Deregister	Request/Response	PCF
	Discovery	Request/Response	NEF, AF, NWDAF, TSCTSF
	Update	Request/Response	PCF
	Subscsribe	Subscribe/Notify	NEF, PCF, AF, TSCTSF, 5G DDNMF
	Unsubscribe	Subscribe/Notify	NEF, PCF, AF, TSCTSF, 5G DDNMF
	Notify	Subscribe/Notify	NEF, PCF, AF, TSCTSF, 5G DDNMF

5.2.13.2 Nbsf_Management service

5.2.13.2.1 General

The Nbsf provides the Nbsf_Management_Register, the Nbsf_Management_Deregister and the Nbsf_Management_Discovery services, the Nbsf_Management_Update, the Nbsf_Management_Subscribe, the Nbsf_Management_Unsubscribe and the Nbsf_Management_Notify operations.

5.2.13.2.2 Nbsf_Management_Register service operation

Service Operation name: Nbsf_Management_Register

Description: Registers the tuple (UE address(es), SUPI, GPSI, MBS session ID, DNN, S-NSSAI, PCF address(es), PCF instance id, PCF Set ID, level of Binding) for a PDU Session or for a UE.

NOTE 1: In some cases only subset of these parameters may be registered (e.g. UE address(es) will be registered only if PCF registration is for a PDU Session and for MBS sessions SUPI and GPSI are also not available).

Inputs, Required: [Required, if PCF registration is for a PDU Session], UE address(es), PCF address(es), DNN [Required, if PCF registration is for a PDU Session], S-NSSAI [Required, if PCF registration is for a PDU Session], MBS session ID as defined in TS 23.247 [78] [Required, if PCF registration is for a MBS Session].

UE address can contain IP address/prefix or MAC address as defined in TS 23.501 [2]. It can optionally include Framed Route information. W-5GAN specific UE IP address information is specified in TS 23.316 [53].

Framed Route information is defined in Table 5.2.3.3.1-1.

NOTE 2: For support of time sensitive communication and time synchronization (as described in clause 5.28.3.2 of TS 23.501 [2]) the UE address contains the DS-TT port MAC address for Ethernet type PDU Session.

Inputs, Conditional: SUPI [Required, if PCF registration is for a UE or required by the local policy in PCF if the registration is for a PDU session, otherwise it is optional].

NOTE 3: The PCF can be configured to always provide a SUPI to the BSF, e.g. to support UE ID retrieval from the BSF.

Inputs, Optional: GPSI, PCF instance ID and PCF Set ID, level of Binding (see clause 6.3.1.0 of TS 23.501 [2]).

NOTE 4: DNN and S-NSSAI are not applicable when the PCF registration is for a UE.

NOTE 5: It is up to stage3 to ensure an unambiguous error proof way for the BSF to differentiate between PCF for a PDU Session and PCF for a UE. This may or may not require providing the BSF additional parameter(s) when a PCF registers itself with the BSF.

Outputs, Required: Result indication, Binding Identifier for a PDU Session, or for a UE, or for an MBS session.

Outputs, Optional: None.

5.2.13.2.3 Nbsf_Management_Deregister service operation

Service Operation name: Nbsf_Management_Deregister

Description: Removes the binding information for a PDU Session or for a UE.

Inputs, Required: Binding Identifier for a PDU Session, or for a UE, or for an MBS session.

W-5GAN specific UE IP address information are specified in TS 23.316 [53].

Inputs, Optional:

Outputs, Required: Result indication.

Outputs, Optional: None.

5.2.13.2.4 Nbsf_Management_Discovery service operation

Service Operation name: Nbsf_Management discovery

Description: Discovers the PCF and PCF set selected for a PDU Session identified by the tuple (UE address(es), SUPI, GPSI, DNN, S-NSSAI), or discovers the PCF and PCF set selected for the UE identified by the tuple (SUPI, GPSI). This operation may also be used to determine the SUPI from the tuple (UE address, DNN, S-NSSAI).

Inputs, Required: UE address (i.e. IP address or MAC address), [Required, for a PDU Session and for a UE], DNN [Conditional], S-NSSAI [Conditional], if the target PCF is for a PDU Session, MBS session ID as defined in TS 23.247 [78], [Required, for an MBS Session].

SUPI and/or GPSI, if the target PCF is for a UE.

NOTE: For support of time sensitive communication and time synchronization (as described in clause 5.28.3.2 of TS 23.501 [2]) the UE address contains the DS-TT port MAC address for Ethernet type PDU Session.

Inputs, Optional: If the target PCF is for a PDU Session, SUPI, GPSI.

Outputs, Required: PCF address(es), PCF instance ID [Conditional, if available] and PCF Set ID [Conditional, if available], level of Binding [Conditional, if available] (see clause 6.3.1.0 of TS 23.501 [2]).

Outputs, Optional: SUPI, if available.

5.2.13.2.5 Nbsf_Management_Update service operation

Service Operation name: Nbsf_Management_Update

Description: Replaces the list of UE address(es) for a PDU Session or replace PCF id or PCF address(es) for a PDU Session or for a UE..

NOTE 1: For example, PCF-2 may update its PCF id when level of binding is NF Instance and PCF-1 fails and PCF-2 is the new NF Instance handling the PDU Session or the UE.

Inputs, Required: Binding Identifier for the PDU Session.

UE address can contain IP address/prefix or Ethernet address as defined in TS 23.501 [2].

Inputs, Optional: UE address(es), PCF id, PCF address(es).

Outputs, Required: Result indication.

Outputs, Optional: None.

5.2.13.2.6 Nbsf_Management_Subscribe service operation

Service Operation name: Nbsf_Management_Subscribe

Description: NEF, AF, TSCTSF or PCF for a UE can subscribe to be notified of newly registered or deregistered PCF for a PDU Session. In addition, NEF or AF can subscribe to be notified of newly registered or deregistered PCF for a UE.

NOTE 1: If BSF has already the requested information at the time of the subscription, it will accept the subscription request and will immediately provide the results in the Outputs parameters.

Inputs, Required: SUPI, DNN(s) [Required, if PCF subscription is for a PDU Session], S-NSSAI(s) [Required, if PCF subscription is for a PDU Session], callback URI.

Inputs, Optional: GPSI, indication of registration/deregistration per (DNN, S-NSSAI).

Indication of registration/deregistration per (DNN, S-NSSAI) indicates to the BSF to report when the first SM policy association is established and when the last SM policy association is terminated to the same (DNN, S-NSSAI) combination.

NOTE 2: It is up to stage3 to ensure an unambiguous error proof way for the BSF to differentiate between PCF for a PDU Session and PCF for a UE. This may or may not require providing the BSF additional input parameter(s).

Outputs, Required: When the subscription is accepted: Subscription Correlation ID.

Outputs, Conditional: One or more instance per (DNN, S-NSSAI) of (UE address(es) [If available], PCF address(es) [If available], PCF instance ID [If available], PCF Set ID [If available], level of Binding [If available] (see clause 6.3.1.0 of TS 23.501 [2])) or notification of registration/deregistration per (DNN, S-NSSAI).

NOTE 3: The parameter UE address(es) is not applicable in the case of PCF for a UE.

5.2.13.2.7 Nbsf_Management_Unsubscribe service operation

Service Operation name: Nbsf_Management_Unsubscribe

Description: NEF, AF, TSCTSF or PCF for a UE can undo a previous subscription.

Inputs, Required: Subscription Correlation ID.

Inputs, Optional: None.

Outputs, Required: result.

Outputs, Optional: None.

5.2.13.2.8 Nbsf_Management_Notify service operation

Service Operation name: Nbsf_Management_Notify

Description: BSF can notify NEF, AF, TSCTSF or PCF for a UE of newly registered PCF for a PDU Session or of deregistered PCF for a PDU Session.

Inputs, Required: Notification Correlation Information, One or more instance per (DNN, S-NSSAI) of (UE address(es) [Required, if PCF notification is for a PDU Session], PCF address(es), PCF instance ID [Conditional, if available] and PCF Set ID [Conditional, if available]), level of Binding [Conditional, if available] (see clause 6.3.1.0 of TS 23.501 [2]) or notification of registration/deregistration per (DNN, S-NSSAI).

Inputs, Optional: None.

Outputs, Required: None.

Outputs, Optional: None.