ETSI TS 129 523 V15.2.0 (2019-10)

5G; 5G System; Policy Control Event Exposure Service; Stage 3 (3GPP TS 29.523 version 15.2.0 Release 15)

RTS/TSGC-0329523vf20

General Information

• Status: Published
• Publication Date: 23-Oct-2019
• Technical Committee: 3GPP CT 3 - Interworking with external networks (formely CN3)
• Current Stage: 12 - Completion
• Completion Date: 24-Oct-2019

Standards Content (Sample)

ETSI TS 129 523 V15.2.0 (2019-10)






TECHNICAL SPECIFICATION
5G;
5G System;
Policy Control Event Exposure Service;
Stage 3
(3GPP TS 29.523 version 15.2.0 Release 15)

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3GPP TS 29.523 version 15.2.0 Release 15 1 ETSI TS 129 523 V15.2.0 (2019-10)



Reference
RTS/TSGC-0329523vf20
Keywords
5G
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3GPP TS 29.523 version 15.2.0 Release 15 2 ETSI TS 129 523 V15.2.0 (2019-10)
Intellectual Property Rights
Essential patents
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Legal Notice
This Technical Specification (TS) has been produced by ETSI 3rd Generation Partnership Project (3GPP).
The present document may refer to technical specifications or reports using their 3GPP identities. These shall be
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Modal verbs terminology
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"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
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3GPP TS 29.523 version 15.2.0 Release 15 3 ETSI TS 129 523 V15.2.0 (2019-10)
Contents
Intellectual Property Rights . 2
Legal Notice . 2
Modal verbs terminology . 2
Foreword . 5
1 Scope . 6
2 References . 6
3 Definitions, symbols and abbreviations . 7
3.1 Definitions . 7
3.2 Abbreviations . 7
4 Npcf_EventExposure Service . 7
4.1 Service Description . 7
4.1.1 Overview . 7
4.1.2 Service Architecture . 8
4.1.3 Network Functions . 9
4.1.3.1 Policy Control Function (PCF) . 9
4.1.3.2 NF Service Consumers . 9
4.2 Service Operations . 9
4.2.1 Introduction. 9
4.2.2 Npcf_EventExposure_Subscribe service operation . 9
4.2.2.1 General . 9
4.2.2.2 Creating a new subscription . 10
4.2.2.3 Modifying an existing subscription . 11
4.2.3 Npcf_EventExposure_UnSubscribe service operation . 12
4.2.3.1 General . 12
4.2.3.2 Unsubscription from event notifications . 12
4.2.4 Npcf_EventExposure_Notify service operation . 13
4.2.4.1 General . 13
4.2.4.2 Notification about subscribed events . 13
5 Npcf_EventExposure Service API . 14
5.1 Introduction . 14
5.2 Usage of HTTP . 15
5.2.1 General . 15
5.2.2 HTTP standard headers . 15
5.2.2.1 General . 15
5.2.2.2 Content type . 15
5.2.3 HTTP custom headers . 15
5.2.3.1 General . 15
5.3 Resources . 15
5.3.1 Resource Structure . 15
5.3.2 Resource: Policy Control Events Subscriptions (Collection) . 16
5.3.2.1 Description . 16
5.3.2.2 Resource definition . 16
5.3.2.3 Resource Standard Methods . 16
5.3.2.3.1 POST . 16
5.3.2.4 Resource Custom Operations . 17
5.3.3 Resource: Individual Policy Control Events Subscription (Document) . 17
5.3.3.1 Description . 17
5.3.3.2 Resource definition . 17
5.3.3.3 Resource Standard Methods . 17
5.3.3.3.1 GET . 17
5.3.3.3.2 PUT . 18
5.3.3.3.3 DELETE . 18
5.3.3.4 Resource Custom Operations . 19
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3GPP TS 29.523 version 15.2.0 Release 15 4 ETSI TS 129 523 V15.2.0 (2019-10)
5.4 Custom Operations without associated resources. 19
5.5 Notifications . 19
5.5.1 General . 19
5.5.2 Policy Control Event Notification . 19
5.5.2.1 Description . 19
5.5.2.2 Target URI . 19
5.5.2.3 Standard Methods . 19
5.5.2.3.1 POST . 19
5.6 Data Model . 20
5.6.1 General . 20
5.6.2 Structured data types . 21
5.6.2.1 Introduction . 21
5.6.2.2 Type PcEventExposureSubsc . 22
5.6.2.3 Type PcEventExposureNotif . 22
5.6.2.4 Type ReportingInformation. 23
5.6.2.5 Type ServiceIdentification . 23
5.6.2.6 Type EthernetFlowInfo . 24
5.6.2.7 Type IpFlowInfo . 24
5.6.2.8 Type PcEventNotification . 24
5.6.2.9 Type PduSessionInformation . 25
5.6.3 Simple data types and enumerations . 25
5.6.3.1 Introduction . 25
5.6.3.2 Simple data types . 25
5.6.3.3 Enumeration: PcEvent . 25
5.7 Error handling . 25
5.7.1 General . 25
5.7.2 Protocol Errors . 26
5.7.3 Application Errors . 26
5.8 Feature negotiation . 26
5.9 Security . 26
Annex A (normative): OpenAPI specification . 27
A.1 General . 27
A.2 Npcf_EventExposure API . 27
Annex B (informative): Change history . 33
History . 34

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3GPP TS 29.523 version 15.2.0 Release 15 5 ETSI TS 129 523 V15.2.0 (2019-10)
Foreword
This Technical Specification has been produced by the 3rd Generation Partnership Project (3GPP).
The contents of the present document are subject to continuing work within the TSG and may change following formal
TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an
identifying change of release date and an increase in version number as follows:
Version x.y.z
where:
x the first digit:
1 presented to TSG for information;
2 presented to TSG for approval;
3 or greater indicates TSG approved document under change control.
y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections,
updates, etc.
z the third digit is incremented when editorial only changes have been incorporated in the document.
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3GPP TS 29.523 version 15.2.0 Release 15 6 ETSI TS 129 523 V15.2.0 (2019-10)
1 Scope
The present document specifies the stage 3 protocol and data model for the Policy Control Event Exposure Service of
the 5G System. It provides stage 3 protocol definitions, message flows and specifies the API for the Npcf Event
Exposure service.
The 5G System stage 2 architecture and the procedures are specified in 3GPP TS 23.501 [2], 3GPP TS 23.502 [3] and
3GPP TS 23.503 [4].
The 5G System stage 3 call flows are provided in 3GPP TS 29.513 [8].
The Technical Realization of the Service Based Architecture and the Principles and Guidelines for Services Definition
are specified in 3GPP TS 29.500 [5] and 3GPP TS 29.501 [6].
The Policy Control Event Exposure Service is provided by the Policy Control Function (PCF). This service exposes
policy control events observed at the PCF.
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
- References are either specific (identified by date of publication, edition number, version number, etc.) or
non-specific.
- For a specific reference, subsequent revisions do not apply.
- For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including
a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same
Release as the present document.
[1] 3GPP TR 21.905: "Vocabulary for 3GPP Specifications".
[2] 3GPP TS 23.501: "System Architecture for the 5G System; Stage 2".
[3] 3GPP TS 23.502: "Procedures for the 5G System; Stage 2".
[4] 3GPP TS 23.503: "Policy and Charging Control Framework for the 5G System; Stage 2".
[5] 3GPP TS 29.500: "5G System; Technical Realization of Service Based Architecture; Stage 3".
[6] 3GPP TS 29.501: "5G System; Principles and Guidelines for Services Definition; Stage 3".
[7] OpenAPI: "OpenAPI 3.0.0 Specification", https://github.com/OAI/OpenAPI-
Specification/blob/master/versions/3.0.0.md.
[8] 3GPP TS 29.513: "5G System; Policy and Charging Control signalling flows and QoS parameter
mapping; Stage 3".
[9] 3GPP TS 29.512: "5G System; Session Management Policy Control Service; Stage 3".
[10] 3GPP TS 29.507: "5G System; Access and Mobility Policy Control Service; Stage 3".
[11] 3GPP TS 29.525: "5G System; UE Policy Control Service; Stage 3".
[12] 3GPP TS 29.514: "5G System; Policy Authorization Service; Stage 3".
[13] 3GPP TS 29.214: "Policy and Charging Control over Rx reference point".
[14] 3GPP TS 29.571: "5G System; Common Data Types for Service Based Interfaces; Stage 3".
[15] 3GPP TS 29.508: "5G System; Session Management Event Exposure Service; Stage 3".
[16] IETF RFC 7540: "Hypertext Transfer Protocol Version 2 (HTTP/2)".
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3GPP TS 29.523 version 15.2.0 Release 15 7 ETSI TS 129 523 V15.2.0 (2019-10)
[17] IETF RFC 8259: "The JavaScript Object Notation (JSON) Data Interchange Format".
[18] IETF RFC 7807: "Problem Details for HTTP APIs".
[19] 3GPP TS 33.501: "Security architecture and procedures for 5G system".
[20] IETF RFC 6749: "The OAuth 2.0 Authorization Framework".
[21] 3GPP TS 29.510: "5G System; Network Function Repository Services; Stage 3".
[22] 3GPP TR 21.900: "Technical Specification Group working methods".
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in 3GPP TR 21.905 [1] and the following
apply. A term defined in the present document takes precedence over the definition of the same term, if any, in
3GPP TR 21.905 [1].
example: text used to clarify abstract rules by applying them literally.
3.2 Abbreviations
For the purposes of the present document, the abbreviations given in 3GPP TR 21.905 [1] and the following apply. An
abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in
3GPP TR 21.905 [1].
AF Application Function
API Application Programming Interface
DNN Data Network Name
ePDG evolved Packet Data Gateway
GPSI Generic Public Subscription Identifier
HTTP Hypertext Transfer Protocol
NEF Network Exposure Function
NF Network Function
NRF Network Repository Function
PCF Policy Control Function
RFSP RAT Frequency Selection Priority
S-NSSAI Single Network Slice Selection Assistance Information
SUPI Subscription Permanent Identifier
URSP UE Route Selection Policy
4 Npcf_EventExposure Service
4.1 Service Description
4.1.1 Overview
The Policy Event Exposure Service, as defined in 3GPP TS 23.502 [3] and 3GPP TS 23.503 [4], is provided by the
Policy Control Function (PCF).
This service:
- allows NF service consumers to subscribe, modify and unsubscribe for policy control events; and
- notifies NF service consumers with a corresponding subscription about observed events on the PCF.
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3GPP TS 29.523 version 15.2.0 Release 15 8 ETSI TS 129 523 V15.2.0 (2019-10)
The types of observed events include:
- PLMN identifier notification; and
- Access type change.
The target of the event reporting may include a group of UE(s) or any UE (i.e. all UEs). When the event occurs, to
which the NF service consumer has subscribed to, the PCF reports the requested information to the NF service
consumer based on the event reporting information definition requested by the NF service consumer (see
3GPP TS 23.502 [3], subclause 4.15.1).
4.1.2 Service Architecture
The 5G System Architecture is defined in 3GPP TS 23.501 [2]. The Policy and Charging related 5G architecture and
signalling flows are also described in 3GPP TS 29.513 [8].
The Policy Event Exposure Service (Npcf_EventExposure) is part of the Npcf service-based interface exhibited by the
Policy Control Function (PCF).
The only known NF service consumer of the Npcf_EventExposure service is the Network Exposure Function (NEF).
The Npcf_EventExposure service is provided by the PCF and consumed by the NEF, as shown in figure 4.1.2-1 for the
SBI representation model and in figure 4.1.2-2 for reference point representation model.
PCF
Npcf
Npcf_EventExposure
NEF


Figure 4.1.2-1: Npcf_EventExposure service Architecture, SBI representation
PC F
N30
NEF

Figure 4.1.2-2: Npcf_EventExposure service Architecture, reference point representation
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3GPP TS 29.523 version 15.2.0 Release 15 9 ETSI TS 129 523 V15.2.0 (2019-10)
4.1.3 Network Functions
4.1.3.1 Policy Control Function (PCF)
The PCF (Policy Control Function) is a functional element that encompasses policy control decision and flow based
charging control functionalities as defined in 3GPP TS 29.512 [9], access and mobility policy decisions for the control
of the UE Service Area Restrictions and RAT/RFSP control as defined in 3GPP TS 29.507 [10] and UE Policy
decisions for the control of Access network discovery and selection policy and UE Route Selection Policy (URSP) as
defined in 3GPP TS 29.525 [11].
The policy control decision and flow based charging control functionalities enable the PCF to provide network control
regarding the service data flow detection, gating, QoS and flow based charging (except credit management) towards the
SMF/UPF. The PCF offers these capabilities to the NF service consumers (e.g. the AF and NEF) as defined in
3GPP TS 29.514 [12] and 3GPP TS 29.214 [13].
The Policy Event Exposure Service enables the PCF to report policy control events observed in one or more PCF
services to NF service consumers.
4.1.3.2 NF Service Consumers
The Network Exposure Function (NEF) is a functional element that supports the following functionalities:
- The NEF securely exposes network capabilities and events provided by 3GPP NFs to AF.
- The NEF provides a means for the AF to securely provide information to 3GPP network and can authenticate,
authorize and assist in throttling the AF.
- The NEF translates the information received from the AF to the one sent to internal 3GPP NFs, and vice versa.
- The NEF supports exposing information (collected from other 3GPP NFs) to the AF.
4.2 Service Operations
4.2.1 Introduction
Service operations defined for the Npcf_EventExposure Service are shown in table 4.2.1-1.
Table 4.2.1-1: Npcf_EventExposure Service Operations
Service Operation Name Description Initiated by
Npcf_EventExposure_Subscribe This service operation is used by an NF service NF service
consumer to subscribe for event notifications on consumer (NEF)
a specified policy control event for a group of
UE(s) or any UE, or to modify a subscription.
Npcf_EventExposure_Unsubscribe This service operation is used by an NF service NF service
consumer to unsubscribe from event consumer (NEF)
notifications.
Npcf_EventExposure_Notify This service operation is used by the PCF to PCF
report UE related policy control event(s) to the
NF service consumer which has subscribed to
the event report service.

4.2.2 Npcf_EventExposure_Subscribe service operation
4.2.2.1 General
This service operation is used by an NF service consumer to subscribe for policy events notifications on a specified
context for a group of UE(s) or any UE, or to modify an existing subscription.
The following are the types of events for which a subscription can be made:
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3GPP TS 29.523 version 15.2.0 Release 15 10 ETSI TS 129 523 V15.2.0 (2019-10)
- PLMN identifier notification; and
- Change of Access Type.
The following procedures using the Npcf_EventExposure_Subscribe service operation are supported:
- creating a new subscription;
- modifying an existing subscription.
4.2.2.2 Creating a
...