ETSI TS 129 536 V19.4.0 (2026-03)

5G; 5G System; Network Slice Admission Control Services; Stage 3 (3GPP TS 29.536 version 19.4.0 Release 19)

RTS/TSGC-0429536vj40

General Information

• Status: Not Published
• Technical Committee: 3GPP CT 4 - MAP/CAMEL/GTP/BCH/SS/TrFO/IMS/GUP/WLAN (formely CN4)
• Current Stage: 8 - Draft receipt by ETSI Secretariat
• Completion Date: 10-Mar-2026

Standards Content (Sample)

TECHNICAL SPECIFICATION
5G;
5G System;
Network Slice Admission Control Services;
Stage 3
(3GPP TS 29.536 version 19.4.0 Release 19)


3GPP TS 29.536 version 19.4.0 Release 19 1 ETSI TS 129 536 V19.4.0 (2026-03)

Reference
RTS/TSGC-0429536vj40
Keywords
5G
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ETSI
3GPP TS 29.536 version 19.4.0 Release 19 2 ETSI TS 129 536 V19.4.0 (2026-03)
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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
interpreted as being references to the corresponding ETSI deliverables.
The cross reference between 3GPP and ETSI identities can be found at 3GPP to ETSI numbering cross-referencing.
Modal verbs terminology
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"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
ETSI
3GPP TS 29.536 version 19.4.0 Release 19 3 ETSI TS 129 536 V19.4.0 (2026-03)
Contents
Intellectual Property Rights . 2
Legal Notice . 2
Modal verbs terminology . 2
Foreword . 7
1 Scope . 9
2 References . 9
3 Definitions, abbreviations . 10
3.1 Definitions . 10
3.2 Abbreviations . 10
4 Overview . 10
4.1 General . 10
4.1A NSAC Architecture Options . 11
4.2 NSAC support in roaming . 12
4.3 Interaction between NSACFs . 12
4.4 NSAC support in Indirect Network Sharing . 12
5 Services offered by the NSACF . 12
5.1 Introduction . 12
5.2 Nnsacf_NSAC Service . 13
5.2.1 Service Description . 13
5.2.2 Service Operations . 14
5.2.2.1 Introduction . 14
5.2.2.2 NumOfUEsUpdate . 14
5.2.2.2.1 General . 14
5.2.2.2.2 NSAC for controlling the number of UEs . 15
5.2.2.2.3 NSAC for controlling the number of UEs in hierarchical NSACF architecture . 17
5.2.2.2.4 NSAC for controlling the number of UEs with at least one PDU session/PDN connection . 19
5.2.2.2.5 NSAC for controlling the number of UEs in case of VPLMN with HPLMN assistance NSAC
mode . 20
5.2.2.3 EACNotify . 21
5.2.2.3.1 General . 21
5.2.2.3.2 NSACF initiated EAC mode configuration . 21
5.2.2.4 NumOfPDUsUpdate . 22
5.2.2.4.1 General . 22
5.2.2.4.2 NSAC for controlling the number of PDU sessions . 22
5.2.2.4.3 NSAC for controlling the number of PDU sessions in hierarchical NSACF architecture . 25
5.2.2.4.4 NSAC for controlling the number of UEs with at least one PDU session/PDN connection per
network slice . 27
5.2.2.4.5 NSAC for controlling the number of LBO PDU Sessions in case of VPLMN with HPLMN
assistance NSAC mode . 27
5.2.2.5 LocalNumberUpdate . 29
5.2.2.5.1 General . 29
5.2.2.5.2 Update of local maximum number of UEs or PDU sessions . 29
5.2.2.6 QuotaUpdate . 30
5.2.2.6.1 General . 30
5.2.2.6.2 Update of maximum number of UEs and/or PDU sessions . 30
5.3 Nnsacf_SliceEventExposure Service . 31
5.3.1 Service Description . 31
5.3.2 Service Operations . 31
5.3.2.1 Introduction . 31
5.3.2.2 Subscribe . 31
5.3.2.2.1 General . 31
5.3.2.2.2 Creation of a subscription . 31
5.3.2.2.3 Modification of a subscription . 33
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5.3.2.2.4 Creation of a one time and immediate reporting subscription . 34
5.3.2.3 Unsubscribe . 35
5.3.2.3.1 General . 35
5.3.2.4 Notify . 35
5.3.2.4.1 General . 35
6 API Definitions . 37
6.1 Nnsacf_NSAC Service API . 37
6.1.1 Introduction. 37
6.1.2 Usage of HTTP . 37
6.1.2.1 General . 37
6.1.2.2 HTTP standard headers . 37
6.1.2.2.1 General . 37
6.1.2.2.2 Content type . 37
6.1.2.3 HTTP custom headers . 37
6.1.3 Resources . 38
6.1.3.1 Overview . 38
6.1.3.2 Resource: Slice Collection Subject to NSAC for UEs . 39
6.1.3.2.1 Description . 39
6.1.3.2.2 Resource Definition . 39
6.1.3.2.3 Resource Standard Methods . 39
6.1.3.2.4 Resource Custom Operations . 41
6.1.3.3 Resource: Slice Collection Subject to NSAC for PDU sessions . 41
6.1.3.3.1 Description . 41
6.1.3.3.2 Resource Definition . 41
6.1.3.3.3 Resource Standard Methods . 41
6.1.3.3.4 Resource Custom Operations . 42
6.1.3.4 Resource: Slice Collection Configurations . 43
6.1.3.4.1 Description . 43
6.1.3.4.2 Resource Definition . 43
6.1.3.4.3 Resource Standard Methods . 43
6.1.3.4.4 Resource Custom Operations . 43
6.1.3.4.4.2.1 Description . 43
6.1.3.4.4.2.2 Operation Definition . 43
6.1.3.5 Resource: Slice Collection Roaming Quotas . 44
6.1.3.5.1 Description . 44
6.1.3.5.2 Resource Definition . 44
6.1.3.5.3 Resource Standard Methods . 45
6.1.3.5.4 Resource Custom Operations . 45
6.1.3.5.4.2.1 Description . 45
6.1.3.5.4.2.2 Operation Definition . 45
6.1.4 Custom Operations without associated resources . 46
6.1.5 Notifications . 46
6.1.5.1 General . 46
6.1.5.2 EAC Mode Notification . 47
6.1.5.2.1 Description . 47
6.1.5.2.2 Target URI . 47
6.1.5.2.3 Standard Methods . 47
6.1.6 Data Model . 47
6.1.6.1 General . 47
6.1.6.2 Structured data types . 49
6.1.6.2.1 Introduction . 49
6.1.6.2.2 Type: UeACRequestData . 50
6.1.6.2.3 Type: UeACResponseData . 51
6.1.6.2.4 Type: EacNotification . 51
6.1.6.2.5 Type: AcuOperationItem . 52
6.1.6.2.6 Type: AcuFailureItem . 53
6.1.6.2.7 Type: PduACRequestData . 53
6.1.6.2.8 Type: PduACResponseData . 54
6.1.6.2.9 Type: UeACRequestInfo . 54
6.1.6.2.10 Type: PduACRequestInfo. 55
6.1.6.2.11 Type: UeAdmissionValue . 55
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6.1.6.2.12 Type: PduAdmissionValue . 56
6.1.6.2.13 Type: ACUpdateData . 56
6.1.6.2.14 Type: QuotaUpdateRequestData . 56
6.1.6.2.15 Type: QuotaUpdateResponseData . 56
6.1.6.3 Simple data types and enumerations . 57
6.1.6.3.1 Introduction . 57
6.1.6.3.2 Simple data types . 57
6.1.6.3.3 Enumeration: EACMode . 57
6.1.6.3.4 Enumeration: AcuFlag . 57
6.1.6.3.5 Enumeration: AcuFailureReason . 57
6.1.6.3.6 Enumeration: SliceQuotaType . 58
6.1.6.3.7 Enumeration: NsacAdmissionMode . 58
6.1.6.3.8 Enumeration: QuotaExceedIndication . 59
6.1.6.4 Data types describing alternative data types or combinations of data types . 59
6.1.6.5 Binary data . 59
6.1.7 Error Handling . 59
6.1.7.1 General . 59
6.1.7.2 Protocol Errors . 59
6.1.7.3 Application Errors . 59
6.1.8 Feature negotiation . 60
6.1.9 Security . 60
6.1.10 HTTP redirection . 61
6.2 Nnsacf_SliceEventExposure Service API . 61
6.2.1 Introduction. 61
6.2.2 Usage of HTTP . 62
6.2.2.1 General . 62
6.2.2.2 HTTP standard headers . 62
6.2.2.2.1 General . 62
6.2.2.2.2 Content type . 62
6.2.2.3 HTTP custom headers . 62
6.2.3 Resources . 62
6.2.3.1 Overview . 62
6.2.3.2 Resource: Subscriptions collection . 63
6.2.3.2.1 Description . 63
6.2.3.2.2 Resource Definition . 63
6.2.3.2.3 Resource Standard Methods . 63
6.2.3.2.4 Resource Custom Operations . 65
6.2.3.3 Resource: Individual subscription . 65
6.2.3.3.1 Description . 65
6.2.3.3.2 Resource Definition . 65
6.2.3.3.3 Resource Standard Methods . 65
6.2.3.3.4 Resource Custom Operations . 69
6.2.4 Custom Operations without associated resources . 69
6.2.5 Notifications . 69
6.2.5.1 General . 69
6.2.5.2 NSACF Event Notification . 69
6.2.5.2.1 Notification Definition . 69
6.2.5.2.2 Notification Standard Methods . 69
6.2.6 Data Model . 70
6.2.6.1 General . 70
6.2.6.2 Structured data types . 71
6.2.6.2.1 Introduction . 71
6.2.6.2.2 Type: SACEventSubscription . 72
6.2.6.2.3 Type: CreatedSACEventSubscription . 73
6.2.6.2.4 Type: SACEventReport . 73
6.2.6.2.5 Type: SACEvent . 74
6.2.6.2.6 Type: SACEventReportItem . 75
6.2.6.2.7 Type: SACEventState . 75
6.2.6.3 Simple data types and enumerations . 76
6.2.6.3.1 Introduction . 76
6.2.6.3.2 Simple data types . 76
6.2.6.3.3 Enumeration: SACEventType . 76
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6.2.6.3.4 Enumeration: SACEventTrigger . 76
6.2.6.4 Data types describing alternative data types or combinations of data types . 76
6.2.6.5 Binary data . 76
6.2.7 Error Handling . 76
6.2.7.1 General . 76
6.2.7.2 Protocol Errors . 77
6.2.7.3 Application Errors . 77
6.2.8 Feature negotiation . 77
6.2.9 Security . 77
6.2.10 HTTP redirection . 78
Annex A (normative): OpenAPI specification . 79
A.1 General . 79
A.2 Nnsacf_NSAC API . 79
A.3 Nnsacf_SliceEventExposure API . 88
Annex B (informative): Change history . 95
History . 99

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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.
In the present document, modal verbs have the following meanings:
shall indicates a mandatory requirement to do something
shall not indicates an interdiction (prohibition) to do something
The constructions "shall" and "shall not" are confined to the context of normative provisions, and do not appear in
Technical Reports.
The constructions "must" and "must not" are not used as substitutes for "shall" and "shall not". Their use is avoided
insofar as possible, and they are not used in a normative context except in a direct citation from an external, referenced,
non-3GPP document, or so as to maintain continuity of style when extending or modifying the provisions of such a
referenced document.
should indicates a recommendation to do something
should not indicates a recommendation not to do something
may indicates permission to do something
need not indicates permission not to do something
The construction "may not" is ambiguous and is not used in normative elements. The unambiguous constructions
"might not" or "shall not" are used instead, depending upon the meaning intended.
can indicates that something is possible
cannot indicates that something is impossible
The constructions "can" and "cannot" are not substitutes for "may" and "need not".
will indicates that something is certain or expected to happen as a result of action taken by an agency
the behaviour of which is outside the scope of the present document
will not indicates that something is certain or expected not to happen as a result of action taken by an
agency the behaviour of which is outside the scope of the present document
might indicates a likelihood that something will happen as a result of action taken by some agency the
behaviour of which is outside the scope of the present document
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might not indicates a likelihood that something will not happen as a result of action taken by some agency
the behaviour of which is outside the scope of the present document
In addition:
is (or any other verb in the indicative mood) indicates a statement of fact
is not (or any other negative verb in the indicative mood) indicates a statement of fact
The constructions "is" and "is not" do not indicate requirements.
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1 Scope
The present document specifies the stage 3 protocol and data model for the Nnsacf Service Based Interface. It provides
stage 3 protocol definitions and message flows, and specifies the API for each service offered by the NSACF.
The 5G System stage 2 architecture and procedures are specified in 3GPP TS 23.501 [2] and 3GPP TS 23.502 [3].
The Technical Realization of the Service Based Architecture and the Principles and Guidelines for Services Definition
are specified in 3GPP TS 29.500 [4] and 3GPP TS 29.501 [5].
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 29.500: "5G System; Technical Realization of Service Based Architecture; Stage 3".
[5] 3GPP TS 29.501: "5G System; Principles and Guidelines for Services Definition; Stage 3".
[6] OpenAPI: "OpenAPI Specification Version 3.0.0", https://spec.openapis.org/oas/v3.0.0.
[7] 3GPP TR 21.900: "Technical Specification Group working methods".
[8] 3GPP TS 33.501: "Security architecture and procedures for 5G system".
[9] IETF RFC 6749: "The OAuth 2.0 Authorization Framework".
[10] 3GPP TS 29.510: "5G System; Network Function Repository Services; Stage 3".
[11] IETF RFC 9113: "HTTP/2".
[12] IETF RFC 8259: "The JavaScript Object Notation (JSON) Data Interchange Format".
[13] IETF RFC 9457: "Problem Details for HTTP APIs".
[14] IETF RFC 6902: "JavaScript Object Notation (JSON) Patch".
[15] Void
[16] 3GPP TS 29.571: "5G System; Common Data Types for Service Based Interfaces Stage 3".
[17] Void
[18] 3GPP TS 23.288: "Architecture enhancements for 5G System (5GS) to support network data
analytics services".
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3 Definitions, 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].
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
5GC 5G Core Network
AMF Access Management Function
DCCF Data Collection Coordination Function
EAC Early Admission Control
MCX Mission Critical Service
MPS Multimedia Priority Service
NEF Network Exposure Function
NID Network identifier
NSAC Network Slice Admission Control
NSACF Network Slice Admission Control Function
NSCE Network Slice Capability Enablement
NWDAF Network Data Analytics Function
SMF Session Management Function
SNPN Standalone Non-Public Network
4 Overview
4.1 General
Within the 5GC of a PLMN or a SNPN, the NSACF offers services to the AMF, SMF (or combined SMF+PGW-C),
NWDAF, NEF, DCCF, NSCE and NSACF via the Nnsacf service based interface (see 3GPP TS 23.501 [2] and
3GPP TS 23.502 [3]).
Figures 4.1 provides the reference model (in service based interface representation and in reference point
representation), with focus on the NSACF and the scope of the present specification.
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AMF
SMF
N80
NEF
N81
N82
NWDAF Nnsacf NSACF
AF
N99
DCCF
NSACF
NSCE
Figure 4-1: Reference model – NSACF
The functionalities supported by the NSACF are listed in clause 6.2.28 of 3GPP TS 23.501 [2].
The services and service operations provided by the Nnsacf interface are listed in clause 5.2.21 of 3GPP TS 23.502 [3].
When the UE connects to EPS and EPS counting is required, it is the combined SMF+PGW-C invokes NSACF services
to perform network slice admission control, during PDN connection establishment procedure and PDN connection
release procedure, as specified in clause 5.15.11.5 of 3GPP TS 23.501 [2].
NOTE: A trusted AF can access NSACF services either via NEF to NSACF or directly to NSACF. An untrusted
AF shall only be allowed to access NSACF services via NEF. If multiple NSACFs are deployed in the
network and the trusted AF is interested in the aggreg
...