ETSI TS 123 379 V19.10.0 (2026-04)

LTE; Functional architecture and information flows to support Mission Critical Push To Talk (MCPTT); Stage 2 (3GPP TS 23.379 version 19.10.0 Release 19)

RTS/TSGS-0623379vja0

General Information

• Status: Not Published
• Technical Committee: 3GPP SA 6 - Mission-critical applications
• Current Stage: 12 - Citation in the OJ (auto-insert)
• Completion Date: 13-Apr-2026

Standards Content (Sample)

TECHNICAL SPECIFICATION
LTE;
Functional architecture and information flows to support
Mission Critical Push To Talk (MCPTT);
Stage 2
(3GPP TS 23.379 version 19.10.0 Release 19)

3GPP TS 23.379 version 19.10.0 Release 19 1 ETSI TS 123 379 V19.10.0 (2026-04)

Reference
RTS/TSGS-0623379vja0
Keywords
LTE
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: [phone]  Fax: [phone]

Siret N° 348 623 562 00017 - APE 7112B
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° w061004871

Important notice
The present document can be downloaded from the
ETSI Search & Browse Standards application.
The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any
existing or perceived difference in contents between such versions and/or in print, the prevailing version of an ETSI
deliverable is the one made publicly available in PDF format on ETSI deliver repository.
Users should be aware that the present document may be revised or have its status changed,
this information is available in the Milestones listing.
If you find errors in the present document, please send your comments to
the relevant service listed under Committee Support Staff.
If you find a security vulnerability in the present document, please report it through our
Coordinated Vulnerability Disclosure (CVD) program.
Notice of disclaimer & limitation of liability
The information provided in the present deliverable is directed solely to professionals who have the appropriate degree of
experience to understand and interpret its content in accordance with generally accepted engineering or
other professional standard and applicable regulations.
No recommendation as to products and services or vendors is made or should be implied.
No representation or warranty is made that this deliverable is technically accurate or sufficient or conforms to any law
and/or governmental rule and/or regulation and further, no representation or warranty is made of merchantability or fitness
for any particular purpose or against infringement of intellectual property rights.
In no event shall ETSI be held liable for loss of profits or any other incidental or consequential damages.

Any software contained in this deliverable is provided "AS IS" with no warranties, express or implied, including but not
limited to, the warranties of merchantability, fitness for a particular purpose and non-infringement of intellectual property
rights and ETSI shall not be held liable in any event for any damages whatsoever (including, without limitation, damages
for loss of profits, business interruption, loss of information, or any other pecuniary loss) arising out of or related to the use
of or inability to use the software.
Copyright Notification
No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm except as authorized by written permission of ETSI.
The content of the PDF version shall not be modified without the written authorization of ETSI.
The copyright and the foregoing restriction extend to reproduction in all media.

© ETSI 2026.
All rights reserved.
ETSI
3GPP TS 23.379 version 19.10.0 Release 19 2 ETSI TS 123 379 V19.10.0 (2026-04)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The declarations
pertaining to these essential IPRs, if any, are publicly available for ETSI members and non-members, and can be
found in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to
ETSI in respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the
ETSI IPR online database.
Pursuant to the ETSI Directives including the ETSI IPR Policy, no investigation regarding the essentiality of IPRs,
including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not
referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become,
essential to the present document.
Trademarks
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
DECT™, PLUGTESTS™, UMTS™ and the ETSI logo are trademarks of ETSI registered for the benefit of its
Members. 3GPP™, LTE™ and 5G™ logo are trademarks of ETSI registered for the benefit of its Members and of the
3GPP Organizational Partners. oneM2M™ logo is a trademark of ETSI registered for the benefit of its Members and of ®
the oneM2M Partners. GSM and the GSM logo are trademarks registered and owned by the GSM Association.
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
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"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 23.379 version 19.10.0 Release 19 3 ETSI TS 123 379 V19.10.0 (2026-04)
Contents
Intellectual Property Rights . 2
Legal Notice . 2
Modal verbs terminology . 2
Foreword . 12
1 Scope . 13
2 References . 13
3 Definitions, symbols and abbreviations . 14
3.1 Definitions . 14
3.2 Symbols . 15
3.3 Abbreviations . 16
4 Introduction . 17
5 Architectural requirements . 17
5.1 Media routing requirements . 17
5.2 Requirements for user identity management . 17
5.3 MCPTT group affiliation and MCPTT group de-affiliation . 18
5.4 MCPTT call requirements . 18
5.4.1 General . 18
5.4.2 Group call requirements . 18
5.5 GCS AS requirements for the MCPTT service . 18
5.6 Group selection . 18
5.7 Bearer management . 18
5.7.1 General . 18
5.7.2 EPS bearer considerations . 18
5.7.2.1 Void. 18
5.7.2.2 Void. 18
5.7.3 EPS unicast bearer considerations for MCPTT . 18
5.7.4 MBMS bearer management . 19
5.8 MCPTT system interconnect requirements . 19
6 Involved business relationships . 19
7 Functional model . 19
7.1 General . 19
7.2 Description of the planes . 20
7.3 Functional model description . 20
7.3.1 On-network functional model . 20
7.3.2 Off-network functional model . 21
7.4 Functional entities description . 22
7.4.1 General . 22
7.4.2 Application plane of MCPTT service . 22
7.4.2.1 General . 22
7.4.2.2 Common services core . 22
7.4.2.3 MCPTT application service . 22
7.4.2.3.1 MCPTT client . 22
7.4.2.3.2 MCPTT server . 22
7.4.2.3.3 Floor participant . 24
7.4.2.3.4 Floor control server . 24
7.4.2.3.5 Media distribution function . 24
7.4.2.3.6 Media mixer . 25
7.4.2.3.7 MCPTT user database . 25
7.4.2.3.8 MC gateway server . 25
7.4.3 Signalling control plane . 25
7.5 Reference points . 25
7.5.1 General reference point principle . 25
ETSI
3GPP TS 23.379 version 19.10.0 Release 19 4 ETSI TS 123 379 V19.10.0 (2026-04)
7.5.2 Application plane of MCPTT service . 25
7.5.2.1 General . 25
7.5.2.2 Reference point MCPTT-1 (between the MCPTT client and the MCPTT server). 25
7.5.2.3 Reference point MCPTT-2 (between the MCPTT server and the MCPTT user database) . 26
7.5.2.4 Reference point MCPTT-3 (between the MCPTT server and the MCPTT server and between the
MCPTT server and the MC gateway server) . 26
7.5.2.5 Reference point MCPTT-4 (unicast between the floor control server and the floor participant) . 26
7.5.2.6 Reference point MCPTT-5 (between the MCPTT server and the EPS) . 26
7.5.2.7 Reference point MCPTT-6 (between the MCPTT server and the EPS) . 26
7.5.2.8 Reference point MCPTT-7 (unicast between the media distribution function and the media
mixer) . 27
7.5.2.9 Reference point MCPTT-8 (multicast between the media distribution function and the media
mixer) . 27
7.5.2.10 Reference point MCPTT-9 (multicast between the floor control server and the floor participant) . 27
7.5.2.11 Reference point IWF-1 (between the MCPTT server and the interworking function to legacy
s yste ms) . 27
7.5.2.12 Reference points of common services core used in the MCPTT service . 27
7.5.2.13 Reference point MCPTT-10 (between the MC gateway server and the MC gateway server in a
different MCPTT system) . 27
8 Identities . 27
9 Application of functional model to deployments . 27
10 Procedures and information flows . 28
10.1 MCPTT service configuration . 28
10.2 User authentication and authorization for MCPTT service . 28
10.3 Affiliation and de-affiliation to/from MCPTT group(s) . 29
10.3a Activation and de-activation of/from functional alias(es) . 29
10.4 MCPTT group selection . 29
10.4.1 General . 29
10.4.2 Information flows for group selection . 29
10.4.2.1 Group selection change request. 29
10.4.2.2 Group selection change response . 29
10.4.2.3 Group selection change notification . 30
10.4.3 Authorized user remotely changes another MCPTT user's selected MCPTT group – mandatory mode . 30
10.5 Pre-established session (on-network) . 31
10.5.1 General . 31
10.5.2 Information flows for pre-established session . 31
10.5.2.1 Pre-established session establishment . 31
10.5.2.2 Pre-established session modification . 32
10.5.2.3 Pre-established session release - client initiated . 32
10.5.2.4 Pre-established session release - server initiated . 33
10.5.2.5 Pre-established session call connect request . 33
10.5.2.6 Pre-established session call disconnect request . 33
10.5.3 Procedures. 34
10.5.3.1 General . 34
10.5.3.2 Call connect and disconnect procedures using pre-established session . 34
10.5.3.2.1 Call connect over unicast . 34
10.5.3.2.2 Call disconnect over unicast . 35
10.6 Group call . 35
10.6.1 General . 35
10.6.2 On-network group call . 35
10.6.2.1 General . 35
10.6.2.2 Information flows for group call in on-network . 36
10.6.2.2.1 MCPTT emergency group call request . 36
10.6.2.2.1a MCPTT emergency group call response . 36
10.6.2.2.2 MCPTT in-progress emergency group state cancel request . 36
10.6.2.2.2a MCPTT in-progress emergency group state cancel response . 37
10.6.2.2.3 Void . 37
10.6.2.2.3a Void . 37
10.6.2.2.3b Void . 37
10.6.2.2.4 Void . 37
ETSI
3GPP TS 23.379 version 19.10.0 Release 19 5 ETSI TS 123 379 V19.10.0 (2026-04)
10.6.2.2.4a Void . 37
10.6.2.2.5 MCPTT imminent peril group call request . 37
10.6.2.2.5a MCPTT imminent peril group call response . 38
10.6.2.2.6 MCPTT in-progress imminent peril group state cancel request . 38
10.6.2.2.6a MCPTT in-progress imminent peril group state cancel response . 38
10.6.2.2.7 Group call request (MCPTT client – MCPTT server) . 39
10.6.2.2.8 Group call request (MCPTT server – group host MCPTT server) . 39
10.6.2.2.9 Group call request (MCPTT server – MCPTT client) . 40
10.6.2.2.10 Group call response (MCPTT server – MCPTT client) . 40
10.6.2.2.11 Group call response (MCPTT server – MCPTT server) . 41
10.6.2.2.12 Group call response (MCPTT client – MCPTT server) . 41
10.6.2.2.13 Group call notify (MCPTT server – MCPTT client) . 41
10.6.2.2.14 Group call release request (MCPTT server – MCPTT client) . 42
10.6.2.2.14a Group call release request (MCPTT client – MCPTT server) . 42
10.6.2.2.15 Group call release request (MCPTT server – MCPTT server) . 42
10.6.2.2.16 Group call release response (MCPTT client – MCPTT server) . 43
10.6.2.2.17 Group call release response (MCPTT server – MCPTT server) . 43
10.6.2.2.18 Group call rejoin request (MCPTT client – MCPTT server) . 43
10.6.2.2.19 Group call rejoin response (MCPTT server – MCPTT client) . 44
10.6.2.2.20 Group join request . 44
10.6.2.2.21 Group join response . 44
10.6.2.2.22 Group call leave request (MCPTT server – MCPTT client) . 45
10.6.2.2.22a Group call leave request (MCPTT client – MCPTT server) . 45
10.6.2.2.23 Group call leave response (MCPTT client – MCPTT server) . 45
10.6.2.2.23a Group call leave response (MCPTT server – MCPTT client) . 46
10.6.2.2.24 Group interrogate request (MCPTT server – MCPTT server) . 46
10.6.2.2.25 Group interrogate response (MCPTT server – MCPTT server) . 46
10.6.2.2.26 Group-broadcast group call request (MCPTT client – MCPTT server) . 46
10.6.2.2.27 Group-broadcast group call request (MCPTT server – MCPTT client) . 47
10.6.2.2.28 Group-broadcast group call response (MCPTT client – MCPTT server) . 47
10.6.2.2.29 Group-broadcast group call response (MCPTT server – MCPTT client) . 48
10.6.2.2.30 Group-broadcast group call release request (MCPTT client – MCPTT server) . 48
10.6.2.2.31 Group-broadcast group call release request (MCPTT server – MCPTT client) . 48
10.6.2.2.32 Group-broadcast group call release response (MCPTT server – MCPTT client) . 49
10.6.2.2.33 Group-broadcast group call release response (MCPTT client – MCPTT server) . 49
10.6.2.2.34 Void . 50
10.6.2.2.35 Void . 50
10.6.2.2.36 Void . 50
10.6.2.2.37 Void . 50
10.6.2.2.38 Void . 50
10.6.2.2.39 Void . 50
10.6.2.2.40 Void . 50
10.6.2.2.41 Void . 50
10.6.2.2.42 Void . 50
10.6.2.2.43 Void . 50
10.6.2.2.44 Void . 50
10.6.2.2.45 Void . 50
10.6.2.2.46 Void . 50
10.6.2.2.47 Void . 50
10.6.2.2.48 Void . 50
10.6.2.2.49 Void . 50
10.6.2.2.50 Void . 50
10.6.2.2.51 MCPTT emergency floor remote trigger . 50
10.6.2.3 Group call within one MCPTT system. 51
10.6.2.3.1 Group call models. 51
10.6.2.3.1.1 Pre-arranged group call . 51
10.6.2.3.1.2 Chat group call . 56
10.6.2.3.2 Exiting group call due to de-affiliation . 63
10.6.2.3.3 MCPTT user leaving a group call . 63
10.6.2.4 Group call involving groups from multiple MCPTT systems . 64
10.6.2.4.1 Group call for non-broadcast temporary groups across multiple MCPTT systems . 64
10.6.2.4.1.1 Group call setup . 64
ETSI
3GPP TS 23.379 version 19.10.0 Release 19 6 ETSI TS 123 379 V19.10.0 (2026-04)
10.6.2.4.1.2 Group call release . 67
10.6.2.4.2 Group call for non-broadcast temporary group formed by group regroup procedure involving

multiple MCPTT systems via trusted mode . 68
10.6.2.4.3 Group call for an MCPTT group defined in the partner MCPTT system . 70
10.6.2.4.3.1 Pre-arranged group call setup procedure – initiating side . 70
10.6.2.4.3.2 Pre-arranged group call setup – terminating side . 71
10.6.2.4.3.3 Chat group call setup . 71
10.6.2.4.4 Merging of groups involving multiple MCPTT systems . 73
10.6.2.5 Broadcast group call . 74
10.6.2.5.1 General . 74
10.6.2.5.2 Common broadcast group call procedure . 74
10.6.2.5.2.1 Group-broadcast group call procedure . 75
10.6.2.5.2.2 Group-broadcast group call procedure when a subordinate group has an on-going MCPTT
emergency group call . 77
10.6.2.5.2.3 Group-broadcast group call release procedure . 78
10.6.2.5.2.4 Server-initiated broadcast group call release procedure. 79
10.6.2.5.3 Void . 80
10.6.2.5.4 Group call for broadcast temporary groups across multiple MCPTT systems . 80
10.6.2.6 Emergency and imminent peril procedures . 82
10.6.2.6.1 MCPTT emergency group call . 82
10.6.2.6.1.1 MCPTT emergency group call commencement. 82
10.6.2.6.1.2 MCPTT group call upgraded to an MCPTT emergency group call . 84
10.6.2.6.1.3 MCPTT in-progress emergency group state cancel . 86
10.6.2.6.2 MCPTT imminent peril group call . 88
10.6.2.6.2.1 MCPTT imminent peril group call commencement . 88
10.6.2.6.2.2 Imminent peril group call upgrade . 90
10.6.2.6.2.3 MCPTT in-progress imminent peril group state cancel . 92
10.6.2.6.3 MCPTT emergency alert (on-network) . 93
10.6.2.6.4 MCPTT emergency floor remote trigger procedure . 93
10.6.2.7 Location of current talker . 94
10.6.2.8 Void. 96
10.6.2.8.1 Void . 96
10.6.2.8.2 Void . 96
10.6.2.8.3 Void . 96
10.6.2.9 Group call handling with preconfigured regroup update. 96
10.6.2.9.1 Void . 96
10.6.2.9.2 Void . 96
10.6.2.9.2.1 Void . 96
10.6.2.9.2.2 Void . 96
10.6.2.9.3 Regroup procedures in multiple MCPTT systems . 96
10.6.2.9.3.1 Void . 96
10.6.2.9.3.2 Void . 96
10.6.2.9.3.3 Void . 96
10.6.2.9.4 Void . 96
10.6.2.9.5 Procedures . 96
10.6.2.9.5.1 Call request to an MCPTT group during an in-progress preconfigured group regroup . 96
10.6.2.9.5.2 Call request to a preconfigured regroup group after group regroup has been cancelled . 97
10.6.2.10 User regroup using group creation procedure . 98
10.6.2.10.1 General . 98
10.6.2.10.2 Temporary group creation and broadcast group call by authorized user . 98
10.6.2.10.3 Temporary group deletion by authorized user . 99
10.6.2.11 Broadcast group regroup call using preconfigured group . 99
10.6.2.11.1 General . 99
10.6.2.11.2 Broadcast group regroup call procedure using preconfigured group in a single MCPTT
system . 100
10.6.2.12 User regroup with preconfigured group . 101
10.6.2.12.1 Voidl . 101
10.6.2.12.2 Void . 101
10.6.2.12.2.1 Void . 101
10.6.2.12.2.2 Void . 101
10.6.2.12.3 Void . 101
10.6.3 Off-network group call . 101
ETSI
3GPP TS 23.379 version 19.10.0 Release 19 7 ETSI TS 123 379 V19.10.0 (2026-04)
10.6.3.1 General . 101
10.6.3.2 Information flows for group call in off-network . 101
10.6.3.2.1 Group call announcement . 101
10.6.3.2.2 MCPTT upgrade to emergency call . 102
10.6.3.2.3 MCPTT emergency group state cancel . 102
10.6.3.2.4 Response . 102
10.6.3.2.5 Void . 103
10.6.3.2.6 Void . 103
10.6.3.2.7 MCPTT upgrade to imminent peril call . 103
10.6.3.2.8 MCPTT imminent peril group call cancel . 103
10.6.3.3 Group call setup . 103
10.6.3.4 Passive join to group call . 104
10.6.3.5 Join to ongoing group call when new entry member initiates the call with on-going group call id . 105
10.6.3.6 Immediate group call announcement to join an ongoing group call . 106
10.6.3.7 Group call release due to inactivity . 107
10.6.3.8 Broadcast group call . 108
10.6.3.9 Emergency and imminent peril procedures . 108
10.6.3.9.1 Emergency group call . 108
10.6.3.9.2 MCPTT imminent peril . 109
10.6.3.9.3 MCPTT emergency alert (off-network) . 109
10.7 Private call .
...