ETSI TS 123 283 V15.4.0 (2025-04)

LTE; Mission Critical Communication Interworking with Land Mobile Radio Systems (3GPP TS 23.283 version 15.4.0 Release 15)

RTS/TSGS-0623283vf40

General Information

• Status: Not Published
• Technical Committee: 3GPP SA 6 - Mission-critical applications
• Current Stage: 12 - Citation in the OJ (auto-insert)
• Completion Date: 03-Apr-2025

Standards Content (Sample)

TECHNICAL SPECIFICATION
LTE;
Mission Critical Communication Interworking
with Land Mobile Radio Systems
(3GPP TS 23.283 version 15.4.0 Release 15)

3GPP TS 23.283 version 15.4.0 Release 15 1 ETSI TS 123 283 V15.4.0 (2025-04)

Reference
RTS/TSGS-0623283vf40
Keywords
LTE
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3GPP TS 23.283 version 15.4.0 Release 15 2 ETSI TS 123 283 V15.4.0 (2025-04)
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ETSI
3GPP TS 23.283 version 15.4.0 Release 15 3 ETSI TS 123 283 V15.4.0 (2025-04)
Contents
Intellectual Property Rights . 2
Legal Notice . 2
Modal verbs terminology . 2
Foreword . 8
1 Scope . 9
2 References . 9
3 Definitions, symbols and abbreviations . 9
3.1 Definitions . 9
3.2 Abbreviations . 10
4 Introduction . 10
5 Assumptions and architectural requirements . 10
5.1 Key management . 10
5.2 Packet format . 11
6 Involved business relationships . 11
7 Functional model . 11
7.1 General . 11
7.2 Functional model description . 11
7.3 Functional entities description . 12
7.3.1 IWF . 12
7.4 Reference points . 12
7.4.1 Reference point IWF-1 (between the IWF and the MCPTT server) . 12
7.4.2 Reference point IWF-2 (between the IWF and the MCData server) . 12
7.4.3 Reference point IWF-3 (between the IWF and the group management server) . 13
8 Identities . 13
8.1 Identity mapping . 13
9 Application of functional model to deployments . 13
10 Procedures and information flows . 13
10.1 Affiliation . 13
10.1.1 Information flows for affiliation . 13
10.1.1.1 General . 13
10.1.1.2 IWF group affiliation request . 13
10.1.1.3 IWF group affiliation response . 14
10.1.1.4 IWF group de-affiliation request . 14
10.1.1.5 IWF group de-affiliation response . 14
10.1.2 Affiliation procedures . 15
10.1.2.1 General . 15
10.1.2.2 Group affiliation to a group defined in the MC system . 16
10.1.2.3 Group de-affiliation from a group defined in the MC system . 17
10.1.2.4 Group affiliation to group defined in the LMR system . 17
10.1.2.5 Group de-affiliation from a group defined in the LMR system . 19
10.2 Group management . 20
10.2.1 Information flows for group management . 20
10.2.1.1 General . 20
10.2.1.2 IWF group regroup teardown notification . 20
10.2.1.3 IWF group regroup teardown notification response . 20
10.2.1.4 IWF group regroup request . 20
10.2.1.5 IWF group regroup response . 20
10.2.1.6 IWF group regroup notification . 21
10.2.1.7 IWF group regroup notification response . 21
10.2.1.8 IWF group information request . 21
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10.2.1.9 IWF group information response . 21
10.2.1.10 IWF group information provision request . 21
10.2.1.11 IWF group information provision response . 22
10.2.1.12 IWF group information subscribe request . 22
10.2.1.13 IWF group information subscribe response . 22
10.2.1.14 IWF group information notify request . 22
10.2.1.15 IWF group information notify response . 23
10.2.2 Group regrouping . 23
10.2.2.1 General . 23
10.2.2.2 MC system initiates the group regroup . 23
10.2.2.3 IWF initiates the group regroup . 25
10.2.2.4 Ownership of the group regroup . 26
10.2.2.5 Simultaneous group regroup requests from each side of the IWF-1 interface . 26
10.2.2.6 Resolution of vocoder and encryption mode for the group regroup . 26
10.2.3 Group configuration for interworking. 26
10.2.3.1 Overview . 26
10.2.3.2 MC system provides group configuration to the IWF . 27
10.2.3.3 IWF requests group configuration from the MC system . 27
10.2.3.4 IWF provides group configuration to the MC system . 28
10.2.3.5 MC system requests group configuration from the IWF . 29
10.2.3.6 IWF subscribes to group configuration . 29
10.2.3.7 MC system notifies group configuration . 30
10.2.3.8 MC system subscribes to group configuration . 30
10.2.3.9 IWF notifies group configuration . 31
10.3 Group call . 32
10.3.1 General . 32
10.3.2 Information flows for group call over interworking group . 32
10.3.2.1 General . 32
10.3.2.2 IWF group call request . 32
10.3.2.3 IWF group call response (IWF – MCPTT server) . 32
10.3.2.4 IWF Group-broadcast group call setup request . 33
10.3.2.5 IWF Group-broadcast group call setup response . 33
10.3.2.6 IWF Group-broadcast group call release request . 33
10.3.2.7 IWF group-broadcast group call release response . 34
10.3.2.8 IWF group join request . 34
10.3.2.9 IWF group join response . 34
10.3.2.10 IWF group call leave request . 35
10.3.2.11 IWF group call leave response . 35
10.3.2.12 IWF group call release request . 35
10.3.2.13 IWF group call release response . 36
10.3.3 Pre-arranged group call . 36
10.3.3.1 General . 36
10.3.3.2 Group call setup initiated by MCPTT user on an interworking group defined in MCPTT system . 36
10.3.3.3 Group call setup initiated by LMR user on an interworking group defined in MCPTT system. . 38
10.3.3.4 Group call setup initiated by MCPTT user on an interworking group defined in the LMR system . 39
10.3.3.5 Group call setup initiated by LMR user on an interworking group defined in the LMR system. . 41
10.3.3.6 Encrypted group call with transcoding . 42
10.3.3.7 Late Entry . 43
10.3.3.7.1 General . 43
10.3.3.7.2 Group call late entry on an interworking group defined in the MCPTT system . 43
10.3.3.7.3 Group call late entry on an interworking group defined in the LMR system . 44
10.3.3.8 Interworking group call release . 46
10.3.3.8.1 General . 46
10.3.3.8.2 Group call release on an interworking group defined in the MCPTT system. 46
10.3.3.8.3 Group call release on an interworking group defined in the LMR system . 47
10.3.4 Group broadcast . 48
10.3.4.1 General . 48
10.3.4.2 Group-broadcast group call procedure with an interworking group where the group-broadcast
group is defined in the MCPTT system. 48
10.3.4.3 Group-broadcast group call procedure with an interworking group where the group-broadcast
group is defined in the LMR system . 51
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10.3.4.4 Group-broadcast group call release with an interworking group procedure where the group-
broadcast group is defined in the MCPTT system . 53
10.3.4.5 Group-broadcast group call release with an interworking group procedure where the group-
broadcast group is defined in the LMR system . 55
10.3.5 Chat group call . 56
10.3.5.1 General . 56
10.3.5.2 MCPTT user initiated chat group call in an interworking group defined in LMR system . 56
10.3.5.3 LMR user initiated chat group call in an interworking group defined in MCPTT system . 57
10.3.5.4 Release chat group call on an interworking group defined in the LMR system . 58
10.3.5.5 Release chat group call on an interworking group defined in the MCPTT system . 59
10.3.5.6 Void. 60
10.3.5.7 Void. 60
10.3.6 Exiting group call due to de-affiliation . 60
10.3.6.1 General . 60
10.3.6.2 Exiting group call defined in the LMR system due to de-affiliation . 60
10.3.6.3 Exiting group call defined in the MCPTT system due to de-affiliation . 61
10.4 Private call . 62
10.4.1 Information flows for private calls . 62
10.4.1.1 General . 62
10.4.1.2 IWF private call request . 62
10.4.1.3 IWF private call response . 62
10.4.1.4 IWF ringing . 63
10.4.1.5 IWF call end request . 63
10.4.1.6 IWF call end response . 63
10.4.2 Private call setup in automatic commencement mode . 64
10.4.2.1 MCPTT user initiating an MCPTT private call . 64
10.4.2.2 LMR user initiating a private call with MCPTT user . 65
10.4.3 Private call setup in manual commencement mode . 66
10.4.3.1 MCPTT user is initiating an MCPTT private call . 66
10.4.3.2 LMR user initiating a private call with MCPTT user . 68
10.4.4 Private call release . 69
10.4.4.1 MCPTT client initiated . 69
10.4.4.2 MCPTT server initiated . 70
10.4.4.3 LMR user initiated . 71
10.4.5 Encryption of private calls . 72
10.5 Floor control . 72
10.5.1 General . 72
10.5.2 Information flows for floor control . 73
10.5.2.1 General . 73
10.5.2.2 IWF floor request . 73
10.5.2.3 IWF floor granted . 73
10.5.2.4 IWF floor rejected . 73
10.5.2.5 IWF floor request cancel . 74
10.5.2.6 IWF floor request cancel response . 74
10.5.2.7 IWF floor request cancel notify . 74
10.5.2.8 IWF floor idle . 74
10.5.2.9 IWF floor release . 75
10.5.2.10 IWF floor taken . 75
10.5.2.11 IWF floor revoked . 75
10.5.2.12 IWF floor acknowledgement . 75
10.5.2.13 IWF queue position request. 76
10.5.2.14 IWF queue position info . 76
10.5.2.15 IWF unicast media stop request . 76
10.5.2.16 IWF unicast media resume request . 76
10.5.3 Interworking floor control . 77
10.5.4 Floor override without using floor revoked on an interworking group . 77
10.5.5 Floor control on an interworking group homed in the LMR system . 79
10.5.6 Floor control on an interworking group homed in the MCPTT system . 80
10.5.7 Floor control without local filtering on an interworking group defined in the LMR system . 81
10.5.8 Floor control without local filtering on an interworking group defined in the MCPTT system . 83
10.6 Emergency and imminent peril . 84
10.6.1 Information flows for emergency and imminent peril . 84
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10.6.1.1 IWF emergency group call request . 84
10.6.1.2 IWF emergency group call response . 84
10.6.1.3 IWF imminent peril group call request . 85
10.6.1.4 IWF imminent peril group call response . 85
10.6.1.5 IWF in-progress imminent peril group state cancel request . 85
10.6.1.6 IWF in-progress imminent peril group state cancel response . 85
10.6.1.7 IWF emergency alert request . 86
10.6.1.8 IWF emergency alert response . 86
10.6.1.9 IWF emergency alert cancel request . 86
10.6.1.10 IWF emergency alert cancel response . 87
10.6.1.11 IWF in-progress emergency group state cancel request . 87
10.6.1.12 IWF in-progress emergency group state cancel response . 87
10.6.2 Emergency calls . 88
10.6.2.1 General . 88
10.6.2.2 Emergency group call . 88
10.6.2.2.1 Emergency group call setup initiated by a user in the LMR system on an interworking group
defined in the MCPTT system . 88
10.6.2.2.2 Emergency group call setup initiated by a user in the MCPTT system on an interworking
group defined in MCPTT system . 90
10.6.2.2.3 Emergency group call setup initiated by a user in the LMR system on an interworking group

defined in the LMR system . 92
10.6.2.2.4 Emergency group call setup initiated by a user in the MCPTT system to an interworking
group defined in the LMR system . 93
10.6.2.3 In-progress emergency group state cancel of an interworking group . 95
10.6.2.3.1 LMR user initiated in-progress emergency group state cancel of an interworking group
defined in the MCPTT system . 95
10.6.2.3.2 MCPTT user initiated in-progress emergency group state cancel of an interworking group
defined in the MCPTT system . 96
10.6.2.3.3 LMR user initiated in-progress emergency group state cancel of an interworking group
defined in an LMR system. 97
10.6.2.3.4 MCPTT user initiated in-progress emergency group state cancel of an interworking group
defined in an LMR system. 98
10.6.2.4 Losing audio . 100
10.6.2.5 Default emergency group . 100
10.6.2.6 Emergency private call . 100
10.6.2.7 LMR systems that do not track group emergencies . 100
10.6.3 Imminent peril calls . 100
10.6.3.1 General . 100
10.6.3.2 Imminent peril group call initiated by an MCPTT user on an interworking group . 100
10.6.3.3 Group call initiated by a user in the LMR system on an interworking group in imminent peril
state . 102
10.6.3.4 In-progress imminent peril state cancel on an interworking group . 104
10.6.4 Emergency alerts . 106
10.6.4.1 Emergency alert initiated by LMR user . 106
10.6.4.2 Emergency alert initiated by MC service user . 107
10.6.5 Emergency alert cancellation . 109
10.6.5.1 Emergency alert cancellation of an LMR user . 109
10.6.5.2 Emergency alert cancellation of an MC service user . 110
10.7 Codec . 112
10.7.1 Information flows for codec. 112
10.7.1.1 IWF codec reconciliation request . 112
10.7.1.2 IWF codec reconciliation response . 112
10.7.2 IWF transcoding . 112
10.7.3 Codec negotiation by the LMR system . 112
10.7.3.1 Description . 112
10.8 MCData short data service . 113
10.8.1 General . 113
10.8.2 Information flows for the short data service . 114
10.8.2.1 General . 114
10.8.2.2 IWF MCData standalone data request. 114
10.8.2.3 IWF MCData data disposition notification . 114
10.8.2.4 IWF MCData group standalone data request (IWF – MCData server) . 115
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10.8.2.5 IWF MCData group standalone data request (MCData server - IWF) . 115
10.8.2.6 IWF MCData data disposition notification(s) (MCData server to IWF) . 115
10.8.2.7 IWF MCData group standalone data request (IWF – MCData server) . 116
10.8.2.8 IWF MCData group standalone data request (MCData server – IWF) . 116
10.8.2.9 IWF MCData group standalone data response . 117
10.8.3 Behaviour at the MCData Client . 117
10.8.4 Behaviour at the IWF . 117
10.8.5 Behaviour at the MCData server . 117
10.8.6 MCData user one-to-one SDS request to an LMR user . 117
10.8.6.1 Signalling control plane . 117
10.8.6.2 Media plane . 118
10.8.7 LMR user one-to-one SDS request to an MCData user . 118
10.8.7.1 Signalling control plane . 118
10.8.7.2 Media plane . 118
10.8.8 MCData user group SDS request to an MCData group including LMR users . 118
10.8.8.1 Signalling control plane . 118
10.8.8.2 Media plane . 118
10.8.9 LMR user group SDS request to an MCData group . 118
10.8.9.1 Signalling control plane . 118
10.8.9.2 Media plane . 119
10.9 IWF as a security gateway . 119
10.9.1 Support for transcoding with encrypted speech .
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