ETSI TS 124 379 V13.14.0 (2020-01)

TECHNICAL SPECIFICATION
LTE;
Mission Critical Push To Talk (MCPTT) call control;
Protocol specification
(3GPP TS 24.379 version 13.14.0 Release 13)


3GPP TS 24.379 version 13.14.0 Release 13 1 ETSI TS 124 379 V13.14.0 (2020-01)

Reference
RTS/TSGC-0124379vde0
Keywords
LTE
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ETSI
3GPP TS 24.379 version 13.14.0 Release 13 2 ETSI TS 124 379 V13.14.0 (2020-01)
Intellectual Property Rights
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Modal verbs terminology
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ETSI
3GPP TS 24.379 version 13.14.0 Release 13 3 ETSI TS 124 379 V13.14.0 (2020-01)
Contents
Intellectual Property Rights . 2
Legal Notice . 2
Modal verbs terminology . 2
Foreword . 21
1 Scope . 22
2 References . 22
3 Definitions, symbols and abbreviations . 25
3.1 Definitions . 25
3.2 Abbreviations . 26
4 General . 27
4.1 MCPTT overview . 27
4.2 URI and address assignments . 28
4.3 MCPTT speech . 28
4.4 Warning Header Field . 29
4.4.1 General . 29
4.4.2 Warning texts . 29
4.5 MCPTT session identity . 32
4.6 MCPTT priority calls and alerts . 33
4.6.1 MCPTT emergency group calls . 33
4.6.2 MCPTT emergency private calls . 34
4.6.3 MCPTT emergency alerts . 35
4.6.4 MCPTT imminent peril group call . 36
4.7 End-to-end communication security . 37
4.8 Protection of sensitive application data. . 38
4.9 Pre-established session . 41
4.10 MCPTT client ID . 42
4.11 Off-network MCPTT . 42
5 Functional entities . 43
5.1 Introduction . 43
5.2 MCPTT client . 43
5.3 MCPTT server . 44
5.3.1 General . 44
5.3.2 Functional connectivity models . 45
6 Common procedures. 47
6.1 Introduction . 47
6.2 MCPTT client procedures . 47
6.2.0 Distinction of requests at the MCPTT client . 47
6.2.0.1 SIP MESSAGE request . 47
6.2.1 SDP offer generation . 47
6.2.2 SDP answer generation . 48
6.2.3 Commencement modes . 49
6.2.3.1 Automatic commencement mode . 49
6.2.3.1.1 Automatic commencement mode for private calls . 49
6.2.3.1.2 Automatic commencement mode for group calls . 49
6.2.3.2 Manual commencement mode . 49
6.2.3.2.1 Manual commencement mode for private calls . 49
6.2.3.2.2 Manual commencement mode for group calls . 50
6.2.4 Leaving an MCPTT session initiated by MCPTT client . 50
6.2.4.1 On-demand session case . 50
6.2.4.2 Pre-established session case . 51
6.2.5 Releasing an MCPTT session initiated by MCPTT client . 51
6.2.5.1 On-demand session case . 51
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6.2.5.2 Pre-established session case . 51
6.2.6 Receiving an MCPTT session release request . 52
6.2.7 Receiving a SIP MESSAGE request . 52
6.2.8 Priority call conditions . 52
6.2.8.1 MCPTT emergency group call conditions . 52
6.2.8.1.1 SIP INVITE request or SIP REFER request for originating MCPTT emergency group calls . 52
6.2.8.1.2 Resource-Priority header field for MCPTT emergency group calls . 53
6.2.8.1.3 SIP re-INVITE request for cancelling MCPTT in-progress emergency group state . 54
6.2.8.1.4 Receiving a SIP 2xx response to a SIP request for a priority call . 55
6.2.8.1.5 Receiving a SIP 4xx response, SIP 5xx response or SIP 6xx response to a SIP request for a
priority group call . 55
6.2.8.1.6 Determining authorisation for initiating or cancelling an MCPTT emergency alert . 56
6.2.8.1.7 Determining authorisation for cancelling the in-progress emergency state of an MCPTT
group . 56
6.2.8.1.8 Determining authorisation for originating a priority group call . 56
6.2.8.1.9 SIP request for originating MCPTT imminent peril group calls . 57
6.2.8.1.10 Determining authorisation for cancelling an imminent peril group call . 58
6.2.8.1.11 SIP re-INVITE request for cancelling MCPTT in-progress imminent peril group state . 58
6.2.8.1.12 Resource-Priority header field for MCPTT imminent peril group calls . 58
6.2.8.1.13 Receiving a SIP INFO request in the dialog of a SIP request for a priority group call . 59
6.2.8.1.14 SIP re-INVITE request for cancelling the in-progress emergency group state of a group by a
third-party . 59
6.2.8.1.15 Retrieving Resource-Priority header field values . 60
6.2.8.1.16 Handling receipt of a SIP re-INVITE request for priority group call origination status within
a pre-established session . 61
6.2.8.1.17 Priority group call conditions upon receiving call release . 61
6.2.8.1.18 Emergency private call conditions upon receiving call release . 62
6.2.8.2 Request for an originating broadcast group call . 62
6.2.8.3 MCPTT emergency private call conditions . 62
6.2.8.3.1 Authorisations . 62
6.2.8.3.1.1 Determining authorisation for initiating an MCPTT emergency private call . 62
6.2.8.3.1.2 Determining authorisation for cancelling an MCPTT emergency private call . 63
6.2.8.3.1.3 Determining authorisation for initiating or cancelling an MCPTT emergency alert to a
MCPTT user . 63
6.2.8.3.2 SIP request for originating MCPTT emergency private calls . 63
6.2.8.3.3 Resource-Priority header field for MCPTT emergency private calls . 64
6.2.8.3.4 Receiving a SIP 2xx response to a SIP request for an MCPTT emergency private call . 64
6.2.8.3.5 Receiving a SIP 4xx response, SIP 5xx response or SIP 6xx response to a SIP request for an

MCPTT emergency private call. 64
6.2.8.3.6 SIP re-INVITE request for cancelling MCPTT emergency private call state. 65
6.2.8.3.7 Receiving a SIP INFO request in the dialog of a SIP request for a priority private call. 66
6.2.8.3.8 SIP re-INVITE request for cancelling the MCPTT emergency private call state by a third-
party . 66
6.2.9 Location information . 67
6.2.9.1 Location information for location reporting . 67
6.3 MCPTT server procedures . 68
6.3.1 Distinction of requests sent to the MCPTT server . 68
6.3.1.1 SIP INVITE request . 68
6.3.1.2 SIP REFER request . 68
6.3.1.3 SIP MESSAGE request . 68
6.3.1.4 SIP SUBSCRIBE request . 69
6.3.2 Participating MCPTT Function. 69
6.3.2.1 Requests initiated by the served MCPTT user . 69
6.3.2.1.1 SDP offer generation . 69
6.3.2.1.1.1 On-demand session . 69
6.3.2.1.1.2 Pre-established session. 70
6.3.2.1.2 SDP answer generation . 70
6.3.2.1.2.1 On-demand session . 70
6.3.2.1.2.2 Pre-established session establishment . 71
6.3.2.1.3 Sending an INVITE request on receipt of an INVITE request . 71
6.3.2.1.4 Sending an INVITE request on receipt of a REFER request . 72
6.3.2.1.5 Response to an INVITE request . 72
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6.3.2.1.5.1 Provisional responses . 72
6.3.2.1.5.2 Final response . 73
6.3.2.1.6 Sending a SIP BYE request on receipt of a SIP BYE request . 73
6.3.2.1.7 Sending a SIP BYE request on receipt of a SIP REFER request . 74
6.3.2.1.8 Priority call conditions . 74
6.3.2.1.8.1 . Determining authorisation for originating a priority group
call. 74
6.3.2.1.8.2 Determining authorisation for initiating or cancelling an MCPTT emergency alert . 75
6.3.2.1.8.3 Validate priority request parameters . 76
6.3.2.1.8.4 Retrieving Resource-Priority header field values . 76
6.3.2.1.8.5 Generating a SIP re-INVITE request for priority group call origination within a pre-
established session . 76
6.3.2.1.8.6 Generating a SIP re-INVITE request for emergency private call origination within a pre-
established session . 77
6.3.2.1.9 Generating a SIP re-INVITE request on receipt of a SIP re-INVITE request . 78
6.3.2.1.10 Sending a SIP INVITE request on receipt of SIP 3xx response . 78
6.3.2.2 Requests terminated to the served MCPTT user . 79
6.3.2.2.1 SDP offer generation . 79
6.3.2.2.2 SDP answer generation . 79
6.3.2.2.2.1 On-demand session . 79
6.3.2.2.2.2 Pre-established session. 79
6.3.2.2.3 SIP INVITE request towards the terminating MCPTT client . 80
6.3.2.2.4 Response to a SIP INVITE request . 80
6.3.2.2.4.1 Provisional response . 80
6.3.2.2.4.2 Final response . 80
6.3.2.2.5 Automatic Commencement Mode . 81
6.3.2.2.5.1 General . 81
6.3.2.2.5.2 Automatic commencement for On-Demand session . 81
6.3.2.2.5.3 Automatic commencement for pre-established session . 83
6.3.2.2.6 Manual Commencement Mode . 84
6.3.2.2.6.1 General . 84
6.3.2.2.6.2 Manual commencement for On-Demand session . 84
6.3.2.2.6.3 Manual commencement for Pre-established session . 85
6.3.2.2.7 SIP MESSAGE request towards the terminating MCPTT client . 87
6.3.2.2.8 SIP BYE request towards the terminating MCPTT client . 87
6.3.2.2.8.1 On-demand. 87
6.3.2.2.8.2 Using pre-established session . 88
6.3.2.2.9 Populate MIME bodies . 88
6.3.2.2.10 Generating a SIP re-INVITE request towards the terminating MCPTT client . 88
6.3.2.2.11 Generating a SIP MESSAGE request towards the terminating MCPTT client . 88
6.3.2.3 Processing I_MESSAGEs containing MKFC and MKFC-ID . 89
6.3.2.3.1 General . 89
6.3.2.3.2 Processing an I_MESSAGE containing MKFC and MKFC-ID . 89
6.3.3 Controlling MCPTT function . 90
6.3.3.1 Request initiated by the controlling MCPTT function . 90
6.3.3.1.1 SDP offer generation . 90
6.3.3.1.2 Sending an INVITE request . 90
6.3.3.1.3 Receipt of a SIP response to a SIP INVITE request . 91
6.3.3.1.3.1 Final response . 91
6.3.3.1.4 Sending a SIP MESSAGE request . 91
6.3.3.1.5 Sending a SIP BYE request . 91
6.3.3.1.6 Sending a SIP re-INVITE request for MCPTT emergency group call . 92
6.3.3.1.7 Sending a SIP INVITE request for MCPTT emergency group call . 92
6.3.3.1.8 Sending a SIP UPDATE request for Resource-Priority header field correction. 94
6.3.3.1.9 Generating a SIP re-INVITE request . 94
6.3.3.1.10 Generating a SIP re-INVITE request to cancel an in-progress emergency . 95
6.3.3.1.11 Generating a SIP MESSAGE request for notification of in-progress emergency or imminent
peril status change . 95
6.3.3.1.12 Populate mcptt-info and location-info MIME bodies for emergency alert . 95
6.3.3.1.13 Authorisations . 96
6.3.3.1.13.1 Determining authorisation for initiating an MCPTT emergency alert . 96
6.3.3.1.13.2 Determining authorisation for initiating an MCPTT emergency group or private call . 97
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6.3.3.1.13.3 Determining authorisation for cancelling an MCPTT emergency alert . 98
6.3.3.1.13.4 Determining authorisation for cancelling an MCPTT emergency call . 98
6.3.3.1.13.5 Determining authorisation for initiating an MCPTT imminent peril call . 98
6.3.3.1.13.6 Determining authorisation for cancelling an MCPTT imminent peril call . 99
6.3.3.1.13.7 Sending a SIP OPTIONS request to authorise an MCPTT user at a non-controlling
MCPTT function of a MCPTT group . 99
6.3.3.1.14 Generating a SIP 403 response for priority call request rejection . 101
6.3.3.1.15 Sending a SIP re-INVITE request for MCPTT imminent peril group call . 101
6.3.3.1.16 Handling the expiry of timer TNG2 (in-progress emergency group call timer) . 102
6.3.3.1.17 Validate priority request parameters . 102
6.3.3.1.18 Sending a SIP INFO request in the dialog of a SIP request for a priority call . 103
6.3.3.1.19 Retrieving Resource-Priority header field values . 103
6.3.3.1.20 Generating a SIP MESSAGE request to indicate successful receipt of an emergency alert or
emergency cancellation . 104
6.3.3.2 Requests terminated by the controlling MCPTT function . 104
6.3.3.2.1 SDP answer generation . 104
6.3.3.2.2 Receipt of a SIP INVITE request . 105
6.3.3.2.3 Sending a SIP response to a SIP INVITE request . 105
6.3.3.2.3.1 Provisional response . 105
6.3.3.2.3.2 Final response . 105
6.3.3.2.4 Receiving a SIP BYE request . 106
6.3.3.3 Handling of the acknowledged call setup timer (TNG1) . 106
6.3.3.4 Generating a SIP NOTIFY request . 108
6.3.3.5 Handling of the group call timer (TNG3) . 109
6.3.3.5.1 General . 109
6.3.3.5.2 Interaction with the in-progress emergency group call timer (TNG2) . 110
6.3.3.6 Generation of I_MESSAGEs containing MKFC and MKFC-ID . 110
6.3.3.6.1 General . 110
6.3.3.6.2 Creation of an I_MESSAGE containing MKFC . 110
6.3.4 Non-controlling MCPTT function of an MCPTT group . 111
6.3.4.1 Request initiated by the non-controlling MCPTT function of an MCPTT group . 111
6.3.4.1.1 SDP offer generation . 111
6.3.4.1.2 Sending an INVITE request towards the MCPTT client . 111
6.3.4.1.3 Sending a SIP INFO request . 112
6.3.4.1.4 Sending an INVITE request towards the controlling MCPTT function . 113
6.3.4.2 Requests terminated by the non-controlling MCPTT function of an MCPTT group . 114
6.3.4.2.1 SDP answer generation . 114
6.3.4.2.2 Sending a SIP response to the SIP INVITE request . 114
6.3.4.2.2.1 Sending a SIP 183 (Session Progress) response. 114
6.3.4.2.2.2 Sending a SIP 200 (OK) response . 114
6.3.4.3 Generating a SIP NOTIFY request . 115
6.3.4.4 Generating an I_MESSAGE containing MKFC . 115
6.3.4.4.1 General . 115
6.3.4.4.2 Creation of an I_MESSAGE containing MKFC . 116
6.3.5 Retrieving and processing a group document . 116
6.3.5.1 General . 116
6.3.5.2 Rules for retrieving Group Document(s) . 117
6.3.5.3 Rules for joining a group session . 120
6.3.5.4 Rules for initiating a prearranged group session . 120
6.3.5.5 Determining the group members to invite . 121
6.3.6 Affiliation check . 121
6.3.7 Error handling . 122
6.3.7.1 Public service identity does not exist . 122
6.3.8 Session release policy . 122
6.3.8.1 Session release policy for group call . 122
6.3.8.2 Session release policy for private call . 122
6.4 Implicit floor request . 122
6.5 Handling of MIME bodies in a SIP message. 123
6.6 Confidentiality and Integrity Protection . 124
6.6.1 General . 124
6.6.1.1 Applicability and exclusions . 124
6.6.1.2 Performing XML content encryption . 124
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6.6.1.3 Performing integrity protection on an XML body . 124
6.6.1.4 Verifying integrity of an XML body and decrypting XML elements . 124
6.6.2 Confidentiality Protection. . 125
6.6.2.1 General . 125
6.6.2.2 Keys used in confidentiality protection procedures . 125
6.6.2.3 Procedures for sending confidentiality protected content . 125
6.6.2.3.1 MCPTT client . 125
6.6.2.3.2 MCPTT server . 126
6.6.2.3.3 Content Encryption in XML elements . 126
6.6.2.3.4 Attribute URI Encryption . 126
6.6.2.4 Procedures for receiving confidentiality protected content . 127
6.6.2.4.1 Determination of confidentiality protected content . 127
6.6.2.4.2 Decrypting confidentiality protected content in XML elements . 127
6.6.2.4.3 Decrypting confidentiality protected URIs in XML attributes . 127
6.6.2.5 MCPTT server copying received XML content . 128
6.6.3 Integrity Protection of XML documents. . 128
6.6.3.1 General . 128
6.6.3.2 Keys used in integrity protection procedures . 130
6.6.3.3 Sending integrity protected content . 131
6.6.3.3.1 MCPTT client . 131
6.6.3.3.2 MCPTT server . 131
6.6.3.3.3 Integrity protection procedure . 131
6.6.3.4 Receiving integrity protected content. 132
6.6.3.4.1 Determination of integrity protected content . 132
6.6.3.4.2 Verification of integrity protected content. 132
6.7 Priority sharing . 132
7 Registration and service authorisation . 132
7.1 General . 132
7.2 MCPTT client procedures . 132
7.2.1 SIP REGISTER request for service authorisation . 132
7.2.1AA SIP REGISTER request without service authorisation . 134
7.2.1A Common SIP PUBLISH procedure . 134
7.2.2 SIP PUBLISH request for service authorisation and MCPTT service settings . 134
7.2.3 Sending SIP PUBLISH for MCPTT service settings only . 135
7.3 MCPTT server procedures . 136
7.3.1 General . 136
7.3.1A Confidentiality and Integrity Protection . 136
7.3.2 SIP REGISTER request for service authorisation . 138
7.3.3 SIP PUBL
...