Content for TS 24.281 Word version: 18.6.0
9 Group call
9.1 General
9.2 On-network group call
9.2.1 Prearranged group call
9.2.2 Chat group (restricted) call
9.2.3 Subscription to the conference event package
9.2.4 Remote change of an MCVideo user's selected group
9.2.5 Change of in-progress imminent peril state of the MCVideo group
9.3 Off-network group call
9.3.1 General
9.3.2 Basic call control
9.3.3 Call type control
9.4 Off-network Broadcast group call
9.4.1 General
9.4.2 Basic call control
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9 Group call p. 201
9.1 General p. 201
9.2 On-network group call p. 202
9.2.1 Prearranged group call p. 202
9.2.1.1 General p. 202
9.2.1.2 MCVideo client procedures p. 202
9.2.1.2.1 On-demand prearranged group call p. 202
9.2.1.2.1.1 Client originating procedures p. 202
9.2.1.2.1.2 Client terminating procedures p. 204
9.2.1.2.1.3 MCVideo upgrade to in-progress emergency or imminent peril p. 205
9.2.1.2.1.4 MCVideo in-progress emergency cancel p. 206
9.2.1.2.1.5 MCVideo in-progress imminent peril cancel p. 207
9.2.1.2.1.6 MCVideo client receives SIP re-INVITE request p. 208
9.2.1.2.3 End group call p. 210
9.2.1.2.3.1 Client originating procedures on-demand p. 210
9.2.1.2.3.3 Client terminating procedures p. 210
9.2.1.2.4 Re-join procedure p. 210
9.2.1.3 Participating MCVideo function procedures p. 210
9.2.1.3.1 Originating procedures p. 210
9.2.1.3.1.1 On demand prearranged group call p. 210
9.2.1.3.1.3 Reception of a SIP re-INVITE request from served MCVideo client p. 213
9.2.1.3.2 Terminating Procedures p. 214
9.2.1.3.3 End group call at the originating participating MCVideo function p. 215
9.2.1.3.4 End group call at the terminating participating MCVideo function p. 215
9.2.1.3.5 Re-join procedures p. 215
9.2.1.3.6 Reception of a SIP re-INVITE request for terminating MCVideo client for priority call p. 215
9.2.1.4 Controlling MCVideo function procedures p. 216
9.2.1.4.1 Originating Procedures p. 216
9.2.1.4.1.1 INVITE targeted to an MCVideo client p. 216
9.2.1.4.1.2 INVITE targeted to the non-controlling MCVideo function of an MCVideo group p. 218
9.2.1.4.2 Terminating Procedures p. 219
9.2.1.4.3 End group call at the terminating controlling MCVideo function p. 228
9.2.1.4.4 End group call initiated by the controlling MCVideo function p. 228
9.2.1.4.4.1 General p. 228
9.2.1.4.4.2 SIP BYE request for releasing MCVideo session for a group call p. 228
9.2.1.4.4.3 SIP BYE request toward a MCVideo client p. 228
9.2.1.4.5 Re-join procedures p. 228
9.2.1.4.6 Late call entry initiated by controlling MCVideo function p. 229
9.2.1.4.7 Receipt of a SIP re-INVITE request p. 230
9.2.1.4.8 Handling of a SIP re-INVITE request for imminent peril session p. 233
9.2.1.5 Non-controlling function of an MCVideo group procedures p. 235
9.2.1.5.1 Originating procedures p. 235
9.2.1.5.2 Terminating procedures p. 235
9.2.1.5.2.1 General p. 235
9.2.1.5.2.2 Initiating a prearranged group call p. 236
9.2.1.5.2.3 Joining an ongoing prearranged group call p. 238
9.2.1.5.2.4 Splitting an ongoing prearranged group call p. 238
9.2.1.5.3 Rejoin procedures p. 239
9.2.1.5.3.1 Terminating procedures p. 239
9.2.1.5.3.2 Late call entry initiated by non-controlling MCVideo function p. 239
9.2.1.5.4 Void
9.2.1.5.5 Initiating a temporary group session p. 239
9.2.2 Chat group (restricted) call p. 241
9.2.2.1 General p. 241
9.2.2.2 MCVideo client procedures p. 241
9.2.2.2.1 On-demand chat group call p. 241
9.2.2.2.1.1 MCVideo client joins a chat MCVideo group session p. 241
9.2.2.2.1.2 MCVideo client receives SIP re-INVITE request p. 243
9.2.2.2.1.3 MCVideo in-progress emergency cancel p. 244
9.2.2.2.1.4 MCVideo upgrade to in-progress emergency or imminent peril p. 245
9.2.2.2.1.5 MCVideo in-progress imminent peril cancel p. 246
9.2.2.2.1.6 MCVideo client receives a SIP INVITE request for an MCVideo group call p. 247
9.2.2.2.2 End group call p. 249
9.2.2.3 Participating MCVideo function procedures p. 249
9.2.2.3.1 On-demand chat group call p. 249
9.2.2.3.1.1 MCVideo chat session establishment p. 249
9.2.2.3.1.2 Reception of a SIP re-INVITE request from served MCVideo client p. 252
9.2.2.3.1.3 Reception of a SIP INVITE request for terminating MCVideo client p. 253
9.2.2.3.1.4 Reception of a SIP re-INVITE request for terminating MCVideo client p. 253
9.2.2.4 Controlling MCVideo function procedures p. 254
9.2.2.4.1 On-demand chat group call p. 254
9.2.2.4.1.1 MCVideo chat session establishment p. 254
9.2.2.4.1.2 Receipt of a SIP re-INVITE request p. 258
9.2.2.4.1.3 Handling of a SIP re-INVITE request for imminent peril session p. 262
9.2.2.4.2 End group call at the terminating controlling MCVideo function p. 264
9.2.2.4.3 End group call initiated by the controlling MCVideo function p. 264
9.2.2.5 Non-controlling function of an MCVideo group procedures p. 265
9.2.2.5.1 Terminating procedures p. 265
9.2.2.5.1.1 General p. 265
9.2.2.5.1.2 Initiating a chat group session p. 265
9.2.2.5.1.3 Joining an ongoing chat group call p. 266
9.2.2.5.1.4 Splitting an ongoing chat group call p. 266
9.2.2.5.1.5 MCVideo client joining the temporary group chat session p. 267
9.2.2.5.1.6 Receipt of a SIP re-INVITE request from an MCVideo client p. 267
9.2.2.5.1.7 Void
9.2.2.5.1.8 Initiating a temporary group session p. 267
9.2.3 Subscription to the conference event package p. 268
9.2.3.1 General p. 268
9.2.3.2 MCVideo client p. 269
9.2.3.3 Participating MCVideo function p. 270
9.2.3.4 Controlling MCVideo function p. 271
9.2.3.4.1 Receiving a subscription to the conference event package p. 271
9.2.3.4.2 Sending notifications to the conference event package p. 271
9.2.3.4.3 Sending subscriptions to the conference event package p. 272
9.2.3.4.4 Terminating a subscription p. 273
9.2.3.5 Non-controlling MCVideo function |R17| p. 273
9.2.3.5.1 Receiving subscriptions to the conference event package p. 273
9.2.3.5.2 Sending notifications to the conference event package p. 274
9.2.3.5.3 Sending a subscription to the conference event package p. 274
9.2.3.6 Coding |R17| p. 275
9.2.4 Remote change of an MCVideo user's selected group p. 276
9.2.4.1 General p. 276
9.2.4.2 Client procedures p. 276
9.2.4.2.1 Remote selected group change initiation p. 276
9.2.4.2.2 Target client procedures for handling remote selected group change request p. 277
9.2.4.3 Participating MCVideo function procedures p. 278
9.2.4.4 Controlling MCVideo function procedures p. 281
9.2.5 Change of in-progress imminent peril state of the MCVideo group |R18| p. 282
9.2.5.1 General p. 282
9.2.5.2 Client procedures p. 282
9.2.5.2.1 MCVideo group in-progress imminent peril state cancel initiation p. 282
9.2.5.2.2 Reception of MCVideo group in-progress imminent peril state cancel notification p. 283
9.2.5.3 Participating MCVideo function procedures p. 284
9.2.5.4 Controlling MCVideo function procedures p. 286
9.3 Off-network group call p. 287
9.3.1 General p. 287
9.3.1.1 Common Procedures p. 287
9.3.2 Basic call control p. 288
9.3.2.1 General p. 288
9.3.2.2 Basic call control state machine p. 288
9.3.2.3 Call Control states p. 289
9.3.2.3.1 S1: start-stop p. 289
9.3.2.3.2 S2: waiting for call announcement p. 289
9.3.2.3.3 S3: part of ongoing call p. 289
9.3.2.3.4 S4: pending user action without confirm indication p. 289
9.3.2.3.5 S5: pending user action with confirm indication p. 289
9.3.2.3.6 S6: ignoring incoming call announcements p. 289
9.3.2.3.7 S7: waiting for call announcement after call release p. 289
9.3.2.4 Procedures p. 290
9.3.2.4.1 General p. 290
9.3.2.4.1.1 Call announcement timer calculation p. 290
9.3.2.4.1.2 Max duration timer calculation p. 290
9.3.2.4.2 Call Probe p. 290
9.3.2.4.2.1 Call probe initiation p. 290
9.3.2.4.2.2 Call probe retransmission p. 291
9.3.2.4.2.3 Receiving GROUP CALL PROBE message when participating in the ongoing call p. 291
9.3.2.4.3 Call setup p. 291
9.3.2.4.3.1 Not receiving any response to GROUP CALL PROBE message p. 291
9.3.2.4.3.2 Receiving a GROUP CALL ANNOUNCEMENT message p. 292
9.3.2.4.3.3 Receiving a GROUP CALL ANNOUNCEMENT message when not participating in the ongoing call p. 292
9.3.2.4.3.4 MCVideo user accepts the terminating call with confirm indication p. 293
9.3.2.4.3.5 MCVideo user accepts the terminating call without confirm indication p. 294
9.3.2.4.3.6 Receiving GROUP CALL ACCEPT message p. 294
9.3.2.4.3.7 MCVideo user rejects the terminating call p. 294
9.3.2.4.3.8 MCVideo user does not act on terminating call p. 294
9.3.2.4.4 Periodic group call announcement p. 295
9.3.2.4.4.1 Sending periodic call announcement p. 295
9.3.2.4.4.2 Receiving periodic call announcement p. 295
9.3.2.4.5 Call release p. 296
9.3.2.4.5.1 MCVideo user leaves the call when GROUP CALL ANNOUNCEMENT was sent or received p. 296
9.3.2.4.5.2 Receiving GROUP CALL ANNOUNCEMENT message for rejected or released call p. 296
9.3.2.4.5.3 MCVideo user initiates originating call for rejected or released call p. 296
9.3.2.4.5.4 No GROUP CALL ANNOUNCEMENT messages for rejected or released call p. 297
9.3.2.4.5.5 MCVideo user leaves the call when GROUP CALL PROBE was sent p. 297
9.3.2.4.5.6 MCVideo user initiates originating call for released call p. 297
9.3.2.4.5.7 Receiving GROUP CALL ANNOUNCEMENT message for released call p. 297
9.3.2.4.5.8 No GROUP CALL ANNOUNCEMENT messages for released call p. 298
9.3.2.4.5.9 Max duration reached p. 298
9.3.2.4.6 Merge of calls p. 298
9.3.2.4.7 Error handling p. 299
9.3.3 Call type control p. 299
9.3.3.1 General p. 299
9.3.3.2 Call type control state machine p. 299
9.3.3.3 Call type control states p. 300
9.3.3.3.1 T0: waiting for call to establish p. 300
9.3.3.3.2 T1: in-progress emergency group call p. 301
9.3.3.3.3 T2: in-progress basic group call p. 301
9.3.3.3.4 T3: in-progress imminent peril group call p. 301
9.3.3.4 Procedures p. 301
9.3.3.4.1 General p. 301
9.3.3.4.1.1 Implicit downgrade (emergency) timer calculation p. 301
9.3.3.4.1.2 Implicit downgrade (imminent peril) timer calculation p. 301
9.3.3.4.2 User initiated the call probe p. 301
9.3.3.4.3 Received GROUP CALL ANNOUNCEMENT message as a response to GROUP CALL PROBE message p. 302
9.3.3.4.4 Received GROUP CALL ANNOUNCEMENT with MCVideo user acknowledgement required p. 303
9.3.3.4.5 Received GROUP CALL ANNOUNCEMENT without MCVideo user acknowledgement required p. 303
9.3.3.4.6 Call started p. 304
9.3.3.4.7 Upgrade call p. 305
9.3.3.4.7.1 Originating user upgrading the call p. 305
9.3.3.4.7.2 Terminating UE receiving a GROUP CALL ANNOUNCEMENT message when participating in the ongoing call p. 306
9.3.3.4.8 Downgrade call p. 307
9.3.3.4.8.1 Originating user downgrading emergency group call p. 307
9.3.3.4.8.2 Retransmitting GROUP CALL EMERGENCY END p. 308
9.3.3.4.8.3 Terminating user downgrading emergency group call p. 308
9.3.3.4.8.4 Originating user downgrading imminent peril group call p. 309
9.3.3.4.8.5 Retransmitting GROUP CALL IMMINENT PERIL END p. 309
9.3.3.4.8.6 Terminating user downgrading imminent peril group call p. 310
9.3.3.4.8.7 Implicit emergency priority end p. 310
9.3.3.4.8.8 Implicit imminent peril priority end p. 310
9.3.3.4.9 Merge of two calls p. 311
9.3.3.4.10 Call release after call establishment p. 311
9.3.3.4.11 Call release or reject before call establishment p. 312
9.3.3.4.12 Error handling p. 312
9.4 Off-network Broadcast group call p. 312
9.4.1 General p. 312
9.4.2 Basic call control p. 312
9.4.2.1 General p. 312
9.4.2.2 Broadcast group call control state machine p. 312
9.4.2.3 Broadcast group call Control states p. 313
9.4.2.3.1 B1: start-stop p. 313
9.4.2.3.2 B2: in-progress broadcast group call p. 313
9.4.2.3.3 B3: pending user action p. 313
9.4.2.3.4 B4: ignoring same call ID p. 313
9.4.2.4 Procedures p. 314
9.4.2.4.1 User initiating a broadcast group call p. 314
9.4.2.4.2 Terminating UE receiving a GROUP CALL BROADCAST message when not participating in the in-progress broadcast group call p. 314
9.4.2.4.3 MCVideo user accepts the terminating call p. 315
9.4.2.4.4 MCVideo user rejects the terminating call p. 315
9.4.2.4.5 MCVideo user does not act on terminating call p. 315
9.4.2.4.6 Terminating user releasing the call p. 315
9.4.2.4.7 Originating user releasing the call p. 315
9.4.2.4.8 Receiving GROUP CALL BROADCAST END message p. 316
9.4.2.4.9 Originating UE retransmitting GROUP CALL BROADCAST message p. 316
9.4.2.4.10 Ignoring same call ID p. 316
9.4.2.4.11 Releasing the call p. 316
