7.1.3 Off-network group communications
23.2813GPPFunctional architecture and information flows to support Mission Critical Video (MCVideo)Release 18Stage 2TS
7.1.3.1 General
This subclause contains procedures for group communications directly between multiple MCVideo clients without involving the network to provide associated functions. Off-network MCVideo communications are based on ProSe capabilities as described in clause 7.18.
The group communication setup is described in subclause 7.1.3.3 and two variations of joining an existing communication group communication are described, the passive variant in subclause 7.1.3.4 and the active variant in subclause 7.1.3.5.
NOTE: When the MCVideo client receives a message that is not addressed to either its MCVideo ID or to any MCVideo group of which the MCVideo client is an affiliated group member, the MCVideo client ignores the message.
7.1.3.2 Information flows for off-network group communications
7.1.3.2.1 Group communication announcement
Table 7.1.3.2.1-1 describes the information flow for the group communication announcement sent from the MCVideo client to other MCVideo clients.
Table 7.1.3.2.1-1: Group communication announcement
|
Information Element |
Status |
Description |
|
MCVideo ID |
M |
The identity of the MCVideo user sending the announcement |
|
MCVideo group ID |
M |
The MCVideo group ID towards which the announcement was sent |
|
Media codec |
M |
The media characteristics like codec, resolution, frame rate and video mode to be used for the communication |
|
Multi-cast port |
M |
Multicast port number for media |
|
Transmission control port number |
M |
Port number for transmission control protocol |
|
Announcement period |
M |
Period of the group communication announcement |
|
Encryption parameters |
O |
Encryption parameters to be used for the communication, if the communication is to be encrypted |
|
Confirm mode indication |
O |
Indicates whether the receiving MCVideo user needs to confirm participation |
|
Emergency indication |
O |
Indicates that the MCVideo group communication is an MCVideo emergency communication |
|
Imminent peril indication |
O |
Indicates that the MCVideo group communication is an MCVideo imminent peril communication |
|
Broadcast communication indication |
O |
Indicates that the MCVideo communication is a broadcast communication |
|
Video push indication |
O |
Indicates that the MCVideo communication is for video push |
|
Video pull indication |
O |
Indicates that the MCVideo communication is for video pull |
7.1.3.2.2 Group communication answer response
Table 7.1.3.2.2-1 describes the information flow for the group communication answer response sent from the MCVideo client to other MCVideo clients.
Table 7.1.3.2.2-1: Group communication answer response
|
Information Element |
Status |
Description |
|
MCVideo ID |
M |
The identity of the MCVideo user sending the response |
|
MCVideo group ID |
M |
The identity of the MCVideo group on which the call is requested |
7.1.3.2.3 MCVideo upgrade to emergency group communication
Table 7.1.3.2.3-1 describes the information flow for the MCVideo upgrade to emergency sent from the MCVideo client to other MCVideo clients.
Table 7.1.3.2.3-1: MCVideo upgrade to emergency group communication
|
Information Element |
Status |
Description |
|
MCVideo ID |
M |
The identity of the MCVideo user upgrading the communication |
|
MCVideo group ID |
M |
The MCVideo group ID towards which the upgrade was sent |
7.1.3.2.4 MCVideo emergency group communication cancel
Table 7.1.3.2.4-1 describes the information flow for the MCVideo emergency group communication cancel sent from the MCVideo client to other MCVideo clients.
Table 7.1.3.2.4-1: MCVideo emergency group communication cancel
|
Information Element |
Status |
Description |
|
MCVideo ID |
M |
The identity of the MCVideo user cancelling the upgrade |
|
MCVideo group ID |
M |
The MCVideo group ID towards which the cancel was sent |
7.1.3.2.5 MCVideo upgrade to imminent peril group communication
Table 7.1.3.2.5-1 describes the information flow for the MCVideo upgrade to imminent peril sent from the MCVideo client to other MCVideo clients.
Table 7.1.3.2.5-1: MCVideo upgrade to imminent peril group communication
|
Information Element |
Status |
Description |
|
MCVideo ID |
M |
The identity of the MCVideo user upgrading the communication |
|
MCVideo group ID |
M |
The MCVideo group ID towards which the upgrade was sent |
7.1.3.2.6 MCVideo imminent peril group communication cancel
Table 7.1.3.2.6-1 describes the information flow for MCVideo imminent peril group communication cancel sent from the MCVideo client to other MCVideo clients.
Table 7.1.3.2.6-1: MCVideo imminent peril group communication cancel
|
Information Element |
Status |
Description |
|
MCVideo ID |
M |
The identity of the MCVideo user cancelling the upgrade |
|
MCVideo group ID |
M |
The MCVideo group ID towards which the cancel was sent |
7.1.3.2.7 MCVideo emergency alert announcement
Table 7.1.3.2.7-1 describes the information flow for the MCVideo emergency alert announcement sent from the MCVideo client to the other MCVideo clients, for the procedures defined in 3GPP TS 23.280 [6].
Table 7.1.3.2.7-1: MCVideo emergency alert announcement
|
Information Element |
Status |
Description |
|
MCVideo ID |
M |
The identity of the MCVideo user sending emergency alert |
|
MCVideo group ID |
M |
The MCVideo group ID towards which the alert was sent |
|
Organization name |
M |
The alerting user’s mission critical organization name |
|
Location |
O |
The alerting client’s location, if known |
7.1.3.2.8 MCVideo emergency alert cancel announcement
Table 7.1.3.2.8-1describes the information flow for the MCVideo emergency alert cancel sent from the MCVideo client to other MCVideo clients, for the procedures defined in 3GPP TS 23.280 [6].
Table 7.1.3.2.8-1: MCVideo emergency alert cancel announcement
|
Information Element |
Status |
Description |
|
MCVideo ID |
M |
The identity of the MCVideo user cancelling emergency alert |
|
MCVideo group ID |
M |
The MCVideo group ID towards which the cancel was sent |
7.1.3.3 Group communication setup
7.1.3.3.1 General
A group communication setup is initiated by one member of a pre-configured MCVideo group and ends up with an established MCVideo group between multiple MCVideo clients ready for video sharing.
7.1.3.3.2 Procedure
Figure 7.1.3.3.2-1 describes procedures to establish a MCVideo group communication with other MCVideo clients.
Once the MCVideo group communication is established the MCVideo clients send Group communication announcement periodically.
Pre-conditions:
1. Information for ProSe direct communications corresponding to the MCVideo group and its mapping to ProSe Layer-2 Group ID are pre-configured in MCVideo client 1 to client N.
2. MCVideo client 1 to MCVideo client N are members of the same MCVideo group.
3. MCVideo user 1 has initiated MCVideo group communication.
Figure 7.1.3.3.2-1: MCVideo group communication setup
1. MCVideo client 1 sends a Group communication announcement message to the MCVideo group.
2. Upon receiving the Group communication announcement message, all MCVideo clients that are not part of an ongoing group communication for the MCVideo group indicated in the Group communication announcement message set parameters for the media plane as described in the Group communication announcement message.
3. The MCVideo clients send a group communication answer response to the MCVideo group confirming the participation in the MCVideo group communication. On receiving a group communication answer response message from at least one MCVideo client, other MCVideo clients need not send a group communication answer response message. If the Group communication announcement message included a confirm mode indication, then the MCVideo clients should send a group communication answer response message.
NOTE 1: MCVideo client 1 should wait for at least one group communication answer response message before transmitting video to the MCVideo group.
4. MCVideo client 1 checks the participants of the MCVideo group communication through the received group communication answer response messages.
NOTE 2: Due to the movement of the participants (in and out of the radio coverage) during the off-network group communication, the Group communication announcement message, including parameters for media delivery, is periodically sent.
NOTE 3: Group communication announcement may include user ID, group ID, media type codec, control port for transmission video, video resolution and video frame rate, video mode, last chage time of video mode etc.
5. MCVideo client 1, MCVideo client 2 and MCVideo client 3 have successfully established the media plane and transmission control for communication.
7.1.3.4 Passive join to group communication
7.1.3.4.1 General
There is ongoing group communication between multiple MCVideo clients. Another MCVideo client, after becoming aware of that group communication and after it has received periodically sent communication parameters, joins the group with or without sending an indication to other group members.
7.1.3.4.2 Procedure
Figure 7.1.3.4.2-1 describes procedures to join a MCVideo group communication passively.
The MCVideo client X passively waits for a Group communication announcement message. Upon receiving a periodic Group communication announcement message, MCVideo client X establishes media plane and joins the MCVideo group communication.
Pre-conditions:
1. Information for ProSe direct communications corresponding to the MCVideo group and its mapping to ProSe Layer-2 Group ID are pre-configured in MCVideo client 1 to client N and client X.
2. MCVideo client 1 to MCVideo client N and MCVideo client X are members of the same MCVideo group.
3. MCVideo client 1 to MCVideo client N are part of an ongoing MCVideo group communication.
Figure 7.1.3.4.2-1: Passive join to MCVideo group communication
1. Another MCVideo client X enters in the communication range after the MCVideo group communication establishment. The MCVideo client X does not do anything and passively waits for a periodic Group communication announcement message.
2. An MCVideo client which is part of the ongoing MCVideo group communication eventually sends a periodic Group communication announcement message.
3. Upon receiving the periodic Group communication announcement message MCVideo client X sets the parameters for media plane as described in the Group communication announcement message.
4. If the Group communication announcement message included a confirm mode indication, MCVideo client X may sends a group communication answer response towards MCVideo group to inform all MCVideo group members of its participation the MCVideo group communication.
5. MCVideo group communication continues with the MCVideo client X.
7.1.3.5 Active join to group communication
7.1.3.5.1 General
There is ongoing group communication between multiple MCVideo clients. Another MCVideo client, after becoming aware of that group communication, sends a request to get the required communication parameters and after feedback joins the group with or without sending an indication to other group members.
7.1.3.5.2 Procedure
Figure 7.1.3.5.2-1 describes procedures to join a MCVideo group communication actively.
The MCVideo client X sends a Group communication announcement message towards the MCVideo group.
Upon receiving a Group communication announcement message with new communication parameters, such as communication identifier, a MCVideo client participating in the on-going group communication for the MCVideo group sends a Group communication announcement message.
The Group communication announcement message contains parameters for the on-going MCVideo group communication. MCVideo client X upon receiving such a Group communication announcement message establishes the media plane as described in the message and joins the MCVideo group communication.
Pre-conditions:
1. Information for ProSe direct communications corresponding to the MCVideo group and its mapping to ProSe Layer-2 Group ID are pre-configured in MCVideo client 1 to client N and client X.
2. MCVideo client 1 to MCVideo client N and MCVideo client X are members of the same MCVideo group.
3. MCVideo client 1 to MCVideo client N are part of an ongoing MCVideo group communication.
Figure 7.1.3.5.2-1: Active join to MCVideo group communication
1. Another MCVideo client X enters in the communication range after the MCVideo group communication establishment. The MCVideo client X sends a Group communication announcement message to start a newMCVideo group communication.
2. Upon receiving a Group communication announcement message with new communication parameters, such as communication identifier, another MCVideo client, which is part of the ongoing MCVideo group communication sends a Group communication announcement message.
3. Upon receiving the Group communication announcement message MCVideo client X sets parameters for the media plane as described in the Group communication announcement message.
4. If the Group communication announcement message included a confirm mode indication, MCVideo client X may send a group communication answer response towards MCVideo group to inform all MCVideo group members of its participation the MCVideo group communication.
5. MCVideo group communication continues with the MCVideo client X.
7.1.3.6 Broadcast group communication
Figure 7.1.3.6-1 describes procedures for broadcast group communication.
Broadcast group communication over group-broadcast group and over user-broadcast group are handled without distinction in off-network.
Figure 7.1.3.6-1: Broadcast group communication
1. MCVideo client 1 initiates group communication setup as described in subclause 7.1.3.3. The group communication announcement message includes the indication of broadcast group communication.
2. MCVideo client 1 initiating broadcast group communication starts to transmit video.
NOTE: Other clients of the group member are not allowed to transmit media in broadcast group communication.
3. The broadcast group communication is released as described in subclause 7.1.3.7.
7.1.3.7 Group communication release due to inactivity
If the on-going MCVideo group communication is inactive for a specific duration, the participating MCVideo clients release the MCVideo group communication. Inactivity is defined as absence of any transmission to or from other communication participants.
NOTE: Inactivity time can be set according to the policy of MC service provider.
7.1.3.8 Emergency and imminent peril procedures
7.1.3.8.1 Emergency group communication
The off-network emergency group communication is a special case of off-network (non-emergency) group communication as defined in subclause 7.1.3.2, subclause 7.1.3.3, subclause 7.1.3.4, subclause 7.1.3.5, subclause 7.1.3.6 and subclause 7.1.3.7. The following are modifications to the aforementioned subclauses to support MCVideo emergency group communications:
– As a pre-condition, the client initiating the emergency communication has previously been provisioned with an MCVideo group designated as the MCVideo emergency group. The MCVideo client initiates MCVideo emergency group communications on this group. Alternatively, the MCVideo client could have been provisioned for emergency behaviour on the selected MCVideo group.
– The group communication announcement contains an indication that the MCVideo group communication is to be an MCVideo emergency communication regardless of whether or not the MCVideo client is in communication. Group communication participants learn of the MCVideo group’s in-progress emergency state from the indication.
– Every communication initiated by the MCVideo client will be an emergency communication while the MCVideo client is in MCVideo emergency state.
– The MCVideo client enters the MCVideo emergency state when initiating an MCVideo emergency communication or emergency alert. Only the MCVideo user of the MCVideo client can clear the client’s local MCVideo emergency state.
– The MCVideo group in-progress emergency state is cancelled when the communication ends.
– The MCVideo user who initiated the emergency communication, or upgraded the group communication to emergency group communication, or an authorized user, may cancel the in-progress emergency state with an MCVideo emergency group communication cancel message. The message is sent to the MCVideo group.
– When the MCVideo group is no longer in the in-progress emergency state, every client returns the value of ProSe Per Packet Priority to its default value.
– An in-progress MCVideo group communication is upgraded to an emergency group communication when the periodic group communication announcement contains the emergency indicator.
– The value of ProSe Per Packet Priority is upgraded according to emergency state of MCVideo group communication.
– An MCVideo group communication upgraded to emergency group communication does not affect the state of other MCVideo communication(s) in the client.
– The MCVideo group remains in the in-progress emergency state until the emergency group communication ends or the in-progress emergency state is cancelled.
7.1.3.8.2 MCVideo imminent peril
The off-network imminent peril group communication is a special case of off-network (non-imminent peril) group communication as defined in subclause 7.1.3.2, subclause 7.1.3.3, subclause 7.1.3.4, subclause 7.1.3.5, subclause 7.1.3.6 and subclause 7.1.3.7. The following are modifications to the aforementioned subclauses to support MCVideo imminent peril communications:
– As a pre-condition, the user initiating the imminent peril communication has previously been provisioned with an MCVideo group to be used as the MCVideo imminent peril group. The MCVideo client initiates MCVideo imminent peril group communications on this group. Alternatively, the MCVideo client could have been provisioned for imminent peril behaviour on the selected MCVideo group.
– The group communication announcement contains an indication that the MCVideo group communication is to be an MCVideo imminent peril communication. Group communication participants learn of the MCVideo group’s in-progress imminent peril condition from the indication.
– The MCVideo group in-progress imminent peril state is considered cancelled when the communication ends.
– The MCVideo user who initiated the in-progress imminent peril communication or upgraded the group communication to imminent peril group communication, or an authorized user may cancel the in-progress imminent peril state with an MCVideo imminent peril group communication cancel message. The message is sent to the communication participants.
– When the MCVideo group is no longer in the in-progress imminent peril state, every MCVideo client returns the value of ProSe Per Packet Priority to its default value.
– An in-progress MCVideo group communication is upgraded to an imminent peril group communication when the periodic group communication announcement contains the imminent peril indicator.
– The value of ProSe Per Packet Priority is upgraded according to imminent peril state of MCVideo group communication.
– The MCVideo group remains in the in-progress imminent peril state until the imminent peril group communication ends or the in-progress imminent peril state is cancelled.
7.1.3.9 MCVideo emergency alert
7.1.3.9.1 General
The MCVideo client use emergency alert initiation and emergency alert cancel procedures defined in 3GPP TS 23.280 [6], with the following clarifications:
– The MC service ID is the MCVideo ID; and
– The MC service group ID is the MCVideo group ID.