Content for  TS 23.281  Word version:  19.4.0

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 7.1.3.2.2-1 describes the information flow for the group communication answer response sent from the MCVideo client to other MCVideo clients.

Table 7.1.3.2.3-1 describes the information flow for the MCVideo upgrade to emergency sent from the MCVideo client to other MCVideo clients.

Table 7.1.3.2.4-1 describes the information flow for the MCVideo emergency group communication cancel sent from the MCVideo client to other MCVideo clients.

Table 7.1.3.2.5-1 describes the information flow for the MCVideo upgrade to imminent peril sent from the MCVideo client to other MCVideo clients.

Table 7.1.3.2.6-1 describes the information flow for MCVideo imminent peril group communication cancel sent from the MCVideo client to other MCVideo clients.

Table 7.1.3.2.7-1 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 TS 23.280.

Table 7.1.3.2.8-1 describes the information flow for the MCVideo emergency alert cancel sent from the MCVideo client to other MCVideo clients, for the procedures defined in TS 23.280.

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.

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.

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.

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.

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.

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.

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.

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.

The MCVideo client use emergency alert initiation and emergency alert cancel procedures defined in TS 23.280, with the following clarifications:

• The MC service ID is the MCVideo ID; and
• The MC service group ID is the MCVideo group ID.