The MCPTT service shall support the procedures and related information flows as specified in subclause 10.8 of TS 23.280 with the following clarifications:
The MC service client is the MCPTT client;
The MC service server is the MCPTT server;
The MC service group is the MCPTT group;
The MC service ID is the MCPTT ID; and
The MC service group ID is the MCPTT group ID.
When an MCPTT user has affiliated to an MCPTT group then the MCPTT user can send and receive MCPTT related media for that MCPTT group. When an MCPTT user has de-affiliated from an MCPTT group then the MCPTT user cannot send and receive MCPTT related media to and from that MCPTT group.
When an MCPTT user wants to transmit on a MCPTT group, an affiliated MCPTT group shall be set as the selected MCPTT group to the MCPTT user. Only one MCPTT group can be set as the selected MCPTT group to an MCPTT user from one particular MCPTT UE at any given time. This subclause describes the detailed procedures for the MCPTT group selection.
Procedure for an authorized user to change other MCPTT users' selected MCPTT group without requiring target user's approval is described in Figure 10.4.3-1.
The MCPTT client 1 has already been provisioned (statically or dynamically) with the target MCPTT user's information and its group information, that the selected MCPTT group of target MCPTT user 2 is allowed to be changed;
When an authorized user changes other MCPTT users' selected MCPTT group, the MCPTT client 1 sends MCPTT group selection change request to the MCPTT server. The information (i.e. target MCPTT ID, MCPTT group ID) used to set the requested MCPTT group as the selected MCPTT group of the target MCPTT user shall be included.
The MCPTT server shall check if the MCPTT user 1 is authorized to change the target MCPTT user's selected MCPTT group. The MCPTT server shall perform the affiliation relationship check based on the stored affiliation status.
If the MCPTT user 1 is authorized to change the target MCPTT user's selected MCPTT group, and if the target MCPTT user is not already affiliated to the requested MCPTT group, the remotely change of affiliation procedures shall be performed (see subclause 10.8 in TS 23.280).