Figure 10.9.1.3.1-1 shows the high level procedure that the floor control is conducted for the MCPTT session already established between the floor participant and the floor control server. Only three UEs involved in the session are shown for the simplicity.
Pre-condition:
MCPTT session is established between MCPTT clients (client A, client B and client C) and MCPTT server.
The user at MCPTT client C is an authorized user (e.g., dispatcher) allowed to remove a floor request of other MCPTT users from the floor queue and can receive notifications about another user when their floor request is queued, when their queued floor request is rejected and when their queued floor request is removed from the queue.
Floor control server makes the determination on what action (grant, deny, or queue) to take on the request based on criteria (e.g., floor priority, participant type) and determines to accept the floor request from floor participant A. The floor control server may limit the time a user talks (hold the floor) as allowed by the configuration.
Floor control server responds with a floor granted message to floor participant A including the maximum floor granted duration e.g., if no other floor participant has the permission for transmission.
Floor control server sends a floor taken message to the other floor participant (floor participant B) including information about who is granted the floor.
Floor control server sends a floor taken message to the other floor participant (floor participant C) including information about who is granted the floor.
Suppose there are one or more users requesting to talk at this time, the floor request(s) are queued as decided by floor control server e.g., based on floor priority.
Floor control server may send the queue position info to floor participant C who is an authorized user to indicate floor participant user B's floor request is queued.
Figure 10.9.1.3.1a-1 shows the high level procedure that allows several participants to talk simultaneously in a MCPTT session already established between the floor participant and the floor control server. Three UEs involved in the session are shown for simplicity.
Pre-conditions:
The MCPTT group is configured to support multi-talker control and audio mixing by the network is applied.
MCPTT session is established between MCPTT clients (client A, client B and client C) and MCPTT server.
Participants and A and B have the permission to talk to all other participants and the floor is granted to floor participant B.
Based on applicable criteria (e.g. floor priority, participant type, allowance to transmit, maximum number of simultaneous talkers) floor control server determines what action (grant, deny, or queue) shall be applied to the request. In this case, the floor request from floor participant A will be accepted. Simultaneous floor requests to transmit are handled in a sequential order. Based on the group configuration repository data, the floor control server may limit the time a floor participant is allowed to talk.
Floor participant A starts sending voice media over the session established beforehand, i.e. participants A and B receive and transmit voice media; participant C only receives voice media.