10.5.7 Floor control without local filtering on an interworking group defined in the LMR system

23.2833GPPMission Critical Communication Interworking with Land Mobile Radio SystemsRelease 18TS

Figure 10.5.7‑1 shows the procedure for floor control on an interworking group defined in the LMR system where local filtering is not performed by the MCPTT server. Simultaneous floor requests are included to show various aspects of interworking floor control.

Pre-conditions:

1. The interworking group is defined in the LMR system.

2. The MCPTT system is configured to send competing floor control requests to the LMR system (represented by the IWF) for floor control arbitration.

3. MCPTT client 1, MCPTT client 2, and LMR users are affiliated to that group.

4. An interworking group call is ongoing involving MCPTT users and LMR users. The floor is currently idle.

Figure 10.5.7-1: Floor control without local filtering on a group defined in the LMR system

1. The users of MCPTT client 1 and MCPTT client 2 both want to send voice media over the session.

2. MCPTT clients 1 and 2 send floor request messages to the MCPTT floor control server.

3. Since the group is defined in the LMR system the MCPTT floor control server forwards these floor requests to the IWF for final floor control determination. The IWF performs floor arbitration in conjunction with the LMR system (not shown). The IWF determines that the floor can be granted to MCPTT client 1.

4. The IWF sends an IWF floor granted message for MCPTT client 1, an IWF floor rejected message for MCPTT client 2, and an IWF floor taken message for MCPTT client 2 to the MCPTT floor control server.

NOTE: If other MCPTT clients are affiliated to this group, the IWF sends an IWF floor taken message to the MCPTT floor control server for each one of them.

5. The MCPTT floor control server sends a Floor rejected message to MCPTT client 2 to notify the user that his/her floor request was rejected.

6. The MCPTT floor control server sends a Floor granted message to MCPTT client 1.

7. The MCPTT floor control server sends a Floor taken message to MCPTT client 2 to notify the user of who is granted the floor.

8. MCPTT client 1 notifies the user that he/she has been granted the floor and may begin speaking.

9. MCPTT client 1 begins sending voice media over the established session. The media is distributed to affiliated group members including the IWF.