10.5.9 Floor control in private call controlled by the LMR system

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

Figure 10.5.9‑1 shows a procedure for a private call with floor control where the LMR system controls the floor. A request for transmission by the MCPTT user while the LMR user has the floor is rejected by the IWF, to show various aspects of interworking floor control.

Pre-conditions:

1. A private call has been set up between an LMR user and MCPTT client 1.

2. The LMR system is controlling the floor, via the IWF.

3. MCPTT client 1 has the floor.

Figure 10.5.9-1: Floor control with control by the LMR system

1. The user of MCPTT Client 1 finishes transmission and MCPTT client 1 releases the floor.

2. The MCPTT server informs the IWF of the floor release.

3. The IWF indicates that the floor is now idle.

4. MCPTT client 1 is informed that the floor is idle.

5. The IWF indicates that the floor has been taken by the LMR user.

6. The MCPTT server informs MCPTT client 1 that the floor has been taken by the LMR user.

7. Media flows from the LMR user to the IWF (7a) and on to MCPTT client 1 (7b).

8. The user of MCPTT client 1 decides to interrupt the transmission from the LMR user.

9. MCPTT Client 1 sends a floor request with an appropriate priority to request interruption of the transmission from the LMR user.

10. The MCPTT server forwards the floor request to the IWF.

11. The LMR system rejects the request, and the IWF informs the MCPTT server of the rejection.

NOTE: The reason that the request is rejected is outside the scope of the present document.

12. The MCPTT server informs MCPTT client 1 that the request for interruption has been rejected.