10.5.8 Floor control without local filtering on an interworking group defined in the MCPTT system

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

Figure 10.5.8‑1 shows the procedure for floor control on an interworking group defined in the MCPTT system where local filtering is not performed by the LMR system. Simultaneous floor requests are included to show various aspects of interworking floor control.

Pre-conditions:

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

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

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

4. The IWF is not affiliating on behalf of LMR users. All LMR group affiliations are passed through the IWF to the MCPTT server.

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

Figure 10.5.8-1: Floor control without local filtering on a group defined in the MCPTT system

1. The user of MCPTT client 1 wants to send voice media over the session. At the same time multiple users in the LMR system (represented by the IWF) want to also send voice media over the session.

2. MCPTT client 1 sends a floor request message to the MCPTT floor control server.

3. The IWF sends floor request messages to the MCPTT floor control server for each LMR user requesting the floor. In this case two LMR users are requesting the floor. These floor requests contain the MCPTT ID of the LMR user (converted by the IWF).

4. Since the group is defined in the MCPTT system the MCPTT floor control server performs final floor control determination. In this case the MCPTT floor control server determines to accept the floor request from MCPTT client 1 based on local policy and arbitration results (e.g., according to priority of the request versus the competing requests from the IWF).

5. The IWF is notified that its floor requests were rejected. The MCPTT floor control server sends an IWF floor rejected message to the IWF for each floor request.

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

7. The MCPTT floor control server sends floor taken messages to MCPTT client 2 and the IWF to inform them of who is granted the floor. In this case a floor taken message is sent to the IWF corresponding to each affiliated LMR user.

NOTE: If the IWF has affiliated to this group on behalf of the group’s LMR users, only one IWF floor taken message is sent to the IWF.

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 LMR users.