Content for &nbsp; TS 23.281 &nbsp; Word version:&nbsp; 19.4.0

The transmission control participant A wants to remove the transmit media request from the video transmission queue. If transmission control participant A is an authorized MCVideo user with the rights to cancel another MCVideo user's transmit media request, the authorized MCVideo user may request for transmit media request cancellation for one or more transmission control participants, whose transmit media request needs to be removed from the video transmission queue.

The transmission control participant A sends a transmit media cancel request (initiating MCVideo ID) message to the transmission control server. If the transmission control participant A wants to remove the transmit media request(s) of other participant(s), the target participant(s)' MCVideo ID should be included in this message.

The transmission control server shall check whether the requesting transmission control participant has authorization to cancel the transmit media request(s). If authorized, the transmit media request(s) will be removed from the video transmission queue. When the on-going transmissions are completed and are within the limit of the maximum simultaneous transmissions, the transmission control server will process the transmit media request from the updated video transmission queue.

If the transmit media cancel request in step 3 is sent by an authorized user (e.g., dispatcher) to cancel the transmit media request(s) of other participant(s) from the video transmission queue, the transmit media cancel request notify message is sent to the transmission control participant whose transmit media request was cancelled from the video transmission queue.

Figure 7.7.1.3.5.2-1: Transmit media request cancellation from queue initiated by transmission control server

The transmission control server provides a transmit media cancel response to the transmission control participant A when the transmit media request cancellation is completed. Optionally, the new queue position information may be notified to the transmission control participants whose transmit media requests are in the video transmission queue (not shown in the figure).

7.7.1.3.5.2 Transmit media request cancellation from the queue - transmission control server initiated p. 143

Figure 7.7.1.3.5.2-1 illustrates the procedure for transmit media request cancellation from the queue initiated by the transmission control server. Only two UEs involved in the session are shown for the simplicity.

Pre-conditions:

It is assumed that transmission control participant B has been granted the permission to transmit media and is transmitting video. There are several other transmission control participants (including transmission control participant A and participant C) requesting the permission to transmit media which have been queued at the transmission control server.

Reproduction of 3GPP TS 23.281, Fig. 7.7.1.3.5.2-1: Transmit media request cancellation from queue initiated by transmission control server

The transmission control server removes the transmit media request from the video transmission queue based on policy. e.g., expiration of a timer. In the case when transmission control server receives repeated transmit media requests from a transmission control participant while the limit for maximum simultaneous media transmissions has reached, the new transmit media request is accepted and added into the video transmission queue and the existing/former transmit media request is removed from the video transmission queue or the new transmit media request is rejected and the existing/former transmit media request of this transmission control participant is retained in the video transmission queue.

The transmission control server sends a transmit media cancel request notify to the transmission control participant(s) whose transmit media request is removed from the video transmission queue.

Figure 7.7.1.3.6.1-1: End a media transmission by an MCVideo user

Optionally, the new queue position information is notified to the other transmission control participants whose transmit media requests are queued.

7.7.1.3.6 End a media transmission during an MCVideo session p. 144

7.7.1.3.6.1 End a media transmission - MCVideo user initiated p. 144

Figure 7.7.1.3.6.1-1 describes the procedure for ending a media transmission during an MCVideo session by a MCVideo user. Only two UEs involved in the session are shown for the simplicity.

Pre-condition:

MCVideo session is established between MCVideo clients (client A and client B) and MCVideo server
Transmission control is established between transmission control participants and transmission control server.
Transmission control participant A and participant B have been granted the permission to transmit media and there are ongoing media transmission from transmission control participant A and participant B.

Reproduction of 3GPP TS 23.281, Fig. 7.7.1.3.6.1-1: End a media transmission by an MCVideo user

Transmission control participant A wants to end its media transmission in a session and sends a transmit media end request message to transmission control server.

Transmission control server terminates the on-going media transmission from transmission control participant A.

Transmission control server responds with a transmit media end response message to transmission control participant A indicating that the transmission control server has terminated the media transmission.

Transmission control server sends a transmit media end notify message to transmission control participant B indicating that the media transmission from transmission control participant A is terminated by the user.

Figure 7.7.1.3.6.2-1: End a media transmission by the transmission control server

The transmit media end notification shall cause the user of the transmission control participant B to be notified of the media transmission termination by the sending user.

7.7.1.3.6.2 End a media transmission - transmission control server initiated p. 145

Figure 7.7.1.3.6.2-1 describes the procedure for ending a media transmission during an MCVideo session by the transmission control server. Only two UEs involved in the session are shown for the simplicity.

Pre-condition:

MCVideo session is established between MCVideo clients (client A and client B) and MCVideo server
Transmission control is established between transmission control participants and transmission control server.
Transmission control participant A and participant B have been granted the permission to transmit media and there are ongoing media transmission from transmission control participant A and participant B.

Reproduction of 3GPP TS 23.281, Fig. 7.7.1.3.6.2-1: End a media transmission by the transmission control server

Transmission control server terminates the on-going media transmission from transmission control participant A due to a termination event (e.g. revoke for another priority media transmission or there are no receiving participants).

Transmission control server sends a transmit media end request message to transmission control participant A indicating the reason for ending the media transmission.

Transmission control participant A responds with a transmit media end response message to transmission control server as acknowledgement.

Figure 7.7.1.3.6.3-1: End a media transmission by a remote MCVideo user

The transmit media end notification shall cause the user of the transmission control participant B to be notified of the media transmission termination by the transmission control server.

7.7.1.3.6.3 End a media transmission - remote MCVideo user initiated p. 146

Figure 7.7.1.3.6.3-1 describes the procedure for ending a media transmission during an MCVideo session by a remote MCVideo user. Only two UEs involved in the session are shown for the simplicity.

Pre-condition:

MCVideo session is established between MCVideo clients (client A and client B) and MCVideo server
Transmission control is established between transmission control participants and transmission control server.
Transmission control participant B has been granted the permission to transmit media and there is ongoing media transmission from transmission control participant B.
Transmission control participant A is authorized to end the on-going media termination from transmission control participant B.

Reproduction of 3GPP TS 23.281, Fig. 7.7.1.3.6.3-1: End a media transmission by a remote MCVideo user

Transmission control participant A sends a remote transmit media end request message to transmission control server including the MCVideo ID of the user at the UE of the transmission control participant B and the MCVideo ID of the user at the UE of the transmission control participant A.

Transmission control server checks whether the user at the UE of transmission control participant A is authorized to end the on-going media transmission from transmission control participant B. If authorized, the transmission control server ends the media transmission from transmission control participant B.

Transmission control server ends the on-going media transmission from transmission control participant B. The transmission control server shall send transmit media end notify messages to the transmission control participants receiving the media transmission from transmission control participant B, indicating that the transmission has ended.

Figure 7.7.1.3.7-1: Remotely initiated media transmission during an MCVideo session

Transmission control server responds with a remote transmit media end response message to transmission control participant A indicating that the transmission control server has ended the requested media transmission.

7.7.1.3.7 Remotely initiated media transmission during an MCVideo session p. 147

Figure 7.7.1.3.7-1 describes the procedure for remotely initiated media transmission during an MCVideo session by an authorized user. Only two UEs involved in the session are shown for the simplicity.

Pre-condition:

MCVideo session is established between MCVideo clients (client A and client B) and MCVideo server
Transmission control is established between transmission control participants and transmission control server and there is no ongoing media transmission.
The user of the UE at the transmission control participant A is authorized to remotely initiate a media transmission from transmission control participant B

Reproduction of 3GPP TS 23.281, Fig. 7.7.1.3.7-1: Remotely initiated media transmission during an MCVideo session

Transmission control participant A sends a remote transmit media request message to transmission control server including the MCVideo ID of the user at the UE of the transmission control participant B and the MCVideo ID of the user at the UE of the transmission control participant A.

Transmission control server checks whether the user at the UE of transmission control participant A is authorized to remotely initiate a media transmission from transmission control participant B. If authorized, the transmission control server makes the determination on what action (grant, deny, or queue) to take on the request based on transmission control criteria (e.g., group policy) and determines to accept the remotely initiated transmit media request from transmission control participant A.

Transmission control server sends a transmit media granted message to transmission control participant B.

Transmission control server provides a remote transmit media response message to transmission control participant A indicating success (media transmission occurs from transmission control participant B) or a failure reason.

Figure 7.7.1.3.8-1: Transmission idle

Transmission control participant B starts sending video media over the session established to the transmission control server.

7.7.1.3.8 Transmission idle during an MCVideo session |R17| p. 147

During silence, i.e., when no video transmission is ongoing, the transmission control server may send the transmission idle message to all transmission participants from time to time. The transmission control server sends the transmission idle message in the beginning of silence.

Figure 7.7.1.3.8-1 describes the procedure once the transmission idle message is sent from the transmission control server to the transmission control participant(s) during an already established MCVideo session. For simplicity, only three MCVideo UEs are participating in the MCVideo session.

Pre-condition:

MCVideo session is established between MCVideo clients (client A and client B) and MCVideo server.
The transmission control is established between the transmission control participants and transmission control server.
The transmission control participant A has been granted the permission to transmit media.

Reproduction of 3GPP TS 23.281, Fig. 7.7.1.3.8-1: Transmission idle

The media transmission has ended according to clause 7.7.1.3.6.

Step 2a-2c.

If no other MCVideo user has permission to transmit the media, then the transmission control server sends the transmission idle message to the transmission control participants.