Content for &nbsp; TS 23.281 &nbsp; Word version:&nbsp; 18.2.0

Transmission control participant A wants to send video media over the session.

Transmission control participant A sends a transmit media request message to transmission control server which includes transmission priority and other information as necessary.

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 transmit media request from transmission control participant A.

Transmission control server responds with a transmit media granted message (4a) to transmission control participant A. Transmission control server may send transmit media rejected message (4b) indicating the cause of rejection or queue position info message (4c) indicating that the transmit media request has been queued.

The transmit media granted shall cause the user of UE A where the transmission control participant A is located to be notified.

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

7.7.1.3.2 Reception control during an MCVideo session p. 133

Figure 7.7.1.3.2-1 describes the procedure for the reception control between the transmission control participant and the transmission control server during an MCVideo session. 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 has been granted the permission to transmit media.

Copy of original 3GPP image for 3GPP TS 23.281, Fig. 7.7.1.3.2-1: Reception control during an MCVideo session

Figure 7.7.1.3.2-1: Reception control during an MCVideo session
(⇒ copy of original 3GPP image)

The transmission control server determines the reception mode for downlink transmission control participants for the media transmission permitted to transmission control participant A. The manual and forced reception modes are determined based on configurations (e.g. auto-receive video transmissions, auto-receive emergency video transmissions) as described in Annex A.

Transmission control server sends a media transmission notification message to the transmission control participant B including information about the video transmitter and the reception mode.

The receipt of the media transmission notification is used to inform the user of UE B the details of video transmission and the video transmitter.

Based on the notification received, the user of UE B may want take actions (receive, reject or cancel) regarding the media available for reception.

If user of UE B wants to receive the media or it required to receive the media via forced reception, it causes the transmission control participant B to send a media receive request message to the transmission control server.

Transmission control server makes the determination on what action (e.g., real-time stream downlink, make stream downloadable, reject) to take on the request based on reception control criteria (e.g., allowed simultaneous reception) and determines to accept the media receive request from transmission control participant B. Transmission control server will also determine the availability of the media at the server to initiate the downlink reception.

Step 7.

Transmission control server sends a receive media response message to transmission control participant B.

Step 8.

Transmission control server sends video media to transmission control participant B.

Step 9.

Optionally, the transmission control server sends media reception notification message to transmission control participant A which includes the information about the video recipient (transmission control participant B).

7.7.1.3.2A End media reception - receiving user initiated p. 134

Figure 7.7.1.3.2A-1 describes the procedure for the receiving user initiated media reception end. 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 has been granted the permission to transmit media.

Copy of original 3GPP image for 3GPP TS 23.281, Fig. 7.7.1.3.2A-1: End media reception - receiving user initiated

Figure 7.7.1.3.2A-1: End media reception - receiving user initiated
(⇒ copy of original 3GPP image)

The MCVideo user determines to end a receiving video stream.

The user sends an media reception end request including the video stream to be ended to the transmission control server.

The transmission control server returns a media reception end response.

Upon receiving the media reception end request, the transmission control server stops sending the video stream selected to the transmission control participant B.

If the end media reception at transmission control participant B causes the video transmission continuation condition to fail, then the transmission control server initiates the media transmission end procedure as described in subclause 7.7.1.3.6.2.

7.7.1.3.2B End media reception - transmission control server initiated p. 135

Figure 7.7.1.3.2B-1 describes the procedure for the transmission control server initiated media reception end. 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 has been granted the permission to transmit media.

Copy of original 3GPP image for 3GPP TS 23.281, Fig. 7.7.1.3.2B-1: End media reception - transmission control server initiated

Figure 7.7.1.3.2B-1: End media reception - transmission control server initiated
(⇒ copy of original 3GPP image)

The transmission control server determines to end a video stream transmitting to transmission control participant B according to events or configurations.

The transmission control server sends an media reception end request including the video stream to be ended to the transmission control participant B.

The MCVideo user is notified about the media reception end.

The transmission control participants B returns a media reception end response.

The transmission control server stops sending the video stream selected to the transmission control participant B.

If the end media reception at transmission control participants B causes the continuation conditions to fail, then the transmission control server initiates media transmission end procedure as described in subclause 7.7.1.3.6.2.

7.7.1.3.2C Reception control on overridden - mandatory mode p. 135

Figure 7.7.1.3.2C-1 describes the procedure for the reception control on overridden with mandatory mode that the transmission control server determines the video stream to be overridden. 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 has been granted the permission to transmit media.

Copy of original 3GPP image for 3GPP TS 23.281, Fig. 7.7.1.3.2C-1: Reception control on overriding/overridden - mandatory mode

Figure 7.7.1.3.2C-1: Reception control on overriding/overridden - mandatory mode
(⇒ copy of original 3GPP image)

A new media stream is to be delivered to the transmission control participant B while the maximum number of simultaneous streams is reached. The transmission control server determines to override another media stream being received by the transmission control participant B accord to the media stream characteristics.

Transmission control server sends a media reception override notification message to the transmission control participant B including information about the video stream being overridden and stop the downlink delivery of the overridden video stream to the transmission control participant B. The overriding video stream information maybe also included.

The user of UE B is notified about the details of overriding/overridden.

The transmission control server initiates the media reception end procedure as described in subclause 7.7.1.3.2B. 5. The transmission control server performs the normal reception control procedure as described in subclause 7.7.1.3.2.

7.7.1.3.2D Reception control on overridden - negotiated mode p. 136

Figure 7.7.1.3.2D-1 describes the procedure for the reception control on overridden with negotiated mode that the transmission control participant determines the video stream to be overridden. 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 has been granted the permission to transmit media.

Copy of original 3GPP image for 3GPP TS 23.281, Fig. 7.7.1.3.2D-1: Reception control on overriding/overridden - negotiated mode

Figure 7.7.1.3.2D-1: Reception control on overriding/overridden - negotiated mode
(⇒ copy of original 3GPP image)

A new media stream is to be delivered to the transmission control participant B while the maximum number of simultaneous streams is received. The transmission control server determines to override another media stream being received by the transmission control participant B according to the media stream characteristics.

Transmission control server sends a media transmission notification message to the transmission control participant B including information about the new video stream.

The user of transmission control participant B is notified about the maximum number of simultaneous streams received. The MCVideo user determines to reject the video stream or accept the video streaming by overriding a receiving video stream.

The transmission control participant initiates the media reception end procedure as described in subclause 7.7.1.3.2A.

Then the transmission control participant B requests to receive the new video stream as the normal reception control procedure described in subclause 7.7.1.3.2.

7.7.1.3.3 Transmission revoke during an MCVideo session p. 137

Figure 7.7.1.3.3-1 describes the procedure for transmission revoke during an MCVideo session. 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 may be ongoing media transmission from transmission control participant B.
The maximum media transmission limit for the MCVideo session is reached.

Copy of original 3GPP image for 3GPP TS 23.281, Fig. 7.7.1.3.3-1: Transmission revoke during an MCVideo session

Figure 7.7.1.3.3-1: Transmission revoke during an MCVideo session
(⇒ copy of original 3GPP image)

Transmission control participant A wants to send video media over the session.

Transmission control participant A sends a transmit media request message to transmission control server which includes transmission priority and other information as necessary.

Transmission control server determines to accept the transmit media request from transmission control participant A and decides to pre-empt the on-going video transmission from transmission control participant B by queuing or ending the on-going video transmission.

Transmission control server responds with a transmission revoked message (4a) to transmission control participant B with the action of pre-emption whether queued or terminated. Transmission control server responds with a transmit media granted message (4b) to transmission control participant A.

The transmission revoked shall cause the transmission control participant B to be notified of the revoke (5a) of the on-going video transmission by queuing or termination. The transmit media granted shall cause the user of UE A where the transmission control participant A is located to be notified.

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

7.7.1.3.4 Queue position during an MCVideo session p. 138

Figure 7.7.1.3.4-1 describes the procedure where the transmission control is conducted for the MCVideo session already established between MCVideo clients (with transmit media granted to transmission control participant B) and server (with an revoke determination at transmission control server). Only two UEs involved in the session are shown for the simplicity.

Copy of original 3GPP image for 3GPP TS 23.281, Fig. 7.7.1.3.4-1: Queue status during an MCVideo session

Figure 7.7.1.3.4-1: Queue status during an MCVideo session
(⇒ copy of original 3GPP image)

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

Transmission control participant A would like to know its current position in the video transmission queue.

Transmission control participant A sends a queue position request message to the transmission control server.

Transmission control server determines the current queue position of transmission control participant A from the video transmission queue.

Transmission control server responds with the current position in queue position info message.

User at transmission control participant A is informed about the current queue position.

7.7.1.3.5 Transmit media request cancellation from the video transmission queue p. 139

7.7.1.3.5.1 Transmit media request cancellation from the queue - MCVideo user initiated p. 139

Figure 7.7.1.3.5.1-1 illustrates the procedure for transmit media request cancellation from the video transmission queue initiated by the MCVideo user. The MCVideo user may be an authorized user who has rights to cancel the transmit media requests of other MCVideo users, whose transmit media requests are in video transmission queue.

Pre-conditions:

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

Copy of original 3GPP image for 3GPP TS 23.281, Fig. 7.7.1.3.5.1-1: Transmit media request cancellation from queue initiated by MCVideo user

Figure 7.7.1.3.5.1-1: Transmit media request cancellation from queue initiated by MCVideo user
(⇒ copy of original 3GPP image)

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.

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. 140

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.

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

Figure 7.7.1.3.5.2-1: Transmit media request cancellation from queue initiated by transmission control server
(⇒ copy of original 3GPP image)

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.

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. 141

7.7.1.3.6.1 End a media transmission - MCVideo user initiated p. 141

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.

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

Figure 7.7.1.3.6.1-1: End a media transmission by an MCVideo user
(⇒ copy of original 3GPP image)

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.

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. 142

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.

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

Figure 7.7.1.3.6.2-1: End a media transmission by the transmission control server
(⇒ copy of original 3GPP image)

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

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. 143

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.

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

Figure 7.7.1.3.6.3-1: End a media transmission by a remote MCVideo user
(⇒ copy of original 3GPP image)

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.

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. 144

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

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

Figure 7.7.1.3.7-1: Remotely initiated media transmission during an MCVideo session
(⇒ copy of original 3GPP image)

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.