Content for TS 23.284 Word version: 18.0.0

1… 4… 4.2… 4.3… 5 6… 6.3… 6.3.2 6.3.3 6.3.4 6.3.5 7… 7.2.4… 7.2.4.2 7.2.4.3 7.2.4.4 7.2.4.5 7.2.4.6 7.3… 7.3.4… 7.3.4.2 7.3.4.3 7.3.4.4 8… 8.2.3 8.3… 8.3.2 8.4… 8.4.1.1.7… 8.4.1.2… 8.4.2… 8.4.2.2… 8.4.5… 8.4.5.6 8.4.5.7 8.4.5.8… 9… 13… 13.4… 13.4.3… 13.4.4… 13.5… 13.6… 13.7… 14… 16… A… A.2…

7.2.4.2 MSC server Initiated
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7.2.4.2 MSC server Initiated p. 51

Figure 7.2.4.2.1 shows the message sequence example for the MSC server initiated LCLS Break.

Copy of original 3GPP image for 3GPP TS 23.284, Fig. 7.2.4.2.1: MSC Server initiated LCLS break

Figure 7.2.4.2.1: MSC Server initiated LCLS break
(⇒ copy of original 3GPP image)

Step 1.

The oMSC server determines that local switching should be disconnected.

Step 2.

The oMSC server sends to the succeeding node the LCLS Status Change Request message with the LCLS-Status-Change IE set to "LCLS-Disconnection-Preparation".

Step 3.

The iMSC server transfers the LCLS Status Change Request message to the succeeding node.

Step 4.

The tMSC server sends to the tBSS the LCLS-Connect-Control message with the LCLS-Connection-Status-Control IE set to "Release LCLS".

Step 5.

The tBSS confirms the reception of the LCLS release request with the LCLS-Connect-Control Acknowledge message but does not change the LCLS-BSS status since LCLS release request is not yet received for the associated call leg.

Step 6.

The tMSC server sends to the preceding node the LCLS Status Change Request Acknowledge message with the LCLS-Status-Change IE set to "LCLS-Disconnection-Preparation" and the Result code IE set to LCLS Status Change Request accepted.

Step 7.

The iMSC server transfers the LCLS Status Change Request Acknowledge message to the preceding node.

Step 8.

The oMSC server sends to the oBSS the LCLS-Connect-Control message with the LCLS-Connection-Status-Control IE set to "Release LCLS".

Step 9.

The BSS reports the LCLS disconnection by sending:

The LCLS-Connect-Control Acknowledge message with the LCLS-BSS-Status IE set to "the call is no longer locally switched" to the oMSC server.
The LCLS-Notification message with the LCLS-BSS-Status IE set to "the call is no longer locally switched" to the tMSC server.

Step 10.

The oMSC server sends the LCLS Status Update Request message with the LCLS-Status IE set to "LCLS Not Connected" to the succeeding node.

Step 11.

The iMSC server transfers the LCLS Status Update message to the succeeding node.

Step 12.

On the receipt of the LCLS-Notification message with the LCLS-BSS-Status indicating LCLS disconnection the tMSC server sends the LCLS Status Update message with the LCLS-Status IE set to "LCLS Not Connected" to the preceding node.