A.2 CCBS Call Set-up for non-supporting MSs

24.0933GPPCompletion of Calls to Busy Subscriber (CCBS)Release 17Stage 3TS

The CCBS recall shall be treated as a mobile terminated call set-up. The network shall send a SETUP message to MS A, which causes the MS to ring indicating that destination B is now idle. If subscriber A accepts the CCBS recall, MS A shall establish a new call with the CONNECT message.

MS A NETWORK SETUP <———————————————————————————————————————————- (Calling Party BCD Number, BearerCapability, CCBS Remote User Free)

CALL CONFIRMED ———————————————————————————————————————————->

ALERTING ———————————————————————————————————————————->

CONNECT ———————————————————————————————————————————->

CONNECT ACKNOWLEDGE <———————————————————————————————————————————-

START DTMF ———————————————————————————————————————————->

START DTMF ACKNOWLEDGE <———————————————————————————————————————————-

STOP DTMF ———————————————————————————————————————————->

STOP DTMF ACKNOWLEDGE <———————————————————————————————————————————-

ALERT <———————————————————————————————————————————-

FACILITY <———————————————————————————————————————————-

Figure A.2: CCBS Call Set-up for non supporting MSs

NOTE*: It is an operator option to request the user if he/she wishes to continue

Editors Note: The network needs to know that this is a CCBS Call so that the destination network can be informed. How does the originating network know that this is a CCBS Call? Can the network determine this based on the transaction identifier?

Editors Note: This area is currently under discussion within SMG1 & SMG3