When destination B becomes free the network shall offer subscriber A the option of recalling destination B.
The network shall prompt MS A to allocate a Transaction Identifier (TI) and establish the CC connection by sending a CM SERVICE PROMPT message. MS A establishes the CC connection by sending a START CC message to the network. The network shall then send a CC ESTABLISHMENT message to MS A and shall include the Setup container. The Setup container contains information necessary to set-up the CCBS Call. The MS can modify the Bearer Capability (BC), High Level Compatibility (HLC) and Low Level Compatibility (LLC) information within the Setup container provided that the same Basic Service Group is maintained. If MS A is compatible with the basic service group it sends CC ESTABLISHMENT CONFIRMED message to the network. Once the network has received the CC ESTABLISHMENT CONFIRMED message it shall send a RECALL message to MS A, which contains information to be presented to the subscriber. At this stage, if the MS detects that ACM ≤ ACMmax, the MS shall interrupt the recall procedure, shall not alert the user and shall send a RELEASE COMPLETE message with the appropriate cause value to the network. If subscriber A accepts the CCBS recall, MS A shall establish a new call with the SETUP message. MSC A shall maintain the RR connection with MS A throughout the time when acceptance of the CCBS Recall is possible. Once the SETUP message is received, normal call handling continues.