6 Exceptional procedures or unsuccessful outcome

22.1353GPPMulticallRelease 17Service descriptionStage 1TS

6.1 Exceptional operation or unsuccessful outcome

The number of simultaneous CS bearers supported by the system may vary in different regions. For instance, after handover the number of simultaneous bearers available to the served subscriber may be lower than the number of already established bearers. Such events shall trigger changes to individual calls in any multicall scenario.

The handover requirements for multicall are specified in 3GPP TS 22.129 [6].

6.2 Registration

If the system cannot accept a registration request, the served mobile subscriber shall receive a notification that Multicall registration was not successful. Possible causes are:

– service not subscribed to;

  • Nbr_User > Nbr_SB;
  • insufficient information.

6.3 Erasure

No exceptional operation identified.

6.4 Activation

No exceptional operation identified.

6.5 Deactivation

No exceptional operation identified.

6.6 Invocation

If the served subscriber attempts to set up a new call with a dedicated bearer while the maximum number of bearers available to the subscriber (Nbr) has been reached, the call attempt shall be rejected by normal procedures, indicating that no more bearers are available.

6.7 Interrogation

When a mobile subscriber who is not provided with the Multicall supplementary service interrogates the service data of the Multicall supplementary service, she shall be notified that she is not subscribed to the service.

6.8 Roaming in non-supporting networks

Roaming into networks not supporting the Multicall supplementary service shall be possible. The served subscriber will not have any access to the Multicall supplementary service and the system should behave accordingly.

When the served subscriber performs any procedure related to Multicall service as described in the clauses above while roaming in a non-supporting network, she shall be notified that the service is not available.