This TS specifies the stage 1 description of Completion of Calls to Busy Subscriber (CCBS) from the subscriber's and user's points of view; in particular:
the procedures for normal operation with successful outcome;
the action to be taken in exceptional circumstances;
the interaction with other supplementary services;
This TS does not deal with the Man-Machine Interface (MMI) requirements, but makes reference to the appropriate specifications. The charging principles applied to CCBS are outside of the scope of this specifcation. Any interactions with other networks not dealt with in this TS are outside the scope of this TS.