Abstract: A trigger is armed to a predetermined detection point (DP) of a basic call state model controlled for each call by a switching system so that a service control point (SCP) can be unconditionally activated. The SCP stores service control information for each time band in such a manner as to correspond to each user. When a first control signal is received from the switching system, the DP which is determined by the service control information is notified to the switching system and the switching system arms the trigger to this DP. When the state of the call shifts to a specific DP to which the trigger is armed because a called party is busy or does not answer, for example, the switching system sends a second control signal to the SCP, and the SCP notifies a terminating terminal equipment determined by the service control information in response to the second control signal.