a telephone system which , when a call terminating subscriber which should receive a call from a call originating subscriber is not at the location of his telephone , a location registration unit is accessed so as to call the telephone nearest to the call terminating subscriber , wherein , even when the registration in the location registration unit is not correct , the location information source is referred to deduce the correct location of the call terminating subscriber . this location information source contains various types of sensor information and schedule management information showing the whereabouts of the call terminating subscriber .