PURPOSE: To prevent mis-communication by informing it to a caller subscriber when a satellite line is used for a line connecting a caller subscriber and a called subscriber and performing preparation for the delay in conversation speech specific to the satellite line.

CONSTITUTION: A call from a caller subscriber 1 reaches an exchange 2 via an incoming line 11. The exchange 2 translates the incoming number information of the call, decides an outgoing path to select the line. A logical number is given to the line and a line attribute table 21 is retrieved by the line logic number and whether the selected line is a satellite line 3 or a ground line 4 is identified. In the case of selecting the satellite line 3, an announcement device 6 is connected to the incoming line 11 and the selection of the satellite line is informed to the caller subscriber 1 for a prescribed time prior to the start of speech and the satellite line 3 of the outgoing line is connected to the exchange 8.