PURPOSE: To attain talking connection on emergency even if other subscriber is busy and radio lines are occupied by holding temporarily a wired line of other subscribers during talking already, giving priority to an emergency caller for interruption connection to a radio line.

CONSTITUTION: An emergency call signal from a radiotelephone set 3 is inputted to a control circuit 10 via an antenna 14, a radio transmission/reception circuit 13 and a voice out-band signal transmission/reception circuit 12. The control circuit 10 transmits a response signal to the emergency call signal in the same path as that of the emergency call signal to the radio telephone set 3, communicates with a subscriber connected to an exchange 1 by using a holding information transmission circuit 6 and, e.g., by means of the information transmission by message with a voice synthesis circuit using a signal processor, then uses a line hold circuit 7 to hold temporarily the subscriber line 26 of the exchange 1, uses a line switch circuit 11 to connect the subscriber line 27 of the exchange 1 of the emergency caller to a radio line and transmits a dial signal to the exchange 1 through a subscriber line 27.