PURPOSE: To improve the loss probability without interrupting the calling and regardless of the presence or absence of the interference by using a speech channel that is acquired while another radio equipment is kept in a stand-by mode if all speech channels of a selected radio equipment are not available.
CONSTITUTION: When the interference is detected by an interference detecting part 41, all speech channels S-CH stored in a memory area are decided unavailable in regard of the radio equipment which contains a receiver 14, a transmitter 16, a synthesizer 18, etc. Thus the channel S-CH of another radio equipment containing a receiver 13, a transmitter 15, a synthesizer 17, etc., is searched in a stand-by mode of the radio equipment is transferred and stored the memory area of the radio equipment having no available S-CH via a control part 19. This searched and stored S-CH is confirmed again in regard of its idle state, and an S-CH designating signal is sent to a salve device. Thus an S-CH is set up between a master device and the slave device.
NISHIMURA NAOYASU
AKAZAWA NOBUYUKI
NIPPON TELEGRAPH & TELEPHONE