Abstract: A mobile communications system having a fixed unit connected to a public telephone network by a subscriber line, and a portable unit connectable to the fixed unit by radio channels which comprise at least one control channel and a plurality of speech channels. The fixed unit includes a transmitter section having a tuner for selectively tuning the transmitter section to one of the radio channels or a first stand-by channel, the frequency of which is not used for communications in the system. The fixed unit also includes a receiving section having a tuner for selectively tuning the first receiver section to one of the radio channels. A controller section control the transmit and receive tuner such that when the fixed unit is in a stand-by condition, the first transmitter and receiver sections are tuned to, respectively, the first stand-by channel and the control channel.

Abstract: In a radio key telephone system connected through N subscriber lines to a telecommunication switching system, each of M (where M is larger than N) terminal stations has a multiple access radio transceiver capable of switching to one of (N+1) radio channels including N two-way communication channels and a two-way signaling channel, a display for indicating busy-idle states of the subscriber lines and a controller for controlling the display.