Abstract: A cordless telephone apparatus comprising a master unit connected to a telephone line and slave units each connected to the master unit via a radio wave channel. The master unit includes a recording/reproducing circuit for recording an incoming message from a calling party on the telephone line and reproducing the recorded message in response to a request. The recording/reproducing circuit has a recording medium to record and reproduce the message, and a management area to manage the messages recorded on the recording medium. When the incoming message from the calling party is recorded on the recording medium in the recording/reproducing circuit, data for managing such message recording is registered in the management area in response to a key designation corresponding to the slave unit. And when a predetermined key operation is performed in the slave unit, the message relative to the key-operated slave unit is reproduced from the recording medium in accordance with the data registered in the management area.

Abstract: A method and system for radio communication between at least one parent communication unit and a plurality of slave communication units. A slave communication unit transmits an automatic answer signal in response to an incomming call receipt signal transmitted from the parent communication unit. When one of the slave communication units makes a called-person's answer to the incomming call receipt signal, it transmits a called-person's answer signal. If interference occurs between the automatic and called-person's answer signals, the parent communication unit provides a command, causing the slave communication units to stop the automatic and called-person's answer signals and permits the slave communication unit which transmits the called-person's answer signal to communicate with the parent communication unit.

Abstract: A method and system for radio communication between at least one parent communication unit and a plurality of slave communication units. A slave communication unit transmits an automatic answer signal in response to an incoming call receipt signal transmitted from the parent communication unit. When one of the slave communication units makes a called-person's answer to the incoming call receipt signal, it transmits a called-person's answer signal. If interference occurs between the automatic and called-person's answer signals, the parent communication unit provides a command, causing the slave communication units to stop the automatic and called-person's answer signals and permits the slave communication unit which transmits the called-person's answer signal to communicate with the parent communication unit.

Abstract: Apparatus for transmitting and receiving signals for use with a so-called cordless telephone, in which an audio signal and an identification code signal are transmitted and received by both the handset and base unit of the telephone and when the identification code signal is not correctly detected, as might be caused by cross-talk interference, the transmitter is disabled and a vacant communication channel is searched for and a communication channel is changed to thereby prevent a cross-talk interference. The unit that does not correctly receive the code signal immediately disables its transmitter and searches for a vacant channel and, because the code signal had been alternately transmitted and received between the two units, the other unit detects the stoppage of code signal transmission, disables its own transmitter, and then also moves to the next vacant channel to await further transmission of the code signal.

Abstract: Signal transmission apparatus is provided for a communications system having a plurality of transmitters for transmitting information signals over any one of several transmission channels, and further having a plurality of receivers for receiving the information signals over any one of the transmission channels. In order to establish a selected transmission channel between a particular transmitter and a particular receiver, the transmitter selects an unoccupied transmission channel and transmits thereon a code identifying the receiver using a wide band signal for high speed bit transmission. When the receiver detects the presence of the identifying code over a particular channel, it first determines that the transmitter is the particular transmitter and, if so, establishes the transmission channel therebetween.