Abstract: In a cordless telephone system, several speech channels are periodically scanned by a base station during a standby mode to detect idle channels from the scanned channels. In response to receipt of a call request from a cordless station or an incoming call from a switched telephone network, the base station transmits a channel indicating signal to the cordless station over a control channel indicating that the detected idle channels can be used as possible candidate channels, switches to a first candidate channel and waits for an end-of-switching signal from the cordless station until a prescribed period of time expires. On receiving the channel indicating signal, the cordless station switches to the first candidate channel and makes a channel check on it and transmits an end-of-switching signal if it determines that the first candidate channel is idle.

Abstract: A base station (coast station) of such a radiotelephone system as a maritime mobile radiotelephone system is connected to a telephone exchange of a public telecommunication network. A ringing signal from a subscriber's station of the telecommunication network which is connected to the exchange is transmitted to an end station (ship station) of the radiotelephone system by way of the line concentrator and a radio section between the base and end stations. When a false calling tone signal is sent from a tone signal delivery circuit included in the line concentrator to an end station for a predetermined short period of time upon completion of a connection between the exchange and the end station, with no regard to a ringing signal from the exchange, a subscriber's telephone at the end station produces a calling tone. Thereafter, the line concentrator delivers a calling tone signal in synchronism with a ringing signal from the exchange.

Abstract: A multi-channel access (MCA) radio telephone system completes calls from conventional telephone systems over a plurality of shared radio channels to a base station serving a plurality of substations connected to a second telephone set. The MCA radio telephone system provides a method for clearing calls after they are completed. The method comprising the steps of: (a) detecting the hang-up at the first and conventional set involved in the clearing call; (b) maintaining the D.C. loop of the subscriber line to the first and conventional telephone set in response to the detection of an on-hook signal and returning the radio channel to an idle and waiting state; (c) detecting the hang-up of the second telephone set which is served by the base station re-establishing a radio channel between the base station and the substation involved in the call being cleared; (d) sending a release signal from the clearing substation through the re-established radio channel to the base station; and (e) opening the D.C.