Kabushiki Kaisha Toshiba

Nec Corporation

Nippon Telegraph and Telephone Corporation

Nippon Telegraph and Telephone Public Corporation

Kazuhiro Yoshizawa

Akio Yotsutani

Noboru Saegusa

Yoshitoshi Murata

Koichi Ito

Syozi Huse

Akio Toki

Ryoji Kawasaki

Isao Sasaki

Kaoru Kato

In a method and apparatus for controlling a radio telephone system, a speech channel is established between the slave radio set of a plurality of radio telephone sets and a radio set of a base unit. An intercom switch for selecting intercom performances is provided for respective radio telephone sets. The slave radio sets of the radio telephone sets are turned OFF when the intercom switch is OFF, and transmitters of the slave radio sets of the radio telephone sets are turned ON. Consequently the connection between a wired telephone channel and the plurality of radio telephone sets can be controlled with a single base unit connected to the wired telephone channel.

Radio telephone system control method

A method and apparatus for controlling a radio telephone system wherein a speech channel is established between one radio telephone handset out of a plurality of radio telephone handsets and a base unit. An interphone switch for selecting intercom communication is provided for respective radio telephone handsets. The transmitters of the radio telephone handsets are turned OFF when the intercom switch is OFF, and transmitters of the radio telephone handsets are turned ON when the intercom switch is ON. Consequently the connection between a wired telephone channel and the plurality of radio telephone handsets can be controlled with a single base unit connected to the wired telephone channel.

Control method and appartus for a radio telephone system

Where a carrier wave is received from a called radio telephone set and where the identification signal of the radio telephone set coincides with a preassigned identification signal, transmission of a paging signal from a base unit is stopped. Even when the identification signals do not coincide with each other, the paging signal is sent continuously over a definite interval. Communication is established only when the signal from a handset to the base station has a predetermined strength and a proper I.D.

Control system of a radio telephone apparatus

A method and apparatus for controlling a radio telephone system of the type wherein a connection between a wired telephone channel and a plurality of radio telephone handsets is controlled by a single base station connected to the wired telephone channel, a ring signal through the wired telephone channel is detected, a paging signal is sent to the radio telephone handsets from the base station when the ring signal is detected and a paging response signal is sent to the base station from the radio telephone handset in response to the paging signal. Further a channel designating signal is sent to the radio telephone handset in accordance with the paging response signal, a radio channel of the base station is switched to a radio channel corresponding to the channel designating signal, the radio channel of the radio telephone handset is switched to a radio channel corresponding to the channel designating signal, and a speech channel is established between a radio telephone handset responding to the paging signal and the wired telephone channel.

Radio telephone system control apparatus and method

A method and an apparatus are disclosed for controlling a radio telephone system comprising a single master apparatus connected to a subscriber line and a plurality of radio telephone sets connected to the master apparatus by way of radio channel. When a call origination operation is made by one of the radio telephone sets, a call originating signal is sent to the master apparatus from the call originating radio telephone set. In response to the call originating signal, the master apparatus switches its radio channel to an idle speech channel, and sends a channel designating signal representing the idle speech channel to the plurality of radio telephone sets including the call originating radio telephone set so as to switch the radio channels of the radio telephone sets which have received the channel designating signal to the idle speech channel.

A portable unit that may be called from a base station through a radio control channel by a succession of terminating call signals that is sent through the control channel from the base station to the portable unit for a first or restricted time duration (T.sub.1), selected in consideration of a battery saving period of a battery saving operation carried out in the portable unit. Within the battery saving period, the portable unit is put into transient active and inactive states during a first time interval and a second time interval, respectively. Selection is made so that the first time duration is longer than the second time interval to receive at least one of the terminating call signals within the first time duration in the portable unit. The base station monitors an acknowledgement signal for a second time duration (T.sub.2) after the lapse of the first time duration and interrupts the control channel when the acknowledgement signal is not received within the first and the second time durations. In the portable unit, the battery saving operation is released when the presence of the terminating call signals is detected by a squelch circuit.

Method of transmitting terminating call signals within a restricted

In a radio telephone system comprising a radio telephone set utilizing a rechargeable battery, and a base unit connected to the radio telepone set through a radio channel for exchanging a speech signal between the radio telephone set and a wired telephone line, there are provided a detector for detecting the charged state of the battery, a terminating device responsive to the output signal of the detector for terminating the radio channel between the radio telephone set and the base unit.

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Kashiwa, Japan

Kazuhiro Yoshizawa