Nec Corporation

Nippon Telegraph and Telephone Corporation

Kabushiki Kaisha Toshiba

Nippon Telegraph & Telephone Co.

K.k. Toshiba

Yukihiro Shimura

Noboru Saegusa

Koji Ono

Shoji Fuse

Yuji Ohta

Shinji Kumataka

Kosuke Hashimoto

Hideki Toyama

Toshihiro Hara

Ryoji Kawasaki

Kazuyuki Tate

Syoji Huse

Yuichiro Takagawa

Ichiro Tamura

Hirokazu Adachi

Shoichi Tozuka

Yasushi Hatakeyama

In a radio telephone apparatus including a host phone unit, a cordless extension unit connected by radio waves to the host phone unit, and a charger unit for charging the cordless extension unit, a phone number inputting keyboard is provided in the charger unit.

Radio phone apparatus having compact cordless extension unit

A cordless telephone instrument is improved in that, even when a portable unit is not in use, it can be determined and notified to the user whether the portable unit is inside or outside of an operational area of the portable unit. In portable unit 2, portable unit timer 28 counts a predetermined first reference time and outputs a time-out signal for each first reference time. Every time the time-out signal is outputted, a registration signal is transmitted from portable unit radio circuit 21 toward a fixed unit. When the registration signal is received by fixed unit radio section 12, fixed unit 1 transmits a response signal toward portable unit 2. Portable unit 2 continuously operates to receive a response signal. However, when no response signal is detected within a counting time of portable unit timer 28, operational area out alarm generation section 27 is activated under the control of portable unit control circuit 24 to perform an operation of notifying that portable unit 2 is outside of the operational area.

Method of indicating a portable unit of a cordless telephone instrument

In a cordless key telephone system in which radio-frequency connections are established between exchange lines and cordless stations in response to a call request, a ringing signal is transmitted in response to an incoming call by containing in it the identification of the line at which the call is terminated. Each cordless station has an array of line keys associated respectively with the exchange lines and an array of line indicators associated respectively with the line keys, and a memory for storing tenant data indicating the lines to which the cordless station is authorized to access. The cordless station examines the tenant data in response to receipt of the ringing signal, and activates one of the line indicators if the indicated line is found in the tenant data, or examines the tenant data in response to an outgoing call originated from the cordless station operating a line key, and allows a connection to be established from that station to an exchange line when the line associated with the operated line key is found in the tenant data.

Cordless key telephone system with multiple tenant facility

In a cordless key telephone system for covering multiple service areas, access units are divided into groups corresponding respectively to the service areas, the access units of each group being located in the corresponding service area for broadcasting a recurrent sequence of address signals on a two-way radio control channel and carrying speech signals on an assigned two-way telephone channel. The access units of each group has a uniquely assigned control channel different in frequency from the control channel of the other group. Cordless stations are switchable to the control channel of a first group of the access units for detecting an address signal and subsequently switchable to the control channel of the access units of a second group if the address signal is not detected in a first sequence for detecting the addressed signal in a second sequence. A main controller is coupled to a switched telephone network for causing the access units to broadcast the address signals in response to an incoming call from the network and for establishing a connection between the network and one of the cordless stations.

Cordless key telephone system for covering multiple service areas having

Radio communication system having control method for shortening call

Disclosed is a radio channel control method for a system including a main apparatus connected to a telephone line and having a channel control function, a plurality of stationary apparatuses connected to the main apparatus and each having a radio transmitter/receiver, and a portable telephone capable of communicating with the stationary apparatuses through a radio channel. In this method, the main apparatus designates each stationary apparatus in a main or sub state to control communication with the portable telephone and monitors a state signal including information of the main or sub state transmitted from each stationary apparatus. When the state signal from a given stationary apparatus does not coincide with a state of the given stationary apparatus designated by the main apparatus, the main apparatus transmits a state designation signal to the given stationary apparatus to coincide with the state designated by the main apparatus.

Method for controlling a plurality of stationary apparatuses in a

Interconnection control method in cordless telephone system

A radio telephone having a base unit connected to a wired telephone line, a handset unit connectable to the base unit over a radio channel and provided with a hook switch, and a charger for selectively charging the handset unit. The handset unit is automatically controlled to either an on-hook state or an off-hook state when removed from the charger, depending upon the hook state in which the handset unit has been held before the start of charging.

Radio telephone

A new cordless telephone is registered to an existing cordless telephone system by transmitting the product identification number of the new cordless telephone from the access unit of the system to the new cordless telephone, receiving the transmitted product identification number at the new cordless telephone and verifying that the transmitted product identification number is correctly received. In response to the verification, the system and telephone identification numbers of the new cordless telephone are transmitted from the access unit to the new cordless telephone and stored into an electrically erasable programmable read-only memory of this telephone to be used for establishing calls.

Registration of a new cordless telephone to an existing system

A base station (10), in a radio communication network having at least two telephone lines (111 to 11n) and a plurality of radio telephone sets (121 to 12m), includes radio transceivers (131 to 13k) capable of selecting one of a control channel and a plurality of communication channels. A producing arrangement (16, 141, to 14n) is coupled between the radio telephone lines and the radio transceivers for producing, in response to a first arrival signal arriving at one of the telephone lines, a first call signal which is sent by a first selected transceiver through a first selected channel towards the radio telephone sets. The first selected channel is selected from the idle channels of the communication channels by a selecting arrangement (16 and 17). Responsive to a second arrival signal arriving at another of the telephone lines while the first call signal is sent through the first selected channel, the producing arrangement adds a channel code of a different one of the idle channels to make the first selected transceiver send the first call signal and the channel code of the different one of the idle channels over the first selected channel. In this manner, traffic is reduced on a control channel and the base station can rapidly respond to an arrival signal which arrives while the base station is sending a call signal.

Rapid processing of immediately successive arrival signals in a base

In a radio communication network comprising a base station (11) and a plurality of wireless telephone sets (12) each of which is communicable with the base station by the use of a plurality of speech radio waves and a control radio wave, a control wave monitoring circuit (22) is included in the base station to monitor the control radio wave on transmission of an allocated one of the speech radio waves and to determine whether or not interference occurs in the control radio wave due to the transmission. On occurrence of such interference in the control radio wave, the allocated speech radio wave is changed to another speech radio wave under control of a line control portion (15). When the control radio wave is divisible into a down control channel directed from the base station towards the wireless telephone sets and an up control channel directed from the wireless telephone sets to the base station, the control wave monitoring circuit monitors the down control channel. Alternatively, the up control channel may be monitored by the control wave monitoring circuit. Each of the wireless telephone sets may be either a cordless telephone set or a mobile telephone set.

Growing community of inventors

Tokyo, Japan

Yukihiro Shimura