Patents
Sitemap › H04 - Electric communication technique › H04M - Telephonic communication › H04M 3 - Automatic or semi-automatic exchanges
Patents for H04M 3 - Automatic or semi-automatic exchanges (99,881)
02/1986
02/18/1986CA1200928A1 Broad band network system
02/11/1986US4570258 Exchange switch
02/11/1986US4570037 Fault detection in a telephone cable pressure monitoring system
02/04/1986US4568802 VF Line fault isolation and diagnostic apparatus and method
02/04/1986US4568800 Multi-channel access (MCA) radio telephone system
02/04/1986CA1200304A1 Time slot interchanger
02/04/1986CA1200303A1 Data conference system
01/1986
01/29/1986EP0169791A2 Music on hold for key systems and pabx systems
01/29/1986EP0169757A1 Method of determining the last intermediate node in a network of several interconnected nodes
01/29/1986EP0169551A2 Circuit arrangement for telecommunication exchanges, in particular for telephone exchanges, with information processing networks and traffic measuring devices
01/28/1986US4567326 Telephone apparatus for selective operation in a normal and repertory dial mode
01/28/1986US4567324 Secretarial telephone station for use with a secretarial answering system
01/28/1986US4567323 For use with a telephone system
01/22/1986EP0168927A2 Data transmission system
01/22/1986EP0168840A2 Remote actuated switch
01/21/1986US4566096 Telephone exchange conference circuit
01/21/1986US4566093 Continuity check tone detector for use with a digital telecommunication system
01/15/1986EP0168039A2 Circuit arrangement for connecting a voice-controlled auxiliary device assigned to a telephone set to a telephone line
01/14/1986US4564940 Broad band network system
01/14/1986US4564728 Apparatus for testing a telephone line
01/14/1986US4564725 Telecommunications system, particularly a telephone exchange system, having overload protected sequential logic systems
01/14/1986CA1199394A1 Switching system with separate supervisory links
01/08/1986EP0167125A2 Method and circuit arrangement for statistically registering running exchange control operations in a communications exchange
01/08/1986EP0167124A2 Method and circuit arrangement for statistically registering the load of operating facilities belonging to a communications exchange
01/08/1986EP0166738A1 Transmission control unit for controlling transmission networks
01/07/1986US4563547 Loop-start/ground-start line interface circuit
01/07/1986CA1199135A1 Remotely actuable line disconnect device
01/07/1986CA1199116A1 Sound-activated code-controlled detection system for telephones and the like
01/02/1986EP0166405A2 Facsimile system
01/02/1986EP0166318A2 Device for the recognition and translation of dial information and also of control information for services of a telephone exchange
01/02/1986EP0166101A1 Circuit arrangement for telecommunication exchanges, especially telephone exchanges, with information processing apparatuses and traffic measuring devices
12/1985
12/31/1985US4562436 Data communication network
12/31/1985US4562313 Electrical systems comprising temperature-sensitive devices
12/31/1985US4562310 Keyboard security for a telephone attendant console
12/31/1985US4562308 Subscriber connection circuit comprising feed resistors which can be bridged in low-ohmic fashion and an indication circuit which effects different indications
12/31/1985CA1198843A1 System for transmitting messages to a telephone set through the subscriber's line in a telephone system
12/27/1985EP0165363A1 Detection circuit for current varations
12/24/1985US4560842 Telecommunication system loop-back unit
12/24/1985US4560837 Call transfer method and circuitry
12/24/1985US4560836 Four-wire communication line circuit and conference network comprising such circuits
12/24/1985US4560833 Method and apparatus for signaling an existing telephone communication between picture telephone apparatuses
12/24/1985CA1198535A1 Matrix elements and switches in series across power supply having current limiter
12/24/1985CA1198514A1 Message delivery system
12/19/1985WO1985005749A1 Message waiting alerting method
12/18/1985EP0164611A2 Switching system and method for network having a plurality of terminal control equipment units
12/18/1985EP0164362A1 Method for customer definable telephone capability.
12/17/1985US4559417 Method of setting operating data in a key telephone system
12/17/1985US4559416 Telephone line activity monitor
12/17/1985CA1198234A1 Method of and a circuit arrangement for determining current criteria in the lines of a telephone system
12/10/1985US4558188 Arrangement for line jumper testing
12/10/1985US4558183 Opto-coupler interfacing circuit
12/10/1985US4558182 Remotely-activated switching apparatus
12/10/1985US4558180 Programmable audio mixer
12/04/1985EP0163307A2 Switching system having capability for telecommunication conference
12/04/1985EP0163103A1 Circuit arrangement for telecommunication exchanges, especially telephone exchanges with counting devices for registering service requests
12/03/1985CA1197639A1 Loop test circuit
11/1985
11/27/1985EP0162658A1 Apparatus and method for checking time slot integrity of a switching system
11/27/1985EP0162174A1 Buffer device used in a voice transmission network
11/27/1985EP0162173A1 Digital transmission system for a packetized voice
11/26/1985US4555592 Wireless hands-free conference telephone system
11/21/1985WO1985005240A1 A two way personal message system with extended coverage
11/21/1985WO1985005238A1 Fault detection arrangement for a digital conferencing system
11/21/1985EP0161253A1 Interface channel unit.
11/19/1985US4554658 System for producing encoded and decoded voice, internal audio tones, and data communication within a time division multiplex network
11/19/1985US4554642 Digital filtering with monitored settling time
11/19/1985US4554416 Low voltage two wire to four wire telephone circuit converter apparatus
11/13/1985EP0161162A1 Automatic exchange with a video switching matrix
11/13/1985EP0161031A1 Telecommunication system, in particular telephone system
11/13/1985EP0160826A1 Space connection network for high bit rate digital signals
11/12/1985US4552997 Arrangement for loop analysis testing for a digital switching system
11/12/1985US4552994 Apparatus for isolating the voice frequency path from the floating battery feed during signalling
11/07/1985WO1985005000A1 Telephone operator voice storage and retrieval system
11/06/1985EP0160472A2 Reprogrammable call forwarding device
11/05/1985US4551585 Arrangement for facilitating external loop analysis testing for a digital switching system
11/05/1985US4551582 Circuit for automatically releasing holding state of telephone system
11/05/1985US4551581 Method and apparatus for sending a data message to a selected station during a silent interval between ringing
11/05/1985CA1196433A1 Active impedance transformer assisted line feed circuit with supervision filtering
11/05/1985CA1196432A1 Videocommunication network between videophone terminals and a picture bank
11/05/1985CA1196380A1 Impedance measurement in 4-wire to 2-wire converters
10/1985
10/30/1985EP0159706A2 Circuit arrangement for telecommunication exchanges, especially telephone exchanges, with a testing device for switching devices of various kinds
10/30/1985EP0159351A1 Centerpoint automatic meter reading system
10/29/1985US4550225 AC Signal-activated switching apparatus
10/29/1985US4550224 Method and apparatus for adding conferees to a conference
10/29/1985US4550223 Test device, and method for locating faults in a two-lead line
10/22/1985US4549047 Digitized voice message storage system
10/22/1985CA1195763A1 Teleconferencing method and system
10/16/1985EP0158548A1 Cable television network
10/16/1985EP0158270A2 Broadcasting system for storing and withdrawal at a later date of speech information
10/15/1985US4547878 Non-linear adder
10/15/1985US4547633 Method of and circuit for locating faults in a digital telecommunication subscriber termination
10/15/1985US4547630 For use in a communication system
10/09/1985EP0157536A2 Telephone line access system for main distribution frame
10/09/1985EP0157474A2 Keyboard security for a telephone attendant set
10/09/1985EP0156905A1 Automated system for establishing telephone voice connections
10/08/1985US4546475 For a two-way plural channel communication system
10/08/1985US4546468 Switching network control circuit
10/08/1985CA1194967A1 Electronic subscriber junctor
10/02/1985EP0033744B1 Voice controlled switching system
10/02/1985EP0026187B1 Communication system tracking arrangement
10/01/1985US4545050 Method of and arrangement for establishing a conference connection in a TDM communication system
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