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)
04/1984
04/17/1984CA1165842A1 Telephone conference bridge system
04/11/1984EP0105184A1 Circuit for decreasing the noise voltages due to longitudinal currents
04/03/1984US4440985 Apparatus for determining the location of faults in a transmission line
04/03/1984US4440984 Method of testing telephone cable pairs
04/03/1984US4440981 Electronic hold circuit
04/03/1984US4440980 For applying current in two directions to one wire
04/03/1984CA1165027A1 Telephone set
03/1984
03/29/1984WO1984001248A1 Pulse width modulated telephone line interface
03/27/1984US4439638 Sound-activated code-controlled detection system for telephones and the like
03/27/1984US4439635 Message delivery system
03/26/1984EP0091932A4 Telephone switching control arrangement.
03/21/1984EP0103293A2 Integrated communication system
03/20/1984US4438506 Message waiting light control system
03/20/1984US4438477 Combination power and communication line protection apparatus
03/20/1984US4438299 On-line telephone troubleshooting apparatus
03/20/1984US4438298 System for accessing and testing subscriber loops
03/20/1984US4438296 Multimessage automatic telephone polling methods and apparatus
03/20/1984CA1164099A1 Test signal generator for simulated speech
03/20/1984CA1164078A1 System for the testing of telephone switching systems
03/15/1984WO1984001072A1 Automatic audience survey system
03/15/1984WO1984001071A1 Data conference system
03/13/1984US4437190 Device for switching signals by optical means and automatic switching units comprising said device
03/13/1984US4436963 Implied principal addressing in a call coverage arrangement
03/13/1984US4436962 Call coverage arrangement
03/06/1984USRE31534 Communication system conferencing arrangement
03/06/1984US4435622 Latching relay hold circuit for a telephone instrument
03/01/1984WO1984000861A1 Demultiplexer circuit
02/1984
02/29/1984EP0101449A1 A method and apparatus for giving identity to, and selecting one of a plurality of function units.
02/28/1984US4434328 Remotely actuated telephone instrument connection block having instrument lockout feature
02/15/1984EP0100704A1 Videocommunication network between videophone terminals and an image bank
02/15/1984EP0100514A2 Device for detecting looping during ringing
02/14/1984US4432087 Demultiplexer circuit
02/14/1984US4431872 Telecommunication receivers
02/14/1984US4431871 Solid state relay
02/14/1984US4431868 Solid state telephone line interface circuit with ringing capability
02/14/1984CA1162336A1 System for entering and processing gamble stakes
02/08/1984EP0100111A1 Four-wire amplified line and conference circuit comprising such fourwire amplified lines
02/07/1984US4430734 Demultiplexer circuit
02/07/1984US4430530 Telephony system with automatic test call generator for remote port groups
02/02/1984WO1984000458A1 Automated data acquisition and analysis
01/1984
01/31/1984US4429187 Audio distributing system
01/31/1984US4429185 Voltage detector circuit
01/31/1984US4429184 Mitigation of faults in a telephone exchange
01/31/1984CA1161533A1 Telephone call restricting apparatus
01/31/1984CA1161506A1 Precision negative impedance circuit with calibration
01/25/1984EP0099013A2 Device for the equalization of differing attenuation characteristics of telecommunication lines
01/17/1984CA1160781A1 Coin telephone monitor circuit
01/17/1984CA1160778A1 Loop detecting circuit
01/17/1984CA1160777A1 Hold circuit for telephone system
01/17/1984CA1160774A1 Service integrated transmission system
01/17/1984CA1160772A1 Conference circuit for time division system
01/10/1984US4425479 Apparatus for annunciating the completion of a telephone call hold interval
01/10/1984US4425478 Conference system for telephony
01/10/1984CA1160377A1 Techniques for detecting a condition of response on a telephone line
01/10/1984CA1160372A1 Trilateral duplex path conferencing system with broadcast capability
01/04/1984EP0097354A2 Circuit arrangement for determining the busy condition of a subscriber line in telecommunication exchanges
01/03/1984US4424421 Apparatus for testing subscriber carrier systems
01/03/1984US4424418 Communication system parkhold conferencing
01/03/1984CA1159975A1 Communication system signaling circuit
01/03/1984CA1159921A1 Enhanced communications network testing and control system
12/1983
12/28/1983EP0096937A1 Method of preventing overloading of the central controller of a telecommunication system and arrangement for performing the method
12/28/1983EP0096756A2 Electronic subscriber junctor
12/20/1983US4422071 Paging receiver
12/20/1983US4421955 Distributed switching system
12/20/1983CA1159131A1 Distributed cbx system employing packet network
12/13/1983US4420656 Interactive telephone answering system
12/08/1983WO1983004359A1 Automatic interactive conference arrangement
12/08/1983WO1983004358A1 Call completion circuit and method
12/08/1983WO1983004357A1 Combined handset and headset arrangement
12/08/1983WO1983004355A1 Method and apparatus for through-connection testing in a digital telecommunication network
12/06/1983US4419753 Network connection system
12/06/1983US4419543 Tone activated hold circuit
11/1983
11/30/1983EP0095178A2 Method to officially record the contributions to a discussion entered in an electro acoustic facility
11/29/1983US4418250 Telephone cable splicers test set and method of testing
11/29/1983CA1157976A1 Automatic calling methods and apparatus
11/23/1983EP0094623A1 Circuit for telecommunication exchanges, especially telephone switching exchanges, with multiprocessor systems for call processing purposes
11/22/1983US4417101 Public telephone station traffic analyzing arrangement
11/22/1983CA1157597A1 Current supplying circuit with shorted-to-ground fault detecting function
11/22/1983CA1157552A1 Device related to a private exchange
11/22/1983CA1157551A1 Electronic audiocommunication system
11/16/1983EP0094253A2 Satellite communications system for computer networks
11/16/1983EP0094162A2 A method of producing voltage signals with a dc component and great dynamic range
11/15/1983US4416007 Digital conferencing method and arrangement
11/15/1983US4415779 Methods of and apparatus for testing telephone subscriber loop to locate a fault relative to a reference point
11/15/1983US4415778 Subscriber telephone test set
11/15/1983US4415776 Telephone music-on-hold device
11/15/1983US4415775 Arrangement for exchanging signals between separated circuits
11/15/1983US4415770 Malfunction detection system for a mobile radio telephone system
11/09/1983EP0093670A2 Multi-channel multi-cell optoelectronic switching networks for multi-service telecommunications systems
11/09/1983EP0093523A1 Digital switching network for telecommunications exchange
11/08/1983CA1156748A1 Optical switch for a very large number of channels
11/08/1983CA1156721A1 Methods of and apparatus for determining electrical characteristics of transmission lines
11/02/1983EP0093022A1 Apparatus for generating a plurality of electric signals
11/02/1983EP0092820A1 Circuit arrangement for the overvoltage protection of intersection circuits
11/02/1983EP0092807A2 A digital supervisory circuit for a telephone system
11/01/1983US4413337 Time division switching system for circuit mode and packet mode lines
11/01/1983US4413163 Portable line tester for telecommunication system
11/01/1983US4413158 Automatic call forwarding telephone apparatus
11/01/1983CA1156349A1 Buffer memory dispersion type video/audio transmission system with spatially and timewise divided inter-office junction lines
10/1983
10/27/1983WO1983003728A1 Method and apparatus for identifying faulty communications circuits
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