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)
05/1986
05/27/1986CA1205228A1 Ring phase loop detector
05/27/1986CA1205168A1 Linear time division multiplexed voice conferencer and data transfer switch
05/27/1986CA1205136A1 Cable load status detector
05/21/1986EP0181349A1 Fault detection arrangement for a digital conferencing system
05/20/1986US4590583 Coin telephone measurement circuitry
05/20/1986US4590336 Special circuit transfer via cable analyzer
05/20/1986US4590331 Hostage negotiation telephone system
05/20/1986CA1204842A1 Maintenance of stored program controlled switching systems
05/14/1986EP0091932B1 Telephone switching control arrangement
05/13/1986US4589107 Simultaneous voice and data communication and data base access in a switching system using a combined voice conference and data base processing module
05/13/1986US4588986 Method of digitizing audio signals
05/13/1986US4588865 Music on hold for key systems
05/13/1986CA1204489A1 Voice switching arrangement for telephone conferencing
05/13/1986CA1204488A1 Method and apparatus for identifying faulty communications circuits
05/09/1986WO1986002796A1 Method and apparatus for testing remote communication systems
05/09/1986WO1986002795A1 Interswitch line circuit
05/07/1986EP0179979A2 Synchronous packet voice/data communications system
05/07/1986EP0179898A1 A two way personal message system with extended coverage.
05/06/1986US4587651 Distributed variable bandwidth switch for voice, data, and image communications
05/06/1986CA1204237A1 Keyboard security for a telephone attendant console
04/1986
04/30/1986EP0179629A2 Packet switching system
04/29/1986US4586086 Facsimile communication relay system
04/29/1986US4585908 Data entry and display control circuit
04/29/1986US4585906 Electronic audio communication system with user controlled message address
04/29/1986US4585905 Overvoltage protection circuit for SLIC
04/29/1986CA1203875A1 Switching system loopback test circuit
04/23/1986EP0178993A2 Front end circuit structure for a subscriber line circuit interface
04/23/1986EP0178403A2 Method for directly calling subscriber lines in telecommunication exchanges, especially in telephone exchanges
04/22/1986US4584680 Use of a tone bus to provide polling and data distribution apparatus for communication system terminal groups
04/22/1986US4584576 Ringing signal generator
04/22/1986CA1203648A1 Demultiplexer circuit
04/16/1986EP0178111A2 Data handling system
04/16/1986EP0177735A2 Circuit arrangement for telecommunication installations, especially for telephone exchanges with centralized and/or decentralized information-processing devices
04/15/1986USRE32115 Self-service terminal
04/15/1986US4583216 Connection system for the supervision of telephone circuits
04/15/1986US4583215 Telephone line access system for main distribution frame
04/15/1986US4582965 Coin trunk test set
04/15/1986US4582964 Remote loop-around carrier test system
04/15/1986US4582960 Subscriber network interface device
04/15/1986US4582959 Message waiting alerting method
04/15/1986US4582958 Secretary telephone system
04/15/1986US4582957 Call interceptor
04/15/1986US4582956 Method and apparatus for displaying at a selected station special service information during a silent interval between ringing
04/15/1986CA1203332A1 Latching relay hold circuit for a telephone instrument
04/15/1986CA1203331A1 Latching relay hold release circuit for a telephone instrument
04/10/1986WO1986002225A1 Telephone switching system switch processor interface
04/10/1986WO1986002219A1 Telephone switching system adjunct call processing arrangement
04/09/1986EP0177465A2 Method and apparatus for operating on companded PCM voice data
04/09/1986EP0177219A2 Origination scan circuit
04/09/1986EP0177218A2 Method and apparatus for sharing operators among assistance systems
04/09/1986EP0176953A2 New simultaneous voice and date communications system, with possibility of connection to public or private networks
04/09/1986EP0176764A2 Circuit arrangement for telecommunication installations, especially for telephone exchangs with centralized and/or decentralized information-processing devices
04/08/1986US4581494 Telephone interface-test device
04/08/1986US4581493 Line condition reporting system
04/08/1986US4581486 Electronic audio communications system with user accessible message groups
04/08/1986CA1203025A1 Parity checking arrangement
04/01/1986US4580292 Communications exchange
04/01/1986US4580259 Switchboard control system
04/01/1986US4580016 Method and apparatus for checking the integrity of a communications channel in a voice store and forward system
04/01/1986US4580012 Electronic audio communications system with automatic user access features
04/01/1986CA1202742A1 Loop-start/ground-start line interface circuit
04/01/1986CA1202741A1 Ringing signal generator employing delta modulation power amplification techniques
03/1986
03/26/1986EP0175147A2 Digital conference circuit
03/26/1986EP0174947A1 Communication system having dynamically assigned station set buttons
03/25/1986US4578789 Simultaneous voice and data communication and data base access in a switching system using a tone bus or broadcast mode
03/25/1986US4578761 Separating an equivalent circuit into components to detect terminating networks
03/25/1986US4578540 Telecommunications systems
03/25/1986US4578536 Centerpoint automatic meter reading system
03/18/1986US4577255 Lightning protection circuit for digital subscriber loop interface
03/18/1986US4577067 Remotely controlled telephone hold program system
03/18/1986US4577065 For use in a communication network
03/18/1986US4577062 Method for dispensing information
03/13/1986WO1986001664A1 Method and apparatus for accessing communication systems
03/13/1986WO1986001663A1 Method and apparatus for testing communication systems
03/13/1986WO1986001662A1 Method and apparatus for supervising the accessing and testing of communication systems
03/11/1986US4575845 Time division multiplex conferencer
03/11/1986US4575841 Method and apparatus for through-connection testing in a digital telecommunication network
03/11/1986US4575840 Telephone line access device for main distribution frame
03/11/1986US4575839 Centralized supervisory system
03/11/1986US4575588 Universal telephone test apparatus
03/11/1986CA1201809A1 Method of an apparatus for generating a plurality of electric signals
03/05/1986EP0173387A1 Opto-electrical signal converter
03/05/1986EP0173283A2 Method for the transmission of evaluation signals in traffic-metering installations
03/05/1986EP0173282A2 Method for the transmission of evaluation and test signals for traffic metering in traffic metering installations
03/05/1986EP0173272A2 Method of obtaining directory assistance in a telephone system and apparatus
03/05/1986EP0173264A2 Method for a programme-controlled telephone exchange, especially a private exchange, wherein several service signals may be activated by an authorized subscriber set
03/05/1986EP0173250A2 Multi-line telephone control system
03/05/1986CN85201749U Party-line secure unit with a ringing
03/04/1986US4574374 Multilocation video conference terminal including rapid video switching
03/04/1986US4574165 Secretarial answering system
03/04/1986US4574164 Ringing signal transmission system for radiotelephone system
02/1986
02/25/1986US4573140 Method of and apparatus for voice communication storage and forwarding with simultaneous access to multiple users
02/25/1986CA1201232A1 Telephone apparatus
02/25/1986CA1201229A1 Ground start detection in telephone loop signalling circuit
02/25/1986CA1201228A1 Detection of ground or loop start configuration in telephone loop signalling circuit
02/19/1986EP0171803A2 Time division exchange for carrying out a loop-back test
02/19/1986EP0171784A2 Circuit arrangement for telecommunication installations, in particular telephone exchanges with centralized and/or decentralized information-processing control circuits
02/19/1986EP0171761A2 Circuit arrangement for telecommunication installations, especially for telephone exchanges comprising information processors and traffic load counters
02/19/1986EP0171692A2 Subscriber line circuit
02/18/1986US4571461 Conference telephone apparatus
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