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)
10/1985
10/01/1985US4545043 Announcement system message playback arrangement
10/01/1985US4544809 Arrangement for subscriber line ring testing
10/01/1985US4544808 Telephone indicator
10/01/1985US4544807 Fault detector test instrument
10/01/1985US4544804 Conference control transfer arrangement
10/01/1985CA1194627A1 Electronic circuit for detecting the lifting of a telephone handset in presence of ringing current
10/01/1985CA1194607A1 Method and apparatus for giving identity to and selecting one of a plurality of function units
09/1985
09/24/1985US4543663 Communications exchange
09/24/1985US4543524 For locating faults in a transmission line
09/24/1985CA1194191A1 Clock selection control circuit
09/18/1985EP0155074A2 Active impedance line feed circuit with improved ground fault protection
09/17/1985US4542507 In a digital transmission system
09/17/1985CA1193737A1 Automated data acquisition and analysis
09/17/1985CA1193701A1 Switchboard control system
09/17/1985CA1193700A1 Combined handset and headset arrangement
09/17/1985CA1193699A1 Call completion circuit and method
09/17/1985CA1193698A1 Call coverage arrangement
09/17/1985CA1193552A1 Voice-actuated switching system
09/11/1985EP0154493A2 Operator station for telephone exchange
09/11/1985EP0154304A2 Method for a telecommunication exchange, especially a private telephone exchange with optional accelerated test course
09/10/1985US4541087 Digital teleconferencing control device, system and method
09/10/1985US4540854 Subscriber line interface circuit
09/10/1985US4540853 Apparatus for detecting a loop during ringing
09/10/1985US4540852 Electronic subscriber junctor
09/10/1985US4540850 Method and apparatus for controlling a conference
09/10/1985CA1193321A1 Test instrument with flexibly connected head
09/04/1985EP0153903A1 Video conference system
09/04/1985EP0153753A2 Method for a telecommunication exchange, especially a private telephone exchange with special operation function assignment to terminals
09/03/1985US4539652 Networks for data communication
09/03/1985US4539436 Programmed conversation recording system
09/03/1985US4539435 Remote interactive communication system
08/1985
08/29/1985WO1985003830A1 Method and apparatus for subscription broadcast
08/29/1985WO1985003828A1 Communication system having dynamically assigned station set buttons
08/28/1985EP0153140A1 Communication system having dynamically assigned station set buttons
08/28/1985EP0153125A2 Tone detection apparatus for use in a telephone system
08/28/1985EP0152908A2 Automatic call transfer system capable of carrying out call transfer without manual operation
08/27/1985US4538269 Programmable coding and decoding arrangement
08/27/1985US4538176 Buffer memory dispersion type video/audio transmission system
08/27/1985US4538033 Communication bridge responsive to a series of control signals
08/27/1985US4538031 Service circuit for a local telephone line
08/27/1985CA1192646A1 Piezoelectric apparatus for positioning optical fibers
08/21/1985EP0151917A2 Time slot exchange with interchange memory
08/21/1985EP0151789A2 Storing method for a memory device installed in a telephone installation, in particular a telephone exchange
08/21/1985EP0101449B1 A method and apparatus for giving identity to, and selecting one of a plurality of function units
08/20/1985US4536706 Magnetic current sensor
08/20/1985US4536618 Telephone line interface
08/20/1985US4536617 Remotely-activated switching apparatus
08/20/1985US4536614 Supervision and dial pulse detection circuit for a telephone subscriber line
08/13/1985US4535454 Multifrequency tone distribution using a conferencing arrangement
08/13/1985US4535445 Conferencing system adaptive signal conditioner
08/13/1985US4535442 Digital switching network for telecommunications exchange
08/13/1985US4535201 Ground start detection in telephone loop signalling circuit
08/13/1985US4535199 Data call transfer preindication
08/07/1985EP0150416A2 Operating method of an operator position and/or of a terminal apparatus of a telecommunication exchange, especially a telephone exchange
08/07/1985EP0150183A1 Method and apparatus for providing call tracing service.
08/06/1985US4533970 Series current limiter
08/06/1985US4533943 Videocommunication network between videophone terminals and a picture bank
08/06/1985US4533864 Test instrument with flexibly connected head
08/06/1985US4533792 Circuit for switching between ring signal and message waiting signal without bell tap
08/06/1985CA1191646A1 Call message service
08/06/1985CA1191644A1 Memory dialer system
08/06/1985CA1191643A1 Telephone apparatus
08/06/1985CA1191640A1 Test device for locating faults in a two-lead line
08/06/1985CA1191630A1 Pcm conference circuit
08/06/1985CA1191553A1 Test system for locating short circuits and open circuits in a two-lead line
07/1985
07/31/1985EP0149642A1 Digital teleconferencing control device, system and method
07/30/1985US4532379 Facsimile relaying method
07/30/1985US4532377 Data call transfer
07/30/1985EP0109432A4 Call completion circuit and method.
07/30/1985CA1191239A1 Implied principal addressing in a call coverage arrangement
07/24/1985EP0149218A2 Circuit arrangement for the supervision and checking of the correct operation of a subscriber line construction group of a digital time-division telephone switching system
07/24/1985EP0148836A1 Method and apparatus for sending a data message to a selected station during a silent interval between ringing.
07/23/1985US4531209 Self-routing steering network
07/23/1985US4531024 Multilocation video conference terminal including video switching contention control
07/16/1985US4529847 Maintenance termination unit
07/16/1985US4529843 Subscribers telephone hold circuit with automatic disconnect
07/16/1985US4529842 For processing equipment unit failures in a communication system
07/16/1985US4529841 Intercept information display for a private automatic branch exchange telephone system
07/16/1985US4529840 Multilocation video conference terminal including controllable conference location reconfiguration
07/16/1985US4529839 Multilocation video conference terminal including an arrangement to reduce disruption in video switching
07/16/1985CA1190678A1 Digital supervisory circuit for a telephone system
07/16/1985CA1190634A1 Device for the referral/transfer of calls in telephone exchanges
07/16/1985CA1190633A1 Arrangement for multiple custom calling
07/09/1985US4528427 Test system and device for locating short circuits and open circuits in a two-lead line
07/09/1985US4528425 Method of and circuitry for detecting, at a telephone exchange, the lifting of a subscriber's handset in response to ringing current emitted by the exchange
07/03/1985EP0146868A1 Signal terminals device for signalling system no. 7
07/03/1985EP0146606A1 Test set
07/02/1985US4527013 Telephone answering system
07/02/1985US4527011 Call concentrator with automatic line supervisor
07/02/1985CA1189939A1 Digital telephone exchange comprising means for processing packet-switched data
06/1985
06/25/1985US4525795 Digital signal generator
06/25/1985US4525789 Programmable network tester with data formatter
06/25/1985US4525605 System for accessing electrical circuits and relay switch thereof
06/25/1985CA1189646A1 Audio distributing system
06/20/1985WO1985002740A1 An improved maintenance termination unit
06/20/1985WO1985002739A1 Transmission control unit for controlling transmission networks
06/19/1985EP0145048A1 Method and testing device for testing of interruption of a communication channel in a device with play - in units
06/19/1985EP0145047A2 Telecommunication line circuit and associated polarity reversal circuit
06/18/1985US4524246 SLIC II--common-mode current rejection
06/18/1985US4524245 Ring trip detection system
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