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)
06/1985
06/18/1985CA1189205A1 Demultiplexer circuit
06/18/1985CA1189138A1 Bi-lateral four quadrant power converter
06/12/1985EP0144072A2 Subscriber line radio concentration system
06/11/1985US4523055 Voice/text storage and retrieval system
06/11/1985CA1188831A1 Telephone indicator
06/11/1985CA1188779A1 Conference system for telephony
06/06/1985WO1985002510A1 Method for costumer definable telephone capability
06/05/1985EP0143473A1 Electronic contacts and associated devices
06/05/1985EP0143455A2 Traffic simulation device
06/05/1985EP0143435A2 Improvements in or relating to telephone circuits, monolithically integrated, for ring trip detection
06/05/1985EP0143431A1 Line group terminal spare device in a digital concentrator
06/04/1985US4521647 Tone detection system and method
05/1985
05/23/1985WO1985002311A1 Multimode data communication system
05/22/1985EP0142292A2 Testing telephone lines
05/22/1985EP0142128A1 Circuit arrangement for the drainage of overvoltages
05/21/1985US4518989 Buffer memory dispersion type video/audio transmission system with spatially and timewise divided inter-office junction lines
05/21/1985US4518825 Telephone interconnect detection system
05/21/1985CA1187564A1 Pulse monitor circuit
05/14/1985US4517513 Magnetic differential current sensor
05/14/1985US4517414 Hookswitch bounce resistant telephone hold-mute circuit
05/09/1985WO1985002083A1 Interface channel unit
05/08/1985EP0140155A2 Test device for error detection in redundant circuits, especially in the control processors of a telephone switching system
05/07/1985US4516156 Teleconferencing method and system
05/07/1985US4516070 Magnetic current sensor with offset and load correction
05/02/1985EP0139594A1 Method and apparatus for the detection of a transition of the direct current component of a periodic signal, in particular for subscriber loop interface circuits
05/02/1985EP0139405A2 Data transmission system
05/02/1985EP0139103A2 Overvoltage protection circuit for slic
05/02/1985EP0138951A1 A self routing steering network.
04/1985
04/30/1985CA1186396A1 Remote testing of subscriber line interface circuits
04/30/1985CA1186381A1 Radio paging system capable of accepting message with access of paging receiver
04/25/1985WO1985001852A1 Centerpoint automatic meter reading system
04/24/1985EP0138536A2 Announcement system
04/24/1985EP0138364A2 Multifrequency tone distribution using a conference arrangement
04/24/1985EP0138108A2 Method of detecting a minimum speech level in a given speech direction at a bidirectional amplifier circuit connected in a telecommunication line, and device for performing the method
04/23/1985US4513179 Loop test circuit
04/23/1985CA1186039A1 Arrangement for multiple custom calling
04/23/1985CA1186038A1 Arrangement for multiple custom calling
04/17/1985EP0137396A2 Circuit for protecting an electronic circuit connected to a four-wire side of a repeater hybrid
04/17/1985EP0137012A1 Method and circuitry for encoding telephone ringing signals
04/16/1985US4512036 Communications exchange
04/16/1985US4511762 Overload detection and control system for a telecommunications exchange
04/11/1985WO1985001628A1 Automated system for establishing telephone voice connections
04/11/1985WO1985001598A1 Multi-processing stored program controlled telecommunication establishment
04/10/1985EP0136933A1 Apparatus for automatically verifying the correspondence between the subscribers', numbers and the various transport and distribution marks on the pair assigned to these subscribers
04/09/1985US4510351 ACD Management information system
04/09/1985US4510349 System and method for transmitting messages to a telephone set through the subscriber's line in a telephone system
04/03/1985EP0136167A2 Ringing signal transmission system for radiotelephone system
04/02/1985US4509166 PCM Communication system and method of operation
04/02/1985US4508937 Method and circuitry for encoding telephone ringing signals
03/1985
03/28/1985WO1985001404A1 Electronic contacts and associated devices
03/27/1985EP0135383A2 Conference bridge circuit arrangements
03/27/1985EP0135342A2 Exchange system
03/27/1985EP0135229A2 Method and circuit for establishing conference connections in a switching system
03/27/1985EP0134886A2 Circuit arrangement for the transmission of signalling information from a public exchange to subscribers of a telephone exchange, especially a private telephone exchange
03/26/1985CA1184641A1 System for forwarding along a telephone connection the identities of the subscribers involved in that connection
03/26/1985CA1184639A1 Arrangement for multiple custom calling
03/26/1985CA1184638A1 Arrangement for multiple custom calling
03/26/1985CA1184637A1 Method and apparatus for transferring the same information to a plurality of receivers
03/26/1985CA1184618A1 Pulse monitor circuit
03/26/1985CA1184611A1 Radio pager with display device
03/19/1985US4506346 Programmable cartridge telephone communication system
03/19/1985US4506115 Message alert system
03/19/1985CA1184282A1 Digital connection network
03/19/1985CA1184281A1 Telephone switching control arrangement
03/13/1985EP0134145A2 Electrical systems comprising temperature sensitive device
03/13/1985EP0134010A1 Circuit arrangement for telecommunication installations, in particular telephone exchanges with centralized and/or partially centralized information processing control circuits
03/13/1985EP0134009A1 Circuit arrangement for telecommunication installations, in particular telephone exchanges with information processing control circuits
03/12/1985CA1183931A1 Wideband switching architecture
03/06/1985EP0133703A2 Digital satellite exchange for subscriber connections
03/05/1985US4503290 Automatic line supervisor for use with a call concentrator
02/1985
02/26/1985US4502139 Howler tone sending-out system in time-division electronic exchanges
02/26/1985US4501935 Detecting a DC nonlinearity terminating a network
02/26/1985CA1183209A1 Telephone cable splicers test set and method of testing
02/19/1985US4501003 Dial pulse measurement circuitry
02/19/1985US4500991 Circuit arrangement for the control of the transmission of digital signals, particularly PCM-signals, between stations of a time division multiplex telecommunication network particularly PCM-time division multiplex telecommunication network
02/19/1985US4500844 Ringing signal generator employing delta-modulation power amplification techniques
02/19/1985US4500754 Solid state off hook phone line load
02/19/1985CA1182934A1 Test device for locating faults in a two-wire line or for switching two-wire lines
02/13/1985EP0067839B1 Voltage controlled transient protection unit
02/12/1985US4499578 Method and apparatus for controlling signal level in a digital conference arrangement
02/12/1985US4499577 Linear time division multiplexed conferencer for data transfer applications
02/12/1985US4499337 Coupler for microtelephone set
02/12/1985CA1182548A1 Signal control system
02/12/1985CA1182527A1 Malfunction detection system for a mobile radio telephone system
02/06/1985EP0066576B1 A method and apparatus for transferring the same information to a plurality of subscribers
02/05/1985US4497978 Method and apparatus for preventing overloading of the central controller of a telecommunication system
02/05/1985CA1182231A1 Hook flash signal actuated telephone control device
02/05/1985CA1182230A1 Subscriber line interface circuit
01/1985
01/31/1985WO1985000494A1 Method and apparatus for providing call tracing service
01/31/1985WO1985000489A1 Method and apparatus for providing a plurality of special services
01/31/1985WO1985000488A1 Method and apparatus for displaying at a selected station special service information during a silent interval between ringing
01/31/1985WO1985000487A1 Method and apparatus for sending a data message to a selected station during a silent interval between ringing
01/29/1985US4496801 Splicing module test set
01/29/1985US4496800 Ringing generator testing arrangement for a digital telephone network
01/29/1985US4496798 Ringing circuit for telephone subset, designed as an integrated circuit
01/29/1985CA1181877A1 Successive frame digital multiplexer with increased channel capacity
01/22/1985USRE31814 Three-party conference circuit for digital time-division-multiplex communication systems
01/22/1985US4495618 Digital switching network
01/22/1985US4495616 PCM Conference circuit
01/17/1985WO1985000261A1 Digital teleconferencing control device, system and method
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