H04M 3 - Automatic or semi-automatic exchanges

Patents for H04M 3 - Automatic or semi-automatic exchanges (99,881)
12/1988
12/07/1988	EP0293876A2 Method for a private branch exchange with two trunk lines comprising a main telephone set and a plurality of extension telephone sets
12/07/1988	EP0293875A2 Method for a private branch exchange with two trunk lines comprising a main telephone set and a plurality of extension telephone sets
12/06/1988	US4790005 Circuit arrangement for telecommunications switching systems, particularly telephone switching systems with information processing switching device and processing load limiting
12/06/1988	US4790004 Implied principal busy status indicator for covered calls
12/06/1988	US4790003 Message service system network
12/06/1988	US4789999 Line circuit for coupling a subscriber set to a switching facility to provide a complex impedance match
12/01/1988	WO1988009587A1 Subscriber/craftsperson ringback apparatus
12/01/1988	DE3717381A1 Circuit arrangement for telecommunications switching systems, in particular telephone switching systems, with an at least partially meshed network of channel groups and with routing devices
12/01/1988	DE3715773A1 Method for operating remote-controllable measuring stations via the trunk dialling network
11/1988
11/30/1988	EP0292769A2 Test adaptor for a digital tone generator
11/29/1988	US4788721 Routing of network traffic
11/29/1988	US4788720 Programmable subscriber set
11/29/1988	US4788719 Telephone call charge allocation arrangement
11/29/1988	US4788718 Call data collection and modification of received call distribution
11/29/1988	US4788715 Announcing waiting times in queuing systems
11/29/1988	US4788712 Howler indicator in cordless telephone system
11/29/1988	US4788710 Telephone line selection and isolation method and apparatus
11/29/1988	US4788697 Method and apparatus for synchronizing a signal to a time base
11/29/1988	US4788682 Telephone system adapted to telemarketing
11/29/1988	CA1245739A1 Method and apparatus for testing communication systems
11/29/1988	CA1245738A1 Method and apparatus for supervising the accessing and testing of communication systems
11/24/1988	EP0268667A4 A telephone line monitoring system.
11/23/1988	EP0292132A2 Telephone trunk line testing circuitry
11/22/1988	US4787080 PCM coder and decoder circuit having digital balancing network
11/22/1988	CA1245381A1 Line circuit for driving a ringer and a service indicating lamp in a telephone set
11/22/1988	CA1245320A1 Method and apparatus for looping around a digital transmission line at a channel unit
11/17/1988	EP0291470A2 A method of attenuating the echo signal in so-called telephone fork converting circuits intended for conference, and an apparatus operating on said method
11/17/1988	EP0291169A1 Protection arrangement for a telephone subscriber line interface circuit
11/16/1988	CN88102480A Emergency d.c. power supply with emergency state being indicated by polarity reversal
11/15/1988	US4785473 Interactive audio telecommunications message storage, forwarding and retrieval system
11/15/1988	US4785408 Method and apparatus for generating computer-controlled interactive voice services
11/15/1988	US4785355 Image communication apparatus
11/15/1988	CA1244979A1 Subscriber set programming module
11/15/1988	CA1244923A1 Expansion port for use in a communication system
11/15/1988	CA1244921A1 Integrated message service system
11/10/1988	DE3714957A1 Method for implementing error analyses in microprocessor-controlled communication systems
11/08/1988	US4783800 Personalized appointment scheduling system
11/08/1988	US4783796 PBX telephone call control system
11/08/1988	CA1244539A1 Dtmf receiver sense and control maintenance arrangement
11/08/1988	CA1244537A1 Switching system and method for network having a plurality of terminal control equipment units
11/08/1988	CA1244536A1 Integrated message service system
11/03/1988	WO1988008654A1 Message service system network
11/02/1988	EP0289387A1 Direct current power supply aided by an emergency condition indication by inversion
11/02/1988	EP0289296A1 Computer-based training for telephone extension users
11/02/1988	EP0288935A2 Arrangement for creating a supplementary ISDN basic access in an ISDN subscriber installation
11/02/1988	EP0288462A1 Routing of network traffic.
11/02/1988	CN87214312U Semi-automatic restorer of spring retainer for telephone
11/01/1988	US4782517 System and method for defining and providing telephone network services
11/01/1988	US4782514 Key telephone system
11/01/1988	US4782510 Telephone answering machine with digital storage of announcements and messages
11/01/1988	US4782509 Apparatus and method for obtaining information in a wide-area telephone system with multiple local exchanges and multiple information storage sites
11/01/1988	US4782508 Method of discouraging the completion of wrong-number calls
11/01/1988	US4782507 Monolithically integratable circuit for measuring longitudinal and transverse currents in a two-wire transmission line
11/01/1988	US4782506 Arrangement for operating and maintaining a telecommunications system
11/01/1988	US4782480 Telephone line access apparatus
11/01/1988	CA1244166A1 Interswitch line circuit
11/01/1988	CA1244165A1 Subscriber line monitoring circuit
11/01/1988	CA1244118A1 Distributed control type electronic switching system
10/1988
10/26/1988	CN87214324U Telephone recalling device
10/25/1988	CA1243790A1 Equipment for sending digitally pre-stored voice announcements to the subscribers connected to a telephone network
10/25/1988	CA1243742A1 Communication system administration method and circuitry
10/19/1988	EP0287415A1 Optic fibre transmission device, particularly for underwater environment
10/19/1988	EP0287369A2 Remote disconnection and shortcircuiting apparatus
10/19/1988	EP0286794A2 Method for setting up call-back connections in telephone exchanges, especially private branch exchanges
10/19/1988	EP0286793A1 Circuitry for the overvoltage protection and the supply of a ringing current at a telecommunication connection line, especially a telephone exchange line
10/18/1988	CA1243386A1 Processing sequence calls in a distributed control switching system
10/12/1988	EP0286295A2 Signaling arrangement
10/11/1988	US4777645 Telephone line test and display circuit
10/11/1988	US4777644 Method and apparatus for testing telephone coin relays
10/05/1988	EP0285320A1 Apparatus and method for determining the values of circuit elements in a three terminal equivalent circuit
10/04/1988	US4776005 Computer based information system for character display phone network
10/04/1988	US4776004 Communication services method and apparatus
10/04/1988	US4776002 Method for prompting at a digital telephone station
10/04/1988	US4775975 Dial tone detection arrangement with a detection notification feature
09/1988
09/27/1988	US4774722 Telephone line activity monitoring method and device
09/27/1988	US4774721 Cable pair to telephone number verification system
09/27/1988	US4774706 Packet handling communications network
09/27/1988	CA1242501A1 Method of recognizing the unauthorized use of an identification
09/22/1988	WO1988007304A1 Communication services method and apparatus
09/22/1988	DE3707894A1 Hand-held unit for testing telecommunications line systems
09/21/1988	EP0283120A1 Multi-user speech recognition system
09/21/1988	EP0282788A1 Method for monitoring of error-free performance of control and connection operations in a circuit arrangement for telecommunication exchanges, especially telephone exchanges
09/20/1988	US4772979 Voltage shock protection circuit
09/20/1988	CA1242265A1 Digital conference circuit
09/20/1988	CA1242264A1 Switching system having capability for telecommunication conferences
09/20/1988	CA1242263A1 Switching system with video switching matrix
09/15/1988	DE3707239A1 Distributor for telecommunication systems
09/14/1988	EP0281888A2 Circuit arrangement for the subscriber line circuits of a digital time division multiplex telecommunication exchange
09/13/1988	US4771451 Polarity ring director
09/13/1988	US4771425 Synchoronous packet voice/data communication system
09/13/1988	US4771422 Priority user protection in multiple priority switching systems
09/13/1988	US4771420 Time slot interchange digital switched matrix
09/13/1988	CA1242039A1 Interface channel unit
09/08/1988	DE3706406A1 Device for simulating telephone sets or ancillary devices operating according to the ISDN system
09/07/1988	WO1988006827A1 Centralized inventory apparatus for a plurality of printed circuit boards in a magazine
09/07/1988	WO1988006823A1 Internal communication system
09/07/1988	EP0281150A2 A paging system
09/07/1988	EP0281147A2 Hold detecting and control circuit for a key telephone system
09/06/1988	US4769834 Inter-exchange carrier access
09/06/1988	US4769796 Time management scheduler

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