| Patents for H04M 3 - Automatic or semi-automatic exchanges (99,881) |
|---|
| 04/12/1990 | DE3833745A1 Changeover switching device for a number of extensions to be operated on a common subscriber line |
| 04/10/1990 | US4916734 Apparatus for separating dc current and ac current components of a composite signal |
| 04/10/1990 | US4916726 Telephone answering service with integrated voice and textual message storage |
| 04/10/1990 | US4916444 Method and apparatus for mapping communications media |
| 04/10/1990 | CA1267727A1 Interface circuit |
| 04/10/1990 | CA1267711A1 Switching network |
| 04/05/1990 | WO1990003707A1 Process for measuring in the user domain of an integrated services digital network (isdn) system |
| 04/05/1990 | WO1990003700A1 Telephone answering service with integrated voice and textual message storage |
| 04/04/1990 | EP0361808A2 Modular test structure for single chip digital exchange controller |
| 04/04/1990 | EP0361697A2 Protection devices and arrangements for telephone lines |
| 04/04/1990 | EP0360913A1 Method of actuating the call state of a subscriber terminal in a processor-controlled communication system |
| 04/04/1990 | EP0360898A1 Method for taking calls which are signalled by a communication exchange at one or more key telephone terminals |
| 04/04/1990 | EP0360891A1 Call coverage method |
| 04/03/1990 | US4914692 Automatic speech recognition using echo cancellation |
| 04/03/1990 | US4914690 Universal PBX interface |
| 04/03/1990 | US4914687 Voice information transmission system |
| 04/03/1990 | US4914572 Method for operating an error protected multiprocessor central control unit in a switching system |
| 03/29/1990 | DE3832491A1 Verfahren zum messen im teilnehmerbereich eines integrated services digital network (isdn)-systems A method for measuring the subscriber base of an integrated services digital network (isdn) system |
| 03/28/1990 | EP0360726A2 Communications network routing and management system |
| 03/28/1990 | EP0360723A2 Method of enhancing communication setup between a commmunication station and a telecommunications network |
| 03/28/1990 | EP0360493A2 More efficient call handling for operator assistance calls |
| 03/28/1990 | EP0360160A2 Logic signal circuit for a releasing relay |
| 03/28/1990 | EP0359757A1 Automated interactive mass communications system |
| 03/28/1990 | EP0211860B1 Integrated message service system |
| 03/28/1990 | CN1040894A Pulse-scanning controlled automatic telephone exchange |
| 03/28/1990 | CN1007400B Railway basic unit service automatic communication system |
| 03/27/1990 | US4912755 Line current test device |
| 03/27/1990 | US4912705 Subscriber RF telephone system for providing multiple speech and/or data signals simultaneously over either a single or a plurality of RF channels |
| 03/27/1990 | US4912699 Pulse code modulation terminal equipment |
| 03/27/1990 | US4912452 ISDN quick connect terminating resistor |
| 03/27/1990 | CA1267208A1 Message signaling arrangement between a switching system and user terminals |
| 03/27/1990 | CA1267207A1 Method and apparatus for automatically transmitting a message to a telephone terminal |
| 03/21/1990 | EP0359723A2 Arrangement in equipment for the reproduction of voice message in telephone line |
| 03/21/1990 | EP0358981A2 Circuit for setting up conference connections in a digital time multiplexed telecommunication exchange |
| 03/21/1990 | CN2054959U Magneto telephone set separator |
| 03/21/1990 | CN1007315B Communication system with remote-controlled signal receiving apparatus |
| 03/20/1990 | US4910769 Telephone line interface circuit |
| 03/20/1990 | US4910766 Quasi reservation-based communication service process system |
| 03/20/1990 | US4910760 Network verification evaluation testing system |
| 03/20/1990 | CA1266883A1 Protector circuit |
| 03/14/1990 | EP0358408A2 Intelligent network |
| 03/14/1990 | EP0358028A2 Device for a time division multiplexed digital telecommunication exchange |
| 03/14/1990 | EP0357819A1 Circuit arrangement for establishing conference connections in a digital time-multiplexed telephone exchange |
| 03/14/1990 | CN1040474A Intelligent telephone-controlling system |
| 03/14/1990 | CN1007203B Wide band signal space coupling arrange ments |
| 03/13/1990 | US4908854 Apparatus for connecting and disconnecting a ringing signal to a called subscriber |
| 03/13/1990 | US4908852 Method and apparatus for altering the access format of telephone calls |
| 03/13/1990 | US4908850 Voice services network with automated billing |
| 03/07/1990 | EP0356568A1 Method and apparatus for speaker recognition in a telephone exchange |
| 03/07/1990 | EP0356567A1 Method and apparatus for speaker recognition in a telephone exchange |
| 03/07/1990 | EP0125279B1 Acd management information system |
| 03/06/1990 | US4907262 Method of transmitting dual tone multi-frequency during communication in a private branch exchange using keyphones |
| 03/06/1990 | US4907261 Universal DC signalling detector |
| 03/06/1990 | US4907260 Telephone line communications control system |
| 03/06/1990 | US4907259 Call appearance reservation arrangement |
| 03/06/1990 | US4907258 Key telephone apparatus |
| 03/06/1990 | US4907256 Exchange system having originating call restriction function |
| 03/06/1990 | US4907221 Apparatus for attenuating the echo signal in telephone fork circuits for telephone conference calls |
| 03/06/1990 | CA1266529A1 Hardware resource management |
| 03/01/1990 | DE3837051C1 Overvoltage protection plug for a plurality of cables which are to be protected against overvoltages |
| 02/28/1990 | EP0356191A2 Methods and apparatus for efficient allocation of resources by optimizing nonlinear, convex functions with linear constraints |
| 02/28/1990 | EP0355714A2 Method and apparatus for initiating communication services |
| 02/28/1990 | EP0355488A2 Method for realizing a control procedure in combination with the realisation of a hold state of a line in a calculator-controlled communication system, especially a key telephone system |
| 02/28/1990 | EP0355487A2 Method for the realization of conference connexions in a computer-controlled communication system, especially a key telephone system |
| 02/28/1990 | EP0355484A2 Method for realizing a control procedure in combination with the possibility of directly addressing a subscriber in a calculator-controlled communication system, especially a key system |
| 02/28/1990 | EP0203151B1 Loop around data channel unit |
| 02/28/1990 | EP0203150B1 Method and apparatus for looping around a digital transmission line at a channel unit |
| 02/28/1990 | EP0127656B1 A telephone switching arrangement |
| 02/28/1990 | CN1007033B Wide-band sythetical switchbord for optical-fibre communication-network |
| 02/27/1990 | US4905273 Data transmission system |
| 02/27/1990 | US4905227 Circuit for subscriber line interface circuits in a digital time-division multiplex communication switching center |
| 02/27/1990 | US4905119 Solid state overvoltage protection circuit |
| 02/22/1990 | WO1990001842A1 Method and apparatus for accessing a facsimile store and forward network |
| 02/22/1990 | DE3832618C1 Checkable line termination for a telephone line |
| 02/22/1990 | DE3827099A1 Method for building up a switching network |
| 02/20/1990 | US4903295 Compact solid state station protector device |
| 02/15/1990 | DE3827492A1 Method for establishing conference connections in a computer-controlled communication system |
| 02/14/1990 | EP0354252A1 Coupling device for broad-band signals |
| 02/14/1990 | EP0354224A1 Nitrogen-containing esters of carboxy-containing interpolymers |
| 02/14/1990 | CN2052995U Small type fully automatic switchboard for local and outside line |
| 02/13/1990 | US4901344 Telephone system digital channel bank interface |
| 02/13/1990 | US4901341 Method and apparatus for caller-controlled receipt and delivery of voice messages |
| 02/13/1990 | US4901308 Digital bridge for a time slot interchange digital switched matrix |
| 02/13/1990 | US4901004 Apparatus and method for mapping the connectivity of communications systems with multiple communications paths |
| 02/13/1990 | US4901003 Telecommunications wiring test apparatus and method including two color display indicating correct wiring |
| 02/13/1990 | CA1265881A1 Direct access test unit for central office |
| 02/13/1990 | CA1265860A1 Communications network |
| 02/08/1990 | WO1990001237A1 Adaptive routing of network traffic |
| 02/07/1990 | EP0353945A1 Method of establishing multi-location video-audio communications |
| 02/07/1990 | EP0353739A2 Telephone-call distributor |
| 02/07/1990 | EP0179898B1 A two way personal message system with extended coverage |
| 02/07/1990 | CN2052590U By-pass continued device for automatic telephone exchange |
| 02/07/1990 | CN1039514A Exchange system having originating call restriction function |
| 02/07/1990 | CN1006752B Speakerphone sensing circuit |
| 02/06/1990 | US4899381 Single-line telephone hold circuit |
| 02/06/1990 | US4899379 Circuit arrangement for the connection of line circuits of a digital time multiplex-telephone network |
| 02/06/1990 | US4899378 Telephone announcement system |
| 02/06/1990 | US4899375 More efficient call handling for operator assistance calls |
| 02/06/1990 | US4899374 Method for a program-controlled telephone switching system in which performance features relating to the setup of a call connection can be initiated from a subscriber station |
| 02/06/1990 | US4899373 Method and apparatus for providing personalized telephone subscriber features at remote locations |