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)
12/1990
12/12/1990EP0401681A2 Installation for operator of a telephone exchange
12/12/1990EP0366788A4 D channel monitor
12/11/1990US4977593 Optical communications network
12/11/1990US4977555 Asynchronous duplex data communication for requesting services
12/11/1990CA1277791C Method and apparatus for providing personalized telephone subscriber features at remote locations
12/11/1990CA1277752C Communication system using switching apparatus
12/11/1990CA1277751C Packet buffer memory control for statistical multiplexing
12/11/1990CA1277750C Time stamping for packet system nodes
12/06/1990DE3918145A1 Functional test of digital communications input-output processor - involves test sequence stored in random-access memory and begun after acceptance acknowledgement by central processor
12/05/1990EP0400911A2 Method and apparatus for restricting credit card communication calls
12/05/1990EP0400879A2 Dynamic shared facility system for private networks
12/04/1990US4975945 Universal telephone call relay system
12/04/1990US4975944 Method of making call-wait and call-alternation in electronic private branch exchange (EPBX)
12/04/1990US4975942 Credit/calling card pay telephone method and system employing telephone unit local card-checking and other intelligence cooperative with local personal host computer
12/04/1990US4975941 Call processor for facilitating call completions
12/04/1990US4975938 Communications link testing
12/04/1990US4975902 Circuit for putting in conference a plurality of participants in telecommunication systems
12/04/1990US4975900 Response delay system of an ISDN terminal in a point to multipoint configuration
12/04/1990US4975896 Communications network and method
12/04/1990CA1277402C Inter-exchange carrier access
12/01/1990WO1990015510A1 Inter-network connection system
11/1990
11/28/1990EP0399520A2 A radio communication system
11/28/1990EP0399018A1 Watching method based on telephone system
11/28/1990EP0398987A1 Communications network state and topology monitor.
11/28/1990CN2066640U Hj-905 type crossbar switchboard administration equipment
11/28/1990CN1047427A Carrier independent network services
11/28/1990CN1010648B Intelligent control system for telephone
11/27/1990US4974256 Load balancing and overload control in a distributed processing telecommunications system
11/27/1990CA1277046C Method of integrating one or more accessory function modules in telecommunications systems and access circuit for use therewith
11/27/1990CA1276983C Modem with call waiting
11/22/1990EP0398626A2 Telephone call forwarding device
11/22/1990EP0398183A2 Carrier independent network services
11/22/1990DE3915949A1 Processor-controlled communications exchange system - performs editing of stored communications information held in speech information server
11/21/1990CN2066214U Long distance automatic telephone channel monitor
11/20/1990US4972462 Multimedia mail system
11/20/1990US4972461 Call message delivery system and method
11/20/1990US4972453 Autonomous expert system for directly maintaining remote telephone switching systems
11/20/1990US4972452 Digital bypass for telephone system
11/20/1990CA1276714C Time stamp and packet virtual sequence numbering for reconstructing information signals from packets
11/16/1990CA2012804A1 Telephone call forwarding device
11/15/1990WO1990013961A1 Voice messaging for pay phone telephone systems
11/15/1990WO1990013960A1 Automatically resetting protection arrangement for a telephone subscriber line interface circuit
11/15/1990WO1990013959A1 Interlock circuit for preventing corruption of telephone line signals
11/15/1990WO1990013828A1 Introduction system for locating compatible persons
11/14/1990CN2065801U Computer recording occasions metering instrument
11/07/1990EP0396062A2 Television system for the interactive distribution of selectable video presentations
11/07/1990CN1046824A Protective arrangement for telecommunications line interface circuit
11/07/1990CN1046804A Speech-screen keyboard
11/06/1990US4969186 Telephone message waiting system and apparatus
11/06/1990US4969185 Automated booking of telecommunications calls
11/06/1990US4969183 Telephone lotto number system and service
11/06/1990US4969182 Method of telephone call wherein status data inhibits calls and indicates to the caller the reason the called subscriber is unavailable
11/06/1990US4969179 Telephone line monitoring circuit for providing a visual and auditory signal if the telephone line becomes inoperative
11/06/1990US4969136 Communications network and method with appointment information communication capabilities
10/1990
10/31/1990EP0395231A2 Protective arrangement for telecommunications line interface circuit
10/31/1990EP0394811A2 Method for the realisation of a communication connector assisted by an EDP device
10/30/1990US4967412 Serial data frame generator for testing telecommunications circuits
10/30/1990US4967408 Telephone exchange including service feature apparatus
10/25/1990DE3913071A1 Telephone private branch exchange with conference facility - has amplifiers inserted between corresponding column lines of different coupling matrices
10/25/1990CA2014086A1 Protective arrangement for telecommunications line interface circuit
10/24/1990EP0393333A2 Telephone lines overvoltage protection circuit
10/24/1990EP0393126A1 Routing of network traffic.
10/24/1990CN1046426A Controller of outgoing toll telephone
10/24/1990CN1046425A Equipment and method for monitoring digital subscribers in telephone network
10/24/1990CN1010155B Circuit protector of communication line
10/23/1990US4965795 D channel monitor
10/23/1990US4965790 Communication system for forming different networks on the same ring transmission line
10/23/1990CA1275483C Centrex attendant console interface
10/23/1990CA1275482C Station number portability
10/17/1990EP0392724A2 Resource allocation arrangement
10/17/1990EP0392061A1 Method of establishing conference connections in a digital time multiplexed telecommunication exchange
10/16/1990US4964160 Protector device
10/16/1990US4964157 Conference speech-channel forming method based on private branch exchange and its conference telephone system
10/16/1990US4964156 Cellular telephone unit capable of automatic interaction with audio services
10/16/1990US4964155 Programmable threshold alert
10/11/1990DE3912230C1 Modular test system for ISDN units - uses plug adaptors to connect units to testing unit which simulates ISDN control and data exchange
10/10/1990EP0391312A2 System for and method of determining cable characteristics
10/10/1990EP0248812B1 Method and apparatus for efficient resource allocation
10/09/1990US4962520 Composite ringing and coin control voltage detector and method
10/04/1990WO1990011661A1 Catalog ordering system with increased security
10/04/1990WO1990011660A1 Switching system for application service
10/04/1990DE3910485A1 Method for automatic through-connection of a link between two terminals of a telephone system
10/03/1990CN1009897B Active impedance line feed circuit
10/02/1990US4961222 Apparatus in a telecommunication system for supplying power to a telephone set
10/02/1990US4961217 Personal-servicing communication system
10/02/1990US4961186 Communication channel reallocation
09/1990
09/26/1990EP0388856A2 Coupling device for broad-band signals
09/26/1990CN2062927U Microcomputerized, program-controlled automatic tester for cross-bar system exchanger
09/26/1990CN1045675A Interface circuit with transient event tolerance
09/26/1990CN1045672A Marker
09/25/1990US4959857 Acoustic calibration arrangement for a voice switched speakerphone
09/25/1990US4959856 Automatic administration of a telecommunication system
09/25/1990US4959855 Directory assistance call processing and calling customer remote signal monitoring arrangements
09/25/1990US4959854 Apparatus and method for automatically reconfiguring telephone network resources
09/25/1990US4959849 End-to-end network surveillance
09/25/1990US4959650 Dual channel A/D and D/A converter with improved isolations
09/19/1990EP0388022A2 Solid state overcurrent protection device
09/19/1990EP0388021A2 Interface circuit with transient event tolerance
09/18/1990US4958370 Control system for a plurality of telephone sets
09/18/1990US4958343 Communication channel reservation
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