TREA

with out-of-voice band signalling frequencies

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  • CPC
  • H04Q1/442
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Parent Industries

HELECTRICITY H04Electric communication H04QSELECTING H04Q1/00Details of selecting apparatus or arrangements for establishing connections among stations for the purpose of transferring information via these connections

Current Industry

H04Q1/442with out-of-voice band signalling frequencies
Industries

Patents Grantslast 30 patents

  • Information Patent Grant

    Sensing circuit
    • Patent number 5,963,885
    • Issue date Oct 5, 1999
    • Alcatel N.V.
    • Damien Luc Francois Macq
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Ring discriminator
    • Patent number 5,610,978
    • Issue date Mar 11, 1997
    • Mitel Corporation
    • Valentin Purits
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Apparatus for selectively enabling subscriber device to respond to...
    • Patent number 5,142,569
    • Issue date Aug 25, 1992
    • Data Accessory Corporation
    • George W. Peters
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Telephone system with several terminals on a single line
    • Patent number 5,119,418
    • Issue date Jun 2, 1992
    • Dolphin Integration
    • Christian Dupillier
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Interlock circuit for preventing corruption of telephone line signals
    • Patent number 4,939,765
    • Issue date Jul 3, 1990
    • Harris Corporation
    • Dean L. Benjamin
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Apparatus for controlling key telephone station set in key telephon...
    • Patent number 4,932,043
    • Issue date Jun 5, 1990
    • Kabushiki Kaisha Toshiba
    • Yasunobu Nakayama
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Circuit for evaluating call signals in a telecommunication system
    • Patent number 4,737,987
    • Issue date Apr 12, 1988
    • U.S. Philips Corporation
    • Erwin Haussmann
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Telephone answering system with line detector
    • Patent number 4,701,950
    • Issue date Oct 20, 1987
    • Amtel Communications, Inc.
    • William J. Curtin
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Supervisory audio tone detection in a radio channel
    • Patent number 4,698,769
    • Issue date Oct 6, 1987
    • American Telephone and Telegraph Company
    • Ross McPherson
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Telephone privacy apparatus
    • Patent number 4,459,435
    • Issue date Jul 10, 1984
    • Peter Foldvary
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    AC supervisory signal detector circuit
    • Patent number 4,133,982
    • Issue date Jan 9, 1979
    • GTE Automatic Electric Laboratories Incorporated
    • David Q. Lee
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Out-of-band signaling method and apparatus to adapt payphones to te...
    • Patent number 4,010,328
    • Issue date Mar 1, 1977
    • The Anaconda Company
    • Ronald F. McGuire
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3546600
    • Patent number 3,546,600
    • Issue date Dec 8, 1970
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3546674
    • Patent number 3,546,674
    • Issue date Dec 8, 1970
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3428755
    • Patent number 3,428,755
    • Issue date Feb 18, 1969
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3281693
    • Patent number 3,281,693
    • Issue date Oct 25, 1966
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3200307
    • Patent number 3,200,307
    • Issue date Aug 10, 1965
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3187234
    • Patent number 3,187,234
    • Issue date Jun 1, 1965
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3173064
    • Patent number 3,173,064
    • Issue date Mar 9, 1965
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3060269
    • Patent number 3,060,269
    • Issue date Oct 23, 1962
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2988600
    • Patent number 2,988,600
    • Issue date Jun 13, 1961
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2949507
    • Patent number 2,949,507
    • Issue date Aug 16, 1960
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2941041
    • Patent number 2,941,041
    • Issue date Jun 14, 1960
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2939391
    • Patent number 2,939,391
    • Issue date Jun 7, 1960
    • F42 - AMMUNITION BLASTING
  • Information Patent Grant

    2939919
    • Patent number 2,939,919
    • Issue date Jun 7, 1960
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2894129
    • Patent number 2,894,129
    • Issue date Jul 7, 1959
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2892896
    • Patent number 2,892,896
    • Issue date Jun 30, 1959
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2838613
    • Patent number 2,838,613
    • Issue date Jun 10, 1958
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2773181
    • Patent number 2,773,181
    • Issue date Dec 4, 1956
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2754369
    • Patent number 2,754,369
    • Issue date Jul 10, 1956
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE

Patents Applicationslast 30 patents