TREA

using one signalling frequency

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  • CPC
  • H04Q1/446
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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

H04Q1/446using one signalling frequency
Industries

Patents Grantslast 30 patents

  • Information Patent Grant

    System for ensuring calling party privacy in a call screening system
    • Patent number 6,493,432
    • Issue date Dec 10, 2002
    • Avaya Technology Corp.
    • Diane Doran Blum
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Line testing in a telecommunications network
    • Patent number 6,385,299
    • Issue date May 7, 2002
    • British Telecommunications public limited company
    • Alvin Brooks
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Method and apparatus for electronic mail notification
    • Patent number 6,212,265
    • Issue date Apr 3, 2001
    • Darin Duphorne
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Line testing in a telecommunications network
    • Patent number 6,169,783
    • Issue date Jan 2, 2001
    • British Telecommunicaitons public limited company
    • Alvin Brooks
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Method and apparatus for defeating a predictive telemarketing system
    • Patent number 5,920,623
    • Issue date Jul 6, 1999
    • Vera-A-Fast
    • Robert M. Bensman
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Low-frequency alternating current signal detector, in particular fo...
    • Patent number 5,218,635
    • Issue date Jun 8, 1993
    • Alcatel Business Systems
    • Andre Bonvallet
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Signal analyzing system
    • Patent number 5,070,526
    • Issue date Dec 3, 1991
    • Active Voice, Inc.
    • Robert L. Richmond
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Method and means for remote testing of unused telephone lines
    • Patent number 4,945,555
    • Issue date Jul 31, 1990
    • Rochester Telephone Corporation
    • Christopher R. Teumer
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Transmitters and systems for tone-in-band transmission
    • Patent number 4,792,985
    • Issue date Dec 20, 1988
    • National Research Development Corporation
    • Joseph P. McGeehan
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Energy detection circuit for a facsimile system controller
    • Patent number 4,567,328
    • Issue date Jan 28, 1986
    • Burroughs Corp.
    • Francis P. Carrasco
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Tone detection method and arrangement for observing and classifying...
    • Patent number 4,384,175
    • Issue date May 17, 1983
    • Bell Telephone Laboratories, Incorporated
    • David B. Brown
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Frequency error correction circuit
    • Patent number 4,099,125
    • Issue date Jul 4, 1978
    • Motorola, Inc.
    • Robert McKay Bennett
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    High speed tone decoder utilizing a phase-locked loop
    • Patent number 4,037,171
    • Issue date Jul 19, 1977
    • Bell Telephone Laboratories, Incorporated
    • Robert Roger Cordell
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    Communication network protection system
    • Patent number 4,018,996
    • Issue date Apr 19, 1977
    • Leonard R. Kahn
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3930127
    • Patent number 3,930,127
    • Issue date Dec 30, 1975
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3873772
    • Patent number 3,873,772
    • Issue date Mar 25, 1975
    • G10 - MUSICAL INSTRUMENTS ACOUSTICS
  • Information Patent Grant

    3842216
    • Patent number 3,842,216
    • Issue date Oct 15, 1974
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3824345
    • Patent number 3,824,345
    • Issue date Jul 16, 1974
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3818146
    • Patent number 3,818,146
    • Issue date Jun 18, 1974
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3764753
    • Patent number 3,764,753
    • Issue date Oct 9, 1973
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3763324
    • Patent number 3,763,324
    • Issue date Oct 2, 1973
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3747009
    • Patent number 3,747,009
    • Issue date Jul 17, 1973
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3732378
    • Patent number 3,732,378
    • Issue date May 8, 1973
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3671939
    • Patent number 3,671,939
    • Issue date Jun 20, 1972
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3637943
    • Patent number 3,637,943
    • Issue date Jan 25, 1972
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3638038
    • Patent number 3,638,038
    • Issue date Jan 25, 1972
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3571522
    • Patent number 3,571,522
    • Issue date Mar 16, 1971
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3557319
    • Patent number 3,557,319
    • Issue date Jan 19, 1971
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3544723
    • Patent number 3,544,723
    • Issue date Dec 1, 1970
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3522544
    • Patent number 3,522,544
    • Issue date Aug 4, 1970
    • G08 - SIGNALLING