Patents by Inventor Mark C. Cavallo

Mark C. Cavallo has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5381475
    Abstract: An echo suppression arrangement for use in a digital portable telephone prevents sidetone echo appearing in the base unit of the telephone from being coupled to and emanating at the handset unit of the telephone. The echo suppression arrangement determines the direction of dominant speech signals appearing in the base unit while communicating with the handset unit. These dominant speech signals either originate at the handset unit or at a remote telephone station and are received by the base unit over a telephone line connected to the base unit. If the dominant signal in the base unit is from the handset unit, the echo suppressor arrangement inserts a predetermined amount of loss into a receive voice path which couples signals to the handset unit. This prevents the sidetone echo from being produced in the handset voice receiver when the user of the handset unit is speaking.
    Type: Grant
    Filed: December 2, 1993
    Date of Patent: January 10, 1995
    Assignee: AT&T Corp.
    Inventor: Mark C. Cavallo