Patents by Inventor Prabhakar Chitrapu

Prabhakar Chitrapu 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).

  • Technique of controlling telephone calls
    Patent number: 5809110
    Abstract: An improved system for minimizing toll charges is disclosed wherein line quality is measured and a call is terminated if the line quality is not at an acceptable level to allow for the highest possible bit rates during data transfer or to guarantee a certain minimum degree of quality.
    Type: Grant
    Filed: January 31, 1996
    Date of Patent: September 15, 1998
    Assignee: Dialogic Corporation
    Inventors: Mark Ulrich, Prabhakar Chitrapu
  • Call processing using previously obtained line characteristics
    Patent number: 5764759
    Abstract: A technique for utilization of call processing resources in a call processing system is disclosed wherein echo characteristics of a telephone line ascertained and utilized by a echo canceler, and are also stored for subsequent use by a different echo canceler which processes a call on that same telephone line. The technique may also be used with call processing resources other than echo cancelers.
    Type: Grant
    Filed: October 6, 1994
    Date of Patent: June 9, 1998
    Assignee: Dialogic Corporation
    Inventors: Chris Hamilton, Prabhakar Chitrapu
  • Tone blocking using variable delay buffer
    Patent number: 5687177
    Abstract: A tone blocking system and method for use preferably in conferencing systems in order to prevent control tones from being transmitted to other conferees is disclosed. The buffer length used to process the signal and detect tones is varied, being increased when a tone is suspected to allow for sophisticated tone detection algorithms, and being decreased when silence is present by trimming the silence away. The technique minimizes delay, and its degrading effect on echo, but nonetheless provides for a lengthy buffer required to do reliable tone detection. The invention is applicable to any signal other than tone as well.
    Type: Grant
    Filed: October 10, 1996
    Date of Patent: November 11, 1997
    Assignee: Dialogic Corporation
    Inventors: Prabhakar Chitrapu, Wei Lin
  • Tone blocking using variable delay buffer
    Patent number: 5604793
    Abstract: A tone blocking system for use preferably in conferencing systems in order to prevent control tones from being transmitted to other conferees is disclosed. The buffer length used to process the signal and detect tones is varied, being increased when a tone is suspected to allow for sophisticated tone detection algorithms, and being decreased when silence is present by trimming the silence away. The technique minimizes delay, and its degrading effect on echo, but nonetheless provides for a lengthy buffer required to do reliable tone detection. The invention is applicable to any signal other than tone as well.
    Type: Grant
    Filed: August 3, 1995
    Date of Patent: February 18, 1997
    Assignee: Dialogic Corporation
    Inventors: Prabhakar Chitrapu, Wei Lin
  • Ring tone detection for a telephone system
    Patent number: 5442694
    Abstract: A technique for software ring tone detection is disclosed utilizing, in the preferred embodiment, a recursive algorithm. The technique provides flexibility in that a digital signal processor may be reprogrammed to detect ring tone frequencies and amplitudes present in numerous different countries.
    Type: Grant
    Filed: April 12, 1994
    Date of Patent: August 15, 1995
    Assignee: Dialogic Corporation
    Inventors: Prabhakar Chitrapu, Zhibing Pan, Chet Juall, Andrew Dumont