Patents by Inventor David J. Hodgdon

David J. Hodgdon 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: 5386417
    Abstract: A communications switch communicates a message to a particular access network endpoint by forwarding an identification of that endpoint along with the message, link-by-link, through the access network, the forwarding being accomplished by using previously stored routing information identifying, at the switch and at each cross-connection point, a particular downstream link over which the endpoint can ultimately be reached. The links connecting the cross-connection points are multiplexed links supporting digital loop carrier and fiber-in-the-loop communications. The routing information is generated and stored automatically by having each network element report information about itself upstream into the network.
    Type: Grant
    Filed: August 27, 1993
    Date of Patent: January 31, 1995
    Assignee: AT&T Corp.
    Inventors: Thomas H. Daugherty, Dennis L. DeBruler, Daniel S. Greenberg, David J. Hodgdon, Douglas J. Murphy
  • Patent number: 5381405
    Abstract: A communications switch communicates a message to a particular access network endpoint by forwarding an identification of that endpoint along with the message, link-by-link, through the access network, the forwarding being accomplished by using previously stored routing information identifying, at the switch and at each cross-connection point, a particular downstream link over which the endpoint can ultimately be reached. The links connecting the cross-connection points am time-division-multiplexed links supporting digital loop carrier and fiber-in-the-loop communications. The routing information is generated and stored automatically by having each network element report information about itself upstream into the network.
    Type: Grant
    Filed: August 27, 1993
    Date of Patent: January 10, 1995
    Assignee: AT&T Corp.
    Inventors: Thomas H. Daugherty, Dennis L. DeBruler, Daniel S. Greenberg, David J. Hodgdon, Douglas J. Murphy
  • Patent number: 5305320
    Abstract: Disclosed is a communications network for peripherals in a digital loop carrier transmission system. A broadcast STAR network is employed so that all peripherals receive any message which is broadcast by any of the peripherals. No peripheral broadcasts without clearance from the active communications hub. Two hubs can be provided to alternatively act as the active hub. Each peripheral includes a controller which transmits a request to send signal, multiplexes the request to send signal with an outgoing message, receives clear to send signals, and demultiplexes the clear to send signals from an incoming message.
    Type: Grant
    Filed: October 6, 1992
    Date of Patent: April 19, 1994
    Assignee: AT&T Bell Laboratories
    Inventors: Michael W. Andrews, Stephen J. Brolin, Robert W. DeMarco, Daniel S. Greenberg, David J. Hodgdon, Chandan Sarkar, Gordon D. Woods
  • Patent number: 5251215
    Abstract: Disclosed is a method and circuit for modifying the check code of a data packet based on a first seed to accommodate the addition or substraction of a header. A number of bits, which include a second seed, an exclusive OR function of the first seed and a portion of a header, and a string of zeros dependent upon the length of an incoming data packet, is sent through a CRC generator. The resulting CRC calculation and the incoming packet check code are exclusive ORed to produce a modified check code taking into account the addition or substraction of the header.
    Type: Grant
    Filed: January 13, 1992
    Date of Patent: October 5, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: Subrahmanyam Dravida, Daniel S. Greenberg, David J. Hodgdon