Patents by Inventor David D. Cleary

David D. Cleary 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: 8244125
    Abstract: This disclosure relates to detection of optical fiber failure and implementation of protection switching in a passive optical network (PON). A protection switch determines whether there is an optical fiber failure in a fiber link between an OLT and a group of ONTs. In the case of an optical fiber failure, an optical fiber may be physically cut or damaged, causing the optical fiber link to be disabled. A protection switch may detect an optical fiber failure by determining a peak optical power of at least a portion of an upstream optical signal transmitted from one or more ONTs via the optical fiber link. If the peak optical power is less than a threshold value, the protection switch may detect a fiber failure. In response to a detected fiber failure, the protection switch may switch upstream and downstream PON transmissions from a primary optical fiber to a secondary optical fiber.
    Type: Grant
    Filed: January 21, 2009
    Date of Patent: August 14, 2012
    Assignee: Calix, Inc.
    Inventors: Mark R. Biegert, Peter O. Lee, David D. Cleary
  • Publication number: 20100183298
    Abstract: This disclosure relates to detection of optical fiber failure and implementation of protection switching in a passive optical network (PON). A protection switch determines whether there is an optical fiber failure in a fiber link between an OLT and a group of ONTs. In the case of an optical fiber failure, an optical fiber may be physically cut or damaged, causing the optical fiber link to be disabled. A protection switch may detect an optical fiber failure by determining a peak optical power of at least a portion of an upstream optical signal transmitted from one or more ONTs via the optical fiber link. If the peak optical power is less than a threshold value, the protection switch may detect a fiber failure. In response to a detected fiber failure, the protection switch may switch upstream and downstream PON transmissions from a primary optical fiber to a secondary optical fiber.
    Type: Application
    Filed: January 21, 2009
    Publication date: July 22, 2010
    Applicant: Calix Networks, Inc.
    Inventors: Mark R. Biegert, Peter O. Lee, David D. Cleary