Patents Represented by Attorney, Agent or Law Firm David Fox
  • Patent number: 6804273
    Abstract: A controller for use with an optical device having an optical source and a frequency reference element. The controller includes a frequency processing module coupled to the optical device. The frequency processing module generates an error signal indicative of a deviation between the output frequency of the optical source and a reference frequency corresponding to a reference point. A driver module communicates with the optical device and the frequency processing module. The driver module adjusts a parameter of the optical source in response to the error signal. An offset processing module is coupled to the frequency processing module. The offset processing module derives an offset signal based on an estimate of a temperature of the frequency reference element. The offset processing module provides the offset signal to the frequency processing module which updates the reference point in response to the offset.
    Type: Grant
    Filed: March 19, 2002
    Date of Patent: October 12, 2004
    Assignee: Ciena Corporation
    Inventor: Paolo Sacchetto
  • Patent number: 6742154
    Abstract: A network optimization method measures the line bit error rate (BER) at a receiver by counting forward error correction corrected errors, and adjusts network parameters to minimize the corrected error rate. Adjustable parameters include, among other things, transmitter extinction ratio, transmitter polarization, and dispersion. The method includes sweeping an adjustable parameter while monitoring the FEC corrected bit error rates at the receiver, and then extrapolating an optimum value of the parameter. In this way, the corrected BER can be maintained below the predetermined BER limit while the digital communication network is in-service.
    Type: Grant
    Filed: May 25, 2000
    Date of Patent: May 25, 2004
    Assignee: Ciena Corporation
    Inventor: Chris Barnard