Method for estimating the polarization mode dispersion compliant capacity fraction of the total optical frequency transmission window of a transport system

• US 7,587,142 B1
• Filed: 12/29/2005
• Issued: 09/08/2009
• Est. Priority Date: 12/29/2005
• Status: Active Grant

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property II LP (AT&T, Inc.)
• Inventors: Brodsky, Mikhail, Boroditsky, Mikhail, Frigo, Nicholas, Magill, Peter David
• Primary Examiner(s): SEDIGHIAN, REZA
• Application Number:
  US11/321,427
• Time in Patent Office: 1,349 Days
• Field of Search: 398/152, 398/158, 398/159, 359/483, 359/484, 359/485, 359/494, 359/497, 359/499, 358/11
• US Class Current: 398/152
• CPC Class Codes: H04B 10/07951 Monitoring or measuring chromatic dispersion or PMD

Abstract

A method and system for estimating a fraction of an optical transmission system'"'"'s transmission window that is compliant with the system'"'"'s polarization mode dispersion (PMD) outage specifications, the optical transmission system including N_s optical fiber segments. The method comprises the steps of: propagating a plurality of optical signals through the N_s optical fiber segments; monitoring the differential group delay (DGD) for each optical signal over time; computing a time average and variance of the monitored DGD for each optical signal; computing statistics of the time averages and variances of the monitored DGD for each optical signal; determining the number of effective PMD sections and effective hinges in the system from the statistics; and determining the size of a PMD capacity compliant fraction for a specified outage probability.

Claims

1. A method for estimating a fraction of an optical transmission system'"'"'s transmission window that is compliant with the system'"'"'s polarization mode dispersion (PMD) outage specifications, the optical transmission system including N_s optical fiber segments, comprising the steps of:

propagating a plurality of optical signals through the N_s optical fiber segments;

monitoring the differential group delay (DGD) for each optical signal over time;

computing a time average and variance of the monitored DGD for each optical signal;

computing statistics of the time averages and variances of the monitored DGD for each optical signal;

determining the number of effective PMD sections and effective hinges in the system from the statistics; and

determining the size of a PMD capacity compliant fraction for a specified outage probability.

2. The method recited in claim 1, further comprising the step of receiving the plurality of optical signals at an optical receiver and monitoring the DGD at the optical receiver.

3. The method recited in claim 2, further comprising the step of monitoring the PMD for each optical signal at the optical receiver.

4. An optical receiver for use in an optical system for estimating a fraction of the optical transmission system'"'"'s transmission window that is compliant with the system'"'"'s polarization mode dispersion (PMD) specifications, the optical transmission system including N_s optical fiber segments, comprising:

a front end for receiving a plurality of optical signals that were propagated through the N_s optical fiber segments; and

a DGD monitoring engine for monitoring the differential group delay (DGD) for each optical signal over time;

a memory medium containing machine readable instructions which, when executed by a processor;

compute a time average of the monitored DGD for each optical signal;

compute statistics of the time averages of the monitored DGD for each optical signal;

determine the number of effective PMD sections in the system from the statistics; and

determine the size of a PMD capacity compliant fraction for a specified outage probability.