Method for monitoring wavelength-division multiplexed signal

• US 8,548,320 B2
• Filed: 11/10/2011
• Issued: 10/01/2013
• Est. Priority Date: 06/10/2008
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Schantz, Howard J., Uhlhorn, Brian L.
• Primary Examiner(s): Vanderpuye, Ken
• Assistant Examiner(s): Wolf, Darren E
• Application Number:
  US13/293,689
• Publication Number:
  US 20120051741A1
• Time in Patent Office: 691 Days
• Field of Search: None
• US Class Current: 398/25
• CPC Class Codes: H04B 10/0775 Performance monitoring and measurement of transmission parameters
• CPC Class Codes: H04B 2210/078 using a separate wavelength

Abstract

A method for monitoring wavelength-division multiplexed (WDM) signal for detecting signal drift of objective signals, including generation of one or more objective signals and a guard signal. The guard signal has a wavelength that is within a range defined by a guard channel. The first and second objective signals and the guard signal are wavelength-division multiplexed to generate a wavelength-division multiplexed signal. The first objective signal, the second objective signal, and the guard signal are assigned to a first multiplexed objective channel, a second multiplexed objective channel, and a multiplexed guard channel, respectively. The wavelength-division multiplexed signal is received by a monitor and then the error rate of the multiplexed guard channel is determined.

Claims

1. A method for monitoring a wavelength-division multiplexed signal, comprising:

generating from a first node, a first optical objective signal including a first objective wavelength λ

_o1,

generating from a second node, a second optical objective signal including a second objective wavelength λ

_o2, and

generating from a monitor, an optical guard signal including a guard wavelength λ

_g that is between λ

_o1 and λ

_o2;

a central hub receiving the first optical objective signal, the second optical objective signal, and the optical guard signal;

the central hub generating the wavelength-division multiplexed signal by wavelength-division multiplexing the first optical objective signal, the second optical objective signal, and the optical guard signal,

wherein the wavelength-division multiplexed signal includes;

a first multiplexed objective channel,

a second multiplexed objective channel, and

a multiplexed guard channel having a range of wavelengths between λ

_o1 and λ

_o2;

receiving the wavelength-division multiplexed signal by the monitor; and

detecting an error of the first multiplexed objective channel by determining an error of the multiplexed guard channel, determining the error includes comparing the multiplexed guard channel to the optical guard signal.

2. The method for monitoring a wavelength-division multiplexed signal according to claim 1, wherein determining the error includes calculating a bit error rate (BER) of the multiplexed guard channel.

3. The method for monitoring a wavelength-division multiplexed signal according to claim 1, wherein determining the error includes calculating a signal-to-noise ratio (SNR) of the multiplexed guard channel.

4. The method for monitoring a wavelength-division multiplexed signal according to claim 1,

wherein the first optical objective signal further includes a first objective power amplitude A_o1;

wherein the optical guard signal further includes a predetermined guard power amplitude A_g; and

wherein A_g is less than A_o1.

5. The method for monitoring a wavelength-division multiplexed signal according to claim 4, wherein the predetermined guard power amplitude A_g is less than or equal to 50% of A_o1.

6. The method for monitoring a wavelength-division multiplexed signal according to claim 1,

wherein the optical guard signal includes a predetermined guard power amplitude A_g, the wavelength-division multiplexed signal further includes a multiplexed guard power amplitude A′

_g; and

wherein determining the error of the multiplexed guard channel includes;

detecting the multiplexed guard power amplitude A′

_g, and

determining an error guard power Δ

A_g,

wherein Δ

A_g=f(A′

_g, A_g).

7. The method for monitoring a wavelength-division multiplexed signal according to claim 1, further comprising:

providing an action protocol associated with the multiplexed guard channel,

wherein when the error of the multiplexed guard channel is determined to meet a criteria according to the action protocol, an output is generated according to the action protocol.

8. The method for monitoring a wavelength-division multiplexed signal according to claim 7, wherein the output is a recommendation for a system inspection.

9. The method for monitoring a wavelength-division multiplexed signal according to claim 8, wherein the recommendation for system inspection includes when to perform the system inspection.

10. The method for monitoring a wavelength-division multiplexed signal according to claim 7, wherein the output is a system malfunction alert.