Prior art — US Patent 6529316

Analysis of Prior Art for U.S. Patent 6,529,316

This analysis details the prior art cited during the examination of U.S. Patent 6,529,316. Each reference has been reviewed to determine its relevance and potential to anticipate the independent claims of the '316 patent.

Cited References and Potential Anticipation

The following patents were cited as prior art during the prosecution of the application for U.S. Patent 6,529,316.

1. U.S. Patent No. 5,412,499: "Wavelength division multiplexing optical system"

Publication Date: May 2, 1995
Filing Date: October 29, 1993
Brief Description: This patent describes an optical amplification system for wavelength division multiplexing (WDM). It includes a mechanism for monitoring the output of the optical amplifier and controlling the gain to maintain a constant output level, aiming to flatten the gain characteristic across different wavelengths.
Potential Anticipation of Claims:
- Claim 1 & 20: This reference discloses the concept of monitoring optical signals in a WDM system and controlling aspects of an optical amplifier. While it focuses on gain flattening rather than generating specific alarms based on power levels going out of a predefined range, its disclosure of monitoring and control provides a foundation. However, it does not explicitly teach generating an "alarm" in the manner described by the '316 patent, which is a key element of claims 1 and 20.

2. U.S. Patent No. 5,504,609: "Optical fiber amplifier"

Publication Date: April 2, 1996
Filing Date: June 6, 1994
Brief Description: This patent details an optical fiber amplifier with a control circuit that monitors the output light and adjusts the pumping light source to maintain a constant output. The system is designed to provide a stable output even when the input signal level fluctuates.
Potential Anticipation of Claims:
- Claim 1 & 20: Similar to the '499 patent, this reference teaches monitoring optical power and controlling the amplifier. The focus is on automatic gain control, not on generating alarms for out-of-range conditions. The absence of an explicit alarm generation function based on predefined thresholds makes it unlikely to fully anticipate claims 1 and 20.

3. U.S. Patent No. 5,978,124: "Method and apparatus for an optical amplifier with dynamic gain equalization"

Publication Date: November 2, 1999
Filing Date: May 29, 1998
Brief Description: This invention relates to an optical amplifier that includes a dynamic gain equalization filter. The system monitors the output signal and adjusts the filter to maintain a flat gain profile across the different WDM channels.
Potential Anticipation of Claims:
- Claim 11: This patent is highly relevant to claim 11. It discloses an optical network component with a dynamic spectral filter and a control unit that monitors its operation to perform adjustments. While the primary purpose described is gain equalization, the monitoring of the filter's operational state is a key element. However, it does not explicitly mention generating an alarm when the filter operates at or near its physical limits. The anticipation would depend on whether monitoring for the purpose of control is considered equivalent to monitoring for the purpose of generating an alarm under § 102.

4. U.S. Patent No. 6,185,022: "Method and apparatus for controlling gain and noise in an optical amplifier"

Publication Date: February 6, 2001
Filing Date: October 13, 1998
Brief Description: This patent describes a method for controlling an optical amplifier by monitoring both the input and output signals to determine the gain and noise figure. This information is then used to adjust the amplifier's parameters.
Potential Anticipation of Claims:
- Claim 1 & 20: The '022 patent discloses monitoring optical channels to determine performance parameters like gain. This is a step towards the functionality described in the '316 patent. However, the claims of the '316 patent are specific about generating alarms based on these measurements, a feature not explicitly detailed in this prior art. For example, it does not describe generating alarms for loss of a band of channels or when the number of active channels falls below a threshold.

5. U.S. Patent No. 6,347,006: "Method and apparatus for a reconfigurable optical network"

Publication Date: February 12, 2002
Filing Date: June 11, 1999
Brief Description: This patent discloses a reconfigurable optical network that includes elements for monitoring the performance of optical channels. It describes using this monitored information to manage the network, including detecting failures.
Potential Anticipation of Claims:
- Claim 1 & 20: This reference comes close to the concepts in claims 1 and 20 by discussing performance monitoring for failure detection. The generation of a signal to indicate a failure could be interpreted as an "alarm." However, the '316 patent provides more specific alarm conditions (e.g., power out of range, ripple out of range) which may not be fully disclosed here.

6. U.S. Patent No. 6,437,896: "Optical amplifying apparatus"

Publication Date: August 20, 2002
Filing Date: March 8, 2001
Brief Description: This patent describes an optical amplifying apparatus with a variable-attenuation optical filter. The system monitors the optical signal and controls the filter to equalize the gain. It also mentions detecting abnormalities in the signal.
Potential Anticipation of Claims:
- Claim 1, 11, & 20: This reference is relevant to all independent claims. It describes an optical channel monitor, a dynamic spectral filter (variable-attenuation filter), and a control unit. The disclosure of detecting "abnormalities" could be construed as generating an alarm. The key question for anticipation would be whether the "abnormalities" described are equivalent to the specific alarm conditions laid out in the claims of the '316 patent, such as the filter operating at its limits or specific power ripple thresholds being exceeded.

7. U.S. Patent No. 6,525,858: "Optical amplification system for WDM transmission"

Publication Date: February 25, 2003
Filing Date: July 10, 2000
Brief Description: This patent, filed before the '316 patent but published after, describes a WDM optical amplification system that monitors the power level of each wavelength channel and controls the gain to maintain uniformity.
Potential Anticipation of Claims:
- Claim 1 & 20: As this patent was not published before the filing date of the '316 patent, it does not qualify as prior art under 35 U.S.C. § 102(a). However, its content, which is similar to other cited references, underscores the state of the art at the time, focusing on monitoring for the purpose of dynamic control rather than explicit, predefined alarm generation.

Disclaimer: This analysis is based on the provided patent documents and does not constitute a legal opinion on the validity of any claim of U.S. Patent 6,529,316. The determination of whether a claim is anticipated is a question of law that can only be decided by a court or the USPTO.