Optical Signal Power Levelling via Attenuation Variation Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In optical communication networks, power oscillations occur due to measurement errors in optical signal power, leading to unnecessary attenuation variations across multiple nodes, which can result in significant power fluctuations despite stable signal power at individual nodes.
Innovation Solution
A method that measures optical signal power, calculates attenuation variations, and applies new attenuation values only when persistent differences are detected, using cumulative summing and smoothing factors to differentiate between noise and actual power differences, thereby reducing oscillations without real-time node communication and without requiring additional hardware.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If nodes independently adjust attenuation based on OCM measurement readings, then each node maintains its local power level, but power oscillations accumulate across the network chain
Solution Approach 1:
The patent implements a feedback mechanism where each node monitors the optical signal power and adjusts attenuation accordingly. The control system continuously measures the actual power level and modifies the attenuation setting to maintain the target power level, creating a closed-loop control system that stabilizes power across the network chain
Solution Approach 2:
The patent changes the attenuation parameter dynamically based on measured power levels. By adjusting the attenuation coefficient according to the difference between actual and target power levels, the system adapts to measurement variations and maintains stable power delivery across multiple nodes
2Ease of operation
If nodes apply attenuation adjustments in response to measurement errors, then local power control is achieved, but cumulative power oscillations occur across the network
Solution Approach 1:
Each node autonomously monitors its own output power and adjusts its attenuation setting without requiring external intervention or coordination with other nodes. The self-service mechanism allows automatic power control while maintaining reliability by using local feedback to correct deviations before they propagate
Solution Approach 2:
The system applies preliminary attenuation adjustments based on predicted power requirements. By proactively setting attenuation levels before power deviations occur, the system prevents oscillations from developing while maintaining ease of automatic operation
3Extent of automation
If OCM measurement readings are used for attenuation control, then power leveling is automated, but measurement noise causes unnecessary attenuation variations
Solution Approach 1:
The patent applies partial attenuation adjustments by only modifying the attenuation setting when the measured power deviation exceeds a predefined threshold. This selective action filters out noise-induced variations while maintaining automated power leveling, applying corrections only when genuinely needed
Solution Approach 2:
The system implements periodic measurement and adjustment cycles with defined intervals. By sampling power levels at regular intervals and comparing changes over time, the system distinguishes between noise and actual power deviations, applying attenuation corrections only when sustained deviations are detected
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method (10) of controlling optical signal power levelling in an optical communication network node configured to apply an optical attenuation, α, to a pass-through optical signal. The method comprises: a. performing the following steps i. to iii. until an attenuation variation value, Δα, is greater than a preselected attenuation variation threshold value (18), ΔαTH: i. measuring (12) an optical signal power of an optical signal; ii. calculating (14) a difference, ΔΡ, between the measured optical signal power and a target optical signal power; iii. calculating (16) a value for the attenuation variation, Δα, to be applied to the optical attenuation taking account of ΔΡ; b. obtaining (20) a current value of the optical attenuation, an, and obtaining (22) a new optical attenuation value, αn+1, in dependence on the current value of the optical attenuation, a current value of the attenuation variation, Δαn, and at least an earlier value of the attenuation variation, Δαn-1; and c. generating (24) a control signal arranged to configure the node to apply the new optical attenuation value, αn+1 .