Optical Cross-Connect Device Error Detection via Signal Parameter Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In optical transmission systems, erroneous connections in WSSs can lead to undetectable mismatches in optical signal power and frame formats, preventing the identification of the transmission source and occurrence of the error.
Innovation Solution
An optical cross-connect apparatus with a monitoring control unit, relay-side optical input/output unit, DSP, and framer unit that changes modulation and frame modes to detect and correct signal mismatches, allowing identification of the transmission source through a management table.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a trace signal is transmitted to detect erroneous connection, then the transmission source can be identified, but when modulation methods or frame formats do not match, the error can only be detected as LOS or LOF and the transmission source cannot be specified
Solution Approach 1:
The patent applies preliminary action by proactively changing the modulation mode and frame mode before trace signal detection. The monitoring control unit sequentially changes these parameters according to a management table, ensuring that the trace signal can be properly received and the transmission source can be identified even when initial parameters do not match. This prevents the loss of transmission source information that would occur with conventional LOS/LOF detection only.
Solution Approach 2:
The patent directly applies parameter changes by systematically varying modulation modes (e.g., QPSK, 16QAM, 64QAM) and frame modes (e.g., OTU2, OTU3, OTU4) to match the incoming optical signal. The monitoring control unit references a management table to determine appropriate parameter combinations, enabling accurate trace signal detection and transmission source identification regardless of the original signal's parameters.
2Adaptability or versatility
If multiple modulation methods and frame methods are supported by the same DSP or framer, then network flexibility is improved, but erroneous connections become harder to detect because mismatches result in generic LOS or LOF errors
Solution Approach 1:
The patent applies feedback by using the trace signal as a unique identifier that provides information about the transmission source. When an optical signal is received, the system attempts to detect the trace signal after parameter adjustments. If successful, the TTI byte in the trace signal provides feedback about which transmission source sent the signal, enabling precise erroneous connection detection despite supporting multiple modulation and frame methods.
Solution Approach 2:
The patent uses the trace signal as an intermediary that carries transmission source information through the optical network. Even when modulation methods or frame formats differ, the trace signal embedded in the optical signal serves as a mediator that allows the receiving end to identify the transmission source, thereby enabling erroneous connection detection while maintaining network flexibility.
3Productivity
If optical signal power levels mismatch due to different modulation methods, then signal transmission continues, but LOS error occurs and necessary information cannot be acquired
Solution Approach 1:
The patent applies dynamics by making the modulation mode and frame mode adjustable rather than fixed. The monitoring control unit dynamically changes these parameters based on the received optical signal characteristics and the management table, allowing the system to adapt to different signal power levels and formats while maintaining the ability to detect and identify transmission sources through trace signal analysis.
Data Source
AI summary
A monitoring control unit (22) of an OXC (20d) stores a management table (22a) in which pieces of information regarding a modulation mode, an FEC, and a frame mode of an optical signal are associated with each other, and sequentially changes the modulation mode, the FEC, and the frame mode according to the management table (22a) upon an LOS alert from a relay-side optical input/output unit (24) or an LOF alert from a DSP (25) being input thereto. Upon successfully receiving an appropriate optical signal according to the change, the monitoring control unit (22) acquires transmission source information included in the optical signal, and detects an occurrence of erroneous connection of an optical transmission line in an OXC (20g), which serves as a relay apparatus, when the acquired transmission source information indicates an optical cross-connect apparatus that is a transmission source different from an original transmission source.