Optical Transmission Device Subcarrier Allocation
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Solution Overview
Problem
The DMT modulation scheme in optical transmission systems faces challenges with subcarriers experiencing deteriorated OSNR, leading to reduced transmission capacity and system activation issues due to power fading and dispersion, making it difficult to allocate the link communication channel effectively.
Innovation Solution
An optical transmission device that allocates the link communication channel to a subcarrier with the bare minimum transmission characteristics based on responses from another device, using a controller to select and negotiate the optimal subcarrier, thereby avoiding dips in transmission characteristics and ensuring reliable system activation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the LCC is allocated to a subcarrier with very good transmission characteristics, then the system activation is reliable, but the transmission capacity is reduced
Solution Approach 1:
The invention changes the selection criterion for LCC allocation from 'best transmission characteristics' to 'bare minimum transmission characteristics'. This parameter change allows the system to use subcarriers with moderate quality for control signals, preserving high-quality subcarriers for data transmission, thus resolving the contradiction between activation reliability and transmission capacity.
2Productivity
If the LCC is allocated to a subcarrier with deteriorated OSNR, then the transmission capacity is maximized, but the LCC establishment fails
Solution Approach 1:
The invention establishes a minimum OSNR threshold parameter for LCC allocation. By changing the selection criterion from 'any subcarrier' to 'subcarrier meeting minimum OSNR requirement', the system ensures reliable LCC establishment while still allowing flexible allocation among acceptable subcarriers, thus resolving the contradiction between transmission capacity and LCC establishment reliability.
3Device complexity
If the LCC is allocated to a subcarrier with dip in transmission characteristics, then the device complexity is reduced, but the OSNR is significantly reduced
Solution Approach 1:
The invention introduces a minimum transmission characteristic threshold as a selection parameter for LCC allocation. This parameter change simplifies the allocation process by providing clear selection criteria (choose any subcarrier meeting the threshold), reducing device complexity while preventing selection of subcarriers with severe dips that would significantly reduce OSNR.
Data Source
AI summary
An optical transmission device includes: an optical transmitter that transmits, at a time of system activation, a control signal to another optical transmission device by using a plurality of subcarriers; and a controller that allocates a link communication channel (LCC) to a subcarrier, among the plurality of subcarriers, for which bare minimum transmission characteristic is obtained, based on a response to the control signal from the other optical transmission device.