Optical Transceiver FEC Mapping via 8B10B Byte Allocation
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Solution Overview
Problem
Current optical transceivers face challenges in implementing Forward Error Correction (FEC) techniques without degrading transmission speed or altering bandwidth, particularly in long-haul optical communication systems using 8B10B codes, where signal loss and errors are prevalent due to the use of optical fibers and numerous connectors.
Innovation Solution
An optical transceiver configuration that includes a demultiplexer, decoder, data mapper, FEC encoding unit, framer, and multiplexer to process 8B10B signals by separating them into parallel signals, decoding, securing extra memory capacity, and mapping FEC data onto this capacity, while maintaining transmission speed and bandwidth through GFP-T framing, thereby enabling efficient FEC without degrading performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Forward Error Correction (FEC) is implemented in optical transceivers, then signal reliability is improved, but transmission speed is degraded
Solution Approach 1:
The patent applies GFP-T transparent mapping to transform the FEC implementation from a time-domain processing approach to a spatial-domain mapping approach. By mapping FEC overhead bytes into specific positions within the 8B10B code blocks without disrupting the original transmission timing, the system achieves error correction capability while preserving the original transmission speed. The FEC data is embedded in the fourth through eighth bytes of each 8B10B block, creating a parallel error correction channel that does not interfere with the main data stream velocity.
Solution Approach 2:
The patent introduces GFP-T transparent mapping as an intermediary layer between the 8B10B encoded data and FEC processing. This intermediary mechanism allows FEC overhead to be inserted and processed without requiring停顿 or speed reduction in the main transmission stream. The mapping function acts as a bridge that integrates error correction capabilities while maintaining the original transmission timing and speed characteristics.
2Reliability
If Forward Error Correction (FEC) is implemented in optical transceivers, then signal reliability is improved, but bandwidth is altered
Solution Approach 1:
The patent applies local quality by inserting FEC overhead bytes into specific local positions within the 8B10B code structure (bytes 4-8 of each block) rather than adding them globally to the transmission stream. This localized insertion method allows FEC functionality to be embedded within existing bandwidth allocations without requiring additional spectral resources. The FEC data occupies specific byte positions that are already part of the standard 8B10B block structure, thus maintaining original bandwidth characteristics.
Solution Approach 2:
The patent makes the 8B10B code blocks multi-functional by enabling them to simultaneously carry both data information and FEC overhead. The same code block structure that transmits data also embeds error correction information in specific byte positions, eliminating the need for separate dedicated bandwidth for FEC. This universal usage of existing code block structures allows error correction without additional bandwidth consumption.
3Productivity
If 8B10B code is used for transmission, then data communication capability is improved, but transmission error probability is increased due to optical fiber loss and connectors
Solution Approach 1:
The patent applies preliminary action by pre-calculating and pre-positioning FEC overhead bytes into the 8B10B code blocks before transmission. The FEC data is prepared in advance and mapped into the fourth through eighth bytes of each code block, creating a pre-configured error correction mechanism that is already in place before the data encounters transmission losses. This proactive error correction preparation allows the system to combat optical fiber loss and connector-induced errors without disrupting the data communication flow.
Data Source
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AI summary
Disclosed is an optical transceiver. The optical transceiver includes a decoder for decoding an 8B10B line-coded signal, a data mapper for separating the decoded signal into block units and securing extra memory capacity by mapping a data code and a block information code onto each of the separated blocks, and an FEC encoding unit for creating a Forward Error Correction (FEC) data and mapping the FEC data onto the extra memory capacity.