Code Block Mapping to OPU Signals for OTN Bandwidth

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Solution Overview

Problem

The existing GFP mapping method in optical transport networks (OTN) faces increased implementation complexity and reduced bandwidth utilization as data rates rise, due to byte-granularity mapping, variable frame lengths, and the need for frequent identification of frame headers, especially when processing high-rate and large-bit-width packet services.

Innovation Solution

A data processing method that involves obtaining a code block stream, performing rate adaptation by inserting or deleting idle code blocks, and mapping the adapted stream to an optical channel payload unit (OPU) signal, ensuring a preset number of code blocks per frame period and using a fixed mapping pattern to optimize bandwidth utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If GFP mapping is used for packet service transmission in OTN, then the packet service can be encapsulated and transmitted, but the implementation complexity increases greatly at high rates due to byte-granularity mapping

Engineering Contradiction:
Improvepacket service transmission capabilityVSAvoidmapping processing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the packet service data stream into fixed-length code blocks (e.g., 64B/66B coded blocks) before mapping to OPU. This code block segmentation replaces the traditional byte-granularity GFP mapping approach, enabling fixed granularities that simplify processing at high rates while maintaining packet service transmission capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the mapping granularity parameter from byte-level (GFP) to code block-level (e.g., 64B/66B blocks). This parameter change fundamentally alters the mapping structure, reducing processing complexity by using fixed-size units that are more suitable for high-rate operations in OTN networks.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If GFP mapping is used for packet service transmission, then packet encapsulation is achieved, but bandwidth utilization is lowered due to added headers and FCS

Engineering Contradiction:
Improvepacket service encapsulationVSAvoidbandwidth utilization
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent extracts and eliminates the redundant GFP-specific overhead elements (GFP frame headers, FCS fields) by directly mapping code blocks to OPU payload. This extraction removes unnecessary bandwidth consumption while preserving the essential packet service encapsulation function through the OPU overhead structure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent utilizes the OPU overhead structure to serve multiple functions simultaneously: it provides packet service identification, rate adaptation information, and mapping control all within the existing OTN overhead framework. This multi-functionality eliminates the need for separate GFP-specific overhead elements, improving bandwidth utilization.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If variable length GFP frames are used, then packet service flexibility is maintained, but the position identification of frame headers becomes more frequent and complex

Engineering Contradiction:
Improvepacket service flexibilityVSAvoidframe header identification complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the data stream into fixed-length code blocks with standardized structures (including synchronization patterns and type fields). This segmentation provides inherent position identification capabilities, eliminating the need for frequent frame header searches while maintaining the flexibility to carry variable-length packet services through the code block sequence.

Inventive Principle:
Principle #1Segmentation

4Adaptability or versatility

If different processing is applied to data in each clock cycle during GFP mapping, then variable rate adaptation is achieved, but processing complexity increases

Engineering Contradiction:
Improvevariable rate adaptationVSAvoidclock cycle processing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent changes the processing approach by using fixed granularities (code blocks) that can be consistently processed at each clock cycle. Rate adaptation is achieved through parameter changes in the code block structure (e.g., adding idle code blocks or adjusting code block types) rather than varying the processing complexity for each clock cycle, simplifying the overall processing architecture.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3297196B1Data processing method, communication device and communication system
Publication Date: 2020.06.03 HUAWEI TECH CO LTD
  • EP3297196B1 patent drawingFigure 1~2
  • EP3297196B1 patent drawingFigure 3~5
  • EP3297196B1 patent drawingFigure 6~7

AI summary

For a data processing method, a communications device, and a communications system that are provided in embodiments of the present invention, in a process of transmitting a packet service, a code block stream that carries the packet service is first obtained; then, rate adaptation is performed on the obtained code block stream; and finally, the rate-adapted code block stream is mapped to an optical channel payload unit OPU signal. Compared with a conventional mapping manner in which a GFP is used, the data processing method, the communications device, and the communications system that are provided in the embodiments of the present invention feature low processing complexity and/or high bandwidth utilization.