OBM-OFDM Network Device Subcarrier Allocation

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Solution Overview

Problem

Current optical communication networks face challenges in achieving terabit/second data transmission capacity due to limitations in channel data rates, spectral efficiency, and flexibility, especially in WDM systems, which are rigid and inefficient in PON access networks.

Innovation Solution

The implementation of an OBM-OFDM (Orthogonal Band Multiplexed OFDM) scheme with dynamically assignable OFDM subcarriers, using a network device that modulates and processes signals to optimize subcarrier allocation and conversion, enabling flexible capacity allocation and efficient downstream transmission in PON access networks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If uncorrelated WDM channels are used to increase channel data rate, then data transmission capacity is improved, but spectral efficiency deteriorates due to unused gaps between channels

Engineering Contradiction:
Improvechannel data rateVSAvoidspectral efficiency
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent combines multiple WDM carriers into a single OFDM signal structure, merging previously separate channels into one unified transmission medium. This eliminates the spectral gaps between individual WDM channels while maintaining high data transmission capacity, thereby improving spectral efficiency without sacrificing productivity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces dynamic subcarrier assignment where OFDM subcarriers can be flexibly allocated to different network subscribers based on demand. This dynamic allocation allows the system to adaptively optimize spectral usage while maintaining high data rates, resolving the contradiction between fixed WDM channel structures and efficient spectrum utilization.

Inventive Principle:
Principle #15Dynamics

2Productivity

If classic WDM systems are used to achieve terabit/second capacity, then data transmission capacity is improved, but device complexity increases due to rigid node assignment and multiple uncorrelated channels

Engineering Contradiction:
Improvedata transmission capacityVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent creates a universal OFDM transmission system that can serve multiple network subscribers through a single optical channel. Instead of requiring separate WDM infrastructure for each subscriber, the system provides multi-functional capability where one channel can dynamically allocate resources to multiple users, thereby reducing device complexity while maintaining terabit/second capacity.

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

Solution Approach 2:

The patent segments the available spectrum into multiple OFDM subcarriers that can be independently assigned to different network subscribers. This segmentation allows flexible resource allocation and simplifies the overall system architecture by replacing rigid WDM node assignments with flexible subcarrier allocation, reducing device complexity while preserving high data transmission capacity.

Inventive Principle:
Principle #1Segmentation

3Loss of energy

If OBM-OFDM modulation is used to improve spectral efficiency, then spectral efficiency is improved, but adaptability to different data rates and PON access networks deteriorates due to rigid point-to-point design

Engineering Contradiction:
Improvespectral efficiencyVSAvoidflexibility for different data rates and PON access
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic subcarrier assignment mechanisms that allow the OFDM system to adapt to different data rates and network configurations. Subcarriers can be flexibly allocated to different network subscribers based on their specific requirements, enabling the system to adapt to various PON access scenarios and data rate demands while maintaining high spectral efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent enables parameter changes in the OFDM system, particularly in the allocation and modulation of subcarriers. By dynamically adjusting subcarrier assignment and modulation parameters, the system can adapt to different data rates and network conditions, thereby improving versatility and adaptability while preserving the spectral efficiency benefits of OBM-OFDM modulation.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2271013B1Network device
Publication Date: 2020.02.12 DEUTSCHE TELEKOM AG
  • EP2271013B1 patent drawingFigure 1
  • EP2271013B1 patent drawingFigure 2
  • EP2271013B1 patent drawingFigure 3a~3c

AI summary

A network device, in particular an optical network device, for modulating a plurality of network subscriber signals which are assigned to different network subscribers, according to the OFDM modulation scheme (OFDM: Orthogonal Frequency Division Multiplexing), comprises an assignment device (105) for assigning a first group of subcarriers to a first network subscriber signal (101), and for assigning a second group of subcarriers to a second network subscriber signal (102), and a modulation device (107) for modulating the first network subscriber signal (101) onto the first group of subcarriers using the inverse Fourier transform to obtain a first multicarrier signal, and for modulating the second network subscriber signal (103) onto the second group of subcarriers using the inverse Fourier transform to obtain a second multicarrier signal.