Optical Network Subcarrier Modulation for Flexible Bandwidth Allocation

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Solution Overview

Problem

Conventional passive optical networks (PONs) face inefficiencies due to latency and high costs from requiring all subscribers to have ONUs capable of handling high data rates, despite only a small portion needing such capabilities, leading to resource wastage and degraded network throughput.

Innovation Solution

The method involves providing a main wavelength for subcarrier modulation, suppressing a portion of the subcarrier modulated signal, and assigning subcarriers to each ONU for point-to-point connections, enabling coherent detection and individual data rates, which allows for flexible and cost-effective data transmission by utilizing optical and/or electrical subcarriers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If all subscribers are equipped with ONUs capable of processing high data rates (e.g., 10 Gb/s), then high data rate capability is provided to all subscribers, but this results in very cost-ineffective resource allocation and waste since only a small portion of subscribers actually receive such high data rates

Engineering Contradiction:

Improvedata rate capabilityVSAvoidcost effectiveness

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The invention segments the optical network into point-to-point connections between the OLT and each ONU, allowing individual data rate allocation for each connection. This enables subscribers to receive only the data rate they actually need, eliminating the waste of equipping all ONUs with high data rate capabilities when only a small portion of subscribers require such rates.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements local quality by assigning different data rates to different point-to-point connections based on individual subscriber needs. Each ONU receives a data rate tailored to its specific requirements rather than uniformly providing high data rates to all, thereby achieving cost-effective resource allocation while maintaining adaptability where needed.

Inventive Principle:

Principle #3Local quality

2Ease of operation

If conventional PONs use broadcast distribution for downstream traffic and TDMA for upstream signals, then network coverage is provided, but this results in latency and degraded network throughput due to electronic processing such as buffering and scheduling at the OLT

Engineering Contradiction:

Improvenetwork coverageVSAvoidnetwork throughput

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The invention replaces the conventional broadcast distribution mechanism with point-to-point optical connections. This substitution eliminates the need for electronic buffering and scheduling at the OLT, thereby removing the source of latency while maintaining network coverage. The optical domain processing replaces electronic processing, improving network throughput.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If the overall bandwidth is divided into orthogonal sub-carriers with each ONU allocated one sub-channel, then bandwidth allocation is achieved, but this requires complex OFDMA processing and coordination

Engineering Contradiction:

Improvebandwidth allocationVSAvoidprocessing complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the bandwidth allocation function from complex OFDMA processing by implementing simple point-to-point optical connections with individual data rates. This removes the need for orthogonal sub-carrier coordination and FFT-based OFDMA processing, significantly reducing device complexity while maintaining flexible bandwidth allocation through direct optical routing.

Inventive Principle:

Principle #2Taking out (Extraction)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach efficiently allocates bandwidth, reduces costs by eliminating the need for expensive components, and provides flexible data rates tailored to individual subscriber demands without the need for active components or complex management systems, enhancing network performance and scalability.

Implementation Method 1

processing subcarrier modulation for the at least one main wavelength, wherein a portion of the obtained subcarrier modulated signal is suppressed

Methodology Applied

Scientific EffectSubcarrier modulation: Phase Modulation

Implementation Method 2

applying coherent detection of the signals received at the optical line terminal and/or the plurality of optical network units

Methodology Applied

Scientific EffectCoherent detection: Homodyne Detection

Implementation Method 3

wherein the method further comprises at least one of optically or electronically providing subcarriers for the subcarrier modulation

Methodology Applied

Scientific EffectOptical filtering: Filter (optical)

Data Source

PatentEP2314003B1Method for data processing in an optical network, optical network component and communication system

Publication Date: 2018.09.12 XIEON NETWORKS SARL

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AI summary

A method for data processing in an optical network is provided comprising the steps of (a) providing at least one main wavelength; and (b) processing a subcarrier modulation for said at least one main wavelength, wherein a portion of the subcarrier modulated signal is suppressed. Furthermore, an optical network component and a communication system comprising such optical network component are suggested.