Dynamic ONU Transfer Between PONs in Shared ODN

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Solution Overview

Problem

The existing Multiple Wavelength (MW) Passive Optical Network (PON) systems lack flexibility due to fixed connections between Optical Line Terminals (OLTs) and Optical Network Units (ONUs), limiting architectural changes and network optimization.

Innovation Solution

A method is introduced to dynamically transfer ONUs between PONs by sending identifier and wavelength information messages between source and target PONs, allowing for flexible network reconfiguration based on load balancing and grouping policies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If multiple PONs share an ODN to lower deployment cost, then cost efficiency is improved, but architectural flexibility deteriorates due to fixed connections between OLTs and ONUs

Engineering Contradiction:
Improvedeployment costVSAvoidarchitectural flexibility
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic ONU transfer between PONs by enabling ONUs to tune their wavelengths and switch between different PONs. The OLTs exchange transfer messages to coordinate wavelength allocation and enable flexible reconfiguration of the network topology, transforming the static architecture into a dynamic one that can adapt to changing network conditions while maintaining cost efficiency through shared ODN infrastructure

Inventive Principle:
Principle #15Dynamics

2Stability of the object's composition

If ONUs are fixed to specific PONs, then network stability is improved, but load balancing capability deteriorates

Engineering Contradiction:
Improvenetwork stabilityVSAvoidload balancing capability
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The system maintains stability through controlled dynamic adjustments. ONUs can transfer between PONs based on load conditions, and the OLTs coordinate these transfers through standardized message exchanges. This dynamic capability allows the network to balance load across PONs while maintaining stable connections during normal operation, resolving the contradiction between stability and load balancing

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the wavelength parameter of ONUs to enable transfer between PONs. By tuning the ONU's operating wavelength to match the target PON's wavelength, the ONU can switch networks dynamically. This parameter-based approach allows flexible load distribution while maintaining stable connections through controlled wavelength switching

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2891261B1Method of supporting transfer of optical network unit between passive optical networks
Publication Date: 2017.10.04 ALCATEL LUCENT SA
  • EP2891261B1 patent drawingFigure 1
  • EP2891261B1 patent drawingFigure 2
  • EP2891261B1 patent drawingFigure 3~5

AI summary

The invention relates to a method of supporting a transfer of an Optical Network Unit (ONU) between a plurality of Passive Optical Networks (PON). Particularly the invention proposes a method of supporting a transfer of a first ONU in a source PON to a target PON, wherein the source PON and the target PON share an Optical Distribution Network (ODN), and the method includes the steps of: sending a first transfer message to a target Optical Line Terminal (OLT) corresponding to the target PON, the first transfer message including first identifier information of the first ONU; and sending a second transfer message to a source OLT corresponding to the source PON, the second transfer message including second identifier information of the first ONU and wavelength information of the target PON. With the solution of the invention, an ONU can be transferred from a source PON where it is located to a target PON in a Multiple Wavelength-Passive Optical Network (MW-PON) to thereby change dynamically the architecture of the optical network System and improve the flexibility thereof. Moreover the dynamic transfer of the ONU between the plurality of PONs can facilitate an improved utilization of bandwidths and energy.