PON ONU Power Saving Synchronization Control

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Solution Overview

Problem

In PON systems, when an ONU does not transmit data for a fixed time, the link is disconnected, leading to increased load on the OLT and requiring re-discovery and re-registration processes, which are inefficient, especially for low-bit-rate communications.

Innovation Solution

A communication method where the ONU remains in a deregistered state until re-registered, monitors synchronization signals, and intermittently enters a power-saving mode by reducing power to transmitters or receivers while maintaining communication links, suppressing shifts to a deregistered state due to synchronization errors after a pause duration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the ONU enters a power saving state to reduce power consumption, then power consumption is reduced, but synchronization may be lost requiring re-registration

Engineering Contradiction:
Improvepower consumptionVSAvoidsynchronization
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The ONU performs preliminary actions by storing synchronization information before entering power saving mode and sets a suppression timer to prevent immediate re-registration upon waking. This preliminary preparation allows the ONU to quickly recover without losing its registered state, resolving the contradiction between power saving and synchronization reliability.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If the link is disconnected when no data is transmitted, then load on OLT is reduced, but re-discovery and re-registration processes increase delay

Engineering Contradiction:
Improvecommunication efficiencyVSAvoidre-registration delay
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The system dynamically adjusts the ONU's state based on traffic conditions. During idle periods, the ONU enters power saving mode rather than being fully disconnected, maintaining its registered state. When traffic resumes, the ONU can quickly reactivate without re-registration delay, thus improving communication efficiency while minimizing time loss.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If the ONU monitors synchronization continuously, then synchronization accuracy is maintained, but power consumption increases

Engineering Contradiction:
Improvesynchronization accuracyVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The ONU performs periodic synchronization monitoring at intervals rather than continuously. During power saving mode, monitoring is suspended and a suppression timer prevents frequent re-registration. This periodic approach maintains adequate synchronization accuracy while significantly reducing power consumption compared to continuous monitoring.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP2615800B1Communications method for optical communications system, optical communications system, secondary station device, control device and program
Publication Date: 2016.03.30 MITSUBISHI ELECTRIC CORP
  • EP2615800B1 patent drawingFigure 1
  • EP2615800B1 patent drawingFigure 2
  • EP2615800B1 patent drawingFigure 3

AI summary

A control device of a communication system according to the present invention relates to a control device of a communication system that connects a plurality of slave station apparatuses to a master station apparatus using a common line. The control device includes a power-saving control unit 11d that intermittently repeats, based on a power saving permission signal transmitted from the master station apparatus, power saving control in which the slave station stops or reduces power supply to a transmitter or a receiver for a predetermined pause duration while maintaining a communication link and a monitoring unit 11c that monitors out of synchronization by comparing a synchronization signal included in a bandwidth allocation signal and a time of the own apparatus. The control device shifts from a registered state to a deregistered state and stops transmission by the transmitter when the monitoring unit 11c detects the out of synchronization. On the other hand, after the pause duration of the power saving control, the control device suppresses the shift to the deregistered state due to the detection of the out of synchronization.