Optical Wake-Up Signal Filtering for PON Energy Efficiency

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Solution Overview

Problem

Passive optical networks face high energy consumption due to the need for continuous data signal distribution to all receivers, even when only a few are actively using the connection, leading to inefficiencies and increased operational costs.

Innovation Solution

A method using optically coded wake-up signals that are passively decoded by wake-up units with filter units, eliminating the need for external energy and allowing only intended receivers to switch from sleep mode, utilizing light-sensitive sensors like photovoltaic cells to generate wake-up commands from the optical signal intensity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If data signals are continuously distributed to all receivers in passive optical networks, then network functionality is maintained for all users, but energy consumption increases significantly

Engineering Contradiction:
Improvenetwork functionalityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic wake-up signals that are sent at specific intervals to activate receivers only when needed. Instead of continuous signal distribution, the system uses periodic activation cycles where receivers switch between sleep and active states based on the presence of wake-up signals, thereby reducing energy consumption while maintaining network functionality.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent employs passive optical wake-up signals that utilize the existing optical infrastructure without requiring additional active components at the receiver end. The receivers self-manage their power states by detecting optical wake-up signals and autonomously switching between sleep and active modes, eliminating the need for external power management infrastructure.

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If all receivers are activated to receive data signals, then any receiver can access the network, but most receivers consume energy unnecessarily during idle periods

Engineering Contradiction:
Improvenetwork access availabilityVSAvoidstandby energy loss
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent segments the receiver population into active and sleep states, allowing selective activation based on individual needs. Instead of treating all receivers uniformly, the system divides them into functional groups that can be independently managed, enabling energy-efficient operation while maintaining access availability for those who need it.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the operational parameters of receivers dynamically by switching between different power states (sleep and active modes) based on network activity requirements. This parameter change allows the system to adapt energy consumption levels to actual usage patterns, reducing standby losses while preserving access capability.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If optical wake-up signals are sent to all monitoring units, then any unit can be activated, but all units must wake up and process signals even when not intended for them

Engineering Contradiction:
Improvereceiver activation flexibilityVSAvoidsignal processing efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent extracts and processes wake-up signals at passive optical network termination (PON LT) equipment before distribution to receivers. By performing preliminary signal processing and identification at the central equipment, the system removes the burden of universal signal processing from individual receivers, allowing them to remain in low-power states while maintaining activation flexibility.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces PON LT equipment as an intermediary that mediates between the optical wake-up signals and the receivers. This intermediary component performs signal processing, filtering, and identification functions, allowing receivers to simply detect the presence of wake-up signals without needing to process or evaluate them, thereby improving overall system efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Significantly reduces energy requirements by allowing most receivers to remain in sleep mode unless explicitly addressed, minimizing standby costs and maintaining network functionality without IT processing of wake-up signals.

Implementation Method 1

In the simplest case, the light-sensitive sensor can be a photovoltaic cell that does not require any additional external energy. As soon as light of a certain intensity hits the photovoltaic cell, a current is output or a voltage is generated.

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Data Source

PatentEP2717592B1Method for operating an optical network
Publication Date: 2016.04.06 DEUTSCHE TELEKOM AG
  • EP2717592B1 patent drawingFigure 1a~1b
  • EP2717592B1 patent drawingFigure 2
  • EP2717592B1 patent drawingFigure 3

AI summary

The method involves triggering a data receiver (11) by a data receiver-specific waking-up signal (15) i.e. optical signal, such that the data receiver is changed from sleeping mode to a receiving mode. The signal is received by a waking-up arrangement. A modified optical waking-up signal is provided by a filter unit of the arrangement and detected by a light-sensitive sensor of the arrangement when the receiver is not in the receiving mode. Electrical or electronic waking-up command (17) is provided to the receiver by the arrangement for changing the receiver to the receiving mode.