Free Space Optical Network Pilot Channel for Rapid Link Reconfiguration

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Solution Overview

Problem

Free space optical communications networks with bent pipe architecture face significant latency and data loss during reconfiguration due to the time-consuming process of re-establishing optical links, especially when outages occur, which can take minutes and require buffering large amounts of data.

Innovation Solution

Implementing a pilot channel within the network for continuous line-of-sight maintenance and rapid reconfiguration by using a pilot-in signal to control optical apertures and re-amplify signals, allowing for automatic switching to a new optical link without the need for spatial reacquisition, thereby reducing latency and data loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a new optical link is re-established after an outage, then the network can resume data transmission, but the spatial and signal acquisition process takes minutes causing data loss and latency

Engineering Contradiction:
Improvenetwork continuityVSAvoidreconfiguration time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements a preliminary action by establishing a dedicated pilot channel that continuously maintains spatial and signal acquisition before actual data transmission is needed. The pilot channel performs acquisition and tracking operations in advance, so when an outage occurs and reconfiguration is needed, the spatial acquisition is already complete and only signal re-establishment is required, reducing reconfiguration time from minutes to seconds

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary element - the pilot channel - that serves as a mediator between the transmitter and receiver for maintaining spatial and signal acquisition. This separate pilot channel continuously transmits pilot signals that enable the receiver to track and maintain acquisition state without requiring full data transmission, allowing rapid reconfiguration when outages occur

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If spatial and signal acquisition is performed to re-establish an optical link, then connectivity is restored, but large amounts of data must be buffered during the minutes-long process

Engineering Contradiction:
Improvelink connectivityVSAvoiddata buffering requirement
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pilot channel performs spatial and signal acquisition in advance before data transmission is interrupted. By maintaining continuous acquisition state through the dedicated pilot channel, the system eliminates the need for extensive data buffering during reconfiguration, as the acquisition process is already complete when reconfiguration is triggered

Inventive Principle:
Principle #10Preliminary action

3Loss of time

If the pilot channel is used for continuous acquisition and tracking, then rapid reconfiguration is enabled, but additional hardware and signal processing are required

Engineering Contradiction:
Improvereconfiguration timeVSAvoidhardware additions
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent applies multi-functionality by designing the pilot channel to serve multiple purposes: it enables continuous spatial acquisition, maintains signal tracking, provides reference for rapid reconfiguration, and supports network management functions. This universal approach allows a single dedicated channel to handle multiple critical functions that would otherwise require separate systems

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

Solution Approach 2:

The system implements partial action by dedicating only a portion of the optical capacity to the pilot channel for acquisition and tracking functions, while the remaining capacity handles data transmission. This partial allocation of resources enables rapid reconfiguration capabilities without requiring complete system redundancy or excessive hardware additions

Inventive Principle:
Principle #16Partial or excessive action

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

The solution enables rapid reconfiguration of the network with minimal data buffering, reducing latency and the risk of data loss, while maintaining continuous line-of-sight connectivity and utilizing existing optical links with minimal hardware additions.

Implementation Method 1

using the pilot-in signal to control the first optical aperture for pointing, acquisition and tracking to continuously maintain optical line of sight with the near companion node

Methodology Applied
Scientific EffectOptical line of sight maintenance: Light

Implementation Method 2

optically re-amplifying the bent pipe-in signal, and sending the re-amplified signal to the far companion node via the second optical link

Methodology Applied
Scientific EffectOptical signal transmission: Light

Data Source

PatentEP3110038B1Free space optical communications network with bent pipe channel and pilot channel
Publication Date: 2020.06.03 THE BOEING CO
  • EP3110038B1 patent drawingFigure 1
  • EP3110038B1 patent drawingFigure 2
  • EP3110038B1 patent drawingFigure 3

AI summary

A method for a plurality of nodes in a free space optical communications network comprises using a bent pipe channel to relay data between at least some of the nodes of the network; and using a pilot channel for pointing, acquisition and tracking to continuously maintain line-of-sight between all of the nodes even when the bent pipe channel is not active.