Satellite Optical Inter-Satellite Link for Gateway Reduction

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Solution Overview

Problem

Current broadband satellite telecommunications systems with multi-beam coverage and frequency reuse face challenges in reducing the number of gateway station sites and increasing bandwidth, leading to high costs and site selection difficulties due to frequency interference and geographical constraints.

Innovation Solution

The system employs a main satellite and companion satellites in geostationary orbit, utilizing inter-satellite infrared optical links and multibeam antennas to reduce the number of gateway stations by at least half, while increasing bandwidth through wavelength division multiplexing and demultiplexing of optical carriers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number of gateway stations is increased to serve more user cells, then the coverage and capacity of the satellite system is improved, but the cost of acquisition and operation becomes very high and site selection becomes difficult

Engineering Contradiction:

Improvesystem capacityVSAvoidnumber of gateway stations

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent merges multiple gateway stations into a single shared gateway station by introducing a gateway station pool concept. Multiple user cells are grouped into a gateway cell group that shares a common gateway station, thereby reducing the total number of gateway stations required while maintaining system capacity through efficient resource sharing and pooling.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The gateway station is designed with multi-functionality to serve multiple user cells simultaneously. The shared gateway station can handle communications for entire gateway cell groups, making it a universal node that performs multiple functions previously requiring separate dedicated gateway stations.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Productivity

If frequency bands are reused between distant gateway stations to increase capacity, then bandwidth is improved, but radiofrequency isolation requirements create minimum distance constraints that complicate site selection

Engineering Contradiction:

ImprovebandwidthVSAvoidsite selection flexibility

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

By merging multiple gateway stations into a shared gateway station serving a gateway cell group, the patent eliminates the need for spatial separation between gateway stations. This allows frequency bands to be reused more freely since the single shared gateway station can manage frequency allocation across the entire group, thereby improving bandwidth while enhancing site selection flexibility.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The shared gateway station acts as an intermediary that manages frequency band allocation and reuse across multiple user cells. It coordinates frequency usage within the gateway cell group, enabling efficient frequency reuse without requiring strict spatial separation, thus resolving the contradiction between bandwidth and site selection flexibility.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If gateway stations are spaced hundreds of kilometers apart to ensure radiofrequency isolation, then frequency interference is reduced, but the number of sites required increases and operational costs increase

Engineering Contradiction:

Improvefrequency isolationVSAvoidnumber of gateway station sites

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent combines multiple geographically distributed gateway stations into a single shared gateway station that serves a gateway cell group. This merging approach maintains frequency isolation reliability through centralized coordination while reducing the number of physical sites required, thereby lowering operational costs and simplifying infrastructure deployment.

Inventive Principle:

Principle #5Merging (Combining)

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 configuration significantly reduces the number of gateway station sites and cells, allowing for increased bandwidth and improved frequency reuse without interference, while optimizing site placement for favorable climatic zones and reducing operational costs.

Implementation Method 1

an inter-satellite link in an infrared optical domain between the satellites

Methodology Applied

Scientific EffectInfrared optical link: Infrared Radiation

Implementation Method 2

with a wavelength division multiplexing and a demultiplexing of the optical carriers

Methodology Applied

Scientific EffectWavelength division multiplexing: Diffraction

Data Source

PatentEP2723001B1High capacity satellite telecommunication system with multibeam coverage and frequency reusing.

Publication Date: 2015.06.24 THALES SA

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AI summary

The system has a main satellite (10) comprising a going intersatellite optical repeater including a wavelength demultiplexer to separate optical carriers transmitted by a bi-directional intersatellite link (13) and optical-electrical demodulators to demodulate optical signals from the link and to restore radio frequency signals. The main satellite includes a return intersatellite optical repeater with electro-optical modulators to modulate the carriers through radiofrequency signals from the cells and a wave length multiplexer to group the carriers to be emitted to a companion satellite (11).