Networking Feasibility of Quantum Key Distribution Constellation Networks

Area of Science:

• Quantum communication
• Satellite networking
• Graph theory applications

Background:

• Global quantum networking requires advanced satellite constellations.
• Feasibility of quantum constellations integrating satellite-to-ground access and inter-satellite routing remains under-researched.
• Existing research lacks graph-theory-based approaches for these complex networking challenges.

Purpose of the Study:

• To model and solve satellite-to-ground access selection and inter-satellite routing problems within quantum key distribution constellations.
• To introduce novel graph theory perspectives for analyzing quantum constellation network feasibility.
• To develop and present algorithms for optimizing quantum network operations.

Main Methods:

• Satellite-to-ground access selection is modeled as finding the longest paths in directed acyclic graphs.
• Inter-satellite routing is modeled as a maximum flow problem in graph theory.
• Algorithms are developed based on these graph theory models.

Main Results:

• The study provides the initial graph-theory-based understanding of quantum constellation networking problems.
• Simulation results for a low-Earth-orbit constellation indicate solar influence is the primary networking constraint.
• Periodic blocking of inter-planar links due to solar activity significantly restricts inter-continental key delivery.

Conclusions:

• The proposed graph theory models and algorithms offer a new framework for quantum constellation network design.
• Solar interference poses a significant challenge to continuous global quantum key distribution via satellite constellations.
• The developed methods are adaptable for various quantum key distribution protocols beyond the BB84 protocol used in simulations.