Dual-satellite system improves long-distance quantum entanglement links
A Dual-Uplink Dual-Satellite Architecture for Entanglement Distribution
Networking and Internet Architecture
Summary
Sending quantum signals between distant places is very hard because the signals get weaker over long distances. The authors looked at how using two satellites instead of one can help send these special quantum signals farther. They studied how the new setup reduces problems caused by Earth's atmosphere and the angle between ground stations and satellites. Their results suggest that using two satellites can make quantum communications work over much larger distances than using just one.
What this means in practice
- •For satellite network engineers: Design satellite-based quantum communication systems that overcome distance limits by linking two satellites for better entanglement distribution.
- •For telecommunications infrastructure planners: Plan long-distance quantum communication networks using dual-satellite setups to extend coverage beyond regional limits.
Authors
Charilaos C. Angelidis, Ioannis K. Marmorkos
Abstract
Satellite-based quantum links are a promising enabler of long-distance entanglement distribution, overcoming the exponential losses of optical fibers. In uplink architectures, entangled photons are generated at ground stations and transmitted to orbiting satellites, reducing space-segment complexity but introducing significant atmospheric and geometric losses. Single-satellite dual-uplink configurations are additionally limited by the requirement of simultaneous visibility between both ground stations and the satellite. In this work, we investigate a dual-uplink dual-satellite network architecture and compare its performance with the single-satellite scheme under identical physical assumptions. The proposed topology introduces an inter-satellite link (ISL) that decouples the ground-station separation from the atmospheric uplink geometry. A realistic channel model is employed, incorporating geometric attenuation, atmospheric turbulence, background noise, and Bell-state measurement efficiency. The overall success probability and practical fidelity are evaluated as functions of satellite altitude and ground-station separation. Our results show that while the single-satellite configuration is suitable for regional-scale networks, it becomes infeasible for large separations due to geometric constraints. The proposed dual-satellite architecture mitigates this limitation and significantly extends the achievable communication distance, representing a key step toward scalable quantum internet infrastructures.