Quantum Internet in the Sky Using Satellites, UAVs, and FSO
The Quantum Internet in the Sky envisions ubiquitous communication using UAVs and satellites.
Quantum Internet in the Sky
Researchers are exploring the possibility of a “Internet in the Sky” since a global internet requires communication links that transcend terrestrial infrastructure. Satellites and UAVs provide safe, long-distance quantum communications using free-space optical (FSO) channels in this global-scale hypothetical network. This method overcomes terrestrial fibre optics' distance limits, which produce exponential loss for quantum transmissions.
Phuc V. Trinh and Shinya Sugiura of the University of Tokyo are leading this ubiquitous connection research. Their effort involves installing quantum communication terminals on non-terrestrial platforms and solving intrinsic difficulties through system designs and analysis. The study provides a big step towards global connectivity by integrating enhanced communication with compute and AI to support many users.
Multi-Layer Quantum Network Design
The intended “Quantum Internet in the Sky” envisions a multi-layered airborne platform network. This design distributes quantum information like entangled photons across an enhanced three-dimensional mesh network to overcome the disadvantages of ground-based quantum communication.
Multiple layers make up the architecture:
Ground Layer: This layer includes terrestrial free-space links and classical fibre networks for connecting metropolitan quantum nodes.
Low-altitude platform stations (LAPS) are the UAV layer. Drones below five km provide a movable, adaptive infrastructure. They aid on-demand local and regional connectivity, especially “last-mile” key exchange in urban or catastrophe situations.
High-Altitude Platform Stations (HAPS): These stratospheric platforms give significant regional coverage at 20 km. HAPS are vital relay nodes that stabilise communication since they fly above most atmospheric disturbance.
Satellite Layer: Low Earth Orbit (LEO) satellites 500–2,000 kilometres above the ground form the world's backbone. QKD and transcontinental entanglement distribution over thousands of kilometres are conceivable due to space's near-vacuum, which greatly reduces signal loss.
Free-Space Optics Aids Quantum Security
This aerial network aims to provide quantum keys and entanglement to faraway nodes. Free-Space Optics (FSO) sends quantum information into space using direct line-of-sight communications and laser beams.
QKD, which provides information-theoretically secure communication, is the most urgent use case. QKD immediately alerts the chatting parties to any eavesdropper attempt to measure the quantum state. Satellites and unmanned aerial vehicles can also transmit entangled photon pairs. This allows Entanglement Swapping, which creates “virtual” entangled connections between nodes without physical links, for long-distance quantum teleportation and distributed quantum computing.
Technical Solutions for Airborne Communication Issues Quantum links employing airborne platforms are complicated by platform movement, atmospheric turbulence, and signal attenuation. Researchers have designed and tested rigorous system designs to solve these issues.
A minimal transmission divergence of 33 microrad achieves fidelity above 80% even during the day, according to studies. To maintain high performance, researchers recommend a beam-divergence control system that dynamically adjusts beam size to balance fidelity and connection availability.
Ground stations use aperture-averaging effects to mitigate turbulence-induced signal fluctuations with 0.4–1.5-meter telescope apertures.
Analysis showed the importance of wavelength selection and adaptive optics. Research shows that 1550 nm is more turbulence-resistant than 810 nm for LEO satellite communications. A cutting-edge adaptive optics system with a 1.5 kHz control bandwidth and 80-degree zenith angles can correct 1550 nm turbulence-induced wavefront aberrations. Use of advanced superconducting nanowire single-photon detectors requires low-loss coupling of the free-space beam into a single-mode fibre. By combining adaptive optics and fine-tracking, this is achieved.
Implementing Quantum Intelligence for Global Services
This work lays the framework for intercontinental terrestrial-non-terrestrial quantum networks. Quantum communication must be combined with cutting-edge quantum technologies like intelligence, processing, and sensing, according to the study.
AI and high-dimensional multipartite quantum communications are the final steps to a fully functional Quantum Internet. This advanced infrastructure promises real-time environmental monitoring and optimized autonomous vehicle operation, enabling ubiquitous quantum services.
