Free-space model for a balloon-based quantum network

TL;DR

This paper proposes a loss model for balloon-based free-space quantum communication, demonstrating balloons as a feasible, cost-effective alternative to satellites for long-distance quantum networks.

Contribution

It introduces a comprehensive loss model for balloon-to-ground and balloon-to-balloon channels and explores their use in quantum key distribution networks.

Findings

Balloons can achieve comparable channel efficiency to satellites under certain conditions.

Trade-offs in hardware parameters significantly affect communication performance.

Balloon-based networks are a viable alternative for national quantum communication infrastructure.

Abstract

Long-distance communication is one of the main bottlenecks in the development of quantum communication networks. Free-space communication is a way to circumvent exponential fiber loss and to allow longer communication distances. Satellite nodes are the main devices currently studied for free-space communication, but they come with downsides such as high cost and low availability. In this work, we study an alternative to satellites, namely aerial platforms such as high-altitude balloons. We provide a loss model to simulate the channel efficiency of balloon-to-ground, ground-to-balloon, and balloon-to-balloon communication channels, considering a large set of hardware parameters. We perform a parameter exploration to exhibit important trade-offs in these channels, as well as simulations of different quantum key distribution network architectures including balloon nodes. We demonstrate that balloons are a realistic alternative to satellites for free-space communications in national network architectures.