Low Earth Orbit (LEO) satellites present a compelling opportunity for the establishment of a global quantum information network. However, satellite-based entanglement distribution from a networking perspective has not been fully investigated. Existing works often do not account for satellite movement over time when distributing entanglement and/or often do not permit entanglement distribution along inter-satellite links, which are two shortcomings we address in this paper. We first define a system model which considers both satellite movement over time and inter-satellite links. We next formulate the optimal entanglement distribution (OED) problem under this system model and show how to convert the OED problem in a dynamic physical network to one in a static logical graph which can be used to solve the OED problem in the dynamic physical network. We then propose a polynomial time greedy algorithm for computing satellite-assisted multi-hop entanglement paths. We also design an integer linear programming (ILP)-based algorithm to compute optimal solutions as a baseline to study the performance of our greedy algorithm. We present evaluation results to demonstrate the advantage of our model and algorithms.

翻译：低地球轨道（LEO）卫星为建立全球量子信息网络提供了引人注目的机遇。然而，从网络视角出发的基于卫星的纠缠分发尚未得到充分研究。现有工作通常未考虑卫星随时间运动时纠缠分发的情况，并且/或者通常不允许沿星间链路进行纠缠分发——本文正是针对这两个不足进行改进。我们首先定义了一个同时考虑卫星随时间运动和星间链路的系统模型。接着在该系统模型下形式化表述了最优纠缠分发（OED）问题，并展示了如何将动态物理网络中的OED问题转化为静态逻辑图中的问题，从而可据此求解动态物理网络中的OED问题。随后我们提出了一种多项式时间贪婪算法，用于计算卫星辅助的多跳纠缠路径。同时我们设计了一种基于整数线性规划（ILP）的算法来计算最优解，作为基准以研究贪婪算法的性能。最后我们通过评估结果展示了所提模型与算法的优势。