IEEE Communications Letters
Optimizing Satellite-to-Ground Station Pair Assignments Using Hybrid Links for Long-Distance Quantum Entanglement Distribution
Zhenhui Yang, Kechao Cai, Zhuoyue Chen, Jinbei Zhang
Abstract
Quantum satellite networks enable entanglement distribution between ground stations, but existing single-satellite solutions relying solely on satellite-to-ground downlinks cannot effectively support long-distance entanglement distribution. To overcome this limitation, we propose a hybrid approach,Entanglement Distribution using Hybrid Links(ED-HL), which integrates bothentanglement distribution using a single satellite(ED-SS) andentanglement distribution assisted by inter-satellite links(ED-IS), where satellites are equipped with quantum memories. The key challenge in ED-HL is to effectively coordinate satellites to distribute entanglement to ground stations via inter-satellite links and downlinks.We formulate this entanglement distribution problem as an integer programming problem, establish its submodularity, monotonicity and non-negativity properties, and design a greedy algorithm for its solution. Simulations based on real-world constellation data show that ED-HL significantly extends the entanglement distribution distance compared to single-satellite approaches.