Fair and Efficient Scheduling Strategies for Satellite Assisted Quantum Key Distribution Systems

Satellite-based quantum key distribution (QKD) systems use constellations of satellites to assist secret key generation among ground station pairs that are far away from each other. In this paper, we study satellite scheduling to establish secret keys among ground station pairs in a fair and efficient manner. While satellite scheduling has been considered in the past, existing scheduling algorithms are not for QKD, and have not explicitly accounted for fairness of resource allocation among ground station pairs. We propose three satellite scheduling strategies that have different tradeoffs in fairness and computational overhead. Using extensive simulation, we evaluate these strategies in a wide range of settings, while considering realistic environmental conditions (time-of-day, cloud coverage). Our results demonstrate that they achieve significantly better fairness at the cost of slightly lower overall number of keys when compared to a baseline strategy that has no fairness considerations.