摘要
Most existing studies on quantum networks (QNs) focus either on fiber-based transmission or on free-space optical (FSO)-based transmission in isolation. However, little attention has been given to architectures that combine both, which are particularly important for data-center QNs to handle heavy transmission requests. To capture the intrinsic characteristics of hybrid transmission, we formulate a novel optimization problem named HRP, which jointly determines the transmission method for each request and identifies entangled paths while ensuring load balancing across network resources. To address this problem, we propose an approximation algorithm named AHRP. The AHRP leverages linear programming (LP) relaxation and tailored rounding, complemented by a practical heuristic, to provide both provable guarantees and practical adaptability. Simulation results show that the AHRP reduces the maximum network utilization by an average of 36%.