Enhancing Future Mobile Fronthaul Networks Security Using QKD-Secured Space Division Multiplexing with Multi-Core Fibers

The integration of Quantum Key Distribution (QKD) into optical networks has emerged as a promising solution for securing sensitive data transmission in mobile fronthaul applications. However, implementing QKD typically requires dedicated dark fibers, which increases network complexity and deployment costs. This paper explores an approach that leverages Multi-Core Fibers (MCF) to integrate both classical and quantum channels within the same optical fiber, utilizing Space Division Multiplexing (SDM). By dedicating separate cores for quantum and classical channels, the proposed system minimizes the need for additional infrastructure while ensuring secure and efficient communication. Crosstalk between cores, a critical factor in MCF design, is analyzed through simulations, considering parameters such as core pitch and operating spectrum. Results demonstrate the feasibility of achieving minimal inter-core crosstalk for reliable quantum and classical channel coexistence. This study underscores the potential of MCF-based SDM as a cost-effective and scalable solution for future quantum-secured mobile networks.