Optimizing RAN X-Haul Performance Through Targeted Hollow-Core Fiber Deployment in Converged Metro-Access Networks

The growing trend of disaggregated and cloud-native RAN architectures in 5G deployments and future 6G networks imposes stringent latency and capacity requirements on optical transport networks. This paper evaluates the feasibility of using standard single-mode fiber (SSMF) and hollow-core fiber (HCF) for supporting x-haul transport across converged metro-access networks. Using a converged metro-access network topology and experimentally modeled performance of a NOKIA ICE-X multi-carrier transceiver, we analyze end-to-end RAN connection from Radio Units (RUs) to Central Units (CUs) via Distributed Units (DUs). Results show that HCF significantly outperforms SSMF in satisfying BER and latency constraints over long distances, particularly in midhaul-dominated scenarios. Case studies with varying DU-CU link lengths further demonstrate HCF's potential to enhance service coverage for future latency-critical and high-capacity deployments. These findings position HCF as a strong candidate for enabling scalable and constraint-compliant optical transport in next-generation RAN infrastructures.