Cell Site Densification Using mmWave and Sub-THz Line-of-Sight Wireless Fronthaul: A Deployment Feasibility Study

This article presents a mobile network deployment analysis aimed at understanding the use of high-frequency wireless fronthaul links to realize dense cell network architectures. A high-resolution digital twin model is built based on real-world datasets to identify line-of-sight (LoS) propagation paths between existing macrocell rooftop sites and lamp post infrastructure locations suitable for new street-level cell sites. The resulting LoS path topology is used to simulate wireless fronthaul links based on industry-standardized fronthaul interfaces across the urban environment. In considering the stringent fronthaul interface requirements for a representative 5G radio configuration, the suitability of emerging mmWave and sub-THz transport bands between 71.124 and 174.8 GHz to fulfill the wireless fronthaul-centralized RAN (C-RAN) deployment is analyzed. Findings in this work have demonstrated that with the right combination of fronthaul interface and spectrum band up to 73% of new street-level cell sites in a dense deployment could be built using a wireless fronthaul transport solution.