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

This paper presents 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 data sets to identify line-of-sight propagation paths between existing macro cell roof top sites and lamp post infrastructure locations suitable for new street level cell sites. The resulting line-of-sight 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 deployment is analyzed. Findings in this work have demonstrated that with the right combination of fronthaul interface and spectrum band upto 73% of new street level cell sites in a dense deployment could be built using a wireless fronthaul transport solution.