Minimum Separation Distances for Local 5G/6G Networks in the 3.8-4.2 GHz Frequency Band

Local 5G and future 6G networks provide geographically confined connectivity, enabling a broad range of stakeholders to deploy mobile communication networks tailored to local requirements, complementing traditional nationwide mobile network operator (MNO) networks. The European Commission has recently made a harmonization decision creating a regulatory framework with technical conditions for the shared use of the 3.8-4.2 GHz frequency band by low-power (LP) and medium-power (MP) terrestrial wireless broadband systems for local area connectivity. This framework will enable the deployment of local 5G/6G networks in a large number of European countries, where the issuing of local spectrum licenses will require careful interference studies. This paper quantifies the minimum separation distances required between two independently deployed outdoor local 5G/6G networks operating in LP and MP configurations, systematically covering all possible deployment combinations (LP-LP, LP-MP, MP-LP, and MP-MP). Results derived from Monte Carlo simulations using European spectrum regulators' SEAM-CAT simulation tool and existing protection requirements show that LP deployments require sub-kilometer separation, whereas MP deployments may require several tens of kilometers separation distances, depending on antenna configuration and downtilt, and downlink transmit power modeling. The findings provide quantitative insight relevant to national implementation of the European harmonized 3.8-4.2 GHz framework and serve as the foundation for developing interference management techniques and local licensing models for efficient implementation of the new framework.