###### Abstract  
This work presents sharing studies between 5G networks and point-to-point fixed service in the 6425-7125 MHz band. In this research, we provide simulations of interference from 5G downlink and uplink to fixed service in the frequency band 6425-7125 MHz. We evaluated several scenarios of interference, which include cross-border scenarios, as well as scenarios of interference within the borders of one administration. The obtained results of this work are presented as protection distance and frequency offsets that are required in order to achieve compatibility between 5G and FS in the 6425-7125 MHz band. The spectrum engineering techniques presented in this research can help different companies and regulatory administrations in their spectrum management and frequency regulation activities and seriously improve the efficiency of implementation for 5G technologies. IMT-2020; 5G IoT; spectrum sharing; spectrum management; spectrum engineering; compatibility studies; Monte Carlo simulation; SEAMCAT; beamforming; frequency regulation; ITU; WRC; coordination; signal-to-interference; interference-to-noise +
Footnote †: journal: _Sensors_  
0000-0002-4000-0000-0000-0000-0000-0000-0000-0000-0000-0000-0000-00000-00000-00000-00000-00000-00000-00000-00000-00000-00000-00000-00000-000000-000000-  
According to analytical forecasts, in 2024, the revenues of the operators in the IoT segment will reach USD 8 billion (compared to USD 525 million in 2020). It is expected that by 2023, 5G IoT will reach 3.5 billion connections, and by 2025, 5G-IoT will share 70% of all IoT connections worldwide. To achieve such ambitious goals, it is crucial to have sufficient spectrum resources to provide enough coverage and throughput of the IoT networks. Today, regulatory bodies worldwide are investigating the use of the 6425-7125 MHz band for 5G technologies. This spectrum range is very attractive, since it's a mid-band frequency range that combines strong sides of FR1 and FR2 bands, effectively balancing between coverage and capacity, providing the perfect environment for 5G connectivity. Extending the bandwidth of 5G through harmonization of 6425-7125 MHz will open new opportunities for the IoT networks and significantly reduce the cost of IoT network deployments, making it more affordable. The World Radiocommunication Conference 2023 (WRC-23) will play an important role in determining future access to the 6425-7125 MHz band. Today the ITU Radiocommunication Sector (ITU-R) considers the identification of the 6425-7025 MHz (Region 1) and 7025-7125 MHz (globally) for IMT, including possible allocations to the mobile service on a primary basis in these bands. Therefore, ITU members worldwide are invited to do sharing and compatibility studies to protect services with an existing primary allocation, without imposing additional regulatory or technical constraints. At present there are no commercial solutions of 5G base stations or user equipment and characteristics of them are preliminary provided by 3 GPP and ITU-R (see 3 GPP TS.38.104 v. 16.6.0 (2020-12) \(\ast\)NR; Base Station (BS) radio transmission and reception\({}_{\ast}\), 3 GPP TS.38.101-1 v.16.6.0 (2020-12) \(\ast\)NR; User Equipment (UE) radio transmission and reception; Part 1: Range 1 Standalone\({}_{\ast}\) and Document 5D/TEMP/422). The architecture options of 5G base stations that are defined in specifications 3 GPP TS 38.104 and 3 GPP TS 38.401, as well as in ITU-T Rec. G.8300 (05/2020), allow using the integration of fronthaul and backhaul in one base station for the bandwidth 6425-7125 MHz (FR1). The architecture solutions that integrate both fronthaul and backhaul in one BS do not influence the issue of spectrum sharing and electromagnetic compatibility, since the architecture is related to network design rather than compatibility issues. Therefore, the obtained results by the authors are applicable for any architecture solution of 5G base stations.