## Materials and Methods
### FSS-ES Interference Model  
Test 1 (T-1), Test 2 (T-2), and Test 3 (T-3) in Figure 2a represent the FS-ES experiments' tests locations of the coexistence model between 5G-BS and FSS-ES. The main parameters for FSS-ES are summarised in Table 3. The 5G DL transmission interferes with an FSS-ES receiver operating in the 3.625 GHz to 4.2 GHz range, as shown in Figure 2b. Therefore, we established the coexistence of 5G-BS and FSS-ES with 85 m distance as an interference source. Several studies, such as [11; 12], have mentioned that C-band communications are seriously affected. Therefore, we installed filters on FSS-ES to determine if the interference coexistence of 5G-BS and FSS-ES affected the performance, and we addressed the interference coexistence. Thus, the 5G-BS can be used near an FSS-ES at an 85 m distance. The 5G-BS and FSS-ES enhance the interference for satellite signal isolation. In order to keep the FSS-ES at a safe distance and prevent interference from the 5G-BS, we must find a way to reduce the interference signals. They can use spatial attenuation or medium isolation and antenna directivity to further reduce the interference. When the 5G-BS and its receiving antenna are configured to have their peak amplitudes pointing in different directions \"direct-facing VSAT and then indirect\", the satellite signal can be better isolated from the 5G interference, and the interference is reduced. The transmission power of the satellite uplink (UL) station and the power of the RF signal are increased to help mitigate the interference to a certain degree. Increased satellite DL signal strength helps reduce the 5G-BS transmission power whilst improving the satellite signal-to-noise ratio and the 5G interference-to-noise ratio.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameters** & **Value** \\ \hline Frequency Supported range & 3400–3800 MHz \\ Bandwidth & 50–100 MHz \\
5G-BS carriers’ frequency: & 3400–3500 MHz; 3500–3600 MHz; 3600–3650 MHz \\ Antenna Gain & 25 dBi \\ Transmitter power (Tx) & 53 dBm (200 W) \\ Antenna & One sector (80\({}^{\circ}\) N) with 3 Active Antenna Units (AAUs) \\ Mechanical tilt & 15\({}^{\circ}\) \\ Site height above mean sea level (AMSL) & \(\sim\)30 m \\ Antenna height AMSL & \(\sim\)35 m \\ EIRP & 78 dBm/100 MHz \\ OOB emission & \(-13\) to \(-15\) dBm/100 MHz \\ \hline \hline \end{tabular}
\end{table}
Table 1: 5G-BS parameters.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Carrier Frequency** & **Guard Band—100 MHz** & **Guard Band—50 MHz** \\ \hline T-1 & 3.4–3.5 GHz & 3.4–3.5 GHz \\ T-2 & 3.5–3.6 GHz & 3.5–3.6 GHz \\ T-3 & 3.6–3.650 GHz & 3.6–3.650 GHz \\ \hline \hline \end{tabular}
\end{table}
Table 2: 5G-BS DL spectrum allocation parameters.  
This section examines the specific effects of 5G interference on fixed-satellite services (FSS-ES). It offers a comprehensive analysis of the interference model and parameters described in Section 2.2, 5G-BS Interference Model, and Section 2.3, FSS-ES Interference Model. The paragraph discusses the use of sector antennas for 5G base stations (5G-BS) in order to generate the most severe interference scenario possible. The required bandwidth for 5G and the designated carrier frequencies for the 5G-BS are described. The paragraph also describes the experiments conducted to test the compatibility of 5G-BS and FSS-ES, as well as the installation of interference-reducing filters. For interference reduction, spatial attenuation, medium isolation, and antenna directivity are suggested. Boosting the transmission capacity of satellite uplink stations and the strength of the satellite downlink signal can also help mitigate 5G interference.  
Figure 2: Schematic of FSS-ES interference measurement; (**a**) The measurements Location; (**b**) The FSS-ESS and 5G-BS test diagram.