# Distance Protection for Coexistence of 5G Base Station and Satellite Earth Station
## 2 Background Knowledge  
### Basic Scenarios and Parameters  
Both the azimuth and elevation planes need to be considered because the antenna gain is closely related to both azimuth and elevation off-boresight angles. Hence, they have a significant impact on the interference from the BS to ES. For the protection target, i.e., the FSS ES, the ES is assumed to be located at the center of the area with a coordinate of (0, 0). Further, the azimuthal orientation of the ES antenna is assumed to be true north, while the ES antenna elevation orientation, i.e., elevation angle, differs for various ESs, according to the ES deployment requirements. The cellular BS (eNodeB/gNodeB) is assumed to be deployed at any possible location (X, Y) around the ES. Moreover, the azimuthal orientation of the BS antenna is assumed to be true south. Herein, we use the 3-dimensional (X, Y, Z) coordinate to present the results. In this coordinate system, the x and y axes are the latitude and longitude coordinates of the BSs, respectively, and the z-axis is the target measurement, such as ES antenna gain, path loss, and I/N, with the line between the BS and ES as the interference axis. We consider three scenarios, including RMa (rural), UMa (urban), and UMi (urban) [13]. The ES antenna heights and their diameters as well as the BS antenna heights \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Our Work**} & [2] & [3] & [6] & [7] & [8] & [9] & [12] \\ \hline \multirow{5}{*}{Protection schemes studied} & Exclusion Zone & o & o & & & o & o \\ \cline{2-8}  & Restriction Zone & o & o & o & o & o & o \\ \cline{2-8}  & Restriction Zone with Power Control Scheme & o & & & & & \\ \cline{2-8}  & Combination of Exclusion Zone \& & & & & & \\ \cline{2-8}  & Zone \& Exclusion Zone & o & & & & \\ \hline \multirow{2}{*}{Deployment scenarios considered} & Rma & o & & o & o & & \\ \cline{2-8}  & Uma & o & & o & o & & \\ \cline{2-8}  & Umi & o & o & & & o & \\ \hline \multicolumn{8}{c}{The effect of different ES Antenna elevation angle} & o & & & & \\ \hline \multirow{5}{*}{Antenna types studied} & Omni & o & o & o & o & o \\ \cline{2-8}  & 4 \(\times\) 4 & o & o & o & & \\ \cline{1-1} \cline{2-8}  & 8 \(\times\) 8 & o & o & o & o & \\ \cline{1-1} \cline{2-8}  & 16 \(\times\) 16 & o & & & o & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The main differences between our work and previous works. where \(P_{BS\ tx}\) is the transmit station signal power density in dBm/MHz [17; 18], \(G_{FSS\ ES}\) represents the antenna gain of the ES in the direction of the transmit station in dBi [11], and \(G_{BS}\) is the 5G BS antenna gain, with an omnidirectional antenna and massive MIMO antenna array in the direction of the ES to account for the beamforming antenna pattern in dBi [14; 19], and \(PL\) is the combined path loss from all possible BS locations to the ES [14]. The FSS ES antenna gain is also described. Spectrum management of the frequency bands shared by the FSS ESs and fixed terrestrial radios may require the calculation of the terrestrial emitter RF power at the input of an ES receiver [20]. This is to ensure that the ES interference threshold is not exceeded. The potential received interference power from terrestrial emitters is partly dependent on the FSS ES antenna gain in the direction of the terrestrial emitter. The FSS ES antenna gain is calculated as follows:  
* ES antenna pattern: Recommendation ITU-R S.465-6 [11] \[G_{ES}(\varnothing)=\left\{ \begin{array}{c}G_{max},\ if\ 0^{\circ}< \varnothing<\varphi_{min}\\ 32-25 log\varnothing,\ if\ \varphi_{min}\leq\varnothing<48^{\circ}\\ -10,\ if\ 48^{\circ}\leq\varnothing\leq 180^{\circ}\end{array} \right.\] (2) \[\varphi_{min}=\left\{ \begin{array}{c}Max(1^{\circ},\ 100\lambda/D),\ if\ D/\lambda\geq 50\\ Max\Big{(}2^{\circ},\ 114(\lambda/D)^{-1.09}\Big{)},\ if\ D/\lambda<50\end{array}