# Challenges of Using the L-Band and S-Band for Direct-to-Cellular Satellite 5G-6G NTN Systems
## 3 Materials and Methods
Table 5 provides link characteristics of the Omnispace F2 satellite for several types of mobile Earth stations (MESs). \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Carrier Assignment** & **Carrier Power, Max (dBW)** & **Carrier Power, Min (dBW)** & **Sat. TX** & & & **ES Slide** & **Noise Tem.** \\
**S** & **Max (dBW)** & **Min (dBW)** & **Gain (dBi)** & **ES Type** & **ES Gain (dBi)** & **Formula** & **(K)** \\ \hline
17 KSG1W– & 1.9 & \(-\)4.3 & 22 & INM-AERO (H) C-21 & 12.0 & IF (topo \(\geq\) 45, \(-\)1,12) & 316.2 \\
7 KSG1W– & 0.3 & \(-\)4.4 & 22 & INM-AERO (H) P-10.5 & 12.0 & IF (topo \(\geq\) 45, \(-\)1,12) & 316.2 \\
7 KSG1W– & \(-\)1.0 & \(-\)7.7 & 22 & INM-AERO (H) C-8.4 & 12.0 & IF (topo \(\geq\) 45, \(-\)1,12) & 316.2 \\
2 KS0G1W– & \(-\)7.6 & \(-\)12.7 & 22 & INM-AERO (H) P-1.2 & 12.0 & IF (topo \(\geq\) 45, \(-\)1,12) & 316.2 \\
2 KS0G1W– & \(-\)10.7 & \(-\)15.8 & 22 & INM-AERO (H) P-6.6 & 12.0 & IF (topo \(\geq\) 45, \(-\)1,12) & 316.2 \\
5 KS0G1W– & \(2.5\) & \(-\)2.2 & 22 & INM-AERO (H) P-4.8 & 6.0 & IF (topo \(\geq\) 80, \(-\)1,6) & 316.2 \\
2 KS0G1W– & \(-\)1.6 & \(-\)6.7 & 22 & INM-AERO (J) P-1.2 & 6.0 & IF (topo \(\geq\) 80, \(-\)1,6) & 316.2 \\
2 KS0G1W– & \(-\)4.7 & \(-\)9.8 & 22 & INM-AERO (J) P-6.6 & 6.0 & IF (topo \(\geq\) 80, \(-\)1,6) & 316.2 \\
2 KS0G1W– & 5.4 & 0.3 & 22 & INM-AERO (J) P-1.2 & 0.0 & Omni & 398.1 \\
2 KS0G1W– & 2.3 & \(-\)2.8 & 22 & INM-AERO (J) P-0.6 & 0.0 & Omni & 398.1 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: The link characteristics of Inmarsat 25E for Aero terminals. Figure 4: Simulation of the wanted Inmarsat Aero link (space-to-Earth) in the L-band. The satellite is located in the MEO orbit at an altitude of 10,500 km with a 45-degree inclination, and the S-band part consists of 163 spot beams. Below, Figure 5 provides a simulation of the wanted Omnispace link where MES-1 is considered.In this figure, pink lines represent each spot beam of the Omnispace satellite. For our study, the MES was placed in a northern region because Omnispace is primarily utilized in the Far North, where the connectivity is especially needed for unserved areas. Another incumbent satellite system considered in this study is Lyra, a low-Earth-orbit (LEO) system that is intended to be implemented by EchoStar for IoT services. Originally known as Sirion, Lyra was previously owned by Helios Wire. In 2019, EchoStar Global, LLC, acquired the Helios Wire Corporation, and the Lyra satellite constellation will be based on the existing Sirion-1 network, which was previously filed with ITU-R. As of now, three satellites have been successfully launched: EG-1 (Tyvak-0172), EG-2 (Tyvak-0171), and EG-3 (Tyvak-0173), which were launched between 2020 and 2021. Table 6 provides the characteristics of Lyra satellite links based on the Sirion-1 ITU-R filing. The Lyra satellite system will comprise twenty-eight satellites distributed across seven orbital planes, with four satellites per plane. These satellites will operate at an altitude of 650 km and have an inclination of 96 degrees. The RAAN increment for Lyra is 51.4 degrees. In our study, we deployed Lyra terminal that receives interference in the European region. It is worth noting that since Lyra was primarily designed for IoT services and does not require continuous communication. As a result, Lyra is more interference-robust compared to voice communication services. Figure 6 illustrates a simulation of the desired Lyra satellite network link. Figure 5: Simulation of the wanted Omnispace F2 link (space-to-Earth).