# Federated Reinforcement Learning Based AANs with LEO Satellites and UAVs
## 4 Performance Evaluation
### Evaluate System with Network Simulator
#### 4.2.2 Configuration  
To evaluate our proposed system, we designed the simulation which aims to measure the total amount of throughput which the AAN or satellite-only network could serve. In the simulation environment, every consumer sends data to one sink node through the non-terrestrial network. We adopted Starlink satellite model [1] as our satellite network model. Furthermore, we adopted the high altitude pseudo-satellite model of Facebook's aquila [13], where satellites could operate at 27 km altitude, as our high altitude UAV model. In addition, the UAVs are equipped with a device capable of ground-satellite link  
Figure 7: Traffic map and UAV deployment of the simple evaluation. (**a**) Initial situation. (**b**) Left side traffic situation. (**c**) Right side traffic situation.  
(GSL) and inter-satellite link (ISL) communication. Similar to the Starlink network, we configured the simulation where UAVs are equipped with communication equipment equivalent to that of Starlinks satellites and the UAVs' operating altitude is 27 km. With this assumption, we configured that the satellites' the ratio of the service area to operating altitude is the same as that of the UAVs. For this reason, we set our UAVs' service area radius to 28.2 km because the satellites' operating altitude is 550 km and the radius of service area is 573.5 km. The detailed simulation configuration is represented at Table 3.  
We selected Iowa State of United States as the simulation area based on population distribution. The state has several densely populated cities and many small towns, so we choose the states as simulation area. The population distribution is represented in Figure 8(a). In the figure, darker and lighter points represent the area with dense and sparse population, respectively. For traffic model, we utilized the monthly data traffic per smartphone according to the Ericsson Mobility Report [42] and daily traffic usage pattern model referring to [43]. Based on the traffic model, total required data rate of the service area is 313.6 Gbps. However, as not all the smartphone users use satellite Internet, we assumed that 5% of them use the satellite Internet. Therefore, we configured the total traffic demand rate of entire environment as ~15.7 Gbps. Within the traffic model, we generate traffic map based on the population distribution according to the work in [44], which is represented at Figure 8(b). In this figure, the intensity of red color represents the degree of traffic demand. Figure 8(c) shows UAVs' position in the simulation. We deployed 10 UAVs to provide more Internet service resources to the service area. Through out the simulation, UAVs were located at the center points of each circle and provided Internet service to the users inside of the circle.  
Figure 8: The overall structure of AAN simulator.  
\begin{table}
\begin{tabular}{l c} \hline \hline
**Simulation Configuration** & **Value** \\ \hline Satellite operating altitude (km) & 550.0 \\ Satellite service area radius (km) & 573.5 \\ High-alt UAV operating altitude (km) & 27.0 \\ High-alt UAV service area radius (km) & 28.2 \\ Maximum ISL range (km) & 5016.6 \\ Maximum GSL range (km) & 794.6 \\ Maximum ISL rate (Gbps) & 10.24 \\ Maximum GSL rate (Mbps) & 720.0 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Aerial access network simulation configuration.