## 5 Experiments and Results
### Performance Evaluation
#### 5.2.3 Throughput  
In this section, we evaluated the throughput to experimentally determine whether the satellite-enabled IoRT network functioned properly. To conduct this analysis, two experiments were performed, i.e., data transmission with and without the packet creation mode.  
In regard to data transmission without the packet creation mode, we performed a field experiment and compared transmitted and received data, and the size of the transmitted data packet was 200 B. A comparison of the transmitted data versus the received data is provided in Table 6. According to the results, given a packet size of 200 B, the received data were consistent with the transmitted data, suggesting that the cached data in the ground IoT terminal could be successfully transmitted to the data center, illustrating that field data transmission via the satellite-enabled IoRT network from remote areas is feasible and that the satellite functioned properly. Note that this result was obtained based on an acceptable 10% packet loss rate, and the assessment criterion of satellite functioning was a packet loss rate of the transmitted and received data lower than 10% under the same time stamp. If this criterion is not satisfied, the satellite is not functioning properly.  
Similarly, regarding data transmission with the packet creation mode, we selected data with a packet size of 400 B, and these data were thus converted into two subdata packets 200 B in size. In this experiment, 400 B data packets were selected for testing with the aim of examining the performance of cached data transmission via satellites under the maximum throughput. The results for the transmitted and received data are listed in Table 7. The  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Test Time**} & \multirow{2}{*}{**Weather**} & \multirow{2}{*}{**Data Size**} & \multicolumn{2}{c}{**Number of**} & **Number of** & **Is the Satellite** \\  & & & **Transmitted** & **Received** & **Functioning** \\  & & & **Packets** & **Packets** & **Property?** \\ \hline
2020.12.12 7:22 & Sunny & 200 B & 120 & 113 & Yes \\
2020.12.12 8:21 & Sunny & 200 B & 220 & 210 & Yes \\
2020.12.12 19:03 & Sunny & 200 B & 185 & 176 & Yes \\
2020.12.12 19:40 & Sunny & 200 B & 280 & 265 & Yes \\ \hline \hline \end{tabular}
\end{table}
Table 6: Throughput (without the packet creation mode).  
Figure 8: Histogram of the packet loss rate. The packet loss rate for the received data versus the transmitted data and the number of data packets versus the transmission time.  
transmitted data constituted a complete packet that is 400 B in size. However, the data comprised two 200 B subdata packets in the ground IoT terminal before transmission to the satellite. Thus, the received data comprised two subdata packets, and packet loss occurred in the transmission of both subdata packets. For example, on 13 December 2020, at 7:22, 125 data points were transmitted, whereas 238 data points were received. We could conclude that these results are consistent with those of the above experiment, suggesting that data exceeding the maximum throughput of the satellite link can be transmitted by employing the packet creation mode, and a highly satisfactory performance was attained. Our experimental results further demonstrated that the established satellite-enabled IoRT network could suitably retrieve data from remote areas.