# Assessing the Capacity and Coverage of Satellite IoT for Developing Countries Using a CubeSat
## 4 Results and Discussion
The received data packets are downlinked at Kyutech ground station, the configuration of which is shown in Figure 22. From the operation experience of previous satellites from the same ground station, approximately 7.9 kB of data can be downlinked per ground pass using 400 MHz UHF frequency. Integrating the data downlinked for four passes a day, all the data collected by the payload receiver can be downlinked and uploaded to the database within a day. The maximum latency between data transmission from the GST to the data reception from the database is 24 h. This latency is acceptable for delay-tolerant applications. The estimation for the capacity of the mission is made as realistic as possible, inclusive of known parameters for the designed system. The unknown parameters are the on-orbit dynamics, which may change the performance and the capacity of the receivers. The capacity shall be re-evaluated once the mission is made fully functional on-orbit. In addition to the technical edge of the designed system for the SIoT mission, the involvement of developing countries for the GST network provided a platform to experience 'hands-on' while building their own GSTs. Each of these participating countries customized the GST design based on material substitutes available locally, optimizing the design for that country. The overall development cost was targeted to be achieved under $150 based on a market survey of components in Japan to achieve low-cost requirements [39] but the actual development cost in the GST countries ranged from $200 to $300 due to variation  
Figure 22: Configuration of ground station at Kyutech. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Parameters**} & \multicolumn{2}{c}{**Short Format**} & \multicolumn{2}{c}{**Long Format**} \\ \cline{2-5}  & **Per Day** & **Per Year** & **Per Day** & **Per Year** \\ \hline Beta angle \textless{} 25 degrees & 9.23 kB & 3.29 MB & 10.76 kB & 3.84 MB \\ Beta angle \textgreater{} 25 degrees & 22.57 kB & 8.04 MB & 26.33 kB & 9.38 MB \\ Total & 31.79 kB & 11.33 MB & 37.09 kB & 13.22 MB \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Summary of SIoT data capacity estimation for one year including efficiency factor. in market prices. The GST community from each country comprises individuals actively involved in developing the space sector, including students from universities, officials in space agencies, and space enthusiasts, who would like to improve space technologies in their country. Most of these countries are participating in demonstrating a proof of concept so that these technologies could be applied in their future projects to solve local issues. Since there are no publications in the literature that discuss the capacity of a SIoT based on the actual design of a CubeSat and the limitations due to the design, the proposed system cannot be compared quantitively for the performance evaluation. Instead, this study could serve as a base for quantitative comparison for satellites that will be developed in the future for S&F remote data-collection missions. There are areas of improvement that are currently being implemented in the Micro Orbiter-1 (MO-1) mission, which is a 1-unit CubeSat being developed at Kyutech. MO-1 will have two S&F payloads, which will have eight receivers each onboard, for the frequencies of 400 MHz and 920 MHz, and the 400 MHz board is a replica of the KITSUNE payload board; however, the 920 MHz is an improvised version of the 400 MHz board with 70 mA lesser power consumption. Communication tests are underway, and the preliminary test results showed similar receiver sensitivity to the KITSUNE S&F receiver. As a result, it is under study to improve the receiver sensitivity further.