# TinyGS vs. SatNOGS: A Comparative Analysis of Open-Source Satellite Ground Station Networks
## 5 Discussion
### Comparison of the Number of GSs That Were Online in the Last 24 h on 29 July 2023
For ThingSat, the reasoning is the same; however, most packets are received with a frequency of 868.1 MHz. According to Figure 10, it is possible to observe that most of the satellites that obey the previous conditions have frequencies around 400, 402, 436 and 437 MHz. It is also noted that the satellite frequencies in Figure 10 were rounded in order to facilitate the visualization of the histogram. Figure 10: Frequency of satellites supported (by the TinyGS) and operational (according to SatNOGS DataBase) that had at least one data packet received by a TinyGS GS as of 29 July 2023. In Figure 11 it is possible to see the frequencies of the satellites that were operational (according to SatNOGS DataBase) on 29 July 2023 and that had at least one data packet received by a SatNOGS GS. Note that on the horizontal axis of Figure 11 are frequency ranges, for example, [100, 149], which covers all frequencies from 100 MHz to 149 MHz, inclusive. Therefore, a satellite communicating at 134 MHz is included in [100, 149]. To create Figure 11, the first step involved accessing all satellites and examining their transmitters. Each transmitter has various parameters, including the downlink frequency, which characterizes the frequency at which the satellite transmits the signal and the saved frequency. However, some satellites have multiple transmitters, and in such cases, downlink frequencies were kept without repetitions. For instance, if a satellite had three transmitters with the same downlink frequency (146 MHz), even if they used different downlink modes (BPSK, USB), the 146 MHz frequency was saved only once and not three times. Furthermore, only the downlink frequencies of transmitters with \"alive\" set to \"True\" [11] were saved, meaning malfunctioning transmitters with \"alive\" set to \"False\" were not considered. It is important to note that among the operational satellites, 37 either lacked transmitters in the database or possessed only inactive transmitters (e.g., were malfunctioning), and therefore, these satellites do not appear in this histogram. Regarding Figure 11, it is possible to observe that most of the satellites, about 60%, work with frequencies between 400 and 450 MHz, as in TinyGS. Furthermore, about 80% of the satellites work with frequencies between 100 and 149 MHz, 400-449 MHz and 2200-2249 MHz. Comparison of the Number of Satellites That Were Operational and Were Able to Send Data to the GSs and That Data Was Decoded as of 29 July 2023  
The next step was to observe the operational satellites that had their data decoded, because the vast majority of people who intend to join and/or contribute to the projects also want to see the content of the packages sent by the satellites. Figure 11: Frequency of operational satellites (according to SatNOGS DataBase) that had at least one data packet received by a SatNOGS GS as of 29 July 2023. To carry out this aim, the reasoning used in the previous sections was applied, but additionally, it was necessary to go through the satellites and see if at least one piece of data was decoded. In TinyGS, to see which satellites have decoded data, the various satellites were examined individually in the web application, and it was determined whether at least one packet was decoded. In SatNOGS, the statistics present in the SatNOGS DB [15] were consulted, and satellites with at least one decoded data packet were saved. The numbers obtained for each category were:  
* SatNOGS: 73;
* TinyGS: 22. Taking into account these numbers and those presented above, it is possible to observe that most of the satellites supported by TinyGS and operational have decoded data. In SatNOGS, this is not the case, and the count went from 611 to 73, thus showing that, for a large majority of satellites, the decoder does not exist or has not yet been implemented. However, the SatNOGS number of continues to be higher than that of TinyGS, about three times greater. This is due to the fact that TinyGS works only with LoRa satellites.