# Best-Suited Communication Technology for Maritime Signaling Facilities: A Literature Review
## 3 Results and Discussion
### Analytical Literature Review
While we acknowledge that relevant research may exist in other languages (e.g., Chinese, Russian, or Turkish), including these articles would have required translation. Figure 3: Comparative representation of the number of found papers in databases per year. A graphical representation of the paper search and filtering process can be found in Figure 2. As shown in Figure 2, out of the initial 214 papers, 36 duplicates were eliminated. Furthermore, 87 papers with inadequate topics and 58 papers covering overly broad research areas were excluded. Only four papers were found to have a language barrier and were not included for further analysis. This exclusion process was carried out to maintain focus and relevance and resulted in 29 papers selected for further analysis in the third stage, \"Document included\". To summarize, according to the analysis of the number of papers before and after filtering, the result yielded 214 and 29 relevant papers, as shown in Table 2.  
In this section, it is important to note that, after filtration, 44.82% of the papers selected for further processing were found using the \"other\" search method. However, it has to be emphasized that most \"other\" results are found, for instance, in the IEEE Xplore database. Table 3 presents an overview of the selected papers, each designated by a unique reference number in the paper's references, along with the first author's name. The table provides the publication year, the communication technology employed in the paper, and a summary of the conclusions derived from each respective paper. \begin{table}
\begin{tabular}{c c c c} \hline
**No.** & **Tech.** & **Ref.** & **Conclusion** \\ \hline
1. & & [36] & AIS can be used for telemetry, but the data are still transferred using satellite communication (Iridium). It has an extensive range but comes with high costs. The specific range is not mentioned but unquestionably sufficient given the satellite communication method. \\ \hline
2. & & [23] & The data are transmitted using the ad hoc method through AIS. \\ \hline
3. & [37] & [37] & The data are transferred using AIS AtoN devices, but only between two devices, utilizing standard pre-defined AIS messages. \\ \hline
4. & & [38] & The data are transferred using AIS AtoN devices, but only between two devices, utilizing standard pre-defined AIS messages. \\ \hline
5. & & [39] & Several communication methods have been used, and a table with a comparative display has been presented. AIS, LTE, and NB-IoT are mentioned as the three most optimal solutions for this type of data transmission. \\ \hline
6. & & [40] & LoRa WAN network is being used experimentally, and a range of over 8 km was achieved, depending on the terrain configuration. In urban areas, the range is 2 km. Additionally, it is highlighted that the costs are very low. \\ \hline
7. & & [41] & LoRa WAN is being used, and it boasts a maximum range of 15 km, low power consumption, and the advantage of using LoRa devices without the need for frequency licensing. \\ \hline
8. & & [42] & LoRa WAN is being utilized, and efforts are being made to optimize the coverage of the LoRa signal. \\ \hline
9. & & [43] & LoRa WAN was in use, and it was noted that communication had been successfully established at a distance of 15 km. The technology features low power consumption and the advantage of using LoRa devices without frequency licensing. \\ \hline
10. & & [44] & LoRa WAN is being used, and the achieved range is 8.33 km in the worst-case scenario. \\ \hline
11. & & [45] & LoRa WAN is being used, and a range of 15 km was achieved. \\ \hline
12. & & [46] & LoRa WAN was used, and a range of 8.33 km was achieved. \\ \hline
13. & & [47] & LoRa WAN is being used, and the achieved range is 110 km in open areas and 20 km in urban environments. \\ \hline
14. & & [48] & LoRa WAN is being used, and a range of 2 km in urban areas was achieved. \\ \hline \end{tabular}
\end{table} 
Table 3: Overview of the selected papers.