## 7 Conclusions  
In conclusion, FSO communication represents a transformative technology poised to address the escalating demands for high-speed, low-latency communication in the 5G and beyond era. This survey has highlighted the critical enabling technologies, such as adaptive optics, advanced modulation schemes, and robust error correction codes, that are essential for overcoming the inherent challenges associated with FSO systems, including atmospheric disturbances and alignment issues. The exploration of hybrid solutions integrating FSO with radio frequency, millimeter-wave, and Terahertz technologies demonstrates the potential for enhancing network reliability and coverage. Moreover, the incorporation of artificial intelligence and machine learning techniques marks a significant trend toward optimizing FSO performance in dynamic environments, paving the way for smarter and more resilient communication systems. By systematically analyzing current trends and challenges, this paper underscores the capacity of FSO to not only meet but exceed the communication requirements of future networks. Looking ahead, several open challenges remain, particularly concerning scalability, deployment strategies, and real-time adaptive capabilities in diverse atmospheric conditions. Addressing these challenges will be pivotal in realizing the full potential of FSO technology. Future research should focus on developing innovative solutions to enhance the robustness and efficiency of FSO systems, ensuring their successful integration into next-generation communication infrastructures. Ultimately, the insights presented in this paper contribute to a deeper understanding of the role of FSO in revolutionizing wireless communication and set the stage for ongoing advancements in this promising field.  
Conceptualization, I.A.A. and P.P.M.; methodology, I.A.A. and P.P.M.; software, I.A.A.; validation, I.A.A. and P.P.M.; formal analysis, P.P.M.; investigation, I.A.A. and P.P.M.; resources, I.A.A. and P.P.M.; data curation, I.A.A. and P.P.M.; writing--original draft preparation, I.A.A.; writing--review and editing, I.A.A. and P.P.M.; visualization, I.A.A. and P.P.M.; project administration, I.A.A. and P.P.M.; funding acquisition, I.A.A. and P.P.M. All authors have read and agreed to the published version of the manuscript.  
This work is supported by the Fundacao para a Ciencia e a Tecnologia (FCT). The author gratefully acknowledges the support of the FCT under the grant agreement \"Ultra-High-Capacity Optical Wireless Communication with Low-Complexity Transceiver for Effective Spectrum Utilization in Beyond-5G Networks,\" DOI 10.54499/2021.03815.CEECIND/CP1653/CT0005 ([[https://doi.org/10.54499/2021.03815.CEECIND/CP1653/CT0005](https://doi.org/10.54499/2021.03815.CEECIND/CP1653/CT0005)]([https://doi.org/10.54499/2021.03815.CEECIND/CP1653/CT0005](https://doi.org/10.54499/2021.03815.CEECIND/CP1653/CT0005))). Acknowledgment is also extended to the European Regional Development Fund (FEDER) through the Competitiveness and Internationalization Operational Programme (CENTRO 2020) for the ORCIP project, under Grant CENTRRO-01-0145-FEDER-022141. Additionally, the technical support provided by the Marie Sklodowska-Curie Actions (MSCA) through the Horizon 2020 Research and Innovation Staff Exchange (RISE) programme, specifically the Deep Intelligent Optical and Radio Communication Networks (DIOR) project under Grant Agreement ID: 101008280, is deeply appreciated.  
The authors declare no conflicts of interest.