## 6 Conclusions  
As we embark on the journey towards the next generation of mobile communication systems, notably 6G, it has become imperative to seamlessly integrate the demands of digitalization and mobilization within the maritime sector, particularly for autonomous ships, within the framework of 6G standardization. This integration holds paramount significance due to the myriad of advantages that the 6G framework offers, centered around the establishment of unified communication ecosystems, built upon the widely embraced 3 GPP standards that have come to dominate in market for the digital revolution of various industries since the advent of 5G. Notably, the realization of 'ubiquitous connectivity' in 6G is poised to play a pivotal role in expanding communication coverage with secure reliability and optimal QoE in the maritime communication environment, a critical requirement for autonomous ships.  
This article contributes significantly by providing a comprehensive overview of the integration of satellites and UAVs as mobile RANs into 5G and beyond systems, which are envisioned as integral components of the 3 GPP access networks supporting the simultaneous utilization of multiple RANs in the forthcoming 6G era, within the framework of 3 GPP standardization. Additionally, we have explored the ATSSS features within 3 GPP as a transport layer-level solution enabling the seamless steering, switching, and splitting of data traffic across multiple access networks over the core networks of 5G and beyond systems.  
Given the unique characteristics arising from the maritime communication environment and the ships themselves, we have highlighted the opportunities and challenges for further exploration and research as we look ahead to the forthcoming 6G era. To succeed in the 6G-based maritime evolution, it is imperative to foster close collaboration among maritime stakeholders including authorities responsible for vessel traffic management and control, and maritime safety. Additionally, the collaboration between maritime stakeholders and 3 GPP experts is vital in developing the relevant requirements that align with the maritime sector's needs. These requirements should be meticulously formulated with substantial input from key stakeholders capable of representing the global maritime sector, including authorities in charge of vessel traffic management and control, and maritime safety, etc., considering both maritime safety and commercial usage perspectives. This collaborative effort serves as a pivotal milestone towards establishing more efficient, adaptable, and reliable communication within the 6G ecosystem for the maritime sector.  
Conceptualization, H.K., C.R.; formal analysis, H.K.; investigation, H.K.; writing--original draft preparation, H.K.; writing--review and editing, H.K., C.R., W.K.; visualization, H.K.; supervision, W.K.; project administration, H.K. All authors have read and agreed to the published version of the manuscript.  
This research was supported by the 'Development of Autonomous Ship Technology (20200615)' funded by the Ministry of Oceans and Fisheries (MOF, Republic of Korea).  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** No new data were created or analyzed in this study. Data sharing is not applicable to this article.  
**Conflicts of Interest:** The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.