## 5 Conclusions  
This research developed an innovative smart ocean aquaculture monitoring system integrating multiple remote control systems and mobile communication technologies as core design components. The comprehensive system architecture comprises three interconnected components: the underwater ROV, the buoy communication relay system, and the cloud server infrastructure. The cloud server incorporates four functional modules (Web Server, MQTT Service, RTSP Service, and MySQL Database) that facilitate smooth integration between heterogeneous control interfaces and mobile communication networks. The underwater ROV features a dual-controller architecture combining microcontroller units (MCUs) and Raspberry Pi 3 B+, equipped with underwater cameras and multifunctional water quality sensors to provide robust hardware foundations for extensive remote monitoring capabilities. The main contribution of this research is integrating multiple control platforms while keeping communication reliable through existing 4G mobile networks. Unlike traditional aquaculture monitoring systems constrained by single control interfaces and limited communication ranges, this system enables operators to access and control the ROV through computers, smartphones, smartwatches, and multi-site central control centers, realizing true anytime, anywhere, multi-platform monitoring capabilities. The system architecturemaintains flexible upgrade pathways to Beyond 5G and low-orbit satellite communications, ensuring long-term scalability for deep-sea aquaculture applications. Comprehensive field validation across five distinct environments--including controlled laboratory settings, the Gongliao Aquatic Center, Keelung Harbor offshore cages, large-scale Pingtung offshore installations, and Xuejia freshwater ponds--demonstrated exceptional operational performance and communication stability. Quantitative analysis of over 500,000 data transmission events showed approximately 63% real-time transmission success within one second and 95.60% overall reliability within two seconds, validating the system's practical applicability across diverse aquaculture environments. The integration enables real-time image transmission and sensor data collection, significantly enhancing water quality monitoring accuracy and operational efficiency compared to traditional manual inspection methods. However, this research acknowledges several limitations that warrant consideration. First, the system's performance remains dependent on 4G network coverage, which may limit applications in extremely remote offshore areas until Beyond 5G infrastructure becomes widely available. Second, the current ROV operational duration of 0.72 h under normal underwater conditions, while sufficient for routine monitoring, may require enhancement for extended inspection missions. Third, the system requires initial technical training for operators to maximize multi-platform capabilities, potentially creating adoption barriers in resource-limited regions. From a cost-effectiveness perspective, the modular design approach utilizing commercial hardware components significantly reduces implementation costs compared to proprietary ROV systems. The system's TWD 3000-5000 estimated cost range make it particularly accessible for small-scale aquaculture operators, representing an approximate 60-80% cost reduction compared to equivalent commercial solutions such as the CHASING M2 PRO or SEAMOR Marine ROV systems. The multi-platform control capability eliminates the need for specialized control equipment, further reducing operational costs while improving monitoring flexibility. The maturation of Beyond 5G and low-orbit satellite communication technologies will significantly expand this system's operational capabilities in remote ocean environments.