Opportunistic Routing Strategies for UAV-Assisted Offshore Unmanned Surface Vessel Networks

Unmanned surface vessels (USVs) are increasingly utilized for maritime sensing and data collection. With advancements in Sixth-Generation (6G) mobile network technologies, such as UAV-assisted communication, it is now possible to utilize UAVs to provide auxiliary data collection services for USVs in offshore areas. Traditionally, UAV-assisted communication involves UAVs serving as dedicated, long-term relays for USVs. However, within the 6G paradigm, UAVs operate as public communication devices, offering only temporary relay services to USVs. This paper focuses on developing opportunistic routing strategies for this scenario. For ordinary data with low time sensitivity, the objective is to maximize the benefits of opportunistic communication, which is achieved using the proposed Utilization Priority (UP) strategy. For critical data with high time sensitivity, the goal is to ensure the fastest possible delivery, addressed through the proposed Completion Priority (CP) strategy. Simulation results demonstrate that employing UAVs as relays enhances network throughput and reduces latency. The UP strategy generally achieves higher throughput in most scenarios, while the CP strategy is more effective in minimizing network latency.