Underwater Real-time Video Transmission via Wireless Optical Channels with Swarms of AUVs

Underwater wireless optical communication (UWOC) has received widespread attention recently due to its distinct advantages in terms of high bandwidth, low power consumption, low delay and confidentiality. However, unlike underwater acoustic communication systems, it suffers from constraints, such as limited communication range and misalignment in oceanic extreme environments. To perform long-distance high bandwidth transmission such as real-time video streaming, it requires relaying technology to perform reliable and robust transmission. Although pre-deploying a large number of sensor nodes is one of the possible solutions, this is impractical in response to emergency events, such as oil pipeline leakage and maritime search and rescue. To this end, in this paper, we propose to leverage a swarm of autonomous underwater vehicles (AUVs) to establish reliable underwater optical communication links in a rapidly changing marine environment for real-time video transmission. We first model the optical transmission channel, and then calculate both the optical angle and the reliable communicating range that satisfy a pre-defined bit error rate (BER). We then formulate the optimization problem based on two aligned solutions while targeting on minimizing both deployment energy consumption and time latency, in which the AUV's uncertainty issue caused by localization error and hovering instability is considered. Finally, we design an adaptive optical beam and power adjustment algorithm to enhance the robustness of the optical link further. Through extensive simulations, the results demonstrate that the proposed scheme is efficient and achieves reliable and robust communication.