At the time of archiving, the student author of this dissertation opted to temporarily restrict access to it. The full text of this dissertation became available to the public after the expiration of the embargo on 2019-08-05.
Oceans form about three quarters of our planet Earth, and house immense resources that are critical for future generations. Exploring and monitoring such resources is becoming essential to protect the effected ones by the irresponsible human behavior, and to discover new ones. The limitations of depths mandate the search for alternatives and where human divers become endangered. Using remotely operated vehicles is commonly used for marine explorations, while tethered to ships. To be fully autonomous and to avoid damaging the fragile marine environment, they must be equipped with wireless communication solutions that enable real-time control and feedback on their maneuvering and mobility. Also, the ultimate tool to monitor, inspect and repair underwater structures is to use video streaming to mimic the reality of those unseen parts of the world.
Existing underwater communications do not provide the necessary features to transmit video from the deep. Acoustic waves as well as the radio frequency waves are either limited in bandwidths or strongly attenuated by the water medium. On the other hand, wireless optical communication is an emerging technology that provides high transmission speeds and can enable video streaming underwater.
This motivates bringing wireless optical technologies for real-time video streaming underwater to a practical implementation by undertaking theoretical and experimental studies of systems and techniques that can provide optimized solutions within our proposed framework. We present our video transmission architecture that facilitates programmable system configurations. Software defined platforms provide us with the means of configuring several setups to test our approach. In order to fully utilize the available optical spectrum, we have additionally implemented several modulation techniques in various laboratory scenarios. Real-time and ultra-high definition video has been successfully demonstrated. The overall system performance and throughput analysis have been provided. A thorough investigation of the system performance under various underwater channel conditions was undertaken. Also, as the delay resulting from queuing, when video packets are waiting for service, is key in time critical applications, we derive the mathematical model and investigate the delay effects and the packet dropping probability on the overall system performance when our setup is extended to a multi-channel configuration.
Al-Halafi, A. (2018). Real-Time and Ultra-High Definition Video Transmission in Underwater Wireless Optical Networks. KAUST Research Repository. https://doi.org/10.25781/KAUST-F49Q5