Multimodal, software defined networking for subsea sensing and monitoring.

The prevalence of oceanic industry and ocean borne interests has given rise to the concept of the Underwater Internet of Things as a vector for automation and data analytics in an environment hostile to anthropomorphic activity. Through the Internet of Underwater Things, it is theorised that sensors along the ocean floor or otherwise can be densely connected to the internet through wireless acoustic or optical links. However, both technologies have significant disadvantages that prevent either becoming a dominant technology. This project proposes a wireless software defined multimodal network infrastructure, that is proven using channel modelling and power analysis calculations, to be capable of robustly transmitting sensor data from source to sink by managing each technology according to its optimal environment. It was found that it is achievable to populate an opto-acoustic network in such a way that Successful Delivery Ratio becomes 90%-100% in clear water whilst achieving a 17% saving in overall energy consumption in a network mounted on a pipeline at 200 m depth when compared to a stand-alone equivalent acoustic network

A simulation into the physical and network layers of optical communication network for the subsea video surveillance of illicit activity.

Criminal activity is increasingly entering the ocean subsurface with acts such as illegal fishing and narco-submarining becoming points of contention. This among other illicit acts taking place in this domain imply a need for surveillance to render these activities apparent. However, subsurface Underwater Sensor Networking which is central to the surveillance is still generations behind terrestrial networking, therefore it is still challenging to monitor for subsurface activities. This is since the current signal transmission standard, acoustic communication, is limited in practical bandwidth and thus channel data-rate, this is, however, caveated with omni-directional propagation and supreme range rendering it reliable but incapable of carrying video or other data intensive sensor information. There is, however, an emerging technology based on optical (visible light) communication that can accommodate surveillance applications with superior data rates and energy savings. This investigation demonstrates how theoretically it is possible to achieve a network of underwater channels capable of sustaining a multimedia feed for monitoring subsurface activity using modern optical communication when in compared to an acoustic network. In addition, a simple topology was investigated that shows how the range limitations of this signaling can be extended by adding floating relay nodes. Through simulations in Network Simulator 3 (NS-3)/Aquasim-NG software it is shown that Visible Light wireless communication in visible light networks have a channel capacity high enough to carry out monitoring in strategic areas, referencing, optical modems that are available in the market. This implies that data-rates of 10 Mb/s are possible for the real-time video surveillance

Fuzzy logic, edge enabled underwater video surveillance through partially wireless optical communication.

Underwater surveillance is inherently tricky to achieve. Even in the clearest waters, the visibility tends to be in the range of tens of meters. Normally, tethered Remotely Operated Vehicles (ROVs) with underwater cameras are used for underwater imaging at closer ranges. Currently, detailed visible light imaging can be achieved utilising green laser technology, and this is limited to close ranges due to the inherent properties of light attenuation in water. The alternative is to utilise sonar based imaging which is capable of visualising distances, however, this technique is vulnerable to noise that interferes with the operating frequency, rendering the applications somewhat limited. The emergence of high data-rate, wireless, optical communication could allow for dense placement of short-range imaging equipment to monitor areas of strategic interest to extend the range, however, there needs to be a reliable method of wirelessly communicating this data to the sea surface regardless of the localised environmental conditions that may interfere with a visible light transmission. This paper proposes a fuzzy logic, edge computing enabled routing algorithm for optical networks that utilises a wired connection among source nodes to "pass" video data around among themselves to decide which seafloor node is best placed to transmit the data according to relative local turbidity, light intensity and sea-life activity, the main factors that hamper a well-considered wireless optical network. From there, a selected node can theoretically transmit the data from the source to the sea-surface through the wireless optical relay network implemented above. This mechanism shows promise in improving link reliability and throughput compared to alternative systems