Oceanographic research is of paramount importance for the future of planet Earth. This is clear and promoted by initiatives such as Horizon’s 2020 Blue Growth, which includes, among other things, the prevention and mitigation of polluting incidents. This concerns the impact on ecosystems and is closely related to the increasing demand for information and communication technologies (ICT) to support researchers from varied disciplines.
We propose a solution that considers dynamic integrated communication between different maritime activities, carried out by researchers and other actors, in challenging environments such as the Arctic.
Nowadays the planet is monitored by several satellite systems that provide insightful research data but that also reveals the need for more detailed information. One way to acquire this data is through dedicated research expeditions, which are costly and dangerous in extreme environments, such as the Arctic. Alternatively, dedicated communication infrastructures have been used to support research in important areas of the globe, but these are limited in resources and extremely costly. Moreover, due to a wide range of interests, several activities may take place in the same areas. For this reason, it is necessary to consider a solution that is able to cope with diverse applications and activities likely to be conducted in maritime environments, as shown in Figure 1.
Scenario and Requirements
Oceans cover a vast majority of the planet and the most common communication solutions rely on satellite-links. Other radio technologies are also used, providing dedicated alternative communication links. Nonetheless, these different technologies are typically not shared or reusable in the vast interest on oceanographic activities, which goes beyond scientific research and includes the economic potential for private, public, governmental and military stakeholders. This lack of integration renders the available communication systems as insufficient since they are not sustainable nor do they scale with the increasing interest on oceanographic activities.
The requirements of envisaged maritime operations are very high for today’s standards, including near real-time access to data and support for high data-transfer rates, supporting highly-complex scientific equipment and thousands of concurrent users. This results not only from a large span of scientific activities, from data collection for applied research in several fields, such as biology, geology or geophysics, but also from industry-related activities, such as fishing, transportation or resource exploitation (e.g. gas and oil), and even from international joint activities such as humanitarian response, environmental response (e.g. oil spills), International Search & Rescue (SAR) or counter-trafficking.
Even though infrastructures are not typically available in many maritime environments, there would be a common interest by multiple entities in accessing such communication infrastructures, if they were available. This encourages the possibility of sharing infrastructures as a requirement, creating a unified and integrated communication architecture.
In the scope of the SINet project, a common networking layer is defined to dynamically handle several communication technologies, their requirements, and mismatched characteristics such as protocols, performance and delays. These technologies include different wireless-based systems between different actors from ships to sensor nodes (see Figure 2), which may also be supported by Cyber-Physical Systems (CPSs), such as Autonomous Underwater Vehicles (AUVs) or Unmanned Air Vehicles (UAVs), as well as by small-satellites acting as communication relays.
The definition of an integrated and heterogeneous communication architecture is also important to support more robust and fail-safe communications, being able to exploit alternative communication paths depending on how critical data may be (e.g. disaster monitoring data). Moreover, the overall system should take into consideration the total lifetime operation, carefully managing existing resources (e.g. energy) and avoiding constant maintenance.
An Integrated Communication Architecture
Flexibility and adaptability are mandatory for a communication solution in maritime and harsh environments, being able not only to accommodate the ever-changing conditions of such environments but also to dynamically support new services and flows from different users or operators. Communication networks for similar conditions can and have been deployed in the past, relying on careful and experimental off-site network planning, providing dedicated solutions for specific scenarios. However, this type of approach is very restrictive in the type of operations it supports and, in particular, does not scale nor does it allow a cost-effective reuse of the deployed network. Dynamic network planning is fundamental and must be considered in areas with limited or non-existent access to nearby infrastructures, as any changes would require costly and dangerous expeditions to reconfigure the deployed equipment.
The proposed approach aims at adapting the network to the technical challenges that may arise from harsh environments. Such communication networks will face fundamental problems including intermittent link availability and variable communication quality, which will have a direct impact in application-related performance. Moreover, this network will be typically composed of a combination of acoustic underwater communications, terrestrial or surface-based links, airborne links, as well as periodic satellite relay links. These transmitters and receivers are expected to be attached to different vehicles and infrastructures such as buoys, base-stations, mobile (underwater, surface, airborne) manned and unmanned vehicles, or even satellites. Finally, due to the ultimate goal of sharing this communication network with several entities, it must not be focused on static applications, or applications that rely on unrealistic models or hardware.
Nodes may have different applications and different and multiple communication systems, but the SINet proposal introduces a common layer that translates all these differences and integrates several distinct nodes together (Figure 3).
This modular routing approach provides also the mitigation of unexpected communication issues, using the heterogeneity of communication technologies for increased operation performance. This will allow to establish a bridge between multiple layers of communication, interconnecting them, as well as providing redundancy and backup communication links for crucial communications.