In today’s interconnected world, seamless data transmission is essential for communication, navigation, emergency response, research, and commercial operations. This necessity extends beyond mere overland structures, culminating beneath the ocean’s surface.
In 2024, underwater wireless communication networks (UWCNs) are gaining traction. While wireless communication is ubiquitous in terrestrial applications, the emerging market for UWCNs is rapidly expanding.
Astute Analytica projects that this market will soar to an impressive USD 21.06 billion by 2032, propelled by increasing demands for real-time data in marine environments.
Advancements in acoustic and optical communication technologies are driving the evolution of underwater networks. These technologies are enhancing connectivity, increasing data transfer speeds, and improving the overall reliability of underwater communications.
As these technologies evolve, they promise to revolutionize how data is transmitted and utilized beneath the waves, presenting new horizons for underwater exploration and industry.
Navigating the Depths
Underwater wireless communication networks (UWCNs) are increasingly integral to modern marine technology. These networks consist of sensors and autonomous underwater vehicles (AUVs) that interact, coordinate, and share information.
In recent years, UWCNs have revolutionized a range of applications, including those prevalent in coastal surveillance and environmental research, oil-rig maintenance, AUV operations, and water quality monitoring. They have also been instrumental in connecting submarines to land.
Unlike their terrestrial counterparts, which rely on radio waves, UWCNs primarily use acoustic waves. Acoustic communication is favored underwater due to its low absorption, making it suitable for transmitting data over medium ranges. However, this structure comes with limitations.
Acoustic technology typically supports data rates of tens of thousands of kilobits per second for distances up to a kilometer, and less than a thousand kilobits per second for distances up to 100 kilometers. The relatively slow speed of sound in water—approximately 1500 meters per second—results in high latency, making real-time communication and synchronization a challenge.
This latency hampers applications that require instantaneous, high-data-rate communication. In response, optical communication offers an alternative that is capable of achieving high data rates. Yet, it is also constrained by the underwater environment's high multi-scattering and absorption, limiting the effective distance between the transmitter and receiver. These physical challenges mean that optical methods work best for short-range communication.
Both acoustic and optical communication technologies have distinct advantages and limitations, and ongoing research and development (R&D) is required to overcome these obstacles and enhance the capabilities of underwater networks for a multitude of critical use cases.
While cellular technology cannot be directly applied underwater due to the physical differences in propagation media, its principles, methodologies, and innovations provide a valuable foundation for advancing UWCNs. By leveraging these technologies, UWCNs can achieve better performance, robustness, and efficiency, addressing the unique challenges of underwater communication.
Hybrid Communication Systems
The underwater acoustic communication market is set to grow significantly, reaching USD 9.2 billion by 2031, driven by increased defense spending and the demand for reliable communication systems in naval operations.
It has also been proven that optical wireless communication can enable high-speed data transmission rates of up to 10 Gbps, presenting new possibilities for data-intensive applications.
With recent advancements in UWCNs, the development of hybrid communication systems combine the two methods to improve performance. For instance, systems that use both acoustic and optical communication can balance long-range connectivity with high-speed data transfer.
These hybrid systems can switch between methods based on the underwater conditions and the specific needs of the communication task, enhancing reliability and efficiency.
Adaptive Modulation and Coding
To cope with the challenging underwater environment, researchers have developed advanced modulation and coding techniques. These systems can adapt their transmission methods in real time, adjusting to changing conditions like water turbulence or obstacles.
For example, Orthogonal Frequency Division Multiplexing (OFDM) has been optimized for underwater use. This aids in the navigation of complex and often noisy underwater channels, thereby improving data rates and communication reliability.
Nevertheless, wireless communication for underwater robots remains a significant challenge, as standard radio frequencies used on land do not effectively propagate through water.
In February 2024, the Autonomous Robotics Research Center (ARRC) at Abu Dhabi’s Technology Innovation Institute (TII) achieved breakthroughs by introducing the Universal Underwater Software Defined Modem (UniSDM) and a network management framework for automatic network slicing (ANS).
The UniSDM offers a flexible communication architecture utilizing sound, magnetic induction, light, and radio waves. Meanwhile, the ANS framework efficiently allocates communication resources within underwater networks, enhancing data sharing and connectivity based on real-time network conditions.
Use of AI and Machine Learning
Artificial Intelligence (AI) and machine learning (ML) technologies significantly contribute to making UWCNs smarter and more efficient. AI can predict underwater channel conditions and optimize communication parameters accordingly, which helps in maintaining reliable connections even in fluctuating environments.
Moreover, AI algorithms can manage network routing and resource allocation dynamically, improving the overall performance and energy efficiency of underwater networks.
In a 2023 scientific report, a comparative analysis of intelligent optimization algorithms highlighted the enhanced effectiveness of the chemical reaction optimization (CRO) algorithm for optimizing node deployment in underwater wireless sensor networks (UWSNs).
The enhanced CRO algorithm surpassed traditional ones upon demonstrating an average coverage rate of 95.66%. This indicates that by integrating robot collaboration technology, the enhanced CRO algorithm has the potential to greatly improve UWSN coverage through optimal node deployment.
Innovative Network Architectures
In addition, innovative network architectures are enhancing the flexibility and robustness of UWCNs. One such architecture is the Delay-Tolerant Network (DTN), which stores and forwards data, enabling communication even when connections are intermittent. This makes it particularly useful for deep-sea explorations.
Additionally, Software-Defined Networking (SDN) principles are being applied to underwater networks to enable centralized control and dynamic adjustments, allowing the network to reconfigure itself based on current conditions and requirements.
In this regard, an ultra-low-power underwater networking system has been developed by MIT researchers to transmit signals across kilometers. This technology is anticipated to benefit aquaculture, hurricane prediction, and climate change modeling, thereby boosting growth in the underwater wireless communication market.
Integration with Internet of Things (IoT)
The concept of the Underwater Internet of Things (UIoT) is gaining traction. This involves integrating smart sensors and devices underwater that can communicate and share data, much like IoT devices on land.
These systems can perform local data processing through edge computing, which reduces the need for constant data transmission and saves energy. This integration is crucial for applications like environmental monitoring and underwater infrastructure inspection.
One scenario that could support UIoT is the collaboration between Wsense and Alcatel Submarine Networks (ASN), announced in January 2024. This partnership aims to develop the next generation of underwater wireless communication systems.
The collaboration will utilize WSense's underwater communication technology and ASN's network to establish telecoms networks underwater.
In the long run, this project aims to enable real-time remote monitoring, enhance disaster prediction capabilities, and support surveillance and naval operations for coastal security.
Enhanced AUV Communication
Due to their capacity to operate independently of direct human control, Autonomous Underwater Vehicles (AUVs) have become indispensable in defense, oil and gas exploration, and oceanographic research.
Advancements in communication technologies are improving the coordination and control of AUVs when it comes to data exchange, remote operation, and enabling collaborative missions between multiple vehicles. New algorithms allow multiple AUVs to work together, sharing data and coordinating their movements to accomplish complex tasks.
Furthermore, Remotely Operated Vehicles (ROVs) are extensively utilized in environmental research, exploration, and maintenance tasks. As they advance towards greater autonomy, there is an increasing demand for robust, real-time data transmission capabilities.
Innovations such as self-organizing networks of AUVs can also adapt to changing conditions and mission requirements, making them highly effective for tasks like search and rescue or large-scale mapping.
Field Deployments and Testing
Real-world deployments and extensive field trials are crucial for validating these advancements. By testing UWCNs in various underwater environments like oceans, lakes, and rivers, researchers can gather practical insights into how these networks perform in actual conditions.
These trials help refine the technology, ensuring it can reliably support applications ranging from scientific research to military surveillance and environmental monitoring.
In 2024, researchers developed an all-light communication network enabling seamless connectivity across space, air, and underwater environments.
Led by Yongjin Wang, the team highlighted its potential in oceans and lakes for ecological data collection, linking sensors with surface buoys. This network facilitates wireless data transmission over water surfaces and long-distance links between cities, extending internet connectivity via modems.
“In today’s world, data transmission is critical for communication, navigation, emergency response, research and commercial activities,” reiterated research team leader, Yongjin Wang.
Moreover, in 2022, researchers at the University of Washington introduced AquaApp, an innovative solution that strives to enhance diver safety during underwater exploration. This app utilizes underwater acoustics to transmit messages effectively. Importantly, AquaApp leverages existing smartphones and smartwatches without requiring additional hardware, making it accessible for divers using current market technology.
Similarly, L3Harris's CUUUWi allows mobile phones and SatCom users to connect with users or platforms beyond ground-level surfaces, supporting critical communications within submarines, which rely on secure transmissions during high-speed and deep operations.
