Underwater Wireless Communication Research Articles

Enhancing Underwater Wireless Sensor Networks With Flexible Communication and Positioning

An innovative approach centred around underwater wireless communication and positioning in Underwater Wireless Sensor Networks, addressing limited coverage by proposing a dual-hop system combining optical fiber and wireless links. Time frame design and Code Division Multiplexing Access enhance multi-user signal transmission efficiency. Proof-of-concept experiments validate feasibility, with the introduction of the hybrid fish eye routing protocol further enhancing performance by intelligently combining fish-eye routing and traditional protocols for improved coverage and reliability. Moreover, the hybrid fish eye protocol incorporates adaptive routing algorithms that dynamically adjust to changes in underwater conditions, ensuring robustness and adaptability in challenging environments. Additionally, the hybrid fish eye protocol optimizes energy consumption by minimizing unnecessary transmissions, thereby prolonging the lifespan of underwater sensor networks. With full-duplex communication, precise positioning, and an extended transmission range, convergent system demonstrates significant potential for supporting high-capacity transmission among mobile nodes in forthcoming underwater scenarios

Joint Energy and Security Optimization in Underwater Wireless Communication Networks

Joint Energy and Security Optimization in Underwater Wireless Communication Networks

Практические аспекты построения систем беспроводной подводной оптической связи для телекоммуникационных приложений

The overview of the principles of organizing underwater wireless optical communication is presented in the paper. The basic features of the optical communication system design with the usage of laser and LED emitters working in the visible range, as well as using various types of modulation, are considered. A comparative review of the developments of underwater wireless optical communication systems, operating at distances up to one hundred meters and with data transfer rates up to tens of Gbit/s, is presented. In addition, a comparative review of design of underwater optical modems is considered. It is shown, that the further prospect of their development is the combination of various methods of underwater wireless communication, including the use of MIMO technology.

Use of the 433MHz band for underwater communications in controlled environments

This research aims to design and implement an underwater communication system using radio frequency modules and Arduino. Underwater wireless communication is challenging due to the attenuation of electromagnetic waves in water. However, radio frequency signals in the 433MHz range and the added antenna have shown successful data transfer. For this purpose, measurements are made at different distances, and data is collected in the aquatic environment and free space. A comparative analysis of the values of arrival powers and losses in the studied environment is carried out to verify the efficiency of this study in terms of range, transmission speed, and reliability.

The Feasibility of Electromagnetic Wave Underwater Wireless Communication in Shallow Pure Water Medium at Frequency Band 0.5GHz-4.5GHz

The Feasibility of Electromagnetic Wave Underwater Wireless Communication in Shallow Pure Water Medium at Frequency Band 0.5GHz-4.5GHz

Neural-network-based end-to-end learning for adaptive optimization of two-dimensional signal generation in UVLC systems.

Visible light communication (VLC) benefits from the underwater blue-green window and holds immense potential for underwater wireless communication. In order to address the limitations of various equipment and harsh channel conditions in the underwater visible light communication (UVLC) system, the researchers proposed to use the method of autoencoder (AE) to tap the potential of the system. However, traditional AE schemes involve replacing the transmitting and receiving components of a communication system with a large multilayer perceptron (MLP) network, and they have significant drawbacks due to their reliance on a single network structure. In this paper, a novel 2D adaptive optimization autoencoder (2D-AOAE) framework is proposed to realize adaptive modulation and demodulation of two-dimensional signals. By implementing this scheme, we experimentally achieved a transmission rate of 2.85 Gbps over a 1.2-meter underwater VLC link. Compared to the traditional 32QAM UVLC system, the 2D-AOAE scheme demonstrated a 15.4% data rate increase. Moreover, the 2D-AOAE scheme exhibited a remarkable 73% improvement when compared to the UVLC system utilizing the traditional AE scheme. This significant enhancement highlights the superior performance and capabilities of the 2D-AOAE scheme in terms of transmission rate.

ОРГАНИЗАЦИЯ ПОДВОДНОЙ БЕСПРОВОДНОЙ СИСТЕМЫ СВЯЗИ

The article discusses underwater wireless communication systems. Research in the field of underwater optical wireless communication system will allow developing science, industry, to find solutions to defense tasks and emergencies, to carry out remote monitoring of environmental pollution of the underwater world and control underwater objects and equipment of oilrigs, to conduct underwater research and much more. The purpose of the work is to develop a classification of the principles of construction and organization of underwater wireless communication, taking into account modern achievements and development of technologies in the field of underwater wireless communication systems, to assess the strengths and weaknesses of underwater acoustic, radio frequency and optical communication systems. It is shown that the underwater optical wireless communication system has a great potential to enhance the traditional underwater acoustic communication system and underwater radio frequency communication system due to the high speed of information transmission, low latency, lower power consumption and compact size. To select the equipment and organize the communication channel, a generalized classification of an underwater optical wireless communication system has been developed, depending on the routing protocols used, on the configuration of the communication channel, on the optical properties of water, on the type of water in which the transmission channel is organized, on the mobility of underwater vehicles and the coverage area, on the type of modulation used, the method of underwater communication and from the factors affecting the organization of the communication channel.

Toward Immersive Underwater Cloud-Enabled Networks: Prospects and Challenges

Underwater engineering significantly increases the liveability and sustainability of our planet's ecosystems. Enhancing the connectivity of ocean-based engineering systems and ensuring its digital resilience is, therefore, indispensable for reaping the benefits of underwater engineering systems. To this end, this work proposes augmenting underwater engineering systems with cloud connectivity platforms as a paradigm shift for upscaling underwater communication networks and applications. The envisioned underwater cloud-assisted network (UCAN) provides joint underwater computing, processing, communication, and acquisition while benefitting from the cooling features of the aquatic environment. We first survey the literature on conventional underwater wireless communication networks. We then describe the prospects for UCANs and advocate the deployment of UCANs for sustainable connectivity. Next, we explore the opportunities stemming from the deployment of UCANs—e.g., resource management, natural cooling, and underwater intelligence. Finally, we highlight the challenges and open issues arising from such a futuristic cloud-enabled underwater communication network—e.g., channel modeling, characterizing achievable-rate, quality-of-service retrofitting, and preserving marine biodiversity.

A Hybrid Optical-Acoustic Modem Based on MimoOfdm for Reliable Data Transmission in Green Underwater Wireless Communication

A Hybrid Optical-Acoustic Modem Based on MimoOfdm for Reliable Data Transmission in Green Underwater Wireless Communication

Inspection Operations and Hole Detection in Fish Net Cages through a Hybrid Underwater Intervention System Using Deep Learning Techniques

Net inspection in fish-farm cages is a daily task for divers. This task represents a high cost for fish farms and is a high-risk activity for human operators. The total inspection surface can be more than 1500 m2, which means that this activity is time-consuming. Taking into account the severe restrictions for human operators in such hostile underwater conditions, this activity represents a significant area for improvement. A platform for net inspection is proposed in this work. This platform includes a surface vehicle, a ground control station, and an underwater vehicle (BlueROV2 heavy) which incorporates artificial intelligence, trajectory control procedures, and the necessary communications. In this platform, computer vision was integrated, involving a convolutional neural network trained to predict the distance between the net and the robot. Additionally, an object detection algorithm was developed to recognize holes in the net. Furthermore, a simulation environment was established to evaluate the inspection trajectory algorithms. Tests were also conducted to evaluate how underwater wireless communications perform in this underwater scenario. Experimental results about the hole detection, net distance estimation, and the inspection trajectories demonstrated robustness, usability, and viability of the proposed methodology. The experimental validation took place in the CIRTESU tank, which has dimensions of 12 × 8 × 5 m, at Universitat Jaume I.

Prospects for visible color for underwater wireless broadband communications

Prospects for visible color for underwater wireless broadband communications

Performance Evaluation of Underwater Routing Protocols DHRP, LASR and DFR for Underwater Wireless Sensor Network using MATLAB

Communication issues in Underwater Wireless Sensor Networks (UWSNs) are the main problem. In this research paper and we proposed “Dolphin Heterogeneous Routing Protocol” (DHRP) and it determine the most efficient path to destination, it balance the energy and it increase the lifetime of nodes. Due to the lack of growth in underwater wireless communications, Communication cables are still used for underwater communication. The use of wires to ensure the communication of sensor nodes at the ocean's depths is extremely costly. In underwater wireless sensor networks, determining the optimum route to convey sensed data to the destination in the shortest amount of time has become a major difficulty (UWSN). Because of the challenging communication medium, UWSN routing protocols are incompatible with those used in traditional sensor networks. Existing routing protocols have the problem of requiring more energy to send data packets, as well as experiencing higher delays due to the selection of ineffective routes. This research introduces the Dolphin Heterogeneous Routing Protocol (DHRP) to tackle the routing issues faced by UWSN. The swarming behavior of dolphins in search of food is the inspiration for DHRP. In order to find the best route in UWSN, DHRP goes through six essential processes are initialization, searching, calling, reception, predation and termination.

A Highly Compatible Optical/Acoustic Modem based on MIMO-OFDM for Underwater Wireless Communication using FPGA

This work is on Underwater Wireless Communication using optical/acoustic modem based on MIMO–OFDM method. Underwater Communication is a vast field where data analysis is performed on sea exploration, aquatic animals, aquatic species etc. But the current system is based on sound as medium for communication. This system faces many significant problems which plays a key role in affecting the performance of the entire system lost the data and resulting in efficiency of the system only for a few meters radius of transmission and reception. In this paper, the modem designed for both optical (light) and acoustic (ultrasound) signals using MATLAB Simulink and implemented on Xilinx System generator using FPGA. This helps in drastic reduction in the data loss. The communication of the proposed optical/acoustic modem is based on MIMO-OFDM multiplexing technique. The combination of MIMO-OFDM was very useful since MIMO does not use multiple generation i.e., it enhances the capacity by transmitting different signals over multiple antennas and OFDM reduces the need for signal equalization and increases the spectrum efficiency without adding additional bandwidth. The efficiency of the system is analyzed through the achieved data transmission and reception of data. The results prove the better performance of the proposed modem for underwater wireless communication.

Editorial for the Special Issue on Underwater Wireless Communications and Sensor Networks Technology

In the scientific, military, and industrial world, the deployment of robust, reliable, secure, and efficient wireless communication links is of particular importance [...]

BECS-II: an updated bio-inspired electrocommunication system for small underwater robots.

Some weakly electric fish can use electric signals to interact and communicate with each other in dark and complex underwater environments where traditional underwater communication fails. In our previous work, we developed a bio-inspired electrocommunication system (BECS) that serves as an effective alternative to traditional methods in this challenging underwater scenario performing communication at a speed of approximately 1200 bps (bits per second) within approximately 3 m. In this study, a novel underwater wireless communication system (BECS-II) is proposed to upgrade the BECS with much better performance. We first propose theoretical and simulation models for electrocommunication, including the effects of the angular frequency and electrode impedance. A custom-made digital communication system is employed in BECS-II to improve the anti-interference ability and channel capacity of the BECS. In addition, a novel circuit optimization strategy was used to develop a customized circuit to enhance the transmitting and receiving capabilities of the BECS-II. Dual-frequency communication is proposed to meet the communication demands of different tasks by taking inspiration from the task allocation and evolution mechanisms of weakly electric fish. The experimental results showed that BECS-II outperformed BECS in high-frequency mode at both the communication speed (approximately 20 kbps) and distance (approximately 10 m), whereas in low-frequency mode, it extended the communication range by transmitting data up to a distance of approximately 20 m at a speed of approximately 200 bps. A substantial increase in the communication distance can expand the robot motion space in a group and improve group flexibility.&#xD.

Underwater Wireless Video Communication Using Blue Light

Interest in wireless blue light communication is increasing because this technology shows promise for realizing high-speed, long-distance and full-duplex underwater communication. Here, we demonstrate an underwater wireless communication system, OceanLink, to establish full-duplex data transmission using blue light. Both the transmitter and receiver are housed together to independently transmit and receive data simultaneously. To obtain a longer transmission distance and better light field distribution, the transmitter is composed of an array of three light-emitting diode (LED) units with the dominant emission peak wavelength centered around 452 nm, each of which merges four LEDs in series. These LEDs are synchronously driven via a main processing unit to pulse blue light using a nonreturn-to-zero on-off keying modulation scheme. At the receiver, light passes through a neutral density (ND) filter and a focus lens to hit the transducer, which converts light signals into electrical signals. The waterproof OceanLink achieves a bidirectional communication rate of 4 Mbps with a wireless transmission distance of 12 m in a swimming pool, wherein the ND factor is 256 and the nephelometric turbidity unit is 1.7. Thus, real-time full-duplex underwater video communication is experimentally demonstrated.

Channel capacity on visible light communication

As a typical application scheme of OWC (Optical Wireless Communication), VLC (Visible Light Communication) plays a more vital role in our daily life. It is expected to be used in the fields of vehicle communication, 6G network, underwater wireless communication, etc. Although so many achievements on VLC have been obtained, researchers still have some obstacles to overcome. Channel capacity as an important quota to evaluate communication quality deserves researchers to study further. This paper not only discusses the basic theory and combines the results of some recent studies on visible light channel capacity, but also highlights a promising application prospect and advantages over other communication methods, including RF (radio frequency), and fiber optical. This paper draws a conclusion that VLC is mainly used in indoor and short-distance communication. There is still a long way to apply VLC in long-distance communication and overcome the fading problem.

Energy harvesting techniques for sustainable underwater wireless communication networks: A review

The emergence of various underwater wireless communication systems has been on the rise due to increasing human activities in the marine environment. In underwater wireless communication networks (UWCNs), several communication devices, such as sensors and autonomous underwater vehicles (AUV) are interconnected to expand communication coverage, monitoring, information gathering, and surveillance. These devices operate on batteries, making their replacement and recharging difficult. Consequently, sustaining the operational lifetime of UWCNs is deemed a major challenge. This leads to the development of various energy harvesting (EH) techniques to perpetuate the power supply to underwater devices. In this paper, we present a review of various energy sources and EH techniques applicable to UWCNs. To achieve this, we classify the energy sources into various categories in order to establish the peculiarities of each source and the type of harvester applicable to each category. Based on this classification, we present discussions on various contributions of articles related to applications of EH techniques in UWCNs. In addition to various insights gained from the presented papers, we establish that energy harvesters based on triboelectric effect, piezoelectric effect, sediment microbial fuel cell, acoustic, and optical power transfer are suitable for low-power (milliwatt-order) consuming devices such as sensors. Also, for devices with high power consumption requirement, such as AUV, solar and inductive power transfer-based harvesters should be employed. Furthermore, we identify several technical challenges that should be taken into consideration during the planning and system design phases. Finally, we highlight open research areas that could further improve the EH and communication processes in UWCNs.

Three-Hop Underwater Wireless Communications: A Novel Relay Deployment Technique

Underwater long-distance wireless communication (ULWC) is a critical challenge in many applications, such as marine environmental monitoring, underwater remote control, and underwater navigation, to name a few. However, very little literature focuses on ULWC, especially where the communication distance ups to thousands of kilometers, which is urgently required in the underwater Internet of Things (UIoT) in the large-scale and deep sea. In this paper, to improve the underwater communication capacity at a level of thousands of kilometers, we propose a three-hop underwater wireless acoustic communication (3H-UWAC) structure based on the Sound Fixing and Ranging (SOFAR) channel. The proposed 3H-UWAC consists of transmitters, relay stations (RSs), and receivers. Different from the existing ULWC, 3H-ULWC can improve energy efficiency with a small vertical directivity angle (VDA). Due to the characteristics of UWAC, the straight-line communication link can be realized in the proposed three hops, and the communication distance can be increased to thousands of kilometers. Respecting the randomness of underwater devices, tools from stochastic geometry are used to model the spatial distributions of transmitters’, receivers’, and RSs’ locations. RSs are set on the SOFAR channel at a known depth. In the first hop, the transmitter sends information to the nearest first relay station (NFRS) on the SOFAR plane. In the second hop, the NFRS sends information to the nearest relay station, which is called the nearest second relay station (NSRS), to the receiver on the SOFAR plane. In the third hop, SNFS sends information to the receiver. All three communication hops can be achieved with a narrow beam width, where the energy efficiency is improved critically. With given densities of transmitters, RSs, and receivers, the coverage probabilities (CPs) of the three hops (transmitter to FRS, FRS to SRS, and SRS to receiver) are analyzed, and the final CP from a transmitter to a receiver through the 3H link is derived. Insights about the effects of VDAs at the transmitters, FNRS, and SNRS, as well as the depths of transmitters and receivers, are revealed. A rapid optimization method is proposed based on the analytical results. The accuracy of the analysis is verified by Monte-Carlo simulations.

Research on duplex underwater wireless laser communication system

To improve the bit error rate (BER) of underwater wireless laser communication and increase communication speed, a duplex underwater wireless laser communication system is designed. The system uses both blue and green lasers to transmit signals simultaneously, and adopts an improved modulation and demodulation algorithm to achieve separate modulation of the two sets of signals. A duplex underwater wireless laser communication system builds based on 440 and 550 nm lasers. On the basis of analyzing the absorption and scattering characteristics of seawater in laser communication, the influence of turbulence on communication efficiency is discussed. Improved the traditional duplex modulation algorithm and conducted communication testing at a depth of 2.0 m underwater. The experimental results show that when the communication distance increases from 5 to 50 m, the BER of the unoptimized duplex mode increases from 2.34 × 10−7 to 3.5 × 10−5. After adopting the optimization algorithm, the BER increases from 2.81 × 10−7 to 1.18 × 10−6, and the signal attenuation has been significantly suppressed. The duplex communication structure and algorithm can effectively reduce the impact of communication distance on bit BER.