Underwater Wireless Communication Networks Research Articles

Joint Energy and Security Optimization in Underwater Wireless Communication Networks

Joint Energy and Security Optimization in Underwater Wireless Communication Networks

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.

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.

Overview of Underwater Wireless Communication Routing Protocols

Underwater wireless communication is the use of acoustic, optical, electromagnetic waves and other technologies to send information underwater. This article reviews existing routing protocols for underwater wireless communication network design. Particular attention is paid to their performance in terms of communication efficiency, data rate, latency, and packet loss. The different types of routing protocols are discussed in detail, highlighting their respective strengths and weaknesses. This article also covers issues related to security and scalability and how they affect the performance of the entire network. Finally, this paper discusses the future trend of underwater routing protocols and proposes promising research directions.

Lifetime Maximization in Underwater Wireless Communication Networks

The rise in demand for underwater wireless communication networks (UWCN) has been driven by the emergence of new applications including unmanned underwater vehicles, deep-sea exploration, maritime and underwater archaeology research, and diver communications. For various applications, underwater network lifetime must be long, since unlike terrestrial sensor networks, it is a major job to change/recharge node batteries in underwater environments. In this paper, we introduce a solution where critical nodes in a UWCN are periodically recharged by small renewable energy sources. Further, a caching mechanism is introduced to relieve critical nodes of heavy workload when their residual energies run low. By leveraging these two techniques of energy replenishment and content-caching, the network lifetime extension challenge is formulated as an optimization problem. The results indicate that our proposed solution offers up to 45% longer UWCN lifetime compared to existing solutions.

State-of-the art and perspectives of underwater optical wireless communications

In scientific, military, and industrial sectors, the development of robust and efficient submarine wireless communication links is of enormous interest. Underwater wireless communications can be carried out through acoustic, radio frequency (RF), and optical waves. Underwater optical communication is not a new idea, but it has recently been considered because seawater exhibits a window of reduced absorption both in the visible spectrum and long-wavelength UV light (UV-A). Compared to its bandwidth limited acoustic counterpart, underwater optical wireless communications (UOWCs) can support higher data rates at low latency levels. Underwater wireless communication networks are important in ocean exploration, military tactical operations, environmental and water pollution monitoring. Anyway, given the rapid development of UOWC technology, documents are still needed showing the state of the art and the progress made by the most current research. This paper aims to examine current technologies, and those potentially available soon, for Underwater Optical Wireless Communication and to propose a new perspective using UV-A radiation.

On underwater acoustic particle velocity channels: Some experimental results

Studies have shown that acoustic particle velocity channels, in addition to the acoustic pressure channel, can be beneficial for underwater acoustic communication [A. Abdi and H. Guo, “A new compact multichannel receiver for underwater wireless communication networks,” IEEE Trans. Wireless Commun. 8, 3326–3329 (2009); A. Abdi, et al., “An overview of underwater acoustic communication via particle velocity channels: Channel modeling and transceiver design,” Proc. Meetings Acoust. 9, 070002 (2010)]. In this paper, we use experimentally measured acoustic particle velocity and acoustic pressure channels, using transmitted linearly frequency modulated (LFM) signals, to investigate and compare various signal and noise characteristics of these channels. Examples include signal and noise powers and ratios, delay spreads of the channels, temporal and spatial auto and cross covariance functions for the particle velocity and acoustic pressure noise components, and frequency responses of the acoustic particle velocity and acoustic pressure channels. Understanding these signal and noise characteristics allows a system designer to design and implement reliable and efficient underwater acoustic communication systems that employ multiple acoustic particle velocity channels, together with the acoustic pressure channel. [The work is supported in part by the National Science Foundation (NSF), Grant IIP-1500123.]

Some measured frequency domain characteristics of the underwater vector and scalar acoustic field components with applications to communication receivers

Vector and scalar components of the underwater acoustic field can be used for multichannel signal demodulation [A. Abdi, et al., “A new vector sensor receiver for underwater acoustic communication,” in Proceedings of the Oceans (2007), pp. 1–10; A. Abdi and H. Guo, “A new compact multichannel receiver for underwater wireless communication networks,” IEEE Trans. Wireless Commun. 8, 3326–3329 (2009)]. In frequency domain-based communication methods such as orthogonal frequency division multiplexing (OFDM) using multiple collected signals, understanding the behavior of the channels in frequency domain is important for proper system design. In this paper, we examine the experimental data obtained by transmitting pilot tones for channel estimation, to estimate various channel frequency responses. More specifically, channel frequency responses of the X, Y and Z components of the underwater acoustic vector field are estimated, in addition to the scalar field component channel frequency response. Analysis of the measured frequency responses reveals differences in parameters such as condition numbers and eigenvalues of measured channel matrices. Knowledge of these parameters is needed for designing communication receivers that utilize the vector and scalar components of the acoustic field in frequency domain. [The work is supported in part by NSF, Grant IIP-1500123.]

On applying stochastic network calculus for Gilbert-Elliot fading channel in underwater wireless communication networks

The main contribution in this research work is thus to use modern mathematical approaches using stochastic network calculus to model the fading effects in underwater channel. Also, the design methodology adopted was to create these mathematical models using Proto-C in Riverbed Modeler Simulation tool and test them using different scenario's representing an underwater communication environment. This work is the first of its kind in terms of applying stochastic network calculus and deriving the necessary stochastic service guarantees for underwater wireless communication. The value of the findings prove that stochastic network calculus can emerge as an elegant mathematical tool for assessing underwater network performance. The significance of the work is that; this approach of modelling underwater networks provides guidelines for modelling the transmission strategies in any underwater simulation studies. The need and purpose of this work is to help researchers adapt stochastic network calculus to model the physical layer and its parameters, that closely represents the real-time underwater scenario. The importance of accurately modelling the physical layer will improve the efficiency of the performance in the upper layers and the entire underwater end-to-end network. The findings derived from stochastic service guarantees verifies that stochastic performance bounds are very close and results in minimal delay, backlog in the designed underwater network.

A multiple-input multiple-output orthogonal frequency division multiplexing underwater communication system using vector transducers

Vector sensors and transducers are compact multichannel devices that can be used for underwater communication via acoustic particle velocity channels (A. Abdi and H. Guo, “A new compact multichannel receiver for underwater wireless communication networks,” IEEE Transactions on Wireless Communications, vol. 8, pp. 3326-3329, 2009). In this paper, a multiple-input multiple-output (MIMO) underwater acoustic communication system is presented using orthogonal frequency division multiplexing (OFDM) modulation. Upon transmitting multiple independent data streams simultaneously over several channels, this MIMO system can increase the transmission rate, whereas the OFDM modulation mitigates the highly frequency selective underwater channels. Various components of the system including vector transducers and algorithms for synchronization, channel estimation, MIMO detection, channel coding, etc., are designed and implemented. Using this system, experiments are conducted to measure and study acoustic particle velocity channels in the MIMO setup. Additionally, system performance parameters such as bit error rate and spectral efficiency are measured and discussed for various conditions and configurations, to understand the performance of the developed vector MIMO-OFDM system. [The work was supported in part by the National Science Foundation (NSF), Grant IIP-1500123.]

Slime Mold Inspired Swarm Robot System for Underwater Wireless Data Communication

Swarm robotics is a collection of mobile robots that displays swarm behavior. This paper presents a simulator of slime mold amoeba inspired swarm robot for underwater wireless communication system. The slime mold inspired robotic swarm is used to overcome the challenges of transmitting data in a large underwater environment. Underwater communication systems today are primarily acoustic technology and characterized by limited and distance dependent bandwidth, presence of multipath, and low speed of sound propagation. The robots navigate and seek the shortest path creating a virtual connection between the data transmitter and receiver similar to the foraging behavior of swarms. Each individual robot going back and forth from the transmitter to the receiver and vice-versa acts as a “physical” carrier of the data. Swarm robots navigate using swarm level intelligence based on the signal propagation technique used by slime mold amoeba aggregation using acoustics communication. The robot swarm system is developed, simulated and tested using the coded simulator. Using the slime mold inspired swarm robot system; the simulation successfully performed the data “foraging” scenario and showed the ability of the swarm to provide a virtual link in an underwater wireless communication network.

Comprehensive Study of Acoustic Channel Models for Underwater Wireless Communication Networks

Comprehensive Study of Acoustic Channel Models for Underwater Wireless Communication Networks

Swarm Robot System for Underwater Communication Network

This paper presents a swarm robot simulator for implementing underwater wireless communication network. Swarm intelligence is based on the collective behavior of social insects and animals such as ants, bees and others. In this paper, swarm was applied to overcome the challenges of transmitting data in a large underwater environment. A robot considered to be a member of the swarm acts as a simple “physical” carrier of the data, it moves until they converge and manage to form a link connecting the data transmitter and receiver. The system is developed, simulated and tested using a coded simulator.

Magnetic Induction for Underwater Wireless Communication Networks

Although acoustic waves are the most versatile and widely used physical layer technology for underwater wireless communication networks (UWCNs), they are adversely affected by ambient noise, multipath propagation, and fading. The large propagation delays, low bandwidth, and high bit error rates of the underwater acoustic channel hinder communication as well. These operational limits call for complementary technologies or communication alternatives when the acoustic channel is severely degraded. Magnetic induction (MI) is a promising technique for UWCNs that is not affected by large propagation delays, multipath propagation, and fading. In this paper, the MI communication channel has been modeled. Its propagation characteristics have been compared to the electromagnetic and acoustic communication systems through theoretical analysis and numerical evaluations. The results prove the feasibility of MI communication in underwater environments. The MI waveguide technique is developed to reduce path loss. The communication range between source and destination is considerably extended to hundreds of meters in fresh water due to its superior bit error rate performance.

Securing underwater wireless communication networks

Underwater wireless communication networks are particularly vulnerable to malicious attacks due to the high bit error rates, large and variable propagation delays, and low bandwidth of acoustic channels. The unique characteristics of the underwater acoustic communication channel, and the differences between underwater sensor networks and their ground-based counterparts require the development of efficient and reliable security mechanisms. In this article, a complete survey of security for UWCNs is presented, and the research challenges for secure communication in this environment are outlined.

A new compact multichannel receiver for underwater wireless communication networks

In this letter it is shown that by taking advantage of the particle velocity, in addition to the pressure, multichannel reception can be accomplished in underwater acoustic wireless channels. Theoretical formulation and Monte Carlo simulations are provided for a vector sensor equalizer that measures the pressure and the velocity at a single point in space. These results demonstrate the usefulness of small-size vector sensors as multichannel equalizers for underwater acoustic wireless systems and sensor networks.

Overview of channel models for underwater wireless communication networks

Acoustic communication in Underwater Wireless Communication Networks (UWCNs) has several challenges due to the presence of fading, multipath and refractive properties of the sound channel which necessitate the development of precise underwater channel models. Some existing channel models are simplified and do not consider multipath or multipath fading. In this paper, a detailed survey on ray-theory-based multipath Rayleigh underwater channel models for underwater wireless communication is presented and the research challenges for an efficient communication in this environment are outlined. These channel models are valid for shallow or deep water. They are based on acoustic propagation physics which captures different propagation paths of sound in the underwater and consider all the effects of shadow zones, multipath fading, operating frequency, depth and water temperature. The propagation characteristics are shown through mathematical analysis. Transmission losses between transceivers are investigated through simulations. Further simulations are carried out to study the bit error rate effects and the maximum internode distances for different networks and depths considering a 16-QAM modulation scheme with OFDM as the multicarrier transmission technique. The effect of weather season and the variability of ocean environmental factors such as water temperature on the communication performance are also shown. The mathematical analysis and simulations highlight important considerations for the deployment and operation of UWCNs.