Maritime Communication Network Research Articles

Sailing into the future: technologies, challenges, and opportunities for maritime communication networks in the 6G era

The maritime domain is a major driver of economic growth with emerging services, comprising intelligent transportation systems (ITSs), smart ports, security and safety, and ocean monitoring systems. Sixth generation (6G) mobile networks will offer various technologies, paving the way for reliable and autonomous maritime communication networks (MCNs), supporting these novel maritime services. This review presents the main enabling technologies for future MCNs and relevant use cases, including ITSs with reduced carbon footprint, ports and maritime infrastructure security, as well as fault detection and predictive maintenance. Moreover, the current trends in integrated satellite-aerial-terrestrial-maritime network architectures are discussed together with the different network segments and communication technologies, and machine learning integration aspects.

A series‐fed high‐quality linear array antenna for 5G maritime communications

AbstractA compact series‐fed high‐quality linear array antenna for 5G maritime communication is proposed. Building upon the wideband high‐efficiency electromagnetic radiation structure (WHEMS), a linear integrated series‐fed method is proposed, enhancing applicability in maritime environments. A self‐decoupling structure without the parasitic elements is introduced, resulting in a 7 dB increase in isolation while achieving array spacing of less than half the wavelength. The antenna has an impedance bandwidth of 19.9% (676–825 MHz) to cover the maritime 700 MHz application band, a high gain of 13–14.2 dBi, and a smaller volume compared to classical Yagi arrays with the same gain level. Furthermore, it exhibits characteristics such as low wind load, cost‐effectiveness, and high voltage resistance. The proposed antenna will play a vital role in the construction of the current 5G maritime communication network.

Game Theoretical Incentive for USV Fleet-Assisted Data Sharing in Maritime Communication Networks

Game Theoretical Incentive for USV Fleet-Assisted Data Sharing in Maritime Communication Networks

Improving Connectivity in 6G Maritime Communication Networks With UAV Swarms

Improving Connectivity in 6G Maritime Communication Networks With UAV Swarms

Joint Resource Management and Trajectory Optimization for UAV-Enabled Maritime Network.

Due to the lack of places to employ communication infrastructures, there are many coverage blind zones in maritime communication networks. Benefiting from the high flexibility and maneuverability, unmanned aerial vehicles (UAVs) have been proposed as a promising method to provide broadband maritime coverage for these blind zones. In this paper, a multi-UAV-enabled maritime communication model is proposed, where UAVs are deployed to provide the transmission service for maritime users. To improve the performance of the maritime communication systems, an optimization problem is formulated to maximize the minimum average throughput among all users by jointly optimizing the user association, power allocation, and UAV trajectory. To derive the solutions with a low computational complexity, we decompose this problem into three subproblems, namely user association optimization, power allocation optimization, and UAV trajectory optimization. Then, a joint iterative algorithm is developed to achieve the solutions based on the successive convex approximation and interior-point methods. Extensive simulation results validate the effectiveness of the proposed algorithm and demonstrate that UAVs can be used to enhance the maritime coverage.

Packet transport for maritime communications: A streaming coded UDP approach

The maritime communication network (MCN) plays an important role in the 6th generation (6G) system development. In MCNs, packet transport over long-distance lossy links will be ubiquitous. Transmission control protocol (TCP), the dominant transport protocol in the past decades, have had performance issues in such links. In this paper, we propose a novel transport approach which uses user datagram protocol (UDP) along with a simple yet effective bandwidth estimator for congestion control, and with a proactive packet-level forward erasure correction (FEC) code called streaming code to provide low-delay loss recovery without data retransmissions at all. We show that the approach can effectively address two issues of the state-of-the-art TCP variants in the long-distance lossy links, namely 1) the low bandwidth utilization caused by the slow increase of the congestion window (CWND) due to long round-trip time (RTT) and the frequent CWND drop due to random and congestion losses, and 2) the high end-to-end in-order delivery delay when re-transmissions are incurred to recover lost packets. In addition, we show that the scheme's goodput has good smoothness and short-term intra-protocol fairness properties, which are beneficial for multimedia streaming and interactive applications that are prominent parts of today's wireless traffic.

Energy harvesting space-air-sea integrated networks for MEC-enabled maritime Internet of Things

In recent years, various maritime applications such as unmanned surface vehicles, marine environment monitoring, target tracking, and emergency response have developed rapidly in maritime communication networks (MCNs), and these applications are often accompanied by complex computation tasks and low latency requirements. However, due to the limited resources of the vessels, it is critical to design an efficient mobile edge computing (MEC) enabled network for maritime computation. Inspired by this motivation, energy harvesting space-air-sea integrated networks (EH-SASINs) for maritime computation tasks offloading are proposed in this paper. We first make the optimal deployment of tethered aerostats (TAs) with the K-means method. In addition, we study the issue of computation task offloading for vessels, focusing on minimizing the process delay of computation task based on the proposed architecture. Finally, because of the NP-hard properties of the optimization problem, we solve it in two stages and propose an improved water-filling algorithm based on queuing theory. Simulation results show that the proposed EH-SASINs and algorithms outperform the existing scenarios and can reduce about 50% of the latency compared with local computation.

Trajectory design for UAV-enabled maritime secure communications: A reinforcement learning approach

This paper investigates an unmanned aerial vehicle (UAV)-enabled maritime secure communication network, where the UAV aims to provide the communication service to a legitimate mobile vessel in the presence of multiple eavesdroppers. In this maritime communication networks (MCNs), it is challenging for the UAV to determine its trajectory on the ocean, since it cannot land or replenish energy on the sea surface, the trajectory should be pre-designed before the UAV takes off. Furthermore, the take-off location of the UAV and the sea lane of the vessel may be random, which leads to a highly dynamic environment. To address these issues, we propose two reinforcement learning schemes, Q-learning and deep deterministic policy gradient (DDPG) algorithms, to solve the discrete and continuous UAV trajectory design problem, respectively. Simulation results are provided to validate the effectiveness and superior performance of the proposed reinforcement learning schemes versus the existing schemes in the literature. Additionally, the proposed DDPG algorithm converges faster and achieves higher utilities for the UAV, compared to the Q-learning algorithm.

Guest editorial: Maritime communications in 5G and beyond networks

With the rapid development of marine activities, there has been an increasing use of Internet-of-Things (IoT) devices for maritime applications. This leads to a growing demand for high-speed and ultra-reliable maritime communications. Current maritime communication networks (MCNs) mainly rely on satellites and on-shore base stations (BSs). The former generally provides limited transmission rate while the latter lacks wide-area coverage capability. As a result, the development of current MCN lags far behind the terrestrial fifth-generation (5G) network.

Reducing cyclic prefix overhead based on symbol repetition in NB-IoT-based maritime communication

With the increasing maritime activities, a great demand of wide-area maritime digital data services is needed. Therefore, Narrowband Internet of Things (NB-IoT) that can provide wide coverage has been expected as an application for maritime communication networks (MCNS). In this paper, we aim to enhance the spectral efficiency in NB-IoT by reducing the cyclic prefix (CP) overhead in random access signal without causing interference. The key point of the proposed scheme is the symbols transmitted for multiple times repeatedly in NB-IoT. Specifically, all CP are removed and multi-path fading effect is eliminated by using a repeated symbol to cover the disturbed symbol to construct a circular convolution structure of the channel with the same effect as adding CP. In addition, a single-tap equalization is still appropriate. To validate the effectiveness of the proposed scheme, simulation results are carried out with respect to the bit error ratio (BER).

Deep Reinforcement Learning Based Latency Minimization for Mobile Edge Computing With Virtualization in Maritime UAV Communication Network

The rapid development of maritime activities has led to the emergence of more and more computation-intensive applications. In order to meet the huge demand for wireless communications in maritime environment, mobile edge computing (MEC) is considered as an effective solution to provide powerful computing capabilities for maritime terminals of resource scarcity or latency sensitive. A basic technology to implement MEC is virtual machine (VM) multiplexing, through which multi-task parallel computing on a server is realized. In this paper, a two-layer unmanned aerial vehicles (UAVs) maritime communication network with a centralized top-UAV (T-UAV) and a group of distributed bottom-UAVs (B-UAVs) is established and MEC is used on T-UAV. We aim to solve the latency minimization problem for both communication and computation in this maritime UAV swarm mobile edge computing network. We reformulate this problem into a Markov decision process (MDP), since it is a non-convex and multiply constrained but has the characteristics of MDP. Based on this MDP model, we take deep reinforcement learning (DRL) as our tool to propose a deep Q-network (DQN) and a deep deterministic policy gradient (DDPG) algorithms to optimize the trajectory of T-UAV and configuration of virtual machines (VMs). Using these two proposed algorithms, we can minimize the system latency. Simulation results show that the given solutions are valid and effective.

Dynamic infrastructure-as-a-service: A key paradigm for 6G networks and application to maritime communications

Although, the advent of the fifth Generation (5G) of communication networks has introduced the technology enablers and system capability to support a large number of devices, and highly-demanding services, as well as ultra-low latency and high reliability, enhancements to the current systems will not suffice for future generation networks. Instead, a disruptive communication paradigm needs to be introduced that will ultimately enable the radical evolution of the current systems to a new ones, capable of self-aggregating extraordinary connectivity and computing capabilities in a seamless manner. To this end, sixth Generation (6G) networks should be able to seamlessly integrate and release, in a dynamic manner, heterogeneous types of resources, such as diverse types of network entities/nodes with nomadic, relaying, and multi-tenancy capabilities, which can enable demand-driven service provisioning, coverage extension, increased network capacity, and reduced energy consumption. This paper presents a novel networking paradigm towards Infrastructure-as-a-Service (IaaS), which introduces a disruptive and dynamic network infrastructure management and service orchestration mechanism, including nomadic networks and Artificial Intelligence (AI)-aware networking approaches for seamless and dynamic management of diverse network resources. In order to emphasize the compelling potential of the proposed paradigm, we detail its application to maritime communication networks, while identifying this use case as a key driver for the proposed dynamic IaaS concept.

A resource friendly authentication scheme for space–air–ground–sea integrated Maritime Communication Network

Recently, the demand for a faster , low-latency, and full-coverage Maritime Communication Network (MCN) has gained attention as marine operations have increased substantially. Using modern information network technologies and integrating space, air, ground, and sea network segments, MCN may be able to offer worldwide coverage and diverse Quality-of-Service (QoS) provisioning. These network segments are expected to provide not only traditional communication services, but also processing, caching, sensing, and control capabilities when linked via Sixth Generation (6G) mobile networks. However, this development in infrastructure growth is subjected to new security and privacy concerns due to open links, moving nodes, and diverse collaborative algorithms. In this paper, we propose an improved and resource friendly authentication scheme for the space–air–ground–sea integrated maritime communication network using Elliptic Curve Cryptography (ECC). To validate the security hardness of the proposed scheme, formal security assessment method such as Random Oracle Model (ROM) is used. Finally, comparisons with relevant authentication schemes are provided in terms of computation and communication costs. The findings support the viability of the proposed scheme.

Hybrid Satellite-UAV-Terrestrial Networks for 6G Ubiquitous Coverage: A Maritime Communications Perspective

In the coming smart ocean era, reliable and efficient communications are crucial for promoting a variety of maritime activities. Current maritime communication networks (MCNs) mainly rely on marine satellites and on-shore base stations (BSs). The former generally provides limited transmission rate, while the latter lacks wide-area coverage capability. Due to these facts, the state-of-the-art MCN falls far behind terrestrial fifth-generation (5G) networks. To fill up the gap in the coming sixth-generation (6G) era, we explore the benefit of deployable BSs for maritime coverage enhancement. Both unmanned aerial vehicles (UAVs) and mobile vessels are used to configure deployable BSs. This leads to a hierarchical satellite-UAV-terrestrial network on the ocean. We address the joint link scheduling and rate adaptation problem for this hybrid network, to minimize the total energy consumption with quality of service (QoS) guarantees. Different from previous studies, we use only the large-scale channel state information (CSI), which is location-dependent and thus can be predicted through the position information of each UAV/vessel based on its specific trajectory/shipping lane. The problem is shown to be an NP-hard mixed integer nonlinear programming problem with a group of hidden non-linear equality constraints. We solve it suboptimally by using Min-Max transformation and iterative problem relaxation, leading to a process-oriented joint link scheduling and rate adaptation scheme. As observed by simulations, the scheme can provide agile on-demand coverage for all users with much reduced system overhead and a polynomial computation complexity. Moreover, it can achieve a prominent performance close to the optimal solution.

Viability and Performance Analysis, at a Physical Level, of a Maritime Communication Network on Medium Frequency

This paper analysed the potentialities that have not yet been exploited of the Automatic Vessel Identification System on Medium Frequency (AVISOMEF) that was previously presented to the scientific community. This system expanded the spectrum of possibilities of the Global Maritime Distress and Safety System (GMDSS). By the time AVISOMEF was presented, one of the unexpected benefits was that it could constitute a platform capable of supporting a Maritime Communication Network on Medium Frequency; all remotely located vessels could communicate with each other by using AVISOMEF, making use of the new established network, within the geographic area of implementation, without needing to use satellite techniques. Medium frequency propagation is stable and is not subject to coverage restrictions. To conduct this experiment, we collaborated with the Spanish Maritime Safety Agency (SASEMAR). It was thanks to them that we gathered real-time information about the nationwide maritime traffic that navigated through the Spanish Search and Rescue jurisdiction waters from 2018 to 2020.

Maritime Broadband Communication: Wireless Channel Measurement and Characteristic Analysis for Offshore Waters

For a long time, the development of maritime communication has been restricted by the low data rate, high-latency and high cost of the current communication systems. The upgrade of new generation mobile communication technologies is attracting more and more attention to conduct a shore-based broadband mobile communication network with high-latency and high reliability to serve the maritime industries. This paper presents a solution by means of building a ship-to-infrastructure (S2I) and a ship-to-ship (S2S) wireless communication networks for an offshore region. We characterize the S2I and S2S channels at 5.9 GHz band based on the channel measurements in realistic environments. The channel characteristics, including power delay profile, delay spread, propagation path loss, are extracted and analyzed. In view of the difference between marine and terrestrial communications, we analyze the influencing factors of the offshore water, including effective reflection, divergence and shadowing from the water surface, and diffraction loss caused by the earth curvature. We also predict the power coverage range and the channel capacity for S2I and S2S wireless communications. Finally, the communication performance is evaluated according to the channel measurement and characterization analysis. The research results can be a reference for the construction of maritime communication networks.

Efficient Energy and Delay Tradeoff for Vessel Communications in SDN Based Maritime Wireless Networks

The maritime communication network is assembled by emergent network technologies. However, the adverse maritime environment impedes the efficiency of resources allocation in maritime communication network. Here we show a joint sleeping scheduling and opportunistic transmission scheme in delay-tolerant maritime wireless communication networks based on software defined networking (SDN) to find a better tradeoff between the energy consumption and the delay. Specifically, an energy-limited delay tolerant networking (DTN) node deployed in the ocean receives/transmits data from/to vessels within its communication range. To further save the energy, a long-term energy minimization problem is formulated with sleeping scheduling and opportunistic transmission. After that, a multi-objective minimization problem of energy and delay is first modeled by Lyapunov optimization (LO), which then is solved by convex optimization. Both mathematical analyses and simulation results demonstrate how the maritime communication network allocates satisfactorily with the proposed allocation scheme.

MagicNet: The Maritime Giant Cellular Network

Recently, the development of marine industries has increasingly attracted attention from all over the world. A wide-area and seamless maritime communication network has become a critical supporting approach. In this article, we propose a novel architecture named the maritime giant cellular network (MagicNet) relying on seaborne floating towers deployed in a honeycomb topology. The tower-borne giant-cell base stations are capable of providing wide-area seamless coverage for maritime users and can construct multihop line-of-sight (LoS) links connecting to terrestrial networks. Then the MagicNet-aided maritime network architecture is expounded in terms of five dimensions (i.e., space, air, shore, surface, and underwater), which is compatible with existing systems including maritime satellite networks and maritime Internet of Things, and supports a range of compelling industrial applications. Moreover, we introduce a joint multicast beamforming and relay system for the sake of supporting high-speed and low-cost information services for near-shore areas, as well as a three-tier space-air-surface hybrid network in order to provide reliable wide-area communications for deep offshore areas. Finally, we discuss the open issues and future works on MagicNet.

Hybrid Satellite-Terrestrial Communication Networks for the Maritime Internet of Things: Key Technologies, Opportunities, and Challenges

With the rapid development of marine activities, there has been an increasing number of Internet-of-Things (IoT) devices on the ocean. This leads to a growing demand for high-speed and ultrareliable maritime communications. It has been reported that a large performance loss is often inevitable if the existing fourth-generation (4G), fifth-generation (5G), or satellite communication technologies are used directly on the ocean. Hence, conventional theories and methods need to be tailored to this maritime scenario to match its unique characteristics, such as dynamic electromagnetic propagation environments, geometrically limited available base station (BS) sites and rigorous service demands from mission-critical applications. Toward this end, we provide a survey on the demand for maritime communications enabled by state-of-the-art hybrid satellite-terrestrial maritime communication networks (MCNs). We categorize the enabling technologies into three types based on their aims: 1) enhancing transmission efficiency; 2) extending network coverage; and 3) provisioning maritime-specific services. Future developments and open issues are also discussed. Based on this discussion, we envision the use of external auxiliary information, such as sea state and atmosphere conditions, to build up an environment-aware, service-driven, and integrated satellite-air-ground MCN.

Networking in Oceans

The ocean is a huge saltwater body that is different from terrestrial environments in terms of deployment circumstance, weather conditions, and user distributions. Therefore, it is difficult to apply terrestrial networking technologies directly in oceans. The cost-effectiveness of satellites is still an issue to be addressed to increase their popularity due to their high cost in construction, launching, and maintenance and high deployment risks. Such situations stimulate many research efforts on networking technologies in the ocean space consisting of coastline, water surface, sky, and underwater. This article conducts a comprehensive survey on the related issues through reviewing the networking environments and communication networks already operating in the ocean space as well as ongoing R8D activities and results reported in the literature. These systems include coastal networks, water surface networks, sky networks, and underwater networks, which are reviewed and discussed along with summaries on the related topics and research issues necessary for further studies. This article, taking into account maritime communication networks and underwater networking together, aims to provide the reader with an overview on the state of the art and corresponding challenging issues for networking in the ocean space.