Marine Communication System Research Articles

Watercraft tracking and monitoring system towards safe and resilient marine communication systems

In this research, Sea-condition Emergency Alert and Warning Apparatus for Vessel Safety (SEAWAVES) is a watercraft tracking and monitoring system developed and deployed to monitor watercraft and sea conditions to provide a safer and more resilient marine communication system. The proposed method puts together an application of contemporary technology using the fused location provider Application Programming Interface (API) to retrieve the device’s current location. In addition to managing the underlying location technologies, like Global Positioning System (GPS) and Wi-Fi, the fused location provider offers a straightforward API that you may use to specify the desired level of service. The work includes calibrating the compass, GPS, and Global System for Mobile Communication (GSM) for watercraft tracking and monitoring using Android sensors of mobile phones. The GPS provides the present site of the watercraft; General packet radio service (GPRS) sends the tracking information to the server and thus an alert message generated is transmitted to the registered monitoring systems. This scheme is deployed in the watercraft to monitor location and sea conditions, which are to be determined on the web page and supervised in real-time. Hence, if the watercraft is at a critical level, alert messages will be sent to the monitoring system, and the registered mobile phone number of the watercraft. Also a warning display and sound are produced by the device. The SEAWAVES tracking and monitoring system could be recommended for use onboard a watercraft throughout the country for effective management and monitoring of the performance of such watercraft, and low-cost instrumentation as a stand-alone system through modern technologies.

Verification and Modeling of the Maritime Channel for Maritime Communications and Navigation Networks

This paper presents a geometric stochastic channel model designed for analyzing maritime communication and navigation services between moving ships using the C-band or sub-6 GHz spectrum, which aligns with the focus of emerging 5G networks on land. The channel model is validated through channel measurements conducted both on the sea and land. A software tool has been developed to integrate and analyze these measurements, which is included with this publication. The main challenge in developing the channel model for maritime services lies in the dynamic nature of the sea surface, leading to constantly changing reflection conditions due to varying reflectors and scatterers on the water. Additionally, the motion conditions of the transmitter and receiver on ships change in all three dimensions, depending on the sea state. To address these complexities, data from several measurement campaigns in diverse areas were collected. The analysis involved examining the propagation conditions over the sea with variations in sea surface roughness, antenna heights, and used bandwidths. Moreover, additional propagation conditions over nearby land were also taken into account. The study demonstrates that the changing antenna height on the ship, influenced by sea conditions, significantly affects the reflection and scattering conditions. The research aims to develop reliable, high-data rate, and broadband marine communication systems. Therefore, a measurement bandwidth of 120MHz was employed to derive the propagation model. This model not only offers absolute timing information but can also be used for time-based ranging or positioning systems. The proposed geometric stochastic channel model provides valuable insights into the complex maritime communication and navigation environment. By accounting for the continuously evolving sea surface and its impact on antenna height, the model offers a robust framework for studying and optimizing marine communication systems. The availability of a software tool integrating real-world measurements further enhances the usability and practicality of the channel model for future maritime communication research and deployment.

Research on a high-frequency unfilled layered symmetrical piezoelectric material with a high effective electromechanical coupling coefficient

As the demand for high-performance hydrophones for marine communication systems grows, this paper develops a high-frequency unfilled layered symmetrical piezoelectric material with high effective electromechanical coupling coefficient. The vibration mode of piezoelectric material is converted into vibration mode of the piezoelectric pillar to improve the effective electromechanical coupling coefficient of the material. The material is determined by the equivalent circuit method and ANSYS finite element simulation method. Test results show that the resonant frequency is 117.8 kHz and the effective electromechanical coupling coefficient is 0.67, which shows that the developed material has a good electromechanical conversion performance.

Deep Learning Method for Evaporation Duct Inversion Based on GPS Signal

Accurate evaporation duct prediction is one of the critical technologies for realizing the over-the-horizon impact of marine communication, ship radar, and other systems. Using GPS signals to invert evaporation ducts provides more benefits in terms of method realization and ease. In order to invert the evaporation duct from GPS-received power data, a deep learning technique based on Bayesian optimization is proposed to increase the prediction accuracy of evaporation ducts. The evaporation duct propagation mechanism of the GPS signal is explored. The GPS-received power is estimated using the two-parameter evaporation duct model, and a better neural network structure is built using Bayesian optimization. The study results show that the Bayesian optimization model has a smaller root mean square error (RMSE) than the human empirical model, which allows for rapid and accurate inversion of duct parameters even in noisy interference.

Marine Internet of Things Platforms for Interoperability of Marine Robotic Agents: An Overview of Concepts and Architectures

The creation of a Marine Internet of Things platform, including the Underwater Internet of Things, is needed to ensure the interaction and digital navigation of heterogeneous marine robotic agents. It is necessary to combine the following robotic agents: autonomous underwater vehicles, remotely operated vehicles, active and passive marine sensors, buoys, underwater sonar stations, coastal communication posts, and other elements of the platform. To ensure the interaction of all these elements, it is necessary to use a common communication system within the platform, as well as a common navigation and control system to solve complex problems of the navigation and control of the movement of robotic agents in order to implement a joint mission to collect and transmit data, including video information in real time. The architecture of the Marine Internet of Things platform must first be defined in order to use a unified approach to data exchange. This article provides an overview of approaches to determining the architectures of network underwater and marine communication systems based on the concept of the Internet of Things. This paper provides a comprehensive study of MIoT applications, challenges, and architectures. The main contributions of this paper are summarized as follows: we introduce potential MIoT applications; we point out the challenges of MIoT (i.e., the differences between MIoT and IoT); and we analyze the MIoT system architecture.

Enhancing Marine Data Transmission with Socially Aware Resilient Vessel Networks

With the multi-dimensional exploration towards oceans, enormous sensing data has been generated with significant volume, velocity, variety and heterogeneity. The resulted Big Marine Data (BMD) thus issue unprecedented architectural challenges on existing marine communication systems. Current dominant marine communication technologies, e.g., shore-based cellular stations, high frequency radio, and expensive satellites, extremely suffer from short coverage, low bandwidth, insecurity, and unavailable cross-domain transmission. In this paper, Resilient Vessel Network (RVN) is proposed to fundamentally enhance BMD transmission. RVNs with widespread self-organized vessels and opportunistic connections reveal advantages of ubiquity, resilience, low cost and cross-domain transmission. To efficiently manage opportunistic vessel-to-vessel (V2V) connections for optimal routing, Social Network Analysis (SNA) on historical vessel interactions is applied for vessel familiarity measurement and community detection. The performance of the proposed community-based routing (CBR) is comprehensively evaluated with real datasets of fishing vessel trajectories. It is demonstrated that CBR achieves much lower transmission cost with comparable delivery ratio compared to typical routing algorithms.

Construction of Marine Culture Communication and Inheritance System Based on Digital Images

Chen, Y., 2020. Construction of marine culture communication and inheritance system based on digital images. In: Liu, X. and Zhao, L. (eds.), Today's Modern Coastal Society: Technical and Sociological Aspects of Coastal Research. Journal of Coastal Research, Special Issue No. 111, pp. 258–262. Coconut Creek (Florida), ISSN 0749-0208.In order to solve the problems of the slow development of marine culture and waning inheritance, this article used digital imaging to build a marine culture communication and inheritance system that effectively improves the situation, which is characterized by narrow audience scope in traditional communication modes and ineffective cultural protection. On the basis of digital image technology, this paper discusses the composition of marine culture by using information communication theory and coding/decoding theory and describes the influence of digital media on marine culture by using communication and inheritance theory. The establishment of a database and interdisciplinary integration enhances public cultural awareness, to ensure that China's marine culture can be effectively protected and inherited.

Design of compact coupler in marine communication systems with uneven power split

The work provides for a theoretical study of the coupler in marine communication systems - design and its main characteristics, computer simulation of a compact coupler. The coupler geometry has been redesigned to provide 1 GHz operating frequency and compact size. Artificial transmission lines were installed. Optimization yielded the most similar characteristics of a compact device with the characteristics of a standard device. The area of the device has been reduced by 76.25%.

The use of 3 dB multi loop directional coupler with reduced dimensions in Marine communication systems

This article describes the process of developing a model of a multi loop directional coupler for marine applications by replacing conventional segments with artificial transmission lines. As a result, a coupler with an area of 2455 mm2 (at a frequency of 0.9 GHz) was obtained, which is 75.15% less than when the coupler is implemented on quarter-wave segments. The relevance of this work lies in the development of compact devices with easily reproducible geometry through the use of artificial transmission lines.

Pilot domain NOMA for grant-free massive random access in massive MIMO marine communication system

We propose a pilot domain non-orthogonal multiple access (NOMA) for uplink massive devices grant-free random access scenarios in massive multiple-input multiple-output (MIMO) maritime communication systems. These scenarios are characterized by numerous devices with sporadic access behavior, and therefore only a subset of them are active. Due to massive potential devices in the network, it is infeasible to assign a unique orthogonal pilot to each device in advance. In such scenarios, pilot decontamination is a crucial problem. In this paper, the devices are randomly assigned non-orthogonal pilots which are constructed by a linear combination of some orthogonal pilots. We show that a bipartite graph can conveniently describe the interference cancellation (IC) processes of pilot decontamination. High spectrum efficiency (SE) and low outage probability can be obtained by selecting the numbers of orthogonal pilots according to the given probability distribution. Numerical evaluations show that the proposed pilot domain NOMA decreases the outage probability from 20% to 2e-12 at the SE of 4 bits/s/Hz for a single device, compared to the conventional method of slotted ALOHA with 1024 antennas at the BS, or increases the spectrum efficiency from 1.2 bits/s/Hz to 4 bit/s/Hz at the outage probability of 2e-12 in contrast with the Welch bound equality (WBE) non-orthogonal pilots.

Marine mobile wireless channel modeling based on improved spatial partitioning ray tracing

In 5G era, it is expected to achieve wireless network coverage including offshore areas. Modeling of marine wireless channels is the basis of constructing a marine communication system. In this paper, a communication scene between an unmanned aerial vehicle (UAV) and a boat is simulated to study the marine wireless channel. Firstly, an improved spatial partitioning ray tracing algorithm is proposed to track the propagation path of electromagnetic waves at sea surface. Secondly, a mobile channel is simulated and modeled based on the track results. Finally, a loss measurement is carried out in the coastal waters based on the simple wireless channel loss measuring platform, and a path loss propagation model is built. Then we compare the actual measurement data with the simulation results and find that the two are have good consistency, which further verifies the reliability of the simulation.

A novel sea communication topology and IP routing algorithm by using LTE and WMN in NS‐3

AbstractThis paper proposes a new heterogeneous network topology and a routing algorithm for a marine communication system involving ships and other marine vessels from a terrestrial point on the shore. Topology involves the use of a collection of Long‐Term Evolution (LTE) systems and Wi‐Fi mesh networks. There are multiple clusters/ships in the network, with an LTE system centered around each cluster. Communication between the clusters happens through LTE, and within the cluster mesh, networking is employed. Every end user in the ship has access to the server application by means of mesh networking from the respective access point in the cluster/ship. The routing algorithm is designed based on the best signal‐to‐interference‐plus‐noise‐ratio path and minimum delay combination, which selects the best modulation scheme and hence the best data rate. The algorithm employs a new parameter that is derived from signal‐to‐interference‐plus‐noise ratio. The topology along with the algorithm provides a connection with a maximum coverage distance of 180 km and minimum data rate around 0.6 Mbps with 2 interconnection clusters. The presence of more interconnection clusters makes the coverage distance, data rate, and reliability greatly improved. Open source network tool Network Simulator 3 is used for the topology design, algorithm implementation, and simulations. The proposed topology and algorithm when implemented can be used to provide long‐distance sea communication with improved reliability and higher data rate.

Design of Ship Communication System Based on CAN Bus

Existing ship electronic equipment are based on serial interfaces in accordance with NEMA0183 Protocol for the exchange of information, complex low transfer rates, lines, nodes exist, poor reliability shortcomings. Fieldbus (CAN) to its high anti-interference ability and higher traffic rates made up for these shortcomings, has been widely applied to automotive electronics, but in application of ship data communication has not been very good. CAN bus technology with outstanding reliability, timeliness and flexibility for the development of modern marine communication system offers a new way.

공간 다중화 해양 통신 시스템에서 채널 특성을 고려한 자원 할당 기법

조선 산업과 IT의 융합으로 인해 선박에서의 데이터 사용량이 계속적으로 증가할 것으로 예상됨에 따라, 많은 양의 데이터를 처리하기 위한 여러 무선통신 기술들이 논의되고 있다. 특히 다중 안테나 시스템은 높은 수율을 제공할 것으로 기대되는 기술 중 하나이다. 본 논문에서는 공간 다중화 해양 통신 시스템에서 채널 특성과 기지국의 빔 전송 각도를 고려하여 기지국이 서비스 할 선박을 선택하는 알고리듬을 제안한다. 무선 채널의 클러스터링 특성을 이용하여 선박이 수신 받는 신호를 최대화하는 방식으로 시스템의 수율을 증가시켰다. 또한 빔 간섭이 큰 선박을 제외하고 선택하는 방식으로 선박 선택에 걸리는 시간을 단축시켰다. 제안하는 알고리듬의 성능 분석을 위해 모의실험 한 결과, 제안하는 알고리듬의 수율은 전수조사 알고리듬과 근사하지만 연산의 복잡성은 크게 줄어드는 것을 확인할 수 있다. As the data traffic between ships and a land station continuously increase through the shipbuilding-IT convergence, several wireless communication technologies are being studied to process large amounts of data traffic. In particular, the multi-antenna system is one of the most expected technologies to provide high throughput. This paper proposes an algorithm for the base station to select the ship in consideration of channel characteristics and the transmission angle for a beam of the land station in spatial multiplexing marine communication systems. We increase the system capacity by maximizing the received signal strength of the ship using clustering characteristic of the radio channel. Also, we reduce the time to select the ship by excluding the ship with the large interference between the beams. On our computer simulation, the proposed scheme dramatically reduces the computational complexity with a little sacrifice of the throughput.

Study on Conditions of Over-the-Horizon Detection Basing on Evaporation Duct

The highest frequency duct is evaporation duct under marine atmospheric environment, and it is a special method of expanding the radar measuring range by using the evaporation duct to achieve the over-the-horizon detection. On what conditions to ensure the realization of the over-the-horizon radar detection is one of key problems. Many aspects, such as evaporation duct discrimination, radar working wavelength and frequency, initial launching angle and the location of radar are studied to get the necessary conditions of the over-the-horizon radar detection. The results show that the four kinds of necessary conditions must meet at the same time instead of only one certain condition, which lays a necessary foundation for the marine radar, ship radar and communication system to exert the largest effects in the evaporation duct environment.

Problems of Paleogene stratigraphy and paleogeography in the middle latitudes of Eurasia

The present-day notions of the Paleogene history, paleogeography, and paleobiogeography of Central Asia middle latitudes are based on studies carried by A.L. Yanshin in the second quarter of the 20th century. Here, main phases in the geologic history of the West Siberian and Turan Plates and Turgai depression are considered. In the Paleocene and Eocene, these regions were key links of a continuous meridional marine communication system connecting the Tethys and Arctic Oceans. Before the emergence of the latitudinal Alpine–Himalayan orogenic belt, the Tethys and its marginal seas formed a united shelf area. The closest linkage of the water bodies and biota exchange between them existed in the Thanetian and in the first half of the Ypresian. There was intense heat transfer from tropical to higher latitudes through the entire system of epeiric seas and straits. From the end of the Paleocene, this system was supplemented and complicated by latitudinal straits that ensured the connection of the seas of the Northern Peri-Tethys with the Northern Sea basin and the Atlantic. The combination of two sea systems determined the climatic history of this region from the Paleocene till the Late Eocene. The Arctic Basin influenced mainly the structure of cold-water benthos, and the Tethys, the composition of planktonic biota in the photic zone. During the Bartonian and Priabonian, in the last phase of marine sedimentation, the West Siberian epeiric sea was completely isolated from the Arctic Basin and connected only with the Turan sea through the Turgai strait. The Azolla beds accumulated during the low stand of the World Ocean in desalted surface waters and in disoxic bottom waters inhabited by depauperated benthos. At the Eocene/Oligocene boundary, the drainage of the Tavda–Chegan sea was followed by the formation of an N-S-directed river network in the vast areas of West Siberia, Turgai, and the northern cis-Aral region. The climate was unstable, moderately warm to subtropical, with variable humidity. The formation of the Turgai ecotype of mesophytic conifer-broadleaved flora was completed by the end of the Early Oligocene.

SBMAC: Smart Blocking MAC Mechanism for Variable UW-ASN (Underwater Acoustic Sensor Network) Environment

In this paper, several MAC scheduling methods applicable to an underwater environment are proposed. Besides, a new marine communication system model was proposed to improve the reliability of the proposed SBMAC method. The scheme minimizes transmission of control frames except for data transmission and various transmission methods and ACK methods can be used together. Simulation models are set indices and analysis of the underwater environment is established to conduct reliable simulations. Consequently, the performance improvement of the proposed method is verified with respect to delay time, data transmission rate, memory utilization, energy efficiency, etc.

Conservation of the egg-laying hormone neuropeptide and attractin pheromone in the spotted sea hare, Aplysia dactylomela

In the marine opisthobranch mollusc, Aplysia, secreted peptides and proteins play an essential role in egg laying and mate attraction. Aplysia californica egg laying is initiated by secretion of the egg-laying hormone (ELH) peptide while mate attraction is made possible by protein pheromones, such as attractin, released into the surrounding seawater with the egg cordon. In this study, we investigated the existence of similar egg-laying hormone and attractin products in the spotted sea hare, Aplysia dactylomela, a species that is widely distributed in almost all tropical and temperate oceans, including Australia's Great Barrier Reef. Immunological analysis revealed that an ELH-like transmitter is present within bag cell somata and processes of the abdominal ganglion. A molecular genetic approach found that the ELH precursor mRNA is synthesized in the abdominal ganglia and encodes a 36-residue peptide (dELH) that is cleaved from the prohormone prior to secretion. It is most closely related to A. californica and A. brasiliana ELH (91.7% identical). We also found that A. dactylomela synthesize an attractin pheromone in the albumen gland that is released during egg laying. The gene encodes a 58-residue mature protein that is 74.9% similar to A. californica attractin. We demonstrate that an increase in seawater temperature can disrupt attractins higher order interactions, such as those with the pheromone temptin, and accelerates attractin degradation. Together, these findings further expands our understanding of pheromone intermolecular interactions and presents an opportunity for further study of how increases in sea water temperature may affect this important marine communication system.