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 maritime mobile terminals, as well as a growing demand for high-speed and ultra-reliable maritime communications to keep them connected. Traditionally, the maritime Internet of Things (IoT) is enabled by maritime satellites. However, satellites are seriously restricted by their high latency and relatively low data rate. As an alternative, shore & island-based base stations (BSs) can be built to extend the coverage of terrestrial networks using fourth-generation (4G), fifth-generation (5G), and beyond 5G services. Unmanned aerial vehicles can also be exploited to serve as aerial maritime BSs. Despite of all these approaches, there are still open issues for an efficient maritime communication network (MCN). For example, due to the complicated electromagnetic propagation environment, the limited geometrically available BS sites, and rigorous service demands from mission-critical applications, conventional communication and networking theories and methods should be tailored for maritime scenarios. Towards this end, we provide a survey on the demand for maritime communications, the state-of-the-art MCNs, and key technologies for enhancing transmission efficiency, extending network coverage, and provisioning maritime-specific services. Future challenges in developing an environment-aware, service-driven, and integrated satellite-air-ground MCN to be smart enough to utilize external auxiliary information, e.g., sea state and atmosphere conditions, are also discussed

Modeling and performance analysis of marine DTN networks with Nodes-cluster in an ad hoc sub-net

The marine communication environment is complex and changeable, and the sea wireless infrastructure is few. The delay tolerant network is proposed and applied in ocean environment. We use the ships to store, carry and forward the messages, so as to solve the problem that the communication links are broken frequently and the message cannot be transmitted due to the movement of the nodes. Under the environment of MATLAB, the random motion trajectory of a fishing vessel in the South China Sea is modeled and simulated. A mobile Ad hoc network is formed between ship and ship, and the base station of the land mobile communication network is connected with the marine radio transmitting point through optical fiber. Data is generated according to Poisson distribution in a heterogeneous network at sea and the data transmission uses the flooding mechanism. Taking into account the limited capacity of the wireless transmission point of the sea, we introduced a forwarding-time-limited mechanism. The performance of it is analyzed in the delayed network at sea, and the effects of the survival time, the number of fishing vessels and the coverage of the wireless network on data delivery are compared. The simulation results show that increasing the survival time of the data and the coverage of the wireless network can improve the data delivery ratio, reduce the network transmission delay, and improve the performance of the maritime wireless communication network

A Survey on UAV-Aided Maritime Communications: Deployment Considerations, Applications, and Future Challenges

Maritime activities represent a major domain of economic growth with several emerging maritime Internet of Things use cases, such as smart ports, autonomous navigation, and ocean monitoring systems. The major enabler for this exciting ecosystem is the provision of broadband, low-delay, and reliable wireless coverage to the ever-increasing number of vessels, buoys, platforms, sensors, and actuators. Towards this end, the integration of unmanned aerial vehicles (UAVs) in maritime communications introduces an aerial dimension to wireless connectivity going above and beyond current deployments, which are mainly relying on shore-based base stations with limited coverage and satellite links with high latency. Considering the potential of UAV-aided wireless communications, this survey presents the state-of-the-art in UAV-aided maritime communications, which, in general, are based on both conventional optimization and machine-learning-aided approaches. More specifically, relevant UAV-based network architectures are discussed together with the role of their building blocks. Then, physical-layer, resource management, and cloud/edge computing and caching UAV-aided solutions in maritime environments are discussed and grouped based on their performance targets. Moreover, as UAVs are characterized by flexible deployment with high re-positioning capabilities, studies on UAV trajectory optimization for maritime applications are thoroughly discussed. In addition, aiming at shedding light on the current status of real-world deployments, experimental studies on UAV-aided maritime communications are presented and implementation details are given. Finally, several important open issues in the area of UAV-aided maritime communications are given, related to the integration of sixth generation (6G) advancements

Density and Mobility Impact on MANET Routing Protocols in a Maritime Environment

Mobile Ad-Hoc Networks (MANETS) are multi hop wireless networks, where a packet hops through a number of intermediate nodes within coverage range of each other to reach the intended destination. The novel application of MANET routing protocols in the marine environment using available technology is one of the contributions of this work. The high cost of other available technologies which require direct connection to IP networks make our approach an attractive proposition for small craft. In this paper we investigate the effect of different maritime traffic patterns on the performance of three different MANET routing protocols which are Ad hoc On-Demand Distance Vector (AODV), Ad hoc On-Demand Multi Path Distance Vector (AOMDV) and Destination-Sequenced Distance Vector (DSDV). The traffic patterns are represented by different node densities and mobility behaviours which are likely to be found in the marine environment. Performance evaluation of the MANET protocols is compared in terms of packet delivery ratio

Optimal Quality-of-Service Scheduling for Energy-Harvesting Powered Wireless Communications

XiaojingChen, Wei Ni, Xin Wang, YichuangSun, “Optimal Quality-of-Service Scheduling for Energy-Harvesting Powered Wireless Communications”, IEEE Transactions on Wireless Communications, Vol. 15 (5): 3269-3280, January 2016. © 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In this paper, a new dynamic string tautening algorithm is proposed to generate the most energy-efficient off-line schedule for delay-limited traffic of transmitters with non-negligible circuit power. The algorithm is based on two key findings that we derive through judicious convex formulation and resultant optimality conditions, specifies a set of simple but optimal rules, and generates the optimal schedule with a low complexity of O(N2) in the worst case. The proposed algorithm is also extended to on-line scenarios, where the transmit schedule is generated on-the-fly. Simulation shows that the proposed algorithm requires substantially lower average complexity by almost two orders of magnitude to retain optimality than general convex solvers. The effective transmit region, specified by the tradeoff of the data arrival rate and the energy harvesting rate, is substantially larger using our algorithm than using other existing alternatives. Significantly more data or less energy can be supported in the proposed algorithm.Peer reviewedFinal Accepted Versio

DTN performance analysis of multi‐asset Mars‐Earth communications

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