Articles de revues : « Satellite terrestrial architecture »

1

Tong, Minglei, Song Li, Xiaoxiang Wang et Peng Wei. « Inter-Satellite Cooperative Offloading Decision and Resource Allocation in Mobile Edge Computing-Enabled Satellite–Terrestrial Networks ». Sensors 23, n^o 2 (6 janvier 2023) : 668. http://dx.doi.org/10.3390/s23020668.

Texte intégral

Résumé :

Mobile edge computing (MEC)-enabled satellite–terrestrial networks (STNs) can provide task computing services for Internet of Things (IoT) devices. However, since some applications’ tasks require huge amounts of computing resources, sometimes the computing resources of a local satellite’s MEC server are insufficient, but the computing resources of neighboring satellites’ MEC servers are redundant. Therefore, we investigated inter-satellite cooperation in MEC-enabled STNs. First, we designed a system model of the MEC-enabled STN architecture, where the local satellite and the neighboring satellites assist IoT devices in computing tasks through inter-satellite cooperation. The local satellite migrates some tasks to the neighboring satellites to utilize their idle resources. Next, the task completion delay minimization problem for all IoT devices is formulated and decomposed. Then, we propose an inter-satellite cooperative joint offloading decision and resource allocation optimization scheme, which consists of a task offloading decision algorithm based on the Grey Wolf Optimizer (GWO) algorithm and a computing resource allocation algorithm based on the Lagrange multiplier method. The optimal solution is obtained by continuous iterations. Finally, simulation results demonstrate that the proposed scheme achieves relatively better performance than other baseline schemes.

Styles APA, Harvard, Vancouver, ISO, etc.

2

Priscoli, F. D. « UMTS architecture for integrating terrestrial and satellite systems ». IEEE Multimedia 6, n^o 4 (1999) : 38–45. http://dx.doi.org/10.1109/93.809232.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

3

Tirmizi, Syed Bilal Raza, Yunfei Chen, Subhash Lakshminarayana, Wei Feng et Aziz A. Khuwaja. « Hybrid Satellite–Terrestrial Networks toward 6G : Key Technologies and Open Issues ». Sensors 22, n^o 21 (6 novembre 2022) : 8544. http://dx.doi.org/10.3390/s22218544.

Texte intégral

Résumé :

Future wireless networks will be required to provide more wireless services at higher data rates and with global coverage. However, existing homogeneous wireless networks, such as cellular and satellite networks, may not be able to meet such requirements individually, especially in remote terrain, including seas and mountains. One possible solution is to use diversified wireless networks that can exploit the inter-connectivity between satellites, aerial base stations (BSs), and terrestrial BSs over inter-connected space, ground, and aerial networks. Hence, enabling wireless communication in one integrated network has attracted both the industry and the research fraternities. In this work, we provide a comprehensive survey of the most recent work on hybrid satellite–terrestrial networks (HSTNs), focusing on system architecture, performance analysis, design optimization, and secure communication schemes for different cooperative and cognitive HSTN network architectures. Different key technologies are compared. Based on this comparison, several open issues for future research are discussed.

Styles APA, Harvard, Vancouver, ISO, etc.

4

Wei, Linhui, Chen Chang, Yu Liu et Yumei Wang. « Energy-Efficient Controller Placement in Software-Defined Satellite-Terrestrial Integrated Network ». Remote Sensing 14, n^o 21 (4 novembre 2022) : 5561. http://dx.doi.org/10.3390/rs14215561.

Texte intégral

Résumé :

The satellite-terrestrial integrated network (STIN), as an integration of the satellite network and terrestrial, has become a promising architecture to support global coverage and ubiquitous connection. The architecture of software-defined networking (SDN) is utilized to intelligently coordinate the global STIN, in which the placement schemes of SDN controllers, including the locations, number, and roles, would produce various performances. However, the uneven distribution of global users leads to the unbalanced energy consumption of satellite resources, which brings a heavy burden for satellites to maintain the control flows for network management. To provide green communication for international economic trade in the countries along the Belt and Road, in this paper, we focus on the energy-efficient controller placement (EECP) problem in the software-defined STIN. The satellite gateways are located in the countries along the Belt and Road, which accounts for a large number of traffic demands and a dense population. The controllers are deployed on the LEO satellites, where each LEO satellite is a candidate controller. The energy consumption for the control paths and the user data links is modeled and then formulated as the flow processing-oriented optimization problem. A modified simulated annealing placement (MSAP) algorithm is developed to solve the EECP problem, in which we use the greedy way to obtain the initial set of controllers, and then the final optimal controller placement result is obtained by the simulated annealing algorithm. Extensive simulations are conducted on the simulated Iridium satellite network topology and statistics data. Compared with other algorithms, the results show that MSAP reduces network energy consumption by 20% and average latency by 25%.

Styles APA, Harvard, Vancouver, ISO, etc.

5

Feng, Bohao, Huachun Zhou, Hongke Zhang, Guanwen Li, Haifeng Li, Shui Yu et Han-Chieh Chao. « HetNet : A Flexible Architecture for Heterogeneous Satellite-Terrestrial Networks ». IEEE Network 31, n^o 6 (novembre 2017) : 86–92. http://dx.doi.org/10.1109/mnet.2017.1600330.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

6

Sapaty, P. S. « Managing multiple satellite architectures by spatial grasp technology ». Mathematical machines and systems 1 (2021) : 3–16. http://dx.doi.org/10.34121/1028-9763-2021-1-3-16.

Texte intégral

Résumé :

The paper reviews some advanced space projects oriented on many satellites moving around the globe in low Earth orbits, and investigates how to organize their collective operation for solving important world problems, especially those related to global security and defense. It analyzes the application of the developed Spatial Grasp model and Technology (SGT), successfully tested on numerous applications, for simulation and management of multiple satellite architectures. Of particular interest is the latest Space Development Agency Next-Generation Space Architecture that uses a great number of cooperating satellites organized on different layers, which appears to be much more advanced than the known Strategic Defense Initiative project of the eighties. SGT is based on mobile recursive scenarios in a special high-level Spatial Grasp Language (SGL) which can self-navigate and self-match distributed environments while leaving throughout them powerful spatial infrastructures capable of solving any distributed problems. Providing basics of the latest SGT version, the paper describes examples of solutions in it of such problems as distributed tracing and elimination of complexly moving cruise missiles and hypersonic gliders, organization of effective custody layer which will be able to observe not only localized dangerous objects on the Earth but also any distributed terrestrial infrastructures as a whole. It also shows how to introduce a higher virtual layer for satellite constellation which may simplify formulation and solution of many problems in both terrestrial and celestial environments, including advanced command and control of complex national and international operations and campaigns from space.

Styles APA, Harvard, Vancouver, ISO, etc.

7

Yan, Lei, Suzhi Cao, Yongsheng Gong, Hao Han, Junyong Wei, Yi Zhao et Shuling Yang. « SatEC : A 5G Satellite Edge Computing Framework Based on Microservice Architecture ». Sensors 19, n^o 4 (18 février 2019) : 831. http://dx.doi.org/10.3390/s19040831.

Texte intégral

Résumé :

As outlined in the 3Gpp Release 16, 5G satellite access is important for 5G network development in the future. A terrestrial-satellite network integrated with 5G has the characteristics of low delay, high bandwidth, and ubiquitous coverage. A few researchers have proposed integrated schemes for such a network; however, these schemes do not consider the possibility of achieving optimization of the delay characteristic by changing the computing mode of the 5G satellite network. We propose a 5G satellite edge computing framework (5GsatEC), which aims to reduce delay and expand network coverage. This framework consists of embedded hardware platforms and edge computing microservices in satellites. To increase the flexibility of the framework in complex scenarios, we unify the resource management of the central processing unit (CPU), graphics processing unit (GPU), and field-programmable gate array (FPGA); we divide the services into three types: system services, basic services, and user services. In order to verify the performance of the framework, we carried out a series of experiments. The results show that 5GsatEC has a broader coverage than the ground 5G network. The results also show that 5GsatEC has lower delay, a lower packet loss rate, and lower bandwidth consumption than the 5G satellite network.

Styles APA, Harvard, Vancouver, ISO, etc.

8

Guo, Xiaotao, Ying Zhang, Yu Jiang, Shenggang Wu et Hengnian Li. « A Novel Decomposed Optical Architecture for Satellite Terrestrial Network Edge Computing ». Mathematics 10, n^o 14 (19 juillet 2022) : 2515. http://dx.doi.org/10.3390/math10142515.

Texte intégral

Résumé :

Aiming at providing a high-performance terrestrial network for edge computing in satellite networks, we experimentally demonstrate a high bandwidth and low latency decomposed optical computing architecture based on distributed Nanoseconds Optical Switches (NOS). Experimental validation of the decomposed computing network prototype employs a four-port NOS to interconnect four processor/memory cubes. The SOA-based optical gates provide an ON/OFF ratio greater than 60 dB, enabling none-error transmission at a Bit Error Rate (BER) of 1 × 10−9. An end-to-end access latency of 122.3 ns and zero packet loss are obtained in the experimental assessment. Scalability and physical performance considering signal impairments when increasing the NOS port count are also investigated. An output OSNR of up to 30.5 dB and an none-error transmission with 1.5 dB penalty is obtained when scaling the NOS port count to 64. Moreover, exploiting the experimentally measured parameters, the network performance of NOS-based decomposed computing architecture is numerically assessed under larger network scales. The results indicate that, under a 4096-cube network scale, the NOS-based decomposed computing architecture achieves 148.5 ns end-to-end latency inside the same rack and zero packet loss at a link bandwidth of 40 Gb/s.

Styles APA, Harvard, Vancouver, ISO, etc.

9

Xie, Renchao, Qinqin Tang, Qiuning Wang, Xu Liu, F. Richard Yu et Tao Huang. « Satellite-Terrestrial Integrated Edge Computing Networks : Architecture, Challenges, and Open Issues ». IEEE Network 34, n^o 3 (mai 2020) : 224–31. http://dx.doi.org/10.1109/mnet.011.1900369.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

10

Yan, Yanjun, Huihui Xu, Ning Zhang, Guangjie Han et Mingliu Liu. « Dynamic Divide Grouping Non-Orthogonal Multiple Access in Terrestrial-Satellite Integrated Network ». Sensors 21, n^o 18 (16 septembre 2021) : 6199. http://dx.doi.org/10.3390/s21186199.

Texte intégral

Résumé :

Non-orthogonal multiple access (NOMA) has been extensively studied to improve the performance of the Terrestrial-Satellite Integrated Network (TSIN) on account of the shortage of frequency band resources. In this paper, the terrestrial network and satellite network synergistically provide complete coverage for ground users, and based on the architecture, we first formulate a constrained optimization problem to maximize the sum rate of the TSIN under the limited spectrum resources. As the terrestrial networks and the satellite network will cause interference to each other, we first investigate the capacity performance of the terrestrial networks and the satellite networks separately, in which the optimal power control factor expression is derived. Then, by constructing the relationship model between user elevation angle, beam angle and distance, we develop a dynamic group pairing schemes to ensure the effective pairing of NOMA users. Based on the user pairing, to obtain the optimal resource allocation, a joint optimization algorithm of power allocation, beam channel and base station channel resource is proposed. Finally, simulation results are provided to evaluate the user paring scheme as well as the total system performance, in comparison with the existing works.

Styles APA, Harvard, Vancouver, ISO, etc.

11

Zhu, Xiangming, Chunxiao Jiang, Linling Kuang, Ning Ge, Song Guo et Jianhua Lu. « Cooperative Transmission in Integrated Terrestrial-Satellite Networks ». IEEE Network 33, n^o 3 (mai 2019) : 204–10. http://dx.doi.org/10.1109/mnet.2018.1800164.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

12

Braun, Hans-Werner. « Architecture and performance of large internets, based on terrestrial and satellite infrastructure ». ACM SIGMETRICS Performance Evaluation Review 25, n^o 1 (juin 1997) : 1. http://dx.doi.org/10.1145/258623.258628.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

13

Wang, Yuxuan, Jun Yang, Xiye Guo et Zhi Qu. « Satellite Edge Computing for the Internet of Things in Aerospace ». Sensors 19, n^o 20 (10 octobre 2019) : 4375. http://dx.doi.org/10.3390/s19204375.

Texte intégral

Résumé :

As one of the information industry’s future development directions, the Internet of Things (IoT) has been widely used. In order to reduce the pressure on the network caused by the long distance between the processing platform and the terminal, edge computing provides a new paradigm for IoT applications. In many scenarios, the IoT devices are distributed in remote areas or extreme terrain and cannot be accessed directly through the terrestrial network, and data transmission can only be achieved via satellite. However, traditional satellites are highly customized, and on-board resources are designed for specific applications rather than universal computing. Therefore, we propose to transform the traditional satellite into a space edge computing node. It can dynamically load software in orbit, flexibly share on-board resources, and provide services coordinated with the cloud. The corresponding hardware structure and software architecture of the satellite is presented. Through the modeling analysis and simulation experiments of the application scenarios, the results show that the space edge computing system takes less time and consumes less energy than the traditional satellite constellation. The quality of service is mainly related to the number of satellites, satellite performance, and task offloading strategy.

Styles APA, Harvard, Vancouver, ISO, etc.

14

Wu, Zeke, Rui Liu, Haifeng Shuai, Shibing Zhu et Changqing Li. « Covert Performance for Integrated Satellite Multiple Terrestrial Relay Networks with Partial Relay Selection ». Sensors 22, n^o 15 (25 juillet 2022) : 5524. http://dx.doi.org/10.3390/s22155524.

Texte intégral

Résumé :

Integrated satellite multiple terrestrial relay network (ISMTRN) is a new network architecture that combines satellite communication with terrestrial communication. It both utilizes the advantages of the two systems and overcomes their shortcomings. However, security issues inevitably arise in the ISMTRN resulting from the broad coverage of the satellite beams and the openness of wireless communication. One of the promising methods to achieve secure transmission is covert communication technology, which has been a hot discussion topic in recent years. In this paper, we investigate the performance of covert communication in the ISMTRN with partial relay selection. Particularly, when the satellite transmits its signal to the user, we consider the scenario that the selected relay opportunistically sends covert information to the destination. Furthermore, the closed-form error detection probability and average covert communication rate are derived. Finally, numerical simulation results are provided to reveal the impact of critical parameters on system covert performance.

Styles APA, Harvard, Vancouver, ISO, etc.

15

Zhu, Xiangming, et Chunxiao Jiang. « Integrated Satellite-Terrestrial Networks Toward 6G : Architectures, Applications, and Challenges ». IEEE Internet of Things Journal 9, n^o 1 (1 janvier 2022) : 437–61. http://dx.doi.org/10.1109/jiot.2021.3126825.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

16

Giambene, Giovanni. « Satellite-3G Hybrid Networks : Impact of ACM and ARQ on TCP Performance ». Journal of Communications Software and Systems 3, n^o 3 (22 septembre 2007) : 177. http://dx.doi.org/10.24138/jcomss.v3i3.252.

Texte intégral

Résumé :

The adoption of satellite systems in providing broadband transmissions to mobile users such as trains, buses and vans is expected to be an interesting solution. The scenariowe considered refers to a hybrid network architecture, where a geostationary satellite forward link and a terrestrial 3G return link are used in order to exploit both the high bandwidth of a satellite channel and the lower propagation delay of a terrestrial path. The resulting round-trip delay is much shorter than that one experienced by using both the forward and return link via satellite. This is particularly appealing for overcoming the TCP efficiency degradation in high delay-bandwidth product and error prone channels. In this hybrid scenario, we used simulation results to compare the goodput of four of the most popular TCP variants, in the presence of a GOOD-BAD satellite channel, as the one experienced by mobile users. We applied an AdaptiveCoding and Modulation (ACM) technique as well, and studied its impact on TCP efficiency, when used both alone and in cooperation with an Automatic Repeat reQuest (ARQ) scheme of the Selective Repeat (SR) type with low persistency. Results obtained indicate that this hybrid architecture is advantageous for TCP transmissions in terms of average goodput, and that ACM is effective only if it is jointly used with ARQ schemes.

Styles APA, Harvard, Vancouver, ISO, etc.

17

Abbasi, Munir, et Lampros K. Stergioulas. « Hybrid Wireless Networks for E-Learning and Digital Literacy ». International Journal of Digital Literacy and Digital Competence 2, n^o 2 (avril 2011) : 40–52. http://dx.doi.org/10.4018/jdldc.2011040104.

Texte intégral

Résumé :

Today, satellite communication networks are being integrated into the infrastructure of modern Terrestrial communication networks and becoming popular for the delivery of educational content and data, as well as education-centric services, including information, tele-conferencing, entertainment, or ‘edutainment’ services. With fresh demand for new services and applications, it is becoming essential that wireless network architecture seamlessly interoperate with new and existing technologies, protocols and standards. This paper presents recent work on the use of hybrid wireless network infrastructures for delivering tele-education and e-learning applications to remote communities by combining a variety of satellite, terrestrial and wireless technologies, and provides the results from live scenarios carried out employing various methods of interoperability testing. The analysis of the results examines a number of different issues such as delay, jitter, packet loss, latency, throughput measurement, and bandwidth. By combining satellite and terrestrial (wireless) technologies, full coverage and high capacity can be achieved for true broadband services for delivering educational content. The interoperability among such diverse networks imposes a number of challenges regarding service provision and management.

Styles APA, Harvard, Vancouver, ISO, etc.

18

Arcidiacono, Antonio, Daniele Finocchiaro, Riccardo De Gaudenzi, Oscar del Rio-Herrero, Stefano Cioni, Marco Andrenacci et Riccardo Andreotti. « Is Satellite Ahead of Terrestrial in Deploying NOMA for Massive Machine-Type Communications ? » Sensors 21, n^o 13 (23 juin 2021) : 4290. http://dx.doi.org/10.3390/s21134290.

Texte intégral

Résumé :

Non-orthogonal multiple access (NOMA) technologies are considered key technologies for terrestrial 5G massive machine-type communications (mMTC) applications. It is less known that NOMA techniques were pioneered about ten years ago in the satellite domain to match the growing demand for mMTC services. This paper presents the key features of the first NOMA-based satellite network, presenting not only the underlying technical solutions and measured performance but also the related deployment over the Eutelsat satellite fleet. In particular, we describe the specific ground segment developments for the user terminals and the gateway station. It is shown that the developed solution, based on an Enhanced Spread ALOHA random access technique, achieves an unprecedented throughput, scalability and service cost and is well matched to several mMTC satellite use cases. The ongoing R&D lines covering both the ground segment capabilities enhancement and the extension to satellite on-board packet demodulation are also outlined. These pioneering NOMA satellite technology developments and in-the-field deployments open up the possibility of developing and exploiting 5G mMTC satellite- and terrestrial-based systems in a synergic and interoperable architecture.

Styles APA, Harvard, Vancouver, ISO, etc.

19

Vargas, Hector, Jorge Aguilar et Miguel Alonso. « Emulator of Communication of SATEX-II Satellite with Earth Station ». Applied Mechanics and Materials 565 (juin 2014) : 223–27. http://dx.doi.org/10.4028/www.scientific.net/amm.565.223.

Texte intégral

Résumé :

We present a project to encourage students to venture into aerospace engineering projects, mainly in the emulation of communicating with the satellite and the earth station. In this exercise was proposed to use all the features of SATEX-II so they could understand a specific project and thus understand all the elements of the TV and play on to scale their communication with the ground station, with the ultimate to generate a comprehensive understanding. And we present to the conceptual design of the various elements of hardware that will Satex-II Satellite and in the most important aspects to consider in choosing the computer. Space conditions are totally different from terrestrial conditions, so the elements of the satellite's computer should be space technology, which require specific materials and fully redundant architecture for the proper functioning of the satellite, which depends mainly on the assigned mission.

Styles APA, Harvard, Vancouver, ISO, etc.

20

Palattella, Maria Rita, Ridha Soua, André Stemper et Thomas Engel. « Aggregation of MQTT Topics over Integrated Satellite-Terrestrial Networks ». ACM SIGMETRICS Performance Evaluation Review 46, n^o 3 (25 janvier 2019) : 96–97. http://dx.doi.org/10.1145/3308897.3308942.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

21

Höyhtyä, Marko, et Jussi Martio. « Integrated Satellite–Terrestrial Connectivity for Autonomous Ships : Survey and Future Research Directions ». Remote Sensing 12, n^o 15 (4 août 2020) : 2507. http://dx.doi.org/10.3390/rs12152507.

Texte intégral

Résumé :

An autonomous vessel uses multiple different radio technologies such as satellites, mobile networks and dedicated narrowband systems, to connect to other ships, services, and the remote operations center (ROC). In-ship communication is mainly implemented with wired technologies but also wireless links can be used. In this survey paper, we provide a short overview of autonomous and remote-controlled systems. This paper reviews 5G-related standardization in the maritime domain, covering main use cases and both the role of autonomous ships and that of people onboard. We discuss the concept of a connectivity manager, an intelligent entity that manages complex set of technologies, integrating satellite and terrestrial technologies together, ensuring robust in-ship connections and ship-to-outside connections in any environment. This survey paper describes the architecture and functionalities of connectivity management required for an autonomous ship to be able to operate globally. As a specific case example, we have implemented a research environment consisting of ship simulators with connectivity components. Our simulation results on the effects of delays to collision avoidance confirm the role of reliable connectivity for safety. Finally, we outline future research directions for autonomous ship connectivity research, providing ideas for further work.

Styles APA, Harvard, Vancouver, ISO, etc.

22

Zhang, Liangyi, Shaohua Wu, Xiyu Lv et Jian Jiao. « A Two-Step Handover Strategy for GEO/LEO Heterogeneous Satellite Networks Based on Multi-Attribute Decision Making ». Electronics 11, n^o 5 (3 mars 2022) : 795. http://dx.doi.org/10.3390/electronics11050795.

Texte intégral

Résumé :

Low Earth Orbit (LEO) satellites can provide high-speed and low-delay services for terrestrial users; however, the rapid movement of LEO satellites and the insufficient size of the LEO constellations incurs the instability of the transmission links. The rapid movement of LEO satellites also leads to frequent handovers. Fortunately, GEO/LEO heterogeneous satellite systems can remedy this shortcoming. As the handover decision strategy which makes the selection among the available satellites will directly impact the performance of GEO/LEO heterogeneous satellite systems, we propose a two-step access and handover decision strategy for heterogeneous satellite networks in this paper. Firstly, a GEO/LEO network selection is carried out based on utility functions that reflect user’s QoS requirements. Then, the multi-attribute decision making (MADM) method is used to select the specific LEO satellite if users select LEO satellite network. We also propose an Importance-TOPSIS scheme to improve the weight setting for handover attributes. Simulation results show that the proposed method can reduce the number of handovers and the forced termination probability of the system, and the overall throughput of the system is also improved.

Styles APA, Harvard, Vancouver, ISO, etc.

23

Zhang, Rui, Yuhan Ruan, Yongzhao Li et Can Liu. « Interference-Aware Radio Resource Management for Cognitive High-Throughput Satellite Systems ». Sensors 20, n^o 1 (29 décembre 2019) : 197. http://dx.doi.org/10.3390/s20010197.

Texte intégral

Résumé :

By providing interactive broadband services to geographical areas underserved by terrestrial infrastructure, multi-beam satellite systems play a central role in future wireless communications. Targeting the terabit throughput requirements in satellite communications, we introduce a cognitive radio-based high-throughput satellite (HTS) system architecture where full frequency reuse is employed among beams. Moreover, by analyzing the characteristics of the considered architecture, we discuss the design challenges of radio resource management in cognitive HTS systems exposed to both intra-system and inter-system co-channel interference. Furthermore, to combat interference with low overhead, we propose a generic interference-aware resource management framework based on joint spatial division and multiplexing (JSDM). Under this framework, user grouping along with two-stage precoding is studied to achieve substantial improvement in the overall system throughput. Finally, some future research directions and challenges are also given.

Styles APA, Harvard, Vancouver, ISO, etc.

24

Qu, Zhicheng, Ziwei Liu, Xiaojin Ding, Haotong Cao et Gengxin Zhang. « Co-Existence Analysis on Satellite-Terrestrial Integrated IMT System ». Mobile Networks and Applications 24, n^o 6 (3 septembre 2019) : 1926–36. http://dx.doi.org/10.1007/s11036-019-01337-0.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

25

Solyman, Ahmad A. A., et Ismail A. Elhaty. « Potential key challenges for terahertz communication systems ». International Journal of Electrical and Computer Engineering (IJECE) 11, n^o 4 (1 août 2021) : 3403. http://dx.doi.org/10.11591/ijece.v11i4.pp3403-3409.

Texte intégral

Résumé :

The vision of 6G communications is an improved performance of the data rate and latency limitations and permit ubiquitous connectivity. In addition, 6G communications will adopt a novel strategy. Terahertz (THz) waves will characterize 6G networks, due to 6G will integrate terrestrial wireless mobile communication, geostationary and medium and low orbit satellite communication and short distance direct communication technologies, as well as integrate communication, computing, and navigation. This study discusses the key challenges of THz waves, including path losses which is considered the main challenge; transceiver architectures and THz signal generators; environment of THz with network architecture and 3D communications; finally, Safety and health issues.

Styles APA, Harvard, Vancouver, ISO, etc.

26

Shan, Yutong, et Gongjie Li. « Obliquity Variability of Terrestrial Planets in the Habitable Zone ». Proceedings of the International Astronomical Union 14, S345 (août 2018) : 291–92. http://dx.doi.org/10.1017/s1743921319000061.

Texte intégral

Résumé :

AbstractObliquity (axial tilt) and its variability could play an important role in the climate and habitability of a planet. We explore the spin-axis dynamics of two specific habitable zone exoplanets, Kepler-62f and Kepler-186f, using numerical and analytical techniques. Based on our current understanding of their orbital architecture, we find that, in contrast with the typical conditions in the Solar System, Kepler-62f and 186f should have low obliquity variations except in fine-tuned conditions. Extra undetected planetary companions and/or the existence of a satellite could either stabilize or destabilize obliquities at a variety of values.

Styles APA, Harvard, Vancouver, ISO, etc.

27

Fang, Xinran, Wei Feng, Te Wei, Yunfei Chen, Ning Ge et Cheng-Xiang Wang. « 5G Embraces Satellites for 6G Ubiquitous IoT : Basic Models for Integrated Satellite Terrestrial Networks ». IEEE Internet of Things Journal 8, n^o 18 (15 septembre 2021) : 14399–417. http://dx.doi.org/10.1109/jiot.2021.3068596.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

28

Zhu, Boxiang, Jiarui Li, Zhongkai Liu et Yang Liu. « A Privacy-Preserving Incentive Mechanism for Data Offloading in Satellite-Terrestrial Crowdsensing ». Wireless Communications and Mobile Computing 2021 (31 décembre 2021) : 1–14. http://dx.doi.org/10.1155/2021/1951095.

Texte intégral

Résumé :

Data offloading algorithm is the foundation of urban Internet of Things, which has gained attention for its large size of user engagement, low cost, and wide range of data sources, replacing traditional crowdsensing in areas such as intelligent vehicles, spectrum sensing, and environmental surveillance. In data offloading tasks, users’ location information is usually required for optimal task assignment, while some users in remote areas are unable to access base station signals, making them incapable of performing sensing tasks, and at the same time, there are serious concerns about users’ privacy leakage about their locations. Until today, location protection for task assignment in data offloading has not been well explored. In addition, existing privacy protection algorithms and data offloading task assignment mechanisms cannot provide personalized protection for different users’ privacy protection needs. To this end, we propose an algorithm known as differential private long-term privacy-preserving auction with Lyapunov stochastic theory (DP-LAL) for data offloading based on satellite-terrestrial architecture that minimizes the total payment. This not only gives an approximate optimal total payment in polynomial time but also improves the issue of poor signal in remote areas. Meanwhile, satellite-terrestrial data offloading architecture integrates wireless sensor networks and cloud computing to provide real-time data processing. What is more, we have considered long-term privacy protection goals. We employ reverse combinatorial auction and Lyapunov optimization theorem to jointly optimize queue stability and total payment. More importantly, we use Lyapunov optimization theorem to jointly optimize queue stability and total payment. We prove that our algorithm is of high efficiency in computing and has good performance in various economic attributes. For example, our algorithms are personally rational, budget-balanced, and true to the buyer and seller. We use large-scale simulations to evaluate the proposed algorithm, and compare our algorithm with existing algorithms, our algorithm shows higher efficiency and better economic properties.

Styles APA, Harvard, Vancouver, ISO, etc.

29

Audah, Lukman, Zhili Sun et Haitham Cruickshank. « QoS based Admission Control using Multipath Scheduler for IP over Satellite Networks ». International Journal of Electrical and Computer Engineering (IJECE) 7, n^o 6 (1 décembre 2017) : 2958. http://dx.doi.org/10.11591/ijece.v7i6.pp2958-2969.

Texte intégral

Résumé :

<p>This paper presents a novel scheduling algorithm to support quality of service (QoS) for multiservice applications over integrated satellite and terrestrial networks using admission control system with multipath selection capabilities. The algorithm exploits the multipath routing paradigm over LEO and GEO satellites constellation in order to achieve optimum end-to-end QoS of the client-server Internet architecture for HTTP web service, file transfer, video streaming and VoIP applications. The proposed multipath scheduler over the satellite networks advocates load balancing technique based on optimum time-bandwidth in order to accommodate the burst of application traffics. The method tries to balance the bandwidth load and queue length on each link over satellite in order to fulfil the optimum QoS level for each traffic type. Each connection of a traffic type will be routed over a link with the least bandwidth load and queue length at current time in order to avoid congestion state. The multipath routing scheduling decision is based on per connection granularity so that packet reordering at the receiver side could be avoided. The performance evaluation of IP over satellites has been carried out using multiple connections, different file sizes and bit-error-rate (BER) variations to measure the packet delay, loss ratio and throughput.</p>

Styles APA, Harvard, Vancouver, ISO, etc.

30

Wittek, Michael, Carsten Fritzsch et Dieter Schroth. « Employing Liquid Crystal‐Based Smart Antennas for Satellite and Terrestrial Communication ». Information Display 37, n^o 1 (janvier 2021) : 17–22. http://dx.doi.org/10.1002/msid.1178.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

31

Chu, Jianhang, et Xiaoming Chen. « Robust Design for Integrated Satellite–Terrestrial Internet of Things ». IEEE Internet of Things Journal 8, n^o 11 (1 juin 2021) : 9072–83. http://dx.doi.org/10.1109/jiot.2021.3055776.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

32

Luglio, Michele, Simon Pietro Romano, Cesare Roseti et Francesco Zampognaro. « Service Delivery Models for Converged Satellite-Terrestrial 5G Network Deployment : A Satellite-Assisted CDN Use-Case ». IEEE Network 33, n^o 1 (janvier 2019) : 142–50. http://dx.doi.org/10.1109/mnet.2018.1800020.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

33

Zhang, Zhenjiang, Wenyu Zhang et Fan-Hsun Tseng. « Satellite Mobile Edge Computing : Improving QoS of High-Speed Satellite-Terrestrial Networks Using Edge Computing Techniques ». IEEE Network 33, n^o 1 (janvier 2019) : 70–76. http://dx.doi.org/10.1109/mnet.2018.1800172.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

34

Sharma, Pankaj K., Budharam Yogesh, Deepika Gupta et Dong In Kim. « Performance Analysis of IoT-Based Overlay Satellite-Terrestrial Networks Under Interference ». IEEE Transactions on Cognitive Communications and Networking 7, n^o 3 (septembre 2021) : 985–1001. http://dx.doi.org/10.1109/tccn.2021.3052507.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

35

Chen, Tien-Chien, James V. Krogmeier et Darcy M. Bullock. « Evaluation of AASHTO SiteManager Performance on High-Latency Satellite Communication Links ». Transportation Research Record : Journal of the Transportation Research Board 1935, n^o 1 (janvier 2005) : 17–27. http://dx.doi.org/10.1177/0361198105193500103.

Texte intégral

Résumé :

Most transportation agencies and departments have deployed transmission control protocol–Internet protocol (TCP-IP) applications in their offices and are beginning to deploy TCP-IP applications in remote or satellite field offices. Deployment of TCP-IP applications where broadband access is not available can be quite challenging. Satellite-based communication offers an opportunity to provide high-bandwidth connections quickly. However, satellite communications incur significant travel time delay that may result in poor performance of applications designed for a low-latency environment. This paper presents an evaluation of the AASHTO SiteManager software suite with two different satellite broadband providers. SiteManager clients performed poorly in the high-latency environment, in some cases up to 50 times slower than with SiteManager running on a low-latency terrestrial network with equivalent bandwidth. In general, the performance of SiteManager was relatively insensitive to the bandwidth provided by the satellite provider. In most tasks, SiteManager performed better over a 50-kbps dial-up connection than over a 384-kbps satellite connection. In an alternative architecture in which SiteManager was operated remotely via a terminal emulation service over a satellite connection, the performance was observed to be robust. This architecture requires considerably more equipment, software, and technical support. Furthermore, the delay in seeing some key-strokes and cursor movements appear can be somewhat awkward for the user. However, given the extensive bursts of short messages between SiteManager clients and the server, the high-latency constraints of a satellite network make a terminal emulation procedure the only viable method of deploying SiteManager via a commercial satellite IP service.

Styles APA, Harvard, Vancouver, ISO, etc.

36

Feng, Bohao, Guanglei Li, Guanwen Li, Yuming Zhang, Huachun Zhou et Shui Yu. « Enabling Efficient Service Function Chains at Terrestrial-Satellite Hybrid Cloud Networks ». IEEE Network 33, n^o 6 (novembre 2019) : 94–99. http://dx.doi.org/10.1109/mnet.2019.1800426.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

37

Sangjan, Worasit, et Sindhuja Sankaran. « Phenotyping Architecture Traits of Tree Species Using Remote Sensing Techniques ». Transactions of the ASABE 64, n^o 5 (2021) : 1611–24. http://dx.doi.org/10.13031/trans.14419.

Texte intégral

Résumé :

HighlightsTree canopy architecture traits are associated with its productivity and management.Understanding these traits is important for both precision agriculture and phenomics applications.Remote sensing platforms (satellite, UAV, etc.) and multiple approaches (SfM, LiDAR) have been used to assess these traits.3D reconstruction of tree canopies allows the measurement of tree height, crown area, and canopy volume.Abstract. Tree canopy architecture is associated with light use efficiency and thus productivity. Given the modern training systems in orchard tree fruit systems, modification of tree architecture is becoming important for easier management of crops (e.g., pruning, thinning, chemical application, harvesting, etc.) while maintaining fruit quality and quantity. Similarly, in forest environments, architecture can influence the competitiveness and balance between tree species in the ecosystem. This article reviews the literature related to sensing approaches used for assessing architecture traits and the factors that influence such evaluation processes. Digital imagery integrated with structure from motion analysis and both terrestrial and aerial light detection and ranging (LiDAR) systems have been commonly used. In addition, satellite imagery and other techniques have been explored. Some of the major findings and some critical considerations for such measurement methods are summarized here. Keywords: Canopy volume, LiDAR system, Structure from motion, Tree height, UAV.

Styles APA, Harvard, Vancouver, ISO, etc.

38

Jiang, Shengming. « Marine Internet for Internetworking in Oceans : A Tutorial ». Future Internet 11, n^o 7 (5 juillet 2019) : 146. http://dx.doi.org/10.3390/fi11070146.

Texte intégral

Résumé :

Ever-increasing human activities in oceans require handy, reliable and cost-effective high-speed network access similar to terrestrial Internet services to be available on and under water. However, terrestrial Internet cannot be extended to oceans seamlessly due to huge differences between terrestrial and oceanic environments, while satellite services are still very expensive especially for ordinary users with communication quality susceptible to weather conditions, and cannot cover underwater networks either. Therefore, marine Internet, proposed about six years ago, is the earliest scheme that tries to systematically address the internetworking issue in oceans and still in its infancy stage. This tutorial aims to introduce the principle, architecture and applications of marine Internet, along with discussion on oceanic environments for communication, currently available and under developing communication systems in oceans, as well as challenging issues necessary for further studies to foster the development of marine Internet.

Styles APA, Harvard, Vancouver, ISO, etc.

39

Li, Jian, Kaiping Xue, Jianqing Liu, Yongdong Zhang et Yuguang Fang. « An ICN/SDN-Based Network Architecture and Efficient Content Retrieval for Future Satellite-Terrestrial Integrated Networks ». IEEE Network 34, n^o 1 (janvier 2020) : 188–95. http://dx.doi.org/10.1109/mnet.2019.1900138.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

40

Ziaragkas, Georgios, Georgia Poziopoulou, José Núñez-Martínez, Jorge Baranda, Isaac Moreno, Christos Tsinos, Sina Maleki, Shree Krishna Sharma, Maha Alodeh et Symeon Chatzinotas. « SANSA-hybrid terrestrial-satellite backhaul network : scenarios, use cases, KPIs, architecture, network and physical layer techniques ». International Journal of Satellite Communications and Networking 35, n^o 5 (27 avril 2017) : 379–405. http://dx.doi.org/10.1002/sat.1207.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

41

Zhou, Wei, Xing Jiang, Qingsong Luo, Shanguo Huang, Bingli Guo, Xiang Sun, Shaobo Li, Xiaochuan Tan, Mingyi Ma et Tianwen Fu. « Design and Implementation of Semi-Physical Platform for Label Based Frame Switching in Integrated Satellite Terrestrial Networks ». Applied Sciences 12, n^o 13 (1 juillet 2022) : 6674. http://dx.doi.org/10.3390/app12136674.

Texte intégral

Résumé :

With the explosion of traffic demand in recent years, the integration of satellite optical networks and terrestrial networks (ISTN) creates a promising networking solution for future low-latency, high-rate, and high-capacity communications. Owing to the high cost of deploying and maintaining a satellite optical network, it is critical to carefully design and plan the network to ensure the performance of the network. Thus, a semi-physical simulation platform based on software-defined networks (SDNs) is developed to simulate a satellite optical network and evaluate the performance of the proposed label-based advanced orbiting system (AOS) frame switching method that adheres to the Consultative Committee for Space Data Systems’ recommended standard (CCSDS). The semi-physical simulation platform has two major innovations: (1) adapting and integrating network protocols between the CCSDS and open system interconnect (OSI) reference models, particularly at the data link layer, and (2) the foundation for an SDN-based satellite optical network. In the control plane, real-time VxWorks Simulators serve as controllers to establish and manage various network protocols and the link manager protocol (LMP). Here, network protocols include open shortest path first (OSPF) for routing managing and controlling messages, constraint shortest path first–traffic engineering (CSPF-TE), and constraint-label distribution protocol (CR-LDP) for routing data services. LMP is used to assign and reserve satellite optical link resources. The performance of the architecture and protocols is evaluated via a semi-physical simulation platform.

Styles APA, Harvard, Vancouver, ISO, etc.

42

Ji, Sijing, Min Sheng, Di Zhou, Weigang Bai, Qixuan Cao et Jiandong Li. « Flexible and Distributed Mobility Management for Integrated Terrestrial-Satellite Networks : Challenges, Architectures, and Approaches ». IEEE Network 35, n^o 4 (juillet 2021) : 73–81. http://dx.doi.org/10.1109/mnet.011.2100070.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

43

Song, Zhengyu, Yuanyuan Hao, Yuanwei Liu et Xin Sun. « Energy-Efficient Multiaccess Edge Computing for Terrestrial-Satellite Internet of Things ». IEEE Internet of Things Journal 8, n^o 18 (15 septembre 2021) : 14202–18. http://dx.doi.org/10.1109/jiot.2021.3068141.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

44

Riva, Carlo G., Lorenzo Luini, Alberto Panzeri, Filippo Morandi, Laura Resteghini, Danilo De Donno, Christian Mazzucco et Renato Lombardi. « A Clutter Loss Model for Satellite Communication Systems ». Electronics 12, n^o 1 (30 décembre 2022) : 186. http://dx.doi.org/10.3390/electronics12010186.

Texte intégral

Résumé :

Buildings and vegetation in the proximity of a terrestrial base station induce a significant additional loss, typically referred to as “clutter loss”, which sums up to free space loss and atmospheric attenuation. Clutter loss is essentially due to the radiowave reflection and diffraction caused by buildings and vegetation, and tends to reduce the interference between terrestrial systems, such as upper 6 GHz (U6G), and satellite systems operating in the same frequency bands. In fact, for example, at low elevation angles, the clutter loss could reach some tens of dB in the U6G band. A novel clutter loss model in urban and suburban environments for frequencies up to 10 GHz is proposed. The model relies on the Monte Carlo simulation approach presented in Report ITU-R P.2402-0, but some limitations have been removed to extend its applicability to more complex scenarios and possibly increase its accuracy for U6G systems. An analytical approach is also proposed to model the clutter loss statistics obtained by properly fitting the obtained statistics for the cities of London and Melbourne. Finally, the proposed model is validated by comparing its results to those obtained by a commercial ray tracer.

Styles APA, Harvard, Vancouver, ISO, etc.

45

Yang, Kongzhe, Bangning Zhang et Daoxing Guo. « Partition-Based Joint Placement of Gateway and Controller in SDN-Enabled Integrated Satellite-Terrestrial Networks ». Sensors 19, n^o 12 (20 juin 2019) : 2774. http://dx.doi.org/10.3390/s19122774.

Texte intégral

Résumé :

The Integrated Satellite-Terrestrial Networks (ISTNs) with Software-Defined Networking (SDN) incorporated have become the emerging architecture and have attracted considerable attention recently. Therein, the joint gateway and controller placement problem is of fundamental significance for designing ISTNs with flexible and efficient management capabilities. Hence, how to achieve network reliability maximization with low network latency in the joint placement problem is worthy of in-depth study. In this paper, a network partition algorithm, Simulated Annealing Partition-based K-means (SAPKM), is proposed and analyzed for further ameliorating the problem. Experiments are performed on real network topologies to validate the effectiveness of our approach for the joint placement problem. Compared with the state-of-the-art existing works, numerical results show that SAPKM outperforms when deploying four or more controllers in terms of network reliability performance, network latency, and inter-plane latency with less than 2 ms to converge.

Styles APA, Harvard, Vancouver, ISO, etc.

46

Zhu, Xiangming, Chunxiao Jiang, Linling Kuang, Zhifeng Zhao et Song Guo. « Two-Layer Game Based Resource Allocation in Cloud Based Integrated Terrestrial-Satellite Networks ». IEEE Transactions on Cognitive Communications and Networking 6, n^o 2 (juin 2020) : 509–22. http://dx.doi.org/10.1109/tccn.2020.2981016.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

47

Wu, Zeke, Kefeng Guo et Shibing Zhu. « Covert Communication for Integrated Satellite–Terrestrial Relay Networks with Cooperative Jamming ». Electronics 12, n^o 4 (17 février 2023) : 999. http://dx.doi.org/10.3390/electronics12040999.

Texte intégral

Résumé :

We explore the influence of cooperative jamming on covert communication for integrated satellite–terrestrial relay networks (ISTRN) in this article, where one full-duplex relay is utilized to support communications and acts as a jammer to confuse eavesdroppers. A cooperative scheme is first proposed to efficiently achieve covert communication in this specific scenario. Further, the probability of detection error (PDE) is derived. Subsequently, the minimum PDE is calculated using the optimal detection threshold. Moreover, a closed-form expression of outage probability (OP) is acquired to quantify the system’s covert performance. Based on this, we design a power optimization algorithm to enhance the effective covert rate under covertness constraints. Lastly, numerical simulation results are given to verify the efficiency of our cooperative jamming scheme when interrupting the eavesdroppers. Notably, an optimal power allocation factor can be obtained, leading to a higher effective covert rate.

Styles APA, Harvard, Vancouver, ISO, etc.

48

Yang, Ying, et Lidong Zhu. « A Knowledge Inference and Sharing-Based Open-Set Device Recognition Approach for Satellite-Terrestrial-Integrated IoT ». Electronics 12, n^o 5 (27 février 2023) : 1143. http://dx.doi.org/10.3390/electronics12051143.

Texte intégral

Résumé :

Satellite-terrestrial-integrated internet of things (IoT) is an inevitable trend in future development, but open satellite link and massive IoT device access will bring serious security risks. However, most existing recognition models are unable to discover and reject malicious IoT devices since they lack the decision information of these unauthorized devices during training. To address this dilemma, this paper proposes a knowledge inference and sharing-based open-set recognition approach to protect satellite-terrestrial-integrated IoT. It proceeds in two steps. First, knowledge inference, where we construct ideal substitutes for unauthorized devices after reasonable inference on the training set, aims to compensate the model’s missing decision information. Second, knowledge sharing, where we inherit the existing knowledge and modify the model’s decision boundaries through model expansion and knowledge distillation, achieves accurate open-set recognition. Experiments on the ORACLE dataset demonstrated that our approach outperforms other state-of-the-art OSR methods in terms of accuracy and running time. In short, our approach has excellent performance while only slightly increasing computational complexity.

Styles APA, Harvard, Vancouver, ISO, etc.

49

Lysogor, Ivan, Leonid Voskov, Alexey Rolich et Sergey Efremov. « Study of Data Transfer in a Heterogeneous LoRa-Satellite Network for the Internet of Remote Things ». Sensors 19, n^o 15 (1 août 2019) : 3384. http://dx.doi.org/10.3390/s19153384.

Texte intégral

Résumé :

In the absence of traditional communication infrastructures, the choice of available technologies for building data collection and control systems in remote areas is very limited. This paper reviews and analyzes protocols and technologies for transferring Internet of Things (IoT) data and presents an architecture for a hybrid IoT-satellite network, which includes a long range (LoRa) low power wide area network (LPWAN) terrestrial network for data collection and an Iridium satellite system for backhaul connectivity. Simulation modelling, together with a specialized experimental stand, allowed us to study the applicability of different methods of information presentation for the case of transmitting IoT data over low-speed satellite communication channels. We proposed a data encoding and packaging scheme called GDEP (Gateway Data Encoding and Packaging). It is based on the combination of data format conversion at the connection points of a heterogeneous network and message packaging. GDEP enabled the reduction of the number of utilized Short Burst Data (SBD) containers and the overall transmitted data size by almost five times.

Styles APA, Harvard, Vancouver, ISO, etc.

50

Qu, Yanyu, Fangling Pu, Jianguo Yin, Lingzi Liu et Xin Xu. « Dynamic Traffic Detection and Modeling for Beidou Satellite Networks ». Journal of Sensors 2020 (22 janvier 2020) : 1–11. http://dx.doi.org/10.1155/2020/4575721.

Texte intégral

Résumé :

Beidou navigation system (BDS) has been developed as an integrated system. The third BDS, BSD-3, will be capable of providing not only global positioning and navigation but also data communication. When the volume of data transmitted through BDS-3 continues to increase, BDS-3 will encounter network traffic congestion, unbalanced resource usage, or security attacks as terrestrial networks. The network traffic monitoring is essential for automatic management and safety assurance of BDS-3. A dynamic traffic detection method including traffic prediction by Long Short-Term Memory (LSTM) and a dynamically adjusting polling strategy is proposed to unevenly sample the traffic of each link. A distributed traffic detection architecture is designed for collection of the detected traffic and its related temporal and spatial information with low delay. A time-varying graph (TVG) model is introduced to represent the dynamic topology, the time-varying link, and its traffic. The BDS-3 network is simulated by STK. The WIDE dataset is used to simulate the traffic between the satellite and ground station. Simulation results show that the dynamic traffic detection method can follow the variation of the traffic of each link with uneven sampling. The detected traffic can be transmitted to the ground station in near real time through the distributed traffic detection architecture. The traffic and its related information are stored by using Neo4j in terms of the TVG model. The nodes, edges, and traffic of BDS-3 can be quickly queried through Neo4j. The presented dynamic traffic detection and representation schemes will support BDS-3 to establish automatic management and security system and develop business.

Styles APA, Harvard, Vancouver, ISO, etc.

Articles de revues sur le sujet « Satellite terrestrial architecture »

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres