• 전자통신동향분석
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• 제39권3호
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• pp.36-47
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• 2024

Low Earth Orbit (LEO) satellite communications has become a crucial technology for next-generation communication networks owing to its hyperconnectivity capabilities. We examine the progress and application areas of LEO satellite communication services. The LEO satellite communication industry has transitioned from being predominantly driven by governments and institutions to being led by the private sector, following the trajectory of the NewSpace movement. Leading corporations such as SpaceX Starlink and Eutelsat OneWeb are deploying LEO satellite networks to offer internet services, while Telesat is preparing to establish its satellite communication network. LEO satellite communications is expected to have a major impact on various sectors of society, particularly for upcoming sixth-generation services. Therefore, the South Korean government must promptly formulate policy support strategies aimed at invigorating the LEO satellite communication industry. This can be achieved through initiatives such as bolstering research and development and extending corporate assistance.

• Journal of information and communication convergence engineering
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• 제3권3호
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• pp.123-130
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• 2005

This study performed five methods of tests and measurements to verify the improvement of connection time and bandwidth efficient of FSS (fixed satellite service) TCP/IP network by means of the cash function and the spoofing function. Tests and measurements are performed with; 1. Not to apply the cash and spoofing function 2. Apply the cash function 4. Apply both cash and spoofing function in HUB station and VSAT 5. In a typical commercial terrestrial Internet with LAN. The study results in this paper show that application of the spoofing and cash function greatly improves the bandwidth efficiency to FSS TCP/IP Internet service.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.61-62
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• 2005

In this paper, we investigate the encoding and decoding method of turbo codes that offer a variety of coding rates from 1/3 to 6/7 in Digital Video Broadcast Return Channel via Satellite (DVB-RCS) standard to provide ship-internet service with high-quality.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.397-398
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• 2007

Currently, most of Passenger Service System is supported to VOD in Korea. This current PSS has not internet access, real time broadcasting system and entertainment. The system did not come up to the expectation of consumer. This paper presents an application of new Passenger Service System for developing multimedia as well as wireless communication technology on internet, satellite broadcasting.

• 대한원격탐사학회지
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• 제15권4호
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• pp.349-356
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• 1999

Korea Multi-Purpose Satellite-l (KOMPSAT-l) has been developed by the Korea Aerospace Research Institute (KARI) with the aid of TRW and will be launched on the December 21, 1999 at the Vandenberg Air Base in CA, U.S. Now, the satellite application group in KARI is preparing for the service with the KOMPSAT-l satellite data. For the purpose of supplying good service to the users, data application planning has to be established before launching satellite. To use satellite data effectively, KARI makes a plan for data policy, data price, mission planning, and commercializing strategy. This study was carried out with the purpose of effective use of satellite data. For this purpose, KARI, first, made 60 user groups to use KOMPSAT-l data for public welfare and research sectors. These user groups include government, public corporations, institutes, and universities. KARI will offer the service to users through online using Internet. Secondly, KARI made a policy for the priority of KOMPSAT-l missions. These are classified by the mission priority, payloads, and operational states etc. Thirdly, KARI will make data policy and data price of KOMPSAT-l based on the basic master plan. Especially, data price will be determined at the KOMPSAT-l committee including Ministry of Science and Technology (MOST). KARI is also trying to commercialize the data with the domestic and foreign companies to expand the use of KOMPSAT-l data in the industries sector. Afterward in this study, KARI will continue the improvement for the effective distribution of KOMPSAT-l data for all users.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권11호
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• pp.4419-4435
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• 2015

The use of an efficient packet scheduling scheme for a forward link in satellite communication networks is very important to support fairness for each return channel satellite terminal (RCST) and the service differentiations for user traffics. To support fairness and QoS for each RCST with service-level agreement (SLA), the Adaptive Coding and Modulation (ACM) system in a satellite hub has to process packets with considering modulation and coding (MODCOD) and packet types. Although a DVB-S2 system with ACM scheme has higher transmission efficiency, it cannot offer fairness or quality of service (QoS) to RCSTs. Because the data are transmitted with high MODCOD in regions with clear skies, while data are transmitted using low MODCOD in regions experiencing rain events. In this paper, we propose a two-step scheduling scheme offering fairness and QoS to RCSTs, while minimizing a decrease in throughput. The proposed scheme is carried out performance evaluations using a computer simulation. As results of this simulation, the proposed scheduler was shown to support bandwidth fairness to an individual RCST, and provide a level of QoS differentiation for user traffics.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권3호
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• pp.1260-1283
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• 2019

Low earth orbit (LEO) satellite broadband network is a crucial part of the space information network. LEO satellite constellation design is a top-level design, which plays a decisive role in the overall performance of the LEO satellite network. However, the existing works on constellation design mainly focus on the coverage criterion and rarely take network performance into the design process. In this article, we develop a unified framework for constellation optimization design in LEO satellite broadband networks. Several design criteria including network performance and coverage capability are combined into the design process. Firstly, the quality of service (QoS) metrics is presented to evaluate the performance of the LEO satellite broadband network. Also, we propose a network stability model for the rapid change of the satellite network topology. Besides, a mathematical model of constellation optimization design is formulated by considering the network cost-efficiency and stability. Then, an optimization algorithm based on non-dominated sorting genetic algorithm-II (NSGA-II) is provided for the problem of constellation design. Finally, the proposed method is further evaluated through numerical simulations. Simulation results validate the proposed method and show that it is an efficient and effective approach for solving the problem of constellation design in LEO satellite broadband networks.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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• pp.198-203
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• 1999

Korea Multi-Purpose Satellite-1 (KOMPSAT-1) is developed by the Korea Aerospace Research Institute (KARI) with the aid of TRW and will be launched on the Nov. 24, 1999 at the Vandenberg Air Base in CA, U.S, Now, the satellite application group in KARI is preparing for the service with the KOMPSAT-1 satellite data. For the purpose of supplying good service to the users, data application planning has to be established before launching satellite. To use satellite data effectively, KARI makes a plan for data policy, data price, mission planning, and commercializing strategy. This study was carried out with the purpose of effective use of satellite data. For this purpose, KARI makes a user group first. There are 58 user groups to use KOMPSAT-1 data for public welfare and research sectors. These user groups include government, public corporations, institutes, and universities. KARI will offer the service to users through online using Internet. Secondly, KARI makes a policy for the priority of KOMPSAT-1 missions. These are classified by the mission priority, payloads, and operational states etc. Thirdly, KARI will make data policy and data price of KOMPSAT- 1 based on the basic master 1)tan. Especially, data price will be determined at trte KOMPSAT-1 committee including Ministry of Science and Technology (MOST). KARI is also trying to commercialize the data with the domestic and foreign companies to expand the use of KOMPSAT-1 data in the industries sector. Afterward in this study, KARI will continue the improvement for the effective distribution of KOMPSAT-1 data for all users.

• 전자통신동향분석
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• 제35권5호
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• pp.83-91
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• 2020

In this paper, the contemporary deployment of broadband and Internet-of-Things (IoT) services based on the Low Earth Orbit (LEO) satellite communication network is presented. First, the global service and key technologies of small and nanosatellites are briefly addressed, and then, the progress of relevant standard technologies is explained. Finally, the overall potential for the future development of the LEO satellite communication network is highlighted.

• Journal of electromagnetic engineering and science
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• 제15권2호
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• pp.111-114
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• 2015

In this paper, we have proposed dual-band Phi-shaped slot gap filler antenna for satellite internet service applications. Some properties of the antenna such as return loss, radiation pattern, and gain have been simulated and measured. The proposed antenna has a Phi-shaped slot on the circular patch and is fabricated on the TLX-9 substrate. The radius of the circular patch is 25 mm, and it has a coaxial feeding structure. The dual-band Phi-shaped slot gap filler antenna has high-gain, small-size, simple-structure, and good radiation patterns at each band. The operating frequency band can be tuned by adjusting the length AL and FL of the Phi-shaped slot.