• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.2A
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• pp.61-65
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• 2005

We propose a soft QoS-based borrowing scheme for call admission control(CAC) in DVB-RCS(Digital Video Broadcast-Return Channel via Satellite). Some of the ongoing calls temporarily and fairly release bandwidths that can be used to accommodate a new call in an overloaded satellite network. The amount of bandwidth borrowed from each call is proportional to each user's critical bandwidth ratio, one of parameters for soft QoS mechanism. Simulation results show that the proposed scheme improves the system performance in terms of call blocking probability and bandwidth utilization.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.9-14
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• 2006

Galileo is the European Global Navigation Satellite System, under civilian control, and consists on a constellation of medium Earth orbit satellites and its associated ground infrastructure. Galileo will provide to their users highly accurate global positioning services and their associated integrity information. The elements in charge of the computation of Galileo navigation and integrity information are the OSPF (Orbit Synchronization Processing Facility) and IPF (Integrity Processing Facility), within the Galileo Ground Mission Segment (GMS). Navigation algorithms play a key role in the provision of the Galileo Mission, since they are responsible for computing the essential information the users need to calculate their position: the satellite ephemeris and clock offsets. Such information is generated in the Galileo Ground Mission Segment and broadcast by the satellites within the navigation signal, together with the expected a-priori accuracy (SISA: Signal-In-Space Accuracy), which is the parameter that in fault-free conditions makes the overbounding the predicted ephemeris and clock model errors for the Worst User Location. In parallel, the integrity algorithms of the GMS are responsible of providing a real-time monitoring of the satellite status with timely alarm messages in case of failures. The accuracy of the integrity monitoring system is characterized by the SISMA (Signal In Space Monitoring Accuracy), which is also broadcast to the users through the integrity message.

• Broadcasting and Media Magazine
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• v.15 no.1
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• pp.49-57
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• 2010

• Journal of Broadcast Engineering
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• v.11 no.3 s.32
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• pp.302-310
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• 2006

ITU-R B.O. 1130-4 Digital System E adopted for Korean satellite DMB service is a multimedia broadcasting system based on DS-CDM-QPSK technique which broadcasts audio and video contents via the satellite or terrestrial gap-filler. However, Digital System E can not provide full loading services because the multi-channel interference (MCI) is increased due to the loss of orthogonality between signature waveforms in multipath fading channels. In this paper a chip equalizer using tap selection algorithm that enhances the receiving performance is proposed and compared to the conventional rake receiver for the satellite DMB system.

• Journal of Advanced Navigation Technology
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• v.13 no.2
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• pp.178-186
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• 2009

SBAS(Satellite Based Augmentation System) provides GNSS satellite orbit and clock corrections for positioning accuracy improvement of GNSS users. In this paper, the accuracy of SBAS satellite orbit and clock corrections were analyzed by comparing with the IGS(International GNSS Service) precise ephemeris. The GPS antenna phase center offsets and the P1-C1 bias are considered for the analysis. The correction data of the US WAAS and the Japanese MSAS were analyzed. The analysis results showed that the SBAS satellite orbit and clock corrections are highly correlated. The correction data accuracy depends on the SBAS ground network size and orbit trajectories.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.99-102
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• 2006

This paper describes a article how to protect from illegal indiscriminate copy of digital broadcasting content using DRM and CCI. With the start of terrestrial / satellite digital broadcast and the preparation of Digital Cable broadcast, we can view HD digital contents through the various channel. Also we can record, play, redistribute digital contents in PVR. The protection of Digital Contents Right became of the important issue to protect CopyRight. In this paper, we implement a manager that prevents indiscriminate digital contents redistribution of the digital broadcast contents. For protection of Digital contents Right, we use BF(Broadcast Flag) and CCI (Copy Control Information) which we can control viewing or copy digital contents with.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.07a
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• pp.310-311
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• 2010

현재 은행들은 종합금융서비스업(Total Financial Solution)인 금융그룹화 추진에 비 은행 사업 분야를 보완하여 금융 업무 대형화를 강화하고 있다. 이에 따라 대형화된 은행권에서는 계열사 간 커뮤니케이션 부재를 해결하고, 각기 다른 기업문화를 통합 할 수 있는 조직 내 커뮤니케이션 매체로 위성영상방송을 찾게 된다. 본 논문에서는 대형화된 은행 내 조직 커뮤니케이션 매체로서의 위성영상방송이 조직에 어떠한 효과를 미치는지 알아보았다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2017.11a
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• pp.24-27
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• 2017

본 논문에서는 빔-호핑 위성 전송 기반의 DVB-S2x 슈퍼프레임 수신기를 위한 프레임 검출 기법을 제안한다. 제안하는 검출 기법은 2 체배 오버샘플링 레이트에서(over-sampling rate)에서 동작을 수행하며, 슈퍼프레임의 헤더를 구성하는 start of super-frame (SOSF)과 super frame format indicator (SFFI)를 모두 이용하여 하드웨어 복잡도를 줄이면서도 견고하게 프레임을 검출할 수 있다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.10-15
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• 1998

In Japan, digital HDTV services via broadcasting satellite are planned to start in 2000. NHK has developed an HDTV codec conforming to the MPEG-2 $MPHL$ and estimated the coded picture quality with diverse image sequences. This paper shows the codec specifications and presents the result of the picture quality assessment.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2018.11a
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• pp.114-116
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• 2018

본 논문에서는 빔-호핑 위성 전송 시스템을 위한 카운터를 기반의 연속적인 beam allocation time schedule (BATS) 변경 기법을 제안한다. 제안하는 기법은 BATS 를 처음 변경할 때, 카운터를 기반으로 gateway (GW)와 space craft (SC) 양단에서 BATS 변경 시점을 동기화 시킨다. 이 후, BATS를 계속 변경하더라도 전송 데이터 손실 없이 BATS 를 변경할 수 있다.