• Broadcasting and Media Magazine
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• v.16 no.1
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• pp.40-53
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• 2011

인터넷의 발달과 웹 어플리케이션의 활성화로 Internet Connected TV가 차지하는 비율이 점차 늘어나고, 스마트폰의 선풍적인 인기와 시장의 영향으로 디지털 TV에도 Smart TV의 바람이 불고 있다. Smart TV의 기술을 수신기 관점에서 살펴보았을 때, 방송과 웹이라는 두 가지 분야의 기술과 표준을 생각할 수 있다. 이에, 방송 분야에 대해서는 북미 ATSC 2.0, ATSC PT-3, 유럽 HbbTV 와 DVB-IPTV, 그리고 한국의 OHTV를 표준 관점에서 서비스 및 기술을 서로 비교하고, 다음으로 웹에 대한 기술과 표준화는 W3C의 HTML5, Web and TV 그리고 MPEG에서의 DASH를 살펴보기로 한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.11a
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• pp.151-154
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• 2019

국내 지상파 방송 3사는 세계최초로 2017년에 지상파 UHD 본방송 서비스를 시작하였다. 지상파 UHD 방송은 ATSC 3.0 표준 기반으로 단일주파수로 방송망을 구축할 수 있으므로 각 송신소별 커버리지 중첩지역에서 방송망을 효율적으로 설계하는 것이 필요하다. 또한, ATSC 3.0 송신 장비를 실 방송환경에서 운용하기 위해서는 H/S 와 같은 안정적인 형태로 장비가 구축되어야 한다. 본 논문에서는 2017년 수도권 UHDTV 본방송이 진행된 이후, KBS에 구축한 수도권 UHD-TVR 구축 과정과 수도권 UHDTV 방송망 분석을 위한 필드테스트 결과에 대해 살펴보고자 한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.11a
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• pp.148-150
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• 2019

이 연구에서는 현 재난 경보에서 재난 약자가 가질 수 있는 취약성에 대해 알아보았다. 그리고 해당 취약성에 대한 해결 방안과 해결을 위해 적용할 수 있는 기술적 요구사항도 함께 알아보았다. 재난 약자는 경보 수신 공백, 맞춤형 서비스 부족, 단독 대응 불가 등과 같은 공통적 재난 경보 취약성과 함께 어린이, 노인, 외국인, 장애인 집단 별로 차별적 취약성을 가지는 것으로 나타났다. 이를 보완하기 위해서는 단말기에 이동통신 수신 모듈과 ATSC 3.0 수신 모듈 모두 탑재, ATSC 3.0 방송망을 통해 재난 약자 유형에 맞춘 복수의 메시지 전송, 단말기의 수신자 프로파일 설정에 의한 메시지 표출, 기존의 AEAT 개선 등이 공통적으로 필요하다. 그리고 어린이, 노인, 외국인, 장애인 집단 별로 차별적 취약성을 보완할 수 있는 차별적 기술도 필요하다.

• Journal of Broadcast Engineering
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• v.23 no.2
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• pp.316-319
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• 2018

When a terrestrial UHD broadcasting service and a mobile HD broadcasting service are provided using the PLP function provided by ATSC 3.0 and domestic UHD broadcasting standard, a small amount of data may be additionally transmitted to further provide high quality UHD-3D broadcasting service. The left and right images of the stereoscopic image are input, one view image is encoded by the SHVC method, and the other view images are encoded by the SHVC method of the two-view cross-referencing method. However, since the base layers (BL) of the two encoders are mutually common, the two encoders correspond to encoders that generate one BL stream and two enhancement layer (EL) streams. The average encoding efficiency is 16% more efficient compared to the third independent HEVC encoding for the UHD-3D broadcast service. The proposed scheme reduces the fluctuation of PSNR per image frame and increases the image quality of minimum PSNR frame by 0.6dB.

• Journal of Korea Multimedia Society
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• v.14 no.5
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• pp.614-621
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• 2011

This paper presents design of a wide tuning range digitally controlled oscillator(DCO) for Mobile-DTV applications. DCO is the key element of the ADPLL block that generates oscillation frequencies. We proposed a binary delay chain(BDC) structure, for wide tuning range DCO, modifying conventional fixed delay chain. The proposed structure generates oscillation frequencies by delay cell combination which has a variable delay time of $2^i$ in the range of $0{\leq}i{\leq}n-1$. The BOC structure can reduce the number of delay cells because it make possible to select delay cell and resolution. We simulated the proposed DCO by Cadence's Spectre RF tool in 1.8V chartered $0.18{\mu}m$ CMOS process. The simulation results showed 77MHz~2.07GHz frequency range and 3ps resolution. The phase noise yields -101dBc/Hz@1MHz at Mobile-DTV maximum frequency 1675MHz and the power consumption is 5.87mW. The proposed DCO satisfies Mobile-DTV standards such as ATSC-M/H, DVB-H, ISDB-T, T-DMB.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.07a
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• pp.447-449
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• 2015

Advanced television systems commitee (ATSC) 3.0 은 효율적 주파수 사용을 위하여 여러 개의 방송 스트림을 계층 분할하여 전송하는 layered division multiplexing (LDM) 기술과 연집오류에 의한 성능저하를 방지하기 위하여 시간 인터리버 (time interleaver) 기술을 채택하였다. 본 논문에서는 LDM 기반 시간 인터리버 기술의 각 계층별 성능을 모의실험을 통하여 다양한 채널 환경에서 평가하고 효과를 분석하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.488-491
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• 2020

공익을 목적으로 제공되는 재난경보 서비스에서 누군가의 해킹으로 잘못된 재난경보 메시지가 전달되면 사회적으로 큰 혼란이 발생할 수 있다. 본 논문에서는 지상파 UHD 방송을 통한 재난경보 메시지가 해킹으로부터 안전하게 보호될 수 있도록 ATSC 3.0 표준에 정의된 서명 방식을 기반으로 하여 보안 기능을 구현하는 방안을 제안한다.

• Journal of Broadcast Engineering
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• v.25 no.2
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• pp.252-264
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• 2020

Korea has launched the world-wide first terrestrial UHD broadcast services on May 31, 2017. While the existing HDTV broadcast services use MPEG-2 TS (Tranport Stream) standard for multiplexing and delivering compressed media with additional data, the terrestrial UHD broadcast services use MMT (MPEG Media Transport) standard, which is the next-generation standard beyond MPEG-2 TS. However, the production cost of UHD contents is so high that only a part of the total broadcast time is filled with UHD contents and the UHD time portion is planned to be gradually increased. On the other hand, the ATSC 3.0 standard that uses MMT is not yet used in full-fledged broadcast services in North America. Hence MMT broadcast equipment is still at an early stage with high prices. In this paper we implemented a multi-thread software running on an ordinary PC that can be utilized to realize a low-cost converter that converts the output of an existing MPEG-2 TS multiplexer to an MMTP (MMT Protocol) packet stream. We also verified the functionality of the software through experiments.

• Journal of Broadcast Engineering
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• v.25 no.1
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• pp.36-47
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• 2020

The improved belief-propagation-based algorithms, such as normalized min-sum algorithm (NMSA) or offset min-sum algorithm (OMSA), are widely used to decode LDPC(Low-Density Parity-Check) codes because they are less computationally complex and work well even at low SNR(Signal-to-Noise Ratio). However, these algorithms work well only when an appropriate normalization factor or offset value is used. A new method that uses a CMD(Check Node Message Distribution) chart and least-square method, which has been recently proposed, has advantages on computational complexity over other approaches to get optimal coefficients. Furthermore, this method can be used to derive coefficients for each iteration. In this paper, we apply this method and propose an algorithm to derive a combination of normalization factor and offset value for a combined normalized and offset min-sum algorithm to further improve the decoding of LDPC codes. Simulations on the next-generation broadcasting standards, ATSC 3.0 LDPC codes, prove that a combined normalized and offset min-sum algorithm which takes the proposed coefficients as correction coefficients shows the best BER performance among other decoding algorithms.

• Journal of Broadcast Engineering
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• v.24 no.2
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• pp.329-340
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• 2019

Recently, broadcasting technologies have evolved as high-quality AV services such as domestic terrestrial UHD(Ultra-High Definition) broadcasting have been increasing, and broadcasting standards have been newly defined. Also, as network technology develops, contents are consumed not only in the country but also the world. Accordingly, content insertion technology, which is a method of providing suitable contents in accordance with the national and local environments, will be needed. This paper proposes a content insertion service system model and synchronization scheme using ATSC(Advanced Television Systems Committee) 3.0 Event Signaling standard under heterogeneous network environment of broadcasting network and internet network based on transmission standard DASH(Dynamic Adaptive Streaming over HTTP)/ROUTE(Real time Object delivery Over Unidirectional Transport) and MMT(MPEG Media Transport) of terrestrial UHD broadcasting. It also verifies that the service operates in an environment that meets the broadcast standard.