• 제목/요약/키워드: Broadcasting and Communications

검색결과 769건 처리시간 0.024초

Broadband Home Network Modeling based on Plastic Optical Fiber

  • Lee Jung wook;Chin Yong ohk
    • 한국통신학회논문지
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    • 제30권3B호
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    • pp.53-64
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    • 2005
  • Rapid growth of digitalization in telecommunication and broadcasting and remarkable enhancement in broadband and high speed transmission capability of media raised a problem of integrating communication and broadcasting. In order to implement this, the government has selected construction of Broadband Convergence Network (BcN) as a main new growth engine of the country. The BcN will be realized based on FTTH and Broadband Home Network (BHN) will be implemented through this solution. Transfer rate and bandwidth required for the BcN to be constructed aiming at integration of communication and broadcasting will be specified and the performance of basic transmission media, the plastic optical fiber, will be discussed in order to present its appropriateness.

Density-Based Opportunistic Broadcasting Protocol for Emergency Situations in V2X Networks

  • Park, Hyunhee;Singh, Kamal Deep;Piamrat, Kandaraj
    • Journal of information and communication convergence engineering
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    • 제12권1호
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    • pp.26-32
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    • 2014
  • Vehicular-to-anything (V2X) technology is attractive for wireless vehicular ad-hoc networks (VANETs) because it allows for opportunistic choice of a vehicular protocol between vehicular-to-vehicular (V2V) and vehicular-to-infrastructure (V2I) communications. In particular, achieving seamless connectivity in a VANET with nearby network infrastructure is challenging. In this paper, we propose a density-based opportunistic broadcasting (DOB) protocol, in which opportunistic connectivity is carried out by using the nearby infrastructure and opposite vehicles for solving the problems of disconnection and long end-to-end delay times. The performance evaluation results indicate that the proposed DOB protocol outperforms the considered comparative conventional schemes, i.e., the shortest path protocol and standard mobile WiMAX, in terms of the average end-to-end delay, packet delivery ratio, handover latency, and number of lost packets.

고품질의 IPTV 서비스를 위한 주요기술에 대한 고찰 (A Study on the IPTV's Element and Core Techniques)

  • 나성훈;신현식
    • 한국전자통신학회논문지
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    • 제4권4호
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    • pp.253-258
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    • 2009
  • 통신기술의 급속적인 발달 및 방송의 디지털화와 같은 기술적 발전에 의해 방송과 통신의 융합이 빠르게 전개 되고 있다. 더욱 광대역화된 인터넷을 이용하여 TV의 방송 프로그램을 시청하면서 다양한 통신 서비스를 이용할 수 있는 IPTV(Internet Protocol Television)가 방송통신 융합의 대표적인 서비스로 나타나고 있다. 이에, IPTV의 서비스 구성에 대하여 알아보고 고품질 서비스를 위한 주요기술 이슈에 대해 알아보고 대안을 제시하고자 한다.

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인터넷 방송 콘텐츠 이용에 관한 연구 (A Study on Practical Use of Internet Broadcast Contents)

  • 오정석;윤호창;윤호영
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2003년도 추계종합학술대회 논문집
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    • pp.468-473
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    • 2003
  • 인터넷의 발전은 통신과 방송의 융합으로 인터넷 방송이라는 새로운 방송형태를 이루었다. 인터넷의 발달로 인해 인터넷방송 또한 그 활용범위가 확대되고있다. 전자상거래에서 인터넷 방송이 적극적으로 활용됨으로써 상품이나 서비스에 대한 설득력이 높아지고 있으며, 교육이나 의료서비스 및 건강관리, 세미나 등에 활용되고 있어 그 수용자도 늘어나고 있다. 인터넷 방송은 그 역사가 오래되지 않고 지금 현재도 발전하는 단계이다. 이에 인터넷의 주 이용자층인 20-30대를 대상으로 인터넷 방송 컨텐츠를 어떻게 이용하는지 알아보고자 하였다.

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지상파 DTV 수신기에서의 NTSC 간섭 제거 필터에 관한 특성 분석 (Analysis on the properties of an NTSC interference rejection filter in terrestrial DTV receivers)

  • 김형남
    • 한국통신학회논문지
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    • 제30권1A호
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    • pp.84-90
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    • 2005
  • 우리나라의 지상파 TV 방송의 디지털 전환이 수도권을 시작으로 본격화 되었지만 2010년까지는 현재의 아날로그 NTSC 방송과 동시에 공존하게 된다. 따라서, 디지털 TV 채널과 동일한 채널에 아날로그 NTSC 방송이 존재하게 되며 이를 효과적으로 제거하기 위해서 DTV 수신기에서는 NTSC 간섭 제거 필터를 채택하고 있다. 본 논문에서는 이러한 NTSC 간섭제거 필터의 특성을 살펴보고 이 필터를 사용함으로서 발생하는 잡음 성능 저하를 수학적으로 분석한다.

위성방송 서비스 중계 시스템용 고성능 편파 식별 혼안테나 디자인 (High Polarization Discrimination Antenna Design for Satellite Broadcasting Service Repeating System)

  • 강남구;김정욱;김성철
    • 한국위성정보통신학회논문지
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    • 제1권1호
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    • pp.1-4
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    • 2006
  • Ku band의 위성 신호 중계 기술은 수신 신호의 편파 변환을 통해 고층 건물이나 나무, 기타 지형지물에 의해 만들어진 전파 음영지역에서도 위성 방송 서비스의 적용이 가능하다. 본 논문은 안테나 패턴과 사용 주파수 대역에 대해 편파 특성을 만족시키는 고성능 편파 식별 안테나의 제작에 초점을 둔다. 축비 개선과 편파 식별 특성 향상의 관점에서 제작된 안테나는 위성 방송 서비스 중계 시스템에 적합한 특성을 보인다.

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방송위성을 이용한 시각비교 측정 (Measurement of Time Comparison via Broadcasting Satellite)

  • 전인덕;이창복;김진옥;정낙삼
    • 한국통신학회논문지
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    • 제12권3호
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    • pp.200-203
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    • 1987
  • 방송위성을 이용하여 시각을 비교하는 방법을 제시하였다. 한국표준연구소와 일본전파연구소가 각기 보유하고 있는 원자시계의 시각비교 실험을 BS-2a을 이용하여 수행하였다. 그리고 본 실험에서는 미해군관측소(USNO)의 이동원자시계를 이용하여 시각비교 오차를 $0.1_mu$s이내로 보정하였다.

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Multiband Meandered Monopole Antenna for Mobile Applications

  • Lee, Jae-Kwan;Pyo, Seong-Min;Kim, Young-Sik
    • ETRI Journal
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    • 제32권3호
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    • pp.475-478
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    • 2010
  • A multiband meandered monopole antenna is proposed for digital video broadcasting handheld (DVB-H), global positioning system, personal communications service, wireless broadband (Wibro), and wireless local area network (WLAN) applications. The proposed antenna consists of a meandered line, a shorted length strip line, and a conductor strip between a meandered line and a microstrip feed line. By tuning a short strip and a conductor, a multiband impedance matching is achieved. The proposed antenna has an omnidirectional radiation and yields an antenna gain of greater than -3 dBi in the DVB-H band and 4.5 dBi in the Wibro and WLAN bands. Details of the proposed antenna design and experimental results are presented.

Degradation Analysis of User Terminal EIRP and G/T due to Station-Keeping Variation of Stratospheric Platform

  • Ku, Bon-Jun;Ahn, Do-Seob;Baek, Dong-Cheol;Park, Kwang-Ryang;Lee, Seong-Pal
    • ETRI Journal
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    • 제22권1호
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    • pp.12-19
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    • 2000
  • Wireless communication systems using airship have been proposed in worldwide. The airship will be located at the stratosphere about $20{\sim}23\;km$ above the sea level. The position of airship will vary within the station keeping range with time due to the drag of the wind in the stratosphere. When the earth station antenna has a high gain without the tracking function, the antenna performance may be degraded by a small variation of the airship. This means that variation of airship location could result in serious degradation of the system performance. In this paper, degradation in earth station's Equivalent Isotropic Radiated Power (EIRP) and Gain to noise Temperature ratio (G/T) due to the stratospheric platform movements has been derived by calculating the deviation angle of the main beam directions between the earth station and the platform antenna. In this case, the antenna of the earth station has been assumed circular and/or patch array antennas.

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Japanese Broadcasting in Shanghai during the Periods of Solitary Island and Occupation: A Case Study on the Great Eastern Broadcasting Station (Daito Hoso Kyoku)

  • Ge, Tao
    • Journal of East-Asian Urban History
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    • 제2권1호
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    • pp.113-128
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    • 2020
  • Right before the outbreak of the War of Resistance Against Japanese Aggression (1937-1954), the Great Eastern Broadcasting Station (GEBS) was established in Shanghai under the aegis of the Ministry of Foreign Affairs of Japan (MOFA). Prior to the launching of the GEBS, Japan had not owned similar radio stations in China for years. As a result, the Embassy of Japan in China held rounds of discussions on the plan and Japanese governments, ranging from the MOFA, the Navy, the Army, the Ministry of Communications (MOC), and NHK-Japan Broadcasting Corporation (Nihon Hoso Kyoku) provided financial, technological, and equipment support. In the mid-1930s when the Sino-Japanese relations became intensified, the GEBS assumed the primary role of disseminating government policies to over 30,000 Japanese expatriates in Shanghai to make sure that they could remain settled while supporting military endeavors of the Japanese army once the war between China and Japanese broke out. After 1937, the GEBS became an essential propaganda tool to advance imperial policies of Japan. Although the station differed from the Army-controlled Greater Shanghai Broadcasting Station (Dai Shanhai Hoso Kyoku) in many aspects, it was in line with the latter in terms of advancing wartime ideology of the Japanese empire. As the Japanese-occupied areas were enlarged, target audience of the GEBS also expanded to Chinese people and foreign nationals when Japanese, English, Russian, and Shanghai-dialect news was broadcast by the station. Suffice it to say that the GEBS was closely related to wartime propaganda of the Japanese imperial expansion.