• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2010.11a
• /
• pp.8-9
• /
• 2010

ATSC-M/H에서 main stream(좌영상)인 TS-M 패킷은 MPEG-2 전송 시스템을 기반이고, M/H stream(우영상)인 M/H 패킷은 RTP 기반의 전송방식을 사용한다. 이와 같이 dual-stream 시스템을 통해 좌우영상이 전송되는 경우에는 기존에 연구되었던 동종 스트림간의 동기화방안을 적용할 수 없다. 본 논문에서는 3차원 방송 서비스를 하기 위해 ATSC-M/H를 통해 전송되는 좌우영상간의 동기화 방안을 제안한다.

• Convergence Security Journal
• /
• v.12 no.1
• /
• pp.43-48
• /
• 2012

In this paper, the requirements for information security are presented in the ubiquitous ecological(u-Eco) city. The various definition of ubiquitous city is analyzed first, the concept of the u-Eco City, services and major projects are then presented. The framework of the integrated operating center for u-Eco city is proposed, the privacy, data security and network facility protection in the center are analyzed. Unlike to previously proposed security algorithms, the light-weight encoding algorithms(such as block/stream encoding, pseudo-random generator, hash function, and public key encoding) in the u-Eco city center are required to communicate the information in the ubiquitous sensor network. Furthermore, the principal policies guaranteeing the secrecy and authentication for the private information are also presented.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37 no.2B
• /
• pp.110-119
• /
• 2012

In this paper, we propose an efficient video streaming system over heterogeneous wireless networks. The proposed system modifies fountain code for the video streaming service and maximizes the target video encoding rate using multiple paths while satisfying delay and block recovery failure rate constraints of fountain code. Finally, the proposed system provides the seamless video streaming service of high quality to subscribers by dynamic adaptation of control parameters based on the states of each path over heterogeneous wireless networks.

• Journal of the Korea Computer Industry Society
• /
• v.5 no.9
• /
• pp.911-920
• /
• 2004

Intensive studies have been made in the area of VOD server. Multimedia files in the VOD sever are characterized with the large volume of data, the requirements of synchronization and real-time playback of streams. The basic goal of the study is to find an efficient mechanism to allow maximum number of users under the limited resources such as Bu11er size and disk bandwidth. we propose a efficient user-grouping policy for multi-casting services with dynamic monitoring and management of VOD sever resources. Simulation results show that the rate of buffer usage and QOS change of proposed scheme are about 23% performance improved than that of traditional methods. This implies that our method can allow much more users for given resources.

• Journal of Advanced Navigation Technology
• /
• v.15 no.3
• /
• pp.364-371
• /
• 2011

In P2P distribution mobile networks, QoS of streaming media services are under heavy influence from overheads such as congestion, latency, and interference. The problem is further complicated by the fact that the popularity of media objects changes over time. This paper proposes a new FSMS+ (Fuzzy Similarity-based Multi-level Streaming Scheme) which minimizes performance degradation of streaming services due to overhead. We then utilize fuzzy similarity-based relevance that can dynamically stream the streaming media object with minimum overhead. The simulation result showed that the proposed scheme has better performance in retransmission rate, congestion control rate and latency rate than the other existing methods of distance method, DC (disk caching) method, and prefix method.

• The KIPS Transactions:PartC
• /
• v.11C no.6 s.95
• /
• pp.765-772
• /
• 2004

Multicast communication is simultaneous transmission of data to multiple receivers and saves considerably sender resources and network bandwidth. It has high risk to attack using group address and inherent complexity of routing packets to a large group of receivers. It is therefore critical to provide source authentication, allowing a receiver to ensure that received data is authentic. In this paper, we propose the multiple chain authentication scheme for secure and efficient multicast stream. To evaluate the performance of our scheme, we compare our technique with two other previously proposed schemes using simulation results. Our scheme provides non-repudiation of origin, low overhead by amortizing the signature operation over multiple packets, and high packet loss resistance.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.8A
• /
• pp.625-632
• /
• 2009

This paper presents the mobile IPTV system for the transmission of FGS-encoded video stream over WiMAX network. The proposed system is implemented to provide more subscribers with an improved mobile IPTV service considering the scarce resource constraint. The proposed system pursues an efficient tradeoff between the number of subscribers that receive the enhancement layer stream and their IPTV service quality. In the proposed system, some parts of the enhancement layer are transmitted with the modulation scheme and the coding rate adaptive to wireless link states of subscribers. Finally, experimental results are provided to show the performance of proposed mobile IPTV system.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2005.11a
• /
• pp.255-259
• /
• 2005

본 논문은 시청자가 TV를 시청하다가 마음에 드는 화면이 있으면, 이를 캡춰해서 친구들에게 메시지로 보내는 서비스를 구현하는 방법을 기술한다. 이를 위해서는 셋톱박스에서 실행되는 Xlet 애플리케이션에서 비디오 스트림의 특정화면을 캡춰할 수 있어야 하는데, 현재 미들웨어는 이런 기능을 제공하고 있지 않다. 따라서, 본 논문에서는 Xlet application 에서 시청자가 지정한 화면의 시점값을 방송국 서버로 전송하고, 서버에서 해당 화면을 캡춰하여 이를 시청자가 원하는 수신자에게 보내주는 방법을 사용한다. 미들웨어 API 표준에서 현재의 NPT (Normal Play Time) 을 알려주는 API 를 제공하므로, 애플리케이션에서 시청자가 원하는 시점의 NPT 를 구해 이를 방송국 서버로 보내고, 서버에서는 이 NPT 에 해당되는 동영상의 미디어 타임을 구해, 그 시간에 해당되는 프레임을 계산하여 화면을 캡춰한다. 본 기술을 활용하면 서버에서 캡춰된 화면을 Mobile, Web 등의 매체에도 전송할 수 있으므로 유무선통합, 방통융합형 서비스로 확장해 나갈 수 있다.

• Journal of Korea Society of Industrial Information Systems
• /
• v.21 no.1
• /
• pp.51-59
• /
• 2016

The progression of broadcasting technology changed the previous analogue broadcasting system into digital, which in result allowed several broadcasting programs to be transmitted as one stream by multiplexing. This multi channel environment interferes with audience to choose the program they want. EPG acts as supporter in this multi channel environment. The existing EPG system is limited in providing searching function with title, genre, date and Wish-list in multi-media environment. Thus, this thesis proposes new type EPG using PSIP information modification to respond with the change of broadcasting market. This type of EPG can be applied to several kinds of broadcasting systems.

• Annual Conference of KIPS
• /
• 2002.04a
• /
• pp.205-208
• /
• 2002

출판, 영화, 방송, 인터넷 등 멀티미디어 정보통신 분야에서는 새로운 영상 매체인 3차원 입체 영상 및 가상현실을 차세대 영상정보의 현실감 부여와 정보전달의 리얼리티를 제공하기 위해 다양한 기술들이 활발히 연구되고 있다. 또한 현대의 정보 통신 분야는 방송, 통신 및 컴퓨터가 통합되고, 무선과 유선이 융합되는 새로운 정보 통신 기술로 진화하고 있다. 이러한 변화의 영향으로 영상 서비스에 대한 기술 개발 경향도 영상 정보의 효율적인 전달 및 저장이라는 기존의 동영상 압축 표준이 갖는 기능 이외에, 보다 더 향상된 기능을 제공하는 방향으로 나아가고 있다. MPEG-4는 현재 각광받고 있는 인터넷 등의 멀티미디어 서비스에 있어서 필수적인 핵심기술이다. 본 논문에서는 MPEG-4 표준을 기반으로 하여, Dual 스트림이 입력되는 멀티미디어 데이터 즉, 입체 영상 재현을 위한 데이터를 효율적으로 인코딩하는 방식을 제안하고, 이에 대한 인코더를 분석, 설계하였다. 제안하는 방식은 MPEG-4를 이용한 입체영상 관련 응용에 적용될 수 있다.