• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2006.05a
• /
• pp.538-541
• /
• 2006

Recently researches of P2P media streaming have been actively published, but the research what kind of P2P overlay networks are better to delivering media data has not been attended. This paper designs a P2P streaming media system model. In this system, we constructs a Half-Structure P2P overlay protocol based on node's capability as the infrastructure of streaming application, which utilizes the heterogeneity of the nodes to maintain topology, presents a active contents diffusing algorithm and Two-stage search algorithm, make it possible for nodes in P2P system to collect information according their capacity and reduces the number of forwarding packet compared with flooding. Also, we give an optimal scheme to scheduling media data.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.1
• /
• pp.40-47
• /
• 2015

We propose a method to provide a selective VoD service during live streaming sessions. In the proposed method, each peer joined the live streaming session receives video stream packets with P2P manner and stores the packets to provide a VoD service. To mitigate the overhead of each peer node to store the video stream packets, the proposed scheme categorizes peers into three different groups based on their link types. To increase data gathering speed and reduce the network load, we also proposes the P2P transmission scheme within the same AP network for the peers with Wi-Fi link. To evaluate the performance of the proposed method, we implement computer simulator using NS-3. Simulation results show that the proposed method reduces the overhead about 66% and increases the P2P data gathering speed about 50% compared to the conventional schemes.

• Journal of Broadcast Engineering
• /
• v.6 no.3
• /
• pp.205-214
• /
• 2001

In this Paper, we present an MP4 file streaming system over IP networks. Using the proposed system a user can access MP4 contents in the servers via H) networks and interact with the contents. The MP4 file format is designed to contain the media information of MPEG-4 and is object-oriented. The presented streaming server system contains GUI, session manager, splitter, SL- packetizer and transmitter. In addition, we knave implemented the client system based on the GUI -2D player, the MPEG-4 reference software. The Presented streaming system is designed use RTF for the media data requiring real-time streaming RTCP for QoS management and TCP for the data such as IOD(Initial Object Descriptor), OD(Object Descriptor) BIFS(Binary Format for Scene), which should be transmitted for the streaming and the data, such as still image and text, which can be entirely transmitted in a packet.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.4
• /
• pp.677-684
• /
• 2008

We propose an grid-based research system that replays the experiment by storing and reusing the previous experiment result data in performing remote experiment from a distance. The proposed system was designed for the real-time hybrid test facility which is being built in Korea Construction Engineering Development(KOCED) Project. To provide users with various data, the experiment result data are maintained by the distributed streaming servers based on the publish/subscribe paradigm. Based on the data characteristics of our project, we compared analyzed the performance of the one-streaming-server case and the distributed-multiple-streaming-server case.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2005.11a
• /
• pp.171-174
• /
• 2005

본 논문은 VOD 스트리밍 데이터에 대한 변형된 Scope Consistency 알고리즘 설계 방안을 제시한다. Consistency Model 은 주로 전자 계산에서 데이터 동기화에 적용될 수 있는 메커니즘이다. 그 중 Scope Consistency는 Memory Consistency Model의 한 종류로, Scope와 같은 lock을 사용하여 임계영역을 정의한다. Scope Consistency를 지원하는 시스템으로 JIAJIA가 있다. JIAJIA는 lock 기반 캐쉬 일관성을 구현한다. 본 논문에서는 JIAJIA에서 사용하는 동기화 메커니즘 중 barrier 메커니즘을 이용하여 일반적으로 전자 계산에서 사용되는 메커니즘을 VOD 스트리밍 데이터가 처리될 수 있는 변형된 Scope Consistency 알고리즘을 설계한다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.10B
• /
• pp.857-865
• /
• 2004

Recently the interest in digital home services and its related technology has increased rapidly. Multimedia data transmission between digital devices that are connected to home network is essential function. This paper presents the design and implementation of multimedia streaming system based on IEEE1394 in Linux environment. The key features of proposed system are as follows. First, it can transmit and receive not only DV format data but also MPEG2-TS format data through IEEE1394 bus. Second, it uses device drivers that handling IEEE1394 and IEC61883 protocol transparently to reduce the complexity of communication program. Third, it applied capacity adaptation technique considering various specifications of PCs to get smooth streaming for HD data. These characteristics are tested on testbed of IEEE1394 based home network. The proposed media streaming technique can be used as a home media sever in Linux environment.

• Proceedings of the Korean Information Science Society Conference
• /
• 2002.04a
• /
• pp.316-318
• /
• 2002

본 논문은 멀티미디어 스트림을 Split 하는 기능을 가진 프록시 서버의 설계와 구현에 대하여 기술한다. Split 기능을 통해 프록시와 스트리밍 서버간의 네트워크 트래픽을 감소시킬 수 있으며 스트리밍 서버 부하를 줄일 수 있다. Split 기능을 구현하기 위해서는 클라이언트와 스트리밍 서버간의 제어 메시지의 필터링과 데이터 자료의 복사 및 전송 방법에 대한 연구가 필요하며 프록시에 연결된 클라이언트들에게 서비스의 안정성과 독립성을 보장해 줄 수 있어야 한다. 구현된 프록시는 RTSP, RTP, RTCP 프로토콜을 지윈하며 실험을 통해 스트림 Split 기능이 올바로 동작함을 보인다.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2001.11a
• /
• pp.95-100
• /
• 2001

본 논문은 시간에 따라 변하는 스크린 이미지의 스트리밍에 적합한 이미지 압축 및 저장 방법을 세안하는 것이다. 이를 위하여 시간에 따라 변화하는 스크린 이미지의 특성을 일반 동영상과 비교하여 분석하였으며, 분석 결과에 의거하여 스크린 이미지의 스트리밍에 가장 적합한 압축 및 저장 방법을 제안하였다. 제안된 방법들은 스트리밍 데이터를 효과적으로 지원하는 DirectShow의 구조에 따라 구현되었으며, 구현된 내용을 보인다. 제안된 방법의 유용성을 보이기 위하여, 구현된 시스템 상에서 압축 성능이 측정되었으며 그 결과를 설명한다.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2001.11a
• /
• pp.60-65
• /
• 2001

본 논문은 MPEG-4 스트리밍을 위한 서버 디멀티플렉싱 기법을 제안한다. 일반적인 스트리밍 서비스에서 클라이언트가 수행하는 디멀티플렉싱을 서버에서 수행한다. 이 기법은 클라이언트의 부하를 감소시킨다. 또한, 다수의 클라이언트에게 스트리밍 서비스를 제공할 경우 데이터 중복 전송에 대한 네트워크 자원 낭비를 막고, 서버 시스템의 부하를 줄일 수 있다. 그러므로, 서버 디멀티플렉싱 기법을 사용할 경우, 기존의 PC 환경에서 뿐 만 아니라 무선환경과 같이 자원이 부족한 환경에서 동작하는 멀티미디어 재생기 개발에 응용될 수 있다.

• The KIPS Transactions:PartD
• /
• v.14D no.3 s.113
• /
• pp.273-284
• /
• 2007

RFID middleware systems collect and filter the RFID streaming data gathered continuously by numerous readers in order to process requests from applications. These requests are called continuous queries because they are kept on executing during certain periods. To enhance the performance of the middleware, it is required to build an index to process the continuous queries efficiently. Several approaches of building an index on not data records but queries, called Query Index, are proposed and widely used for evaluating continuous queries over streaming data. The EPCglobal proposed an Event Cycle Specification (ECSpec) model, which is a standard query interface for RFID applications. Continuous queries based on ECSpec consist of a large number of segments for representing the query conditions. The problem with using any of the existing query indexes on these continuous queries is that it takes a long time to build the index because it is necessary to insert a large number of segments into the index. To solve this problem, we propose an Aggregate Transformation that converts a group of segments into a compressed data which is representative of the segments. We compare the performance of a transformed index with the existing query indexes.