• Journal of KIISE
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• v.44 no.11
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• pp.1219-1230
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• 2017

Real-time streaming services over the Internet have increased with the explosive growth of the various mobile platforms, with a focus on smart phones, and the demand for them is growing. In addition, the bandwidth occupied by the streaming services over the Internet had already surpassed 50% in 2010. Because of the shortage of network bandwidth for multimedia services traffic, restrictions on quality and capacity will become more and more serious. CCN is a future Internet architecture that improves how existing host-based Internet architecture handles content-oriented structure, but it is designed for the transmission of general contents and is not suitable for transmitting real-time streaming contents. In this paper, we focus on the inefficient aspects of CCN and propose a hierarchical grade-based scheme for real-time service for a more efficient environment in real-time streaming services. Experiments have shown better performance in terms of bandwidth, network load, and reliability.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.11
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• pp.2143-2159
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• 2011

The hybrid architecture of content delivery networks (CDN) and peer-to-peer overlay networks (P2P) is a promising technology enables effective real-time streaming services. It complements the advantages of quality control and reliability in a CDN, and the scalability of a P2P system. With real-time streaming services, however, high connection setup and media delivery latency are becoming the critical issues in deploying the CDN-P2P system. These issues result from biased peer selection without location awareness or content awareness, and can lead to significant service disruption. To reduce service disruption latency, we propose a group-based CDN-P2P hybrid architecture (iCDN-P2P) with a location/content-aware selection of peers. Specifically, a SuperPeer network makes a location-aware peer selection by employing a content addressable network (CAN) to distribute channel information. It also manages peers with content awareness, forming a group of peers with the same channel as the sub-overlay. Through a performance evaluation, we show that the proposed architecture outperforms the original CDN-P2P hybrid architecture in terms of connection setup delay and media delivery time.

• Convergence Security Journal
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• v.7 no.2
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• pp.135-143
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• 2007

This study proposes a DRM system for VOD streaming services in a mobile environment. The proposed system consists of DRM client manager (Consumer), in which core components for client services are independently constructed to be used in a mobile environment, and DRM server, which provides DRM services. Consumer independently exists in the client to maximize efficiency and processing capacity in such a mobile environment, and consists of license service, content service, access service, and tracking service. DRM server consists of streaming server for VOD streaming, distributor, license server, and provider. The proposed system has an architecture suitable for a mobile environment that is difficult to process in the existing DRM system and can solves the super-distribution using license manager in client manager.

• Journal of KIISE
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• v.41 no.11
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• pp.974-981
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• 2014

These days, use of multimedia streaming service and demand of QoS (Quality of Service) improvement have been increased because of development of network. QoS of streaming service is influenced by a jitter, delay, throughput, and loss rate. For guaranteeing these factors which are influencing QoS, the role of transport layer is very important. But existing TCP which is a typical transport layer protocol increases the size of congestion window slowly and decreases the size of a congestion window drastically. These TCP characteristic have a problem which cannot guarantee the QoS of UHD multimedia streaming service. In this paper, we propose a router buffer based congestion control method for improving the QoS of UHD streaming services. Our proposed scheme applies congestion window growth rate differentially according to a degree of congestion for preventing an excess of available bandwidth and maintaining a high bandwidth occupied. Also, our proposed scheme can control the size of congestion window according to a change of delay. After comparing with other congestion control protocols in the jitter, throughput, and loss rate, we found that our proposed scheme can offer a service which is suitable for the UDH streaming service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.12B
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• pp.758-766
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• 2007

IStreaming services with a client-server architecture have scalability problem because a server cannot accomodate clients more than its processing capability. This paper introduces a case study for implementing H.264 streaming system based on P2P architecture in order to provide scalable and stable broadcast streaming services over the internet. The prototype system called OmniCast264 consists of the H.264 encoding server, the streaming server, the proxy server, and peer nodes. The proxy server dynamically manages placement of the peer nodes on the P2P network. Omnicast264 has the concepts of distributed streaming loads, real-time playback, error-robustness and modularity. Thus, it can provide large-scale broadcast streaming services. Finally, we have built P2P streaming systems with 12 PCs connected serially or in parallel. The experiment shows that OmniCast264 can provide real-time playback.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.5
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• pp.137-144
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• 2021

The IETF has recently been standardizing the QUIC protocol for HTTP/3 services. It is noted that HTTP/3 uses QUIC as the underlying protocol, whereas HTTP/1.1 and HTTP/2 are based on TCP. Differently from TCP, the QUIC uses 0-RTT or 1-RTT transmissions to reduce the connection establishment delays of TCP and SCTP. Moreover, to solve the head-of-line blocking problem, QUIC uses the multi-streaming feature. In addition, QUIC provides various features, including the connection migration, and it is available at the Chrome browser. In this paper, we analyze the performance of QUIC for HTTP-based web and streaming services by comparing with the existing TCP and Streaming Control Transmission Protocol (SCTP) in the network environments with different link delays and packet error rates. From the experimental results, we can see that QUIC provides better throughputs than TCP and SCTP, and the gaps of performances get larger, as the link delays and packet error rates increase.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.670-672
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• 2021

The video streaming technologies are used in diverse areas including aerospace. UAV (Unmanned Aerial Vehicle) is still being developed so that we are able to use the UAV not only in military areas but also in civil areas. Remotely monitoring and observing a certain area is possible via using video streaming service based on the UAV nowadays. However, UAV is vulnerable to weather conditions, plane's weight, battery capacity and so on, which makes many restrictions of flight time and video streaming services. In order to prolong the video streaming services, we can use a number of UAVs, fly them one by one, and switch video streaming channels. In the paper, we propose the methods how to interchange UAVs' missions and their video streaming channels to provide seamless video stream services.

• Journal of the Korea Convergence Society
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• v.8 no.9
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• pp.231-236
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• 2017

This study analyzes the characteristics of mobile live streaming service, the illegal and harmful information characteristics of mobile live streaming service for the purpose of eradicating illegal and harmful broadcasting, and shows illegal and harmful broadcast on the mobile live streaming service and eradication plan. First, we reviewed the mobile live streaming service, illegal and harmful broadcasts through literature review, and secondly surveyed illegal and harmful broadcasts of mobile live streaming services and their awareness and countermeasures. As a result, it is confirmed that the mobile live streaming service is illegal, harmful broadcasting exposure frequency is high, illegal, and harmful broadcasting exposure is caused by characteristics of real time broadcasting rather than user's. In order to eradicate the illegal and mobile information about the mobile live streaming service, it is necessary to fix the illegal service and harmful broadcasting reporting system, but the government has confirmed the requirements for regulatory measures. From a microscopic point of view, it will be necessary to investigate the illegal use of mobile live streaming services and the eradication of harmful information.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.7
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• pp.467-476
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• 2014

Recently, various services which use the fused form of broadcasting and communication are being offered over the Internet globally. To provide various interactive services through connected smart TV on wired or wireless network, the seamless multimedia service is key feature. In this paper, Dynamic Adaptive Streaming over HTTP (DASH)is adopted to develop cost-effective adaptive streaming system for Open Hybrid TV(OHTV) service. This system can provide seamless adaptive streaming service for IP VOD, Video Clips, Ad insertion which are defined in OHTV.

• Journal of Korea Multimedia Society
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• v.18 no.7
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• pp.853-863
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• 2015

In this paper, we proposed cross-layered approach of video codec and communication system for the efficient video streaming service. Conventional video streaming is served by divided system which consist of video codec layer and communication layer. Its disintegration causes the limitation of the performance of video streaming service. With the cross-layered design, each layer could share the information and the service is able to enhance the performance. And we proposed the selective retransmission method in communication system based on the cross-layered system that reflect the information of encoded video data. Selective retransmission method which consider the characteristics of video data improves the performance of video streaming services. We verified the proposed method with raw format full HD test sequence with H.264/AVC codec and MATLAB simulation. The simulation results show that the proposed method improves about 10% PSNR performance.