• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제22권3호
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• pp.83-91
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• 2022

This paper proposes a scalable hybrid P2P(peer-to-peer) cloud architecture for MMOGs(massively multiplayer online games) which includes load management schemes for each region. A game world is divided into several game regions and each game region is serviced by at least one peer(player) in this MMOG cloud environment. The load must be managed regionally to support smooth interactions among them even in the presence of a high concentration of players in a specific region. In the proposed architecture where an efficient and effective provisioning of resources is realized, it is suitable for players to interact with cloud servers effectively and it avoids bottlenecks of the current client-server MMOG architecture. This architecture also relieves a lot of computational power and network traffic, the load on the servers in the cloud by exploiting the capacity of the players. Simulation results show that the proposed hybrid P2P cloud architecture can reduce the considerable bandwidth at the server compared to the client server architecture as the available resources grow with the number of players in crowding or hotspots.

• The Transactions of the Korea Information Processing Society
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• 제5권11호
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• pp.2763-2775
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• 1998

In mobile computing environments, to efficiently use the narrow bandwidth of wireless networks a mobile host caches the data that are frequently accessed. But, because the cached data can be inconsistent with the data n a server due to the host mobility and the disconnection from a server, the usefullness of cached data may be losted. The traditional methods emphasize on the cache consistency and assume that broadcasting times are synchronized at all mobile supprot stations. In this paper, we propose a strategy to maintain cache consistency, which resolves the problems that be caused by the migration of mobile host. The proposed strategy has asynchronous broadcasting time and reduces the communication overhead caused by the synchronization. Also, by preventing the unnecessary messages transmitting from the mobile support station to a mobile host, this strategy can reduce the communication cost and use the narrow bandwidth of wireless networks efficiently.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 2003년도 춘계종합학술대회
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• pp.782-786
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• 2003

It requires protection technologies to permit consumer to store a digital broadcasting content and at the same time to protect the intellectual property from illegal action. There is content encryption as one of protection technologies. In this paper, we proposed a protection scheme for digital broadcasting content that broadcasting server. Multiplexes the encryption key into MPEG-2 TS(transport stream) to be able to encrypt received TS at set top box. The proposed method is to modify PMT(program map table) for the information related encryption key and to multiplex key as TS packets. After then the encryption key is extracted from TS stream which is encrypted in set top box.

• Journal of Korea Multimedia Society
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• 제21권3호
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• pp.415-422
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• 2018

Advances of telecommunication technology bring various changes in journalism field. Reporters started to gather, edit, and transmit content to main server in media company using hand-held smart media and notebook computer. This paper tried to testify valid bit-rate of visual news content using LTE network and mobile phone. Field news like natural disasters need real-time transmission of video content. But broadcasting company normally use heavy ENG system and transmission satellite trucks. We prepared and experimented different types of visual content that has different bit-rates. Transmission tool was LU-60HD mobile system of LiveU Corporation. Transmission result shows that bit-rate of 2Mbps news content is not suitable for broadcasting and VBR (Variable Bit Rate) transmission has better definition quality than CBR (Constant Bit Rate) method. Three different bit-rate of VBR transmission result shows that 5Mbps clip has better quality than 1Mbps and 3Mbps. The higher bit-rate, the better video quality. But if the content has much movements, that cause delay and abnormal quality of video. So optimizing the balance between stability of signal and quality of bit-rate is crucial factor of real-time broadcasting news gathering business.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 한국방송공학회 2004년도 정기총회 및 학술대회
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• pp.43-46
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• 2004

MPEG-21 is an on-progress project of the Moving Picture Expert Group (MPEG) that has been started in many independent parts such as part for standardizing the declaration of a digital item (MPEG-21 Part 2: Digital Item Declaration), right expression language (MPEG-21 Part S: Rights Expression Language), way to process the digital item (MPEG-21 Part 10: Digital Item Processing), etc. All this part is intended to form a framework to enable transparent and augmented use of multimedia resources across a wide range of networks and devices (1). In this paper, we show our research initiative to develop a web-based application that utilized many parts of MPEG-21 technology. The implemented concept uses a digital item and license providers in the server side while the MPEG-21 Conformant application is implemented as a plug-in application that will be downloaded to the user terminal when user accesses the webpage for the frist time. The result of this research shows that with some combination of MPEG-21 parts, we can develop an authorized multimedia delivery and consumption application.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 한국방송공학회 2005년도 학술대회
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• pp.255-259
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• 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.

• ETRI Journal
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• 제38권5호
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• pp.847-857
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• 2016

Broadcasting services such as multi/single channel HDTV and 3DTV/2DTV use a multi-channel encoder that changes the bitrate and composition of the video service depending on the time. However, this type of multi-channel encoder could cause a longer latency owing to the variable bitrate and relatively bigger size of the buffers, which results in the same delay as in 3DTV even for a conventional DTV service. On the other hand, systems built based on separate encoders, each of which is optimized for the target service, might not have such latency problems. Nevertheless, there might be a distortion problem in the image and sound at the time of a switchover between two encoders with different output bitrates and group of picture structures. This paper proposes a system that can realize a seamless video service conversion using two different video encoders optimized for each video service. An overall functional description of the video service change control server, which is a main control block for the proposed system, is also provided. The experiment results confirm the seamless switchover and reduced broadcasting latency of DTV services compared with a broadcasting system composed of a multi-channel encoder system.

• Journal of Broadcast Engineering
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• 제14권2호
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• pp.189-196
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• 2009

We propose a hybrid broadcast scheduling based on a combination of periodic and on-demand data scheduling methods for mobile data broadcasting in convergence networks from communication and broadcasting. We consider an environment in which the forward channel is for data broadcasting and the reverse channel is for sending data requests via cellular phones, WLAN, WiBro, etc. Collecting statistics of requests from clients, the server partitions the data items into hot-item and cold-item sets. Hot items are sent based on a push-based scheduling. An on-demand scheduling method is applied to cold items. Performance evaluation from simulations shows that our proposed scheduling algorithm yields small response time with high successful response ratio.

• Journal of the Korean Society for information Management
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• 제34권4호
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• pp.293-320
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• 2017

This study aims to analyze the current status of records management in local broadcasting stations. To that end, it conducted interviews with personnels in charge of keeping records in KBS in J province, MBC in J province, and 2 local commercial broadcasting stations as well as KBS headquarter. The findings show that the local broadcasting stations keep digital files of born-digital broadcast records in a server in a relatively systematic way. However, they never digitalized their analog records and do not even know the exact volume of total records they own. In addition, they have significant difficulties in preserving and utilizing broadcast records because of outdated preservation facilities and information retrieval systems. Based on the findings, this study suggests ways to improve current broadcast record management such as preparation of record management guidelines, construction of an inventory for owned records, digitalization initiative, and provision of metadata education for PDs, etc.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제16권4호
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• pp.31-40
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• 2016

In vehicular ad-hoc networks (VANETs), vehicles sense information on emergency incidents (e.g., accidents, unexpected road conditions, etc.) and propagate this information to following vehicles and a server to share the information. However, this process of emergency message propagation is based on multiple broadcast messages and can lead to broadcast storms. To address this issue, in this work, we use a novel approach to detect the vehicles that are farthest away but within communication range of the transmitting vehicle. Specifically, we discuss a signal-to-noise ratio (SNR)-based linear back-off (SLB) scheme where vehicles implicitly detect their relative locations to the transmitter with respect to the SNR of the received packets. Once the relative locations are detected, nodes that are farther away will set a relatively shorter back-off to prioritize its forwarding process so that other vehicles can suppress their transmissions based on packet overhearing. We evaluate SLB using a realistic simulation environment which consists of a NS-3 VANET simulation environment, a software-based WiFi-IP gateway, and an ITS server operating on a separate machine. Comparisons with other broadcasting-based schemes indicate that SLB successfully propagates emergency messages with latencies and hop counts that is close to the experimental optimal while reducing the number of transmissions by as much as 1/20.