• Journal of Internet Computing and Services
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• v.11 no.5
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• pp.9-17
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• 2010

During the last decade, Internet protocol television(IPTV), broadcasting of multimedia services using well understood Internet technologies, is a fast spreading technology for distributing multimedia content to consumers. As IPTV services advance, an increasing user demand and tremendous content volume of multimedia content cause some difficulties in network resource management. In this paper, we propose an improved load balancing algorithm for video-on-demand(VoD) service. Unlike existing algorithms, the proposed algorithm considers user's behaviors for VoD service, and determines the most efficient allocation of VoD requests by estimating expected server load and expected user waiting time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11B
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• pp.784-791
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• 2005

To provide VoD Service on the Internet VoD server is required to have a large amount of system resource and network bandwidth. Therefore, overlay Multicast schemes are considered as suitable alternatives but they also have some drawbacks to support on-demand media services. In this paper, we propose an overlay multicast based on-demand media service scheme which could exploit server's system resource and its network bandwidth efficiently. Proposed scheme uses shared buffer of clients involving the relay of traffic and Patching while it gives no restrictions to this scheme compared with unicast. Our simulation results show that proposed scheme can support more user than unicast and improve the network performance at the same time.

• International Journal of Advanced Culture Technology
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• v.2 no.1
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• pp.14-19
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• 2014

In this paper, we propose a stream based patching technique in order to reduce demands of network output bandwidth required to provide the true video-on-demand (VoD) service in a Multimedia server. The proposed scheme calculates required streams to clients accurately by analyzing temporal relationships between already arrived requests in a multimedia server and still progressing streams, and then transmits streams freshly. Since our stream based patching technique induces new linking stream which is playing a link role between long and short patching streams, it reduces demand of network output bandwidth required to provide the true VoD service in a multimedia server. Accordingly, we know that the proposed scheme improves service latency and defection rate than those of existing patching technique by a simulation study.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.108-110
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• 1999

컴퓨터 하드웨어의 발달로 고속 네트워킹과 대용량 저장 장치가 가능해지면서 기존의 단순 계산 데이터가 아닌 멀티미디어 데이터를 조작하는 기술이 필요로 하게 되었다. 이 기술을 이용하는 대표적인 것이 VoD 서버 처리 기술이다. 기존 VoD 서버에서는 데이터의 분산 및 버퍼 구조 또는 병렬 I/O를 통하여 해결하려는 노력이 있어 왔다. 본 논문에서는 서버의 성능을 극대화시켰다. 디스크 저장 매체와 서버의 수를 증가시켜 시험하므로써 이 구조가 확장성 있음을 보였다.

• Journal of Korea Multimedia Society
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• v.9 no.7
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• pp.904-913
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• 2006

The QoS(Quality of Service) of VoD(Video on Demand) systems can be improved by reducing the faults that the stream service request from clients is rejected by the VoD server or lost during the service. This paper proposes a model of Dynamic Workload Balancer that can adjust the workload dynamically through the periodical monitoring of the VoD system, and so increase the throughput. The proposed model runs independently from the VoD system by adopting the agent concept. The model comprises the agency part interfacing the VoD system and the intelligence part reasoning or teaming the facts required for the adjustment of workload. An experiment of implementing a simulator was conducted to see whether or not application of the proposed model to VoD system is effective. As a result of the experiment, it was found that the throughput was relatively increased when the proposed model was applied compared to existing means.

• Journal of Korea Entertainment Industry Association
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• v.5 no.1
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• pp.149-153
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• 2011

In this study, a configuration method for a cloud technology based VoD system through two different scenarios is proposed. The first scenario virtualizes DMC, content storages for each SO, and stream servers in the conventional VoD system in order to efficiently use the additionally required storage capacity and stream server. In the second scenario, it is proposed that cable broadcasting systems including VoD systems are to be changed as cloud in which the subscriber STB should have minimum programs and storage regions to connect networks, and the operating system and middle ware presented in the existing subscriber STB is moved to the cloud data center. In addition, the comparison of the application of the cloud technology for the cost of changing the existing system to STB and the cost of establishing a cloud VoD system is performed in order to analyze the cost reduction in broadcasting businesses based on the establishment of VoD systems.

• Journal of Communications and Networks
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• v.14 no.3
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• pp.286-295
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• 2012

To meet the increased demand of video-on-demand (VoD) services, peer-to-peer (P2P) mesh-based multiple video approaches have been recently proposed, where each peer is able to find a video segment interested without resort to the video server. However, they have not considered the constraint of the server's upload bandwidth and the fairness between upload and download amounts at each peer. In this paper, we propose a novel P2P VoD streaming system, named peer cache adaptation (PECAN) where each peer adjusts its cache capacity adaptively to meet the server's upload bandwidth constraint and achieve the fairness. For doing so, we first propose a new cache replacement algorithm that designs the number of caches for a segment to be proportional to its popularity. Second, we mathematically prove that if the cache capacity of a peer is proportional to its segment request rate, the fairness between upload and download amounts at each peer can be achieved. Third, we propose a method that determines each peer's cache capacity adaptively according to the constraint of the server's upload bandwidth. Against the proposed design objective, some selfish peers may not follow our protocol to increase their payoff. To detect such peers, we design a simple distributed reputation and monitoring system. Through simulations, we show that PECAN meets the server upload bandwidth constraint, and achieves the fairness well at each peer. We finally verify that the control overhead in PECAN caused by the search, reputation, and monitoring systems is very small, which is an important factor for real deployment.

• The Journal of Korean Association of Computer Education
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• v.11 no.2
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• pp.107-117
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• 2008

The agent system that can adjust the workload dynamically through thc periodical monitoring of the VoD system comprises the agency part interfacing the VoD system and the intelligence part reasoning or learning the facts required for the adjustment of workload. This paper proposes a learning method that can apply to the intelligence part of the agent system. The proposed method can adjust the workload more efficiently by the rule's reasoning process and case-based learning process. An experiment of implementing a simulator was conducted to see whether or not application of the proposed method to VoD systems is efficient. As a result of the experiment, it was found that the throughput and the average waiting time of the VoD server were relatively improved when the proposed method was applied compared to existing means.

• Journal of Korea Society of Industrial Information Systems
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• v.13 no.1
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• pp.46-56
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• 2008

Double Patching is a multicasting technique for a VoD system which has been proposed to provide a true VoD service by making clients share a long patching stream as well as a regular stream For subsequent short patching streams, the technique always makes the long patching stream have extra data that will be played back during a double period of a patching window. In this paper, we propose a technique, using the start time of the latest short patching stream, optimizes Double Patching by deleting the useless data included in the long patching stream when the patching window of the long patching stream closes. The mean requirement for the server's bandwidth to provide the true VoD service is used as a performance metric, and the effect of the request inter-arrival time, the size of the client's local buffer and the video length on the mean bandwidth requirement is evaluated. Performance evaluation result shows that the proposed technique optimizes Double Patching in all cases.

• Journal of the Korea Society for Simulation
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• v.15 no.2
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• pp.23-29
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• 2006

This paper studies the Internet stream server which serves multimedia stream services such as VoD and MoD. The Internet multimedia stream server is developed to provide 50 users with continuous multimedia stream contents simultaneously. This paper focuses on introducing design concepts, operation details and on evaluating system performance and doing sensitivity analysis with respect to the change of the system components. The performance evaluation is performed using simulation in order to identify the system component that mostly affects the system performance. The sensitivity analysis shows the service delay rates of the multimedia stream server depending on the user's service request pattern. Also, the analysis is made on the utilization rates of the core system components such as the PCI bus and the Ethernet card, and on the system performance change by adding more system components.