• Journal of the Korea Society of Computer and Information
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• v.10 no.4 s.36
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• pp.93-102
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• 2005

Excessive traffic of P2P applications in the limited communication environment is considered as a network bandwidth problem. Moreover, Though P2P systems search a resource in the phase of search using weakly connected systems(peers' connection to P2P overlay network is very weakly connected), it is not guaranteed to download the very peer's resource in the phase of download. In previous P2P search algorithm (1), we had adopted the heuristic peer selection method based on Random Walks to resolve this problems. In this paper, we suggested an adaptive P2P search algorithm based on the previous algorithm(1) to reform the node distribution rate which is affected in unit peer ability. Also, we have adapted the discriminative replication method based on a query ratio to reduce traffic amount additionally. In the performance estimation result of this suggested system, our system works on a appropriate point of compromise in due consideration of the direction of searching and distribution of traffic occurrence.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.523-524
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• 2009

Peer-to-Peer(P2P) 시스템은 분산된 대용량 데이터를 효율적으로 공유하게 하여 사용자들에게 제공되는 killer application 으로 최근까지 여러 분야에서 연구가 되고 있다. 하지만 P2P 네트워크에서 피어가 소유한 데이터나 공통 관심사 또는 사회적인 관계를 고려하지 않고 무작위로 오버레이가 구성되기 때문에 검색 결과의 제약이 발생한다. 따라서 본 논문에서는 P2P 오버레이상의 효율적인 데이터 검색을 위해서 각 피어가 가지고 있는 데이터와 공통의 관심사를 기반으로 유사성을 측정하여 semantic overlay를 구성하는 기법을 제안한다. 그리고 피어들 간의 semantic proximity는 데이터 요약 기법을 사용하여 측정되며 측정 과정상에서 popular content을 고려하여 semantic proximity의 왜곡현상을 방지하여 semantic link quality의 향상을 가져오는 방안을 도입한다.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.1
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• pp.42-48
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• 2015

Generally, the current commercial cloud system is hosted by the centralization large datacenter. However, the other clouding forms existed and one of them is the P2P cloud. The P2P Cloud is a distributed systems, is freedom to join and leave and is possible to provide the IaaS. Commonly, P2P Cloud System is based on Pure-P2P System. Since a number of connection paths exist, it has a high reliability and easily scalability of the network. However, there are disadvantages of the slow rate of route because of looking up the all peers in order to search for the peer. In this paper, it proposes the P2P cloud system based on super-peer P2P. Super-peer P2P system has fast routing time, because of searching for cluster unit and it also can has high reliability and high scalability. We designs the super Peer cloud service and proposes the system model and Resource Allocation Algorithm for IaaS in Super peer P2P environment.

• 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.

• Journal of Communications and Networks
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• v.12 no.3
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• pp.209-215
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• 2010

In an asymmetrical speed channel environment like asymmetric digital subscriber line, the up-link bandwidth is normally smaller than the down-link bandwidth, which will lead to extremely low utilization of down-link bandwidth when current P2P video transmission is applied. To overcome this, a new fast P2P video transmission method applied in an asymmetrical speed channel environment is proposed in this paper. On the basis of the many-to-one concept, the proposed method uses a new multipeer aggregation technique to enhance the utilization of down-link bandwidth. In addition, an adaptive peer assignment algorithm is also introduced in order to minimize the overall transmission time. Experimental results show that by using our proposed method, the utilization of down-link bandwidth is significantly improved, and the overall transmission time is greatly reduced.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.9
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• pp.1955-1964
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• 2011

With fast deployment of high-speed networks and various online services, the demand for massive content distribution is also growing fast. An approach that is increasingly visible in communication research community and in industry domain is peer-to-peer (P2P) networks. The P2P swarming technique enables a content distribution system to achieve higher throughput, avoid server or network overload, and be more resilient to failure and traffic fluctuation. Moreover, as a P2P-based architecture pushed the computing and bandwidth cost toward the network edge, it allows scalability to support a large number of subscribers on a global scale, while imposing little demand for equipment on the content providers. However, the P2P swarming burdens message exchange overheads on the system. In this paper, we propose a new protocol which provides confidentiality, authentication, integrity, and access control to P2P swarming. We implemented a prototype of our protocol on Android smart phone platform. We believe our approach can be straightforwardly adapted to existing commercial P2P content distribution systems with modest modifications to current implementations.

• Journal of the Korea Society of Computer and Information
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• v.12 no.6
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• pp.49-57
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• 2007

The P2P distributed systems are proceeded various studies lively to use the idleness computing resources under the network connected computing environments. It's a general mean to communication from the peer of the shortest downloaded time among same target files to be searched. The P2P search algorithms are very important primary factor to decide a real downloaded time in the criteria to select the peer of a shortest downloaded time. However the peer to give resources could be changed into offline status because the P2P distributed systems have very weakness connection. In these cases. we have a choice to retransmit resources mainly. In this study, we suggested an effective backtracking search algorithm to improve the performance about the request to retransmit the resource.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.11a
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• pp.466-469
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• 2003

PC의 컴퓨팅 능력과 네트워크 성능이 급속도로 향상됨에 따라 이러한 인프라를 바탕으로 떠오르고 있는 Peer-to-Peer (P2P) 시스템은 자원의 복제 및 공유를 통하여 컴퓨팅 시스템 전반에 걸친 신뢰성과 결함감내 능력을 향상시킨다. 그러나 현재까지 연구된 P2P 네트워크는 각 노드가 복제한 데이터의 일관성 유지를 위해 필요한 그룹통신에 대한 고려가 부족하다. 본 논문은 SpanningTree 방식의 링 구성을 통하여, P2P 시스템에서의 그룹통신을 위해 설계된 메시지 전송 방식을 설명하고 기존 P2P 메시지 전송방식과의 비교를 통하여 성능향상의 근거를 보인다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.4B
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• pp.200-207
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• 2007

Many P2P systems which are designed to implement large-scale data sharing have been introduced in internet recently. They exhibit interesting features like sell-configuration, sell-healing and complete decentralization, which make them appealing for deployment in ad hoc environments as well. This paper proposes an Gnutella-based P2P system that can operate efficiently in ad hoc networks. The objectives of this paper are to extend the overall system lifetime, to reduce overheads, and to provide enhanced performance. The proposed system uses an ultrapeer election scheme based on metric values and proactive distribution of ultrapeer information. According to the simulation results, the proposed system can provide better performance than Gnutella in terms of query success rate, query response time, overhead and residual battery power by utilizing network resources efficiently.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.460-462
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• 2002

컴퓨터 네트워킹의 새로운 패러다임으로 떠오르고 있는 P2P(Peer-to-peer)통신은 기존의 서버-클라이언트 모델의 한계점을 극복하는 많은 해법을 제시하고 있다. 이에 최근여러 가지 플랫폼의 각기의 서비스를 제공하는 애플리케이션들이 속속 등장하고 있다. SunMicro systems에서 시작되어 현재 Open Project로 진행중인 Project JXTA는 이러한 분산 Computing, 특히 Peer-to-Peer Computing이나 Peer-to-Peer 네트워킹이라는 영역에서 폭넓게 발생하는 문제를 해결하기 위해 만들어진 테크놀로지로서 Peer to Peer를 비롯한 분산 Computing들을 위한 Infra Service를 제공하고 있다. JXTA 테크놀로지를 이용하여 제공할 수 있는 여러 서비스 중에 일반 Peer들의 대용량 데이터 전송에서 있을 수 있는 문제점을 해결할 수 있는 서비스를 제안한다. 대용량의 데이터를 여러 서버에서 나누어 받을 수 있도록 하여 Peer-to-Peer 어플리케이션에서 사용자는 찾고자 하는 자료를 검색했을 때 자료의 위치와 함께 제공자의 status와 capability를 monitoring 함으로써 실제 제공할 수 있는 또는 제공하고자 하는 속도와 다운받을 서버와 가져올 데이터의 용량을 결정함으로써 대용량 데이터를 단시간에 효율적으로 주고받을 수 있다.