• Journal of Korea Society of Industrial Information Systems
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• v.11 no.1
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• pp.21-28
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• 2006

This paper describes the design and implementation of video conference system using hybrid type P2P(Peer to Peer). The proposed video conference system has hybrid type P2P architecture based on a client-server and P2P(Peer to Peer), where client-server is used for exchange of account management, client list and status information and P2P is used for the real time video conference. The proposed video conference system decreases the traffic of server, and cuts down the load of a network. Because the multimedia data is decentralized to client by P2P. Also, this system is tested by the multi-party video conference system using communication protocol and application software through high speed networks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1B
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• pp.73-85
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• 2004

SIn this paper, we introduce our experience for designing and implementing new concept of a global XML-based Peer-to-Peer (P2P) engine to support various P2P applications, and interconnection among PC, Web and mobile computing environments. The proposed P2P engine can support to heterogeneous data exchanges and web interconnection by facilitating with the text-base XML while message exchange are necessary. It is also to provide multi-level security functions as well as to apply different types of security algorithms. The system consist of four modules; a message dispatcher to scheduling and filtering the message, a SecureNet to providing security services and data transmission, a Discovery Manager to constructing peer-to-peer networking, and a Repository Manager to processing data management including XML documents. As a feasibility test, we implement various P2P services such as chatting as a communication service, white-board as an authoring tool set during collaborative working, and a file system as a file sharing service. We also compared the proposed system to a Gnutella in order to measure performance of the systems.

• Review of KIISC
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• v.12 no.5
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• pp.17-26
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• 2002

P2P(peer to peer)는 인터넷에서 중간에 서버 컴퓨터를 거치지 않고 정보를 찾는 사람과 정보를 가지고 있는 사람의 컴퓨터를 직접 연결시켜 데이터를 공유할 수 있게 해주는 기술과 그 기술을 응용해서 제공되는 서비스를 말한다. P2P 서비스는 서버 없이 컴퓨터와 컴퓨터간에 데이터를 전송함으로서 의도적이거나 고의적인 공격자에 의해 정보보호 위협에 상당히 노출되어 있는 실정이다. 본 연구는 P2P 서비스 모델의 분류와 현재 제공되고 있는 대표적인 P2P 서비스인 냅스터와 그누텔라의 어플리케이션 구조에 대해 분석하였고 P2P 환경에서 발생할 수 있는 정보보호 위협과 안전한 통신을 위해 요구되는 정보보호 서비스에 대해 고찰하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.932-935
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• 2007

모바일 기기 사용이 급증함에 따라 모바일환경에서 이루어지는 P2P방식 연구가 활발히 진행되고 있다. 본 논문에서는 기존의 모바일환경에서의 P2P방식이 지닌 peer들 사이의 multi-broadcasting 방식의 문제점을 보완하고, 새로운 routing table을 구축하기 위해 peer들을 2개의 계층으로 구분하였다. 즉, peer들을 super peer들과 각 super peer에 의해 관리되는 sub peer들로 구분하였다. 파일의 탐색과 전송은 super peer들이 관리하므로, 기존의 불필요한 multi-broadcasting 방식을 피할 수 있다. 본 논문에서는 분산 네트워크를 위한 peer의 계층화 작업을 설계하였다. MIS(Maximal Independent Set)알고리즘을 이용하여 peer들의 계층화 작업을 외부의 도움 없이 peer들간의 통신으로 할 수 있게 만들었다. 이처럼 peer들을 super peer와 sub peer로 구분하면 불필요한 broadcasting을 피할 수 있어 시스템 성능이 향상되며, 이를 실험을 통하여 증명하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.11
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• pp.1216-1223
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• 2014

Internet traffic is rapidly increasing due to the spread of personal smart devices and the demand for multimedia contents. When designing a large ship such as cruise, network architecture is also considered which supports various IT services in a maritime environment similar to the ground environment. In this paper, we consider wireless P2P (peer-to-peer) communication for efficient multimedia content sharing and propose novel handover scheme for efficient download service. The proposed handover method shows that it can improve the download symbol rates for handover in a wireless P2P system considering the signal strength and quality of peers as well. The proposed system is expected to provide efficient contents distribution and reliable communication in the ship-area-network (SAN).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.12
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• pp.870-872
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• 2014

In this paper, we devise a cost function by considering the energy consumption rate and the remaining energy of a peer. Then, we propose a parent peer selection method that chooses the least cost peer in the system in a distributed manner. On the contrary to the conventional method that makes each peer select the least cost neighbor as a parent peer, the proposed method chooses a parent peer using the swarm intelligence formed among a set of peers. Therefore, the proposed method could extent distributedly the number of peers searched for parent peer selection. Thus, compared to the conventional method, the proposed method increases the probability of being a parent peer as the cost of a peer becomes smaller with less operational load.

• International journal of advanced smart convergence
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• v.4 no.2
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• pp.38-45
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• 2015

Peer-to-Peer(P2P) systems are generally classified into two categories; hybrid and pure P2P. Hybrid systems have a single central index server keeping the details of shared information, so that undesirable effects such as heavy load on that server and lack of fault-tolerance can be caused. Pure P2P causes the other problems such as message flooding and scalability although it shows high degree of fault-tolerance. Recently, mobile agent-based distributed computing has been receiving wide attention for its potential to support disconnected operations, high asynchrony, and thus saving network bandwidth. In this paper, a new scheme of peer coordination is proposed for a decentralized P2P network with self-organizing structure. We deployed mobile agents for incorporating the advantages of usage of mobile agents into our P2P network. Proposed P2P network has both advantages of hybrid and pure P2P. The problems of heavy load on the server and lack of fault-tolerance are improved by using multiple special peers called super-peers. And the problems of pure P2P can be reduced by using mobile agents.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4B
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• pp.311-322
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• 2006

Peer-to-peer (P2P) systems have become a popular medium through which to share huge amounts of data. On the basis of network topology, P2P systems are divided into three types: centralized, structured distribution, unstructured distribution. Unstructured P2P systems such as Gnutella are novel in the sense that they are extensible and reliable. However, as the number of nodes increases, unstructured P2P systems would suffer from the high complexity of search operations that have to scan the network to find the required data items. Efficient replication of data items can reduce the complexity, but it introduces another problem of maintaining consistency among replicated data items when each data item could be updated. In this paper, we propose a new update propagation algorithm that propagates an updated data item to all of its replica. The proposed algorithm can reduce the message transfer overhead by adopting the notion of timestamp and hybrid push/pull messaging.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.4
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• pp.389-400
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• 2008

As the wireless network technologies and the capability of the mobile terminals are evolving, advanced peer to peer applications for mobile users are attracting interests. In this paper, we propose the mobile P2P communication platform(MPCP) which provides transparency to the wireless network technologies and solutions to the limited resources of the mobile terminals. MPCP classifies the connection into two levels: a virtual channel and a session. A virtual channel is the network layer connection between the terminals whereas a session is the application layer connection. MPCP classifies the sessions into four types and applies different scheduling priority and data processing policies such as segmentation and reassembly. It selects proper wireless network technologies depending on the distance between the communication endpoints. To acquire dynamically changed access address, we harness the Session Initiation Protocol. We implemented MPCP on embedded Linux simulator and utilized the implementation in mobile P2P service development. For the quantitative analysis, we compared the performance of MPCP with that of ftp. Regardless of the number of simultaneous sessions, MPCP maintains the relative performance.

• Journal of the Korea Society for Simulation
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• v.15 no.4
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• pp.97-105
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• 2006

Popular content stored within the Internet may be convenient to download via modern 3G connections, but costly due to a fee charged by telecommunication providers on the basis of the amount of data transferred. This paper presents a network in which several mobile devices, called the peers, cooperate to download their assigned portion of the content using a 3G connection in order to reduce the overall cost. Then, the peers exchange their assigned portion of the content with other peers via a wireless ad hoc network and the peers reconstruct the whole content using the exchanged portion. This paper focuses on the per-peer based distribution method, and presents the performance comparison with a similar method, called the per-packet distribution method. Both methods are designed to reduce packet collisions while content is exchanged. The simulation result indicates that the per-peer based method outperforms the per-packet based method, and approximately 90% of the telecommunication cost is saved with as few as 10 peers.