• Convergence Security Journal
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• v.21 no.1
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• pp.121-127
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• 2021

MANET, which does not have any infrastructure other than wireless nodes, has the advantage of being able to construct a fast network. However, the movement of nodes and wireless media are also the causes of security vulnerabilities of MANET. In particular, the damage caused by the attacking nodes existing on the network is considerably greater than that of other networks. Therefore, it is necessary to detection technique for attacking nodes and techniques to reduce damage caused by attacks. In this paper, we proposed a hierarchical structure technique to increase the efficiency of intrusion detection and collaboration-based intrusion detection technique applying a P2P mesh network configuration technique to reduce damage caused by attacks. There was excluded the network participation of the attacking node in advance through the reliability evaluation of the nodes in the cluster. In addition, when an attack by an attacking node is detected, this paper was applied a method of minimizing the damage of the attacking node by transmitting quickly the attack node information to the global network through the P2P mesh network between cluster heads. The ns-2 simulator was used to evaluate the performance of the proposed technique, and the excellent performance of the proposed technique was confirmed through comparative experiments.

• Journal of the Korea Society of Computer and Information
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• v.17 no.5
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• pp.49-57
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• 2012

In P2P streaming management, peer's churning and finding efficient topology architecture optimization algorithm that reduces streaming delay is important. This paper studies a topology optimization algorithm based on the P2P streaming using peer's link information. The proposed algorithm is based on the estimation of peer's upload bandwidth using peer's link information on mesh-network. The existing algorithm that uses the information of connected links is efficient to reduce message overload in the point of resource management. But it has a risk of making unreliable topology not considering upload bandwidth. And when some network error occurs in a server-closer-peer, it may make the topology worse. In this paper we propose an algorithm that makes up for the weak point of the existing algorithm. We compare the existing algorithm with the proposed algorithm using test data and analyze each simulation result.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.01a
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• pp.307-310
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• 2011

IPTV의 스트리밍 서비스를 위해 P2P를 이용하는 방법이 활발하게 연구되어지고 있다. 이 논문에서는 topology를 최적화하는 방안으로 P2P에서 각 peer 간에 연결 및 전송 정보를 이용하는 방법을 제안한다. 제안하는 방법은 mesh-network에서 각 peer에 연결된 link의 수를 이용하여 업로드 대역폭을 추정하는 알고리즘을 기반으로 한다. 이 방법은 자원의 관리를 위해 업로드 대역폭을 판단하기 위한 메시지 과부하를 효과적으로 줄여주지만 스트리밍에서 주어진 연산만을 수행할 경우 업로드 대역폭과 무관한 형태로 network topology가 잘못 구성될 가능성을 가지고 있다. 본 논문에서는 기존 연구에서 부족했던 부분들을 정리하고 극복할 수 있는 각각의 알고리즘들과 적용했을 시에 예상되는 결과를 제시한다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.1
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• pp.89-99
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• 2017

Many works have attempted to solve the scalability, the availability, and the low-latency problems of peer-to-peer (P2P) live video streaming; yet, the problems still remain. While tree-based systems are vulnerable to churn, the mesh-based systems suffer from high delay and overhead. The DHT-aided chunk-driven overlay (DCO) [1] tried to tackle these problems by using the distributed hash table (DHT), which structures into a mesh-based overlay to efficiently share the video segment. However, DCO fully depends on the capacity of the users' device which is small and unstable, i.e., the users' device may leave and join the network anytime, and the video server's bandwidth can be insufficient when the number of users joining the network suddenly increases. Therefore, cloud assist is introduced to overcome those problems. Cloud assist can be used to enhance the availability, the low-latency, and the scalability of the system. In this paper, the DHT is used to maintain the location of the streaming segments in a distributed manner, and the cloud server is used to assist other peers when the bandwidth which required for sharing the video segment is insufficient. The simulation results show that by using the threshold and cloud assist, the availability and the low-latency of the video segments, and the scalability of the network are greatly improved.

• Journal of Digital Contents Society
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• v.15 no.2
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• pp.251-261
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• 2014

In the typical P2P VOD system, it is very important to develop the fast and efficient peer searching scheme since the peers frequently join and leave to/from P2P system. This paper proposes a new peer searching scheme for P2P VOD system based on DHT network environment. The proposed scheme constructs DHT network by managing the peers having close playback starting times and close network locations into a peer all together. The peer information is mapped onto DHT nodes by hashing the key values each of which consists of the starting time and network location of the peer. From the simulation results, the number of messages required to search the partner peers are decreased, and the number of buffer maps exchanging among the peers are also decreased. The proposed scheme can reduce the average network distances among the partner peers. As a result, the proposed scheme makes routing more efficient and it saves the network resources by decreasing communication traffic overhead.

• Journal of KIISE:Information Networking
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• v.36 no.6
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• pp.481-491
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• 2009

In this paper, we proposed a hybrid P2P overlay structure for live media streaming. The proposed structure consists of the mesh overlay organized by peers according to the geographical proximity and similar bandwidth range and the tree overlay formed by the peers for which the stability of participation is approved. The proposed scheme enhances the robustness of tree overlay and the long delay of mesh overlay by intelligently combining the utilization of the tree overlay and the mesh overlay. Furthermore, the peers with a large up-link bandwidth are located near to the media source peer. Therefore, it reduces the height of tree, and as a result, the stream transmission delay. Through simulation, we evaluated the performance of the proposed scheme in terms of scalability and quality of services.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1669-1675
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• 2005

Recently, the small sized wireless terminals have problems of processing of large sized file because of the trends of a small sized terminals and a large sized files. Moreover, the web servers or the file servers have problems of the overload because of the concentration with many number of files to the them. Also, There is a security vulnerability of the data processing caused by the processing with a unit of the independent file. To resolve the problems, this paper proposes a new scheme of fat splining distribution using the P2P networks with the mesh topology. The proposed scheme is to distribute blocks of file into any peer of P2P networks. It can do that the small sized wireless terminals can process the large size file, the overload problems of a web or file servers can solve because of the decentralized files, and, the security vulnerability of the data processing is mitigated because of the distributed processing with a unit of the blocks to the peers.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.6
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• pp.590-596
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• 2020

In the island areas where system connection with the commercial power grid is difficult, it is quite important to find a method to efficiently manage energy produced with independent microgrids. In this paper, a prosumer management system for P2P power transaction was realized through the testing the power meter and the response rate of the collected data for the power produced in the small-scale microgrids in which hybrid models of solar power and wind power were implemented. The power network of the microgrid prosumer was composed of mesh structure and the P2P power transaction was tested through the power meter and DC power transmitter in the off-grid sites which were independently constructed in three places. The measurement values of the power meter showed significant results of voltage (average): 380V + 0.9V, current (average): + 0.01A, power: 1000W (-1W) with an error range within ±1%. Stabilization of the server was also confirmed with the response rate of 0.32 sec. for the main screen, 2.61 sec. for the cumulative power generation, and 0.11 sec for the power transaction through the transmission of 50 data in real time. Therefore, the proposed system was validated as a P2P power transaction system that can be used as an independent network without transmitted by Korea Electric Power Corporation (KEPCO).

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.2
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• pp.608-627
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• 2016

Wireless mesh networks (WMNs) based on IEEE 802.11s have emerged as one of the prominent technologies in multi-hop communications. However, the deployment of WMNs suffers from serious interference problem which severely limits the system capacity. Using multiple radios for each mesh router over multiple channels, the interference can be reduced and improve system capacity. Nevertheless, interference cannot be completely eliminated due to the limited number of available channels. An effective approach to mitigate interference is to apply dynamic channel switching (DCS) in WMNs. Conventional DCS schemes trigger channel switching if interference is detected or exceeds a predefined threshold which might cause unnecessary channel switching and long protocol overheads. In this paper, a P-learning based dynamic switching algorithm known as learning automaton (LA)-based DCS algorithm is proposed. Initially, an optimal channel for communicating node pairs is determined through the learning process. Then, a novel switching metric is introduced in our LA-based DCS algorithm to avoid unnecessary initialization of channel switching. Hence, the proposed LA-based DCS algorithm enables each pair of communicating mesh nodes to communicate over the least loaded channels and consequently improve network performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.12
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• pp.2179-2187
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• 2008

The P2P technology has been widely used to distribute files efficiently, and its use in streaming is rapidly increasing. P2P streaming has issues about startup-delay, scalability, and real-time playback, however, what affects these factors has not been researched sufficiently. This paper suggests a buffering model for progressive download within mesh-based P2P system, which corresponds to downloading and playing the content at the same time. It is used to analyze PDF(Playback Deadline First), Rarest algorithms which are block-selection strategies of P2P streaming and proposes a mixed selection of them. The mixed block selection strategy dynamically performs different strategies based on whether the blocks to be played are received or not. In consequence, it enhances the QoS of streaming in a single peer point of view, as well as improving block distributions in an overlay network.