• Journal of information and communication convergence engineering
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• 제10권2호
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• pp.141-148
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• 2012

This paper presents a simple but efficient scheme incorporating a reputation-based approach and a cross-layer approach, called the SIM scheme, for maintaining reliable connectivity and high performance in ad-hoc wireless networks. The SIM scheme incorporates the following two things: an ad-hoc routing scheme with a reputation-based approach exploiting the game theory concept based on an evolutionarily stable strategy, and a cross-layer approach between the network layer and the transport layer employing a reputation-based approach.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제9권1호
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• pp.58-64
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• 2005

The nodes of Ad-hoc network are made up of location registration for sending information and a great number of packet transmissions to maintain routing route among the nodes. under this environment, a huge number of traffics would be generated as mobility variable occurs more than in physical network. Hence, in this paper, focused on to study the relationship of nodes to analyze the extend of the traffic in order to control the traffics of the multi-hop in Ad-hoc.

• Journal of Satellite, Information and Communications
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• 제9권3호
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• pp.98-103
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• 2014

In this paper, we propose and analyze a novel interference cancellation scheme in cooperation communication environment in which a large number of users exist. In cooperative communication system consisting a source, destination, and relay, ad-hoc groups undergo a rapid degradation because of interference data form adjacent ad-hoc groups. To solve these problems, we propose Zero Forcing (FC) and Minimum Mean Square Error (MMSE) and make a dent in the magnitude of interference. Finally, we can obtain orignal data using Successive Interference Cancellation (SIC). The performance of proposed scheme is analyzed in terms of a bit error probability. The results of the paper can be applied to design of various ad-hoc networks for cooperation communication systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제36권11B호
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• pp.1413-1421
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• 2011

A next generation military communication system called Tactical Information Communication Network(TICN) is designed to advance into large capacity, high speed, and long distance wireless relay transmission. To support mobility in battlefield, the application of Ad-hoc networking technology to its wireless communication is being considered. In Ad-hoc network, the key management technique is very important to ensure the confidentiality, integrity, and authentication. In this paper, we propose a new hybrid key management scheme considering the hierarchical characteristics of the tactical ad-hoc such as TICN. For upper layer with sufficient energy and computation capability, we apply PKI based key management scheme. For lower layer with restricted resources, we propose a new key management scheme using the location-based authentication to ensure the energy efficiency.

• Journal of the Korea Institute of Military Science and Technology
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• 제10권1호
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• pp.44-54
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• 2007

In the military field, according to the MIL-STD-188-220, which is an Ad-Hoc communication protocol used for sending out or receiving data and voice smoothly among nodes in the situation that wireless communication nodes move arbitrarily, data communication is cut off because nodes can not know topology changes perpetually in the link disconnection state due to node movement in the case that transmitters do not confirm whether data is delivered to receivers or not, and transmit only the data having routine precedence continuously. In order to solve this problem, we have proposed the technique that makes efficient data communication possible by achieving a rapid topology change detection and link information update using TEST frame. We have analyzed TEST frame application effects in the two aspects of the topology update delay time and the data transmission success ratio.

• Journal of the Korea Institute of Military Science and Technology
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• 제12권3호
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• pp.333-343
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• 2009

Tactical Information Communication Network(TICN) is a concept-type integrated Military Communication system that enables precise command control and decision making by unifying the diversified military communication network and conveying diverse range of battle field information on real-time, at right place at right time. TICN is designed to advance into high speed, large capacity, long distance wireless relay transmission. To support mobility in battlefield environments, the application of Ad-hoc networking technology to its wireless communication has been examined. Ad-hoc network is consist of mobile nodes and nodes in the network depends on the cooperation of other nodes for forwarding of packets. In this context, some non-cooperating nodes may delay forwarding of packets or drop the packets. This may hamper the network as a whole and disrupt communication between the cooperating nodes. To solve this problem, we present a solution with a Node Weight Management Server(NWMS), which manages each node's weight according to its behavior in local area. When the NWMS detects misbehaving node, it increases the node's weight. If the node's weight exceeds a predefined threshold then the NWMS broadcasts the node's information into network to isolate the misbehaving node from the network. These mechanisms show that they are highly effective and can reliably detect a multitude of misbehaving node.

• Proceedings of the Korea Information Processing Society Conference
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• 한국정보처리학회 2006년도 춘계학술발표대회
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• pp.1179-1182
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• 2006

Ad Hoc 무선망은 기존 인프라에 영향을 받지 않으면서, 노드들이 네트워크를 구성하기 때문에 TCP의 혼잡(Congestion) 제어가 나쁜 영향을 미친다. 기존의 TCP에 무선망의 요소와 거리에 따른 노드 홉수의 영향을 반영해서 새로운 환경에 적합한 TCP를 개선해야한다. 본 논문에서는 혼잡의 원인을 구별하여, 패킷 손실을 최소화할 수 있는 알고리즘을 제안한다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• 제3권2호
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• pp.46-49
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• 2010

This paper has proposedfor wireless Ad-hoc networks with robust route maintenance schemes. The device feature Bluetooth and/or IEEE 802.11 network interfaces and communicate in a decentralized manner. The nodes have the responsibility of self-organizing so that the network is robust to the variations in network topology due to node mobility as well as the fluctuations of the signal quality in the wireless environment.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제11권3호
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• pp.31-39
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• 2011

In this paper, we propose an evenly distributed mesh scheme to support services in mobile ad-hoc networks. Two strategies, the adaptive upgrading of forwarding nodes and the adaptive downgrading of forwarding nodes, are presented in the scheme. Our proposed scheme can support construction of better multicast mesh that can give higher packet delivery ratio with lower duplicate data as well as solve the problem of serious congestion especially when node mobility and data transmission rate are high in mobile ad-hoc networks. The performance evaluation is performed via simulation using OPNET.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제13권8호
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• pp.1561-1570
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• 2009

Being different from traditional mobile communication networks or wireless LAN with access points, ad hoc network can provide direct communications between homogeneous stations. Thus, it can be considered as a much advanced network. Somehow, many researches have been done to enhance system performance of ad hoc networks up to now, one of which is cooperative communications. In this paper, a cooperative MAC protocol, called CO-MAC protocol, is proposed and its performance is evaluated with a mathematical approach. Numerical results show that this scheme provides more enhanced system throughput especially when frame transmission error probability is high than DCF scheme, which is the key protocol in IEEE 802.11 standard, and rDCF scheme.