• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.3
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• pp.106-114
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• 2008

In this paper we suggest a protocol and an algorithm which connect a secure channel between a server and a client over a TCP layer. To make key exchange time the most quickly, the protocol adopts ECC Diffie Hellman(ECCDH) algorithm. And the protocol does not use Hello message for key exchanges and state changes. We also implement this protocol over an open TCP/IP program and check the secure channel connecting time over the military computer network. The suggested protocol could be practically used on the military computer network without a hardware implementation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11B
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• pp.1607-1617
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• 2010

In this paper we propose MA-CBRP, mesh adaptive algorithm for wireless mesh networks. MA-CBRP is a hybrid algorithm based on ad-hoc CBRP protocol. In MA-CBRP, the mesh router periodically sends the ANN message as like Hello-message in CBRP. ANN message allows to all clients periodically store a route towards the mesh-router and renewal information in their routing cache. While CBRP periodically reply Hello-message, MA-CBRP does not reply to achieve less overhead. After receiving ANN message, mesh client send JOIN message to mesh router when the route towards mesh router changed. at the same time Register the entry to mesh router, it can achieve to reduce overhead of control the route and shorten the time to find route. consequently, MA-CBRP shows 7% reduced overhead and shortened time to find route than CBRP with regardless of clients number.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06d
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• pp.155-159
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• 2008

비능률적인 스펙트럼 이용률과 제한적인 스펙트럼 밴드 사용의 문제점을 해결하기 위하여, Cognitive Radio가 중요한 솔루션으로써 많은 연구가 진행되고 있다. 본 논문에서는 다중 채널 무선 네트워크에서의 QoS 보장을 위하여 Cognitive Radio 기반의 동적인 스펙트럼 할당 (Dynamic Spectrum Allocation)을 이용한 새로운 MAC 프로토콜을 제안한다. 사용자의 요청에 따라서, 유동적인 스펙트럼은 DSA 메커니즘을 통한 QoS 보장을 위하여 할당 된다. 그리고 동적인 스펙트럼 할당 (DSA)은 컨트롤 채널의 FRQ/FRP/ACK-hello와 데이터 채널의 DATA/ACK에 의하여 동작한다. 스펙트럼 공유의 성능을 증가시키기 위한 협력 검출 (Cooperative Detection)을 위하여, MAC 프로토콜에서는 Hello 메시지가 주기적으로 교환된다. 추가적으로, 성능 평가를 통하여 본 논문에서 제안한 DSA-MAC이 IEEE 802.11 MAC에 비하여 높은 데이터 처리량을 보임을 증명했다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.5
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• pp.1102-1109
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• 2017

In Train Control Network(TCN), to support advanced services beyond control applications, it was revised to support high speed ethernet as IEC 61375-2-5(ETB) and IEC 61375-3-4(ECN). And Train Topology Discovery Protocol(TTDP) was included by which train-consist can be automatically configured. Meanwhile, to adopt wireless LAN as an next onboard network, TTDP need to be modified to reflect the characteristics of WLAN. This paper proposed a TTDP for WLAN using transmission power control and the number of HELLO-ACK handshake. And it determined whether the TTDP executed using the two WLAN interfaces having different bandwidths is correct or not. The proposed TTDP can allow to reduce interference from other nodes. For evaluation of performance of TTDP, NS-2 was used. The evaluation result shows the high reliability of the TTDP in wireless environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.12B
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• pp.1211-1218
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• 2010

OSPF is the optimized routing protocol in wired network and considered as a tactical routing protocol in wireless tactical communication network. However because it is designed basically based on wired environment, it runs inadequately in wireless tactical environment: noise and jamming signal. So, we proposed new OSPF cost function to develop active routing protocol in wireless tactical communication network. In redefined cost function, there are four parameters that are relative transmission speed, link weight, router utilization, link average BER(Bit Error Rate). These parameters reflect wireless tactical characters. Also, we remodel the option field in Hello packet. It can help user to periodically check the link state. From the simulation result, it is shown that proposed OSPF is better than OSPF in jamming situation and has accumulative delay gain with dispersion of traffic load in entire network.

• Proceedings of the KIPE Conference
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• 2001.12a
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• pp.63-66
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• 2001

This paper aims at developing remote control system to control and monitor distributed various devices such as photovoltaic Inverter system through internet. TCP/IP (Transmission Control Protocol/Internet Protocol) and photovoltaic inverter system operated in a row are adopted for network management protocol and applied device, respectively. For controlling and monitoring distributed devices in real-time, java-environment software is constructed. Also, HelloDevice, general-use interface controller between network device and applied device is proposed. Finally, serial communication such as RS-232C is used between controller and applied device.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.219-224
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• 2002

This paper aims at developing remote control system to control and monitor distributed various devices such as UPS or photovoltaic inverter system through internet. TCP/IP(Transmission Control Protocol/Internet Protocol) and photovoltaic inverter system operated in a row are adopted for network management protocol and applied device, respectively. For controlling and monitoring distributed devices in real-time, java-environment software is constructed. Also, HelloDevice, general-use interface controller between network device and applied device is proposed. Finally, serial communication such as RS-232C is used between controller and applied device.

• Journal of Communications and Networks
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• v.13 no.6
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• pp.583-590
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• 2011

Full-mesh IPSec tunnels pass through a black ("unsecure") network (B-NET) to any red ("secure") networks (RNETs). These are needed in military environments, because they enable dynamically changing R-NETs to be reached from a BNET. A dynamically reconfiguring security policy database (SPD) is very difficult to manage, since the R-NETs are mobile. This paper proposes advertisement process technologies in association with the tunnel gateway's protocol that sends 'hello' and 'prefix advertisement (ADV)' packets periodically to a multicast IP address to solve mobility and security issues. We focus on the tunnel gateway's security policy (SP) adaptation protocol that enables R-NETs to adapt to mobile environments and allows them to renew services rapidly soon after their redeployment. The prefix ADV process enables tunnel gateways to gather information associated with the dynamic changes of prefixes and the tunnel gateway's status (that is, 'down'/restart). Finally, we observe two different types of performance results. First, we explore the effects of different levels of R-NET movements on SP adaptation latency. Next, we derive the other SP adaptation latency. This can suffer from dynamic deployments of tunnel gateways, during which the protocol data traffic associated with the prefix ADV protocol data unit is expected to be severe, especially when a certain tunnel gateway restarts.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.3
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• pp.55-70
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• 2016

The most critical research issue in MANET environment is on supporting reliable communication between various devices. Various Multi-Hop Routing Protocol studies have proceeded. However, some problems you might have found when you use the existing link state routing technique are that it increases Control Message Overhead and it is unstable when node moves in CR circumstance which has transformation of using channel and MIMC circumstance which uses a number of interfaces. This essay offers a technique which is based on On-Demand Hello and the other technique which used Broadcast Interface of optimization as a solution to decrease Control Message Overhead. Also it proposes Quick Route Restoration technique which is utilized by GPS and MPR Selection technique which consider mobility as a solution of stable communication when node moves. Those offered Routing Protocol and OPNET based simulator result will be expected to be an excellent comparison in related research fields.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.1299-1302
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• 2004

본 연구에서는 MANET(Mobile Ad Hoc Network)에서 분산 PKI(Public Key Infrastructure) 메커니즘을 라우팅 프로토콜에 적용하기 위한 방법을 제안한다. 이를 위해 MANET이 사용하는 라우팅 프로토콜로 CBRP(Cluster Based Routing Protocol)를 고려한다. 제안하는 프로토콜은 CBRP의 기능과 분산 PKI 메커니즘을 활용하여 효율적으로 인증서 체인을 찾을 수 있고, 이를 통해 통신노드 상호간의 세션키 설정과 송수신하고자 하는 데이터에 대한 암호화를 지원한다. 또한, 라우팅 프로토콜의 안전한 동작을 위해 제안하는 프로토콜은 전자서명된 HELLO 메시지를 교환하여 악의적인 공격자들에 대해 신뢰성을 제공하고, 안전한 라우팅을 가능하게 한다.