• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.6C
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• pp.659-667
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• 2003

IPsec refers to a standardized set of security protocols and algorithms which can provide the integrity, the authentication and the confidentiality services for IP packets in the Internet. Between two security gateways, IPsec provides the access control, the connectionless Integrity, data origin authentication, the anti-replay, and the confidentiality services, not only to the IP layer but also to the upper layers. In this paper, we describe a VPN (Virtual Private Network) testbed configuration using the FreeS/WAN and analyze the ISAKMP messages exchanged between the linux security gateway during the IKE SA setup. Also, we describe our development of an IPSEC encryption verification tool which can be used conveniently by VPN administrators.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.951-958
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• 2004

This paper describes problems when visited ISP subscriber gets dynamic IP address in home ISP for wireless internet service on GPRS network. We propose a specific DHCP relay for wireless internet service of visited ISP subscriber on GPRS network. We designed and implemented the specific DHCP relay and installed it in ISP testbed. We show the allocated dynamic IP address using specific DHCP relay for visited ISP subscriber on GPRS network. Now we think it is possible the visited ISP subscriber can access wireless internet service on GPRS network using specific DHCP relay, and UMTS system can be managed IP address for subscriber roaming.

• Journal of Korea Multimedia Society
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• v.25 no.8
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• pp.1085-1096
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• 2022

The manufacturing industry is continuously pursuing advanced technology and smartization as it converges with innovative technology. Improvement of manufacturing productivity is achieved by monitoring, analyzing, and controlling the facilities and processes of the manufacturing site in real time through a network. In this paper, we proposed a new OPC-UA based digital twin model for smart factory facilities. A testbed system for USB flash drive packaging facility was implemented based on the proposed digital twin model and OPC-UA data communication scheme. Through OPC-UA based digital twin model, equipment and process status information is transmitted and received from PLC to monitoring and control 3D digital models and physical models in real time. The usefulness of the developed digital twin testbed system was evaluated through usability test.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.10
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• pp.1912-1921
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• 2015

In this paper, we introduce a testbed for testing the RF energy transfer technology in the Internet of Things (IoT) environment, and provide experimental results obtained by using the testbed. The IoT environment considered in this paper consists of a power beacon, which is able to wirelessly transfers energy via microwave, and multiple sensor nodes, which makes use of the energy received from the power beacon. We have implemented the testbed to experiment the RF energy transfer in such IoT environment. We have used off-the-shelf hardware components to build the testbed and have made the tesbed controlled by software so that various energy and data transmission protocol experiments can easily be conducted. We also provide experimental results and discuss the future research direction.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.234-237
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• 2014

This paper provides insights into the sFlow monitoring system of OF@KREONET. OF@KREONET is software defined network (SDN) testbed adapted by KREONET (Korea Research Environment Open NETwork). OF@KREONET uses SDN-based network virtualization to slice the network among multiple concurrent experimenter. Flow Monitoring of OF@KREONET using sFlow. sFlow and OpenFlow can be used to provide an integrated flow monitoring system where OpenFlow controller can be used to define flows to be monitored by sFlow. OF@KREONET flow monitoring system supports monitoring of per slice FlowSpace. An Experimental can monitor his/her own FlowSpace while network administrator can monitor all spaces.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.111-118
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• 2013

The connection based TCP protocol provides reliable packet delivery, but it takes certain overhead compare to the connection-less UDP protocol. Thus, 3GPP devise the upper-layer RLC protocol which provides reliability based upon the UDP protocol. Consequently, each implement of a base station and/or mobile terminal require the development of the RLC protocol, and it must qualify various interoperable tests. In this paper, we implement a testbed which verifies the RLC protocol under various packet losses/inversion circumstances of networks. Finally, we propose our testbed as the RLC protocol tester for the developments.

• The Magazine of the IEIE
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• v.22 no.6
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• pp.83-93
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• 1995

정부에서는 다가오는 2000년대에 우리나라의 과학기술을 선진 7개국 수준으로 진입시킴은 물론 기술개발을 통한 국가 경쟁력의 확보를 목표로 여러 기술분야에 걸쳐 HAN(highly Advanced national) 프로젝트를 기획하고 1992년부터 기술개발에 착수하였다. 현재 국가 초고속 정보통신망 기반 구축사업의 일부로 추진되고 있는 HAN/BISDN 프로젝트는 통신망, 교환, 전송, 및 단말 분야로 나뉘어 초고속 정보통신망의 구축에 소요되는 다양한 장치들을 단계적으로 개발할 예정이다. 장기간에 걸쳐 여러 기관들이 다양한 장치들을 공동으로 개발하게 되는 이러한 대형 프로젝트의 경우 개발 결과물을 통신망에 적용하여 사업화하기 이전에 검증하기 위한 통신망 테스트베드(Network Testbed:NTB)의 구축과 운용이 절실히 필요하다. 본고는 이러한 NTB의 목적 및 필요성 등에 관하여 언급한 뒤 세계 여러 나라에서 구축 및 운용되는 테스트베드들의 사례를 살펴보고, HAN/BISDN 프로젝트중 NTB 구축 계획에 관하여 기술한 것이다.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.1009-1021
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• 1999

This paper describes the design principles and structure of a prototype system for collaborative authoring over a wide area network. The system includes extensive support for commenting and comment review, facilities for document space navigation, and tools for controlling and monitoring work group activity, including document locking and activity recording. The operational prototype provides a testbed for the examination of human computer interaction, group interaction, group support, document structures, and the problem and the history of efforts to address it.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.295-295
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• 2004

• Journal of Communications and Networks
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• v.15 no.2
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• pp.179-190
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• 2013

Given the bandwidth assignment for dedicated short range communications for use in vehicular ad-hoc network (VANET) and the expected introduction of equipment in the next few years, we elaborate on how VANET can support infotainment services. We define an architectural model for the integration of VANETs and cellular networks, according to a push mode paradigm where VANETs are used primarily to disseminate service announcements and general interest messages. Cooperation with cellular network is addressed by comparing architecture alternatives. A set of information dissemination protocols for VANETs is compared via simulations on a real urban map. Some results from a lab testbed based on IEEE 802.11p boards are presented along with an application developed for Android operating system to demonstrate the concept of the paper.