• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.9
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• pp.828-837
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• 1991

본 논문에서는 CCITT에서 채택된 X.2.5 network과 IBM이 채택한 System network architecture(SNA)의 synchronous data link control(SDLC)간의 protocol converter의 성능 분석을 한다. 여기서 protocol converter의 link level map-ping method를 사용하여 구현 되었다고 가정한다. 성능 분석을 통하여 각종 parameter에 대한 throughput과 mean waiting time을 구하며, 다양한 paramerter에 대하여 최적의 값을 조사한다. 특히 converter가 추정한 SDLC frame이 X.25. network packetizing과 규정한 최대 data packet size 보다 더 클 경우에 frame을 분할하게 되는데. 분할방식에 있어서 full and remainder packetzing과 equal packetizing 도입하여 서로간의 성능을 비교한다. message를 분할 할 때 조격으로 나누는 것이 frame의 오류를 줄일 수 있기 때문에 전자보다 후자가 성능면에서 우수함을 알 수 있다.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2219-2221
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• 2001

A communication protocol for automatic meter reading is designed for electronic power meter. Communicational functions and data structures are standardized and data reading software is developed according to the developed protocol. The communication protocol is designed with reference specifications, IEC 62056-31 and Distributed Network Protocol(DNP). For design, communicational functions and specifications of the industrial meters were analyzed for the purpose of developing a new one for KEPCO meters. The protocol is designed with 3 layer model, physical layers, data link layer and application layer. A documentation was completed with data gathering, data classification, authentication, error detection. An emulator system was made for testing the protocol. A meter reading software was developed using the protocol. Many different protocols and meter reading softwares are integrated into one with the developed protocol and software as KEPCO's standard.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.2
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• pp.218-226
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• 2010

The tactical data-link is useful to exchanging automatic information and controling command in combat environment. This is a essential factor of interoperability in the future combat situation of network centric warfare. In a aspect of a weapon system development, Modeling & Simulation can save expense. HLA RTI is a standard communication protocol in M&S. So, we suggest that Link Simulator connect tactical data-link through RTI. This simulator has the interoperability between M&S and tactical data-link, the reusability through adabing M&S framework, and the wide usability by automatic engagement function.

• Journal of Advanced Navigation Technology
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• v.12 no.6
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• pp.554-558
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• 2008

In this paper, we show that the SIDMA(Self-organized Time Division Multiple Access) protocol using aviation surveillance data link now, designs to the ICAO DO 9816 documentation sequence. This protocol makes use of the VDL(VHF Data Link) Mode 4 and UAT(Universal Access Transceiver) system's MAC(Media Access Control) layer. We make sure of the simulation result and implementation of STDMA protocol program in accompany with the ICAO documentation sequence. This program operates the slot allocation and reservation with report rate when protocol transmits data and calculates slot address.

• Journal of IKEEE
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• v.2 no.1 s.2
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• pp.122-133
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• 1998

The CL network fer CBDS(Connectionless Broadband Data Service) defined by ITU-(International Telecommunication Union-Telecommunication) consists of CL(ConnectionLess) servers which route frames and links which connect between CL user and CL server or between CL servers[1][2]. In this configuration, two kinds of congestion, CL link congestion and CL server congestion may occur. Therefore this paper has proposed the scheme that can deal with the above congestion state of LAN traffic efficiently in interworking LANs in ATM network. Proposed schemes ale link-by-link scheme and hybrid scheme. Link-by-link scheme uses the ABR feedback loops of AIM layer between CL user and CL server or between CL servers, and the header translation table carrying out the routing function of frame. And hybrid scheme is the scheme that adds end-to-end loop to link-by-link scheme and then uses RM message using CLNAP-PDU(ConnectionLess Network Access Protocol - Protocol Data Units) of CL layer. These schemes can be implemented easily because of using the ABR loop of ATM layer, end-to-end loop of CL layer, and the routing function of CL server. In this paper the characteristic and effects of two schemes in CL server bas been compared and analyzed.

• Journal of Computing Science and Engineering
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• v.4 no.3
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• pp.225-239
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• 2010

This paper introduces a new approach to modeling relative distance among nodes under a variety of communication rates, due to node's mobility in Mobile Ad-hoc Networks (MANETs). When mobile nodes move to another location, the relative distance of communicating nodes will directly affect the data rate of transmission. The larger the distance between two communicating nodes is, the lower the rate that they can use for transferring data will be. The connection certainty of a link also changes because a node may move closer to or farther away out of the communication range of other nodes. Therefore, the stability of a route is related to connection entropy. Taking into account these issues, this paper proposes a new routing metric for MANETs. The new metric considers both link weight and route stability based on connection entropy. The problem of determining the best route is subsequently formulated as the minimization of an object function formed as a linear combination of the link weight and the connection uncertainty of that link. The simulation results show that the proposed routing metric improves end-to-end throughput and reduces the percentage of link breakages and route reparations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10A
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• pp.1532-1538
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• 1999

In general, because error rate of wireless link is higher than that of wired link, DLC layer protocol for wired network with low error rate is not proper for wireless environments. In addition, the conventional DLC layer protocol for wireless network is optimized for the low-speed data service, so it is difficult to use conventional DLC protocol in the current mobile communication environments handing high-speed and multimedia services. Therefore, a DLC layer protocol that is suitable to current wireless communication environments is required. In this paper, we propose a novel error control scheme that supports a variety of traffic attribute and is applicable to high-speed and multimedia data service in WATM. The proposed scheme provides enhanced throughput performance for real-time traffic by using modified ASR ARQ without ACK and reduces loss rate by using FEC in the case of high error condition. Also, for non real-time traffic, the use of ASR ARQ without ACK enhances throughput performance and delay time is decreased by using FEC in the case of high error rate channel. As a result of simulation, the proposed scheme has better performance than conventional ASR ARQ protocol in view of delay and throughput.

• Journal of the Korean Institute of Navigation
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• v.22 no.4
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• pp.21-29
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• 1998

The marine self-organizing VHF data link is a digital radio link with self-organizing ability, which exploits the STDMA algorithm and operates in marine VHF channels. It can support the applications of surveillance, situation awareness and communication. It is the core technology of the Universal AIS which is considered as a future surveillance system at sea by the IMO. In this paper, the operational principle of the marine self-organizing VHF data link is introduced. Simultaneously, a new access protocol is proposed to enhance the marine self-organizing VHF data link so as to support point-to-point communication. The point-to-point communication is one of the most important bases to establish dynamic internetworks among computers on the bridges in the future.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.2
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• pp.187-196
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• 2021

The Network-Centric warfare over weapon data link networks has been developed for the recent decade. Since the US navy had begun to develop tactical digital information chain, it has gradually transformed into weapon data link technology. As data link network system and its protocol have been advanced into high-technology, focusing and targeting on moving targets become possible in net-enabled environments. However, it is difficult to identify the primary information from numerous battlefields and understanding approaches to damage a target in a timely manner. In this paper, to better understand the targeting assessment, we suggest a specific solution: Bomb Hit Indication(BHI) using information in weapon data link messages. In order to prove our suggestion, we implement the BHI solution and apply it into the weapon data link integrating system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.5
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• pp.574-580
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• 2019

Conventional energy efficient routing protocols apply high weight to energy among routing metrics, causing nodes to concentrate on energy efficient paths and quickly exhaust energy on those paths. The unbalanced energy consumption of these wireless sensor networks causes network division and malfunction, and reduces network lifetime. Therefore, in this paper, it proposes a link cost based routing protocol to solve the unbalanced energy consumption of wireless sensor networks. The proposed routing protocol calculates the link cost by applying the weight of the routing metric differently according to the network problem situation and selects the path with the lowest value. As a result of the performance analysis, it confirmed that the proposed routing protocol has 22% longer network life, 2% energy consumption standard deviation and 2% higher data reception rate than the existing AODV protocol.