• Journal of the Korea Society of Computer and Information
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• v.23 no.12
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• pp.65-72
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• 2018

In this paper, we have studied how to reuse common data link software by applying software product line engineering. Existing common data link software performed different stages of design, implementation, and testing without sharing the accumulated knowledge of different developers. In this situation, developers agreed that sharing the assets of each project and reusing the previously developed software would save human and time costs. Even with the initial difficulties, the common Data Link is a continually proposed project in the defense industry, so we decided to build a product line. The common data link software can be divided into two domains. Among them, the initial feature model for the GUI software was constructed, and the following procedure was studied. Through this, we propose a plan to build a product line for core assets and reuse them in newly developed projects.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.10
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• pp.965-976
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• 2012

Multi-Platform Image and Intelligence Common data link(MPI-CDL) systems are designed to transmit the imaginary and signal intelligence data at an aeronautical to ground line of sight(LOS) link. This paper proposes a method to predict a link availability and analyzes the required link margin to satisfy a given link availability for MPI-CDL systems. To estimate a link availability the proposed method applies the conditional probability so that both a rain attenuation and a multipath fading are considered simultaneously. Link margins to meet the link availability for MPI-CDL systems are calculated according to an operating environment including frequencies, flight altitudes and transmission ranges. The required link margins for actual unmanned air vehicle systems are also given by simulation results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.11
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• pp.1528-1538
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• 2016

Common data link systems are designed to transmit the imaginary and signal intelligence data at long distance air-ground line of sight(LOS) link. In this paper, we analyze the received power variation according to the communication distance of the common data link using curved earth 2-Ray model suitable for received signal power analysis of long distance air-ground wireless channel. We propose optimal elevation angle control method of the receiving antenna to reduce a power variation caused by ground-reflected wave. Proposed method can get additional link margin compared to the conventional method without any additional hardware performance enhancement.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.3
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• pp.209-222
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• 2014

NCW is a new operational concept for modern warfare to improve the ability to conduct combat by connecting command and control system via network. To realize NCW integrating information sharing system between multiple platforms, CDL is considered as a key component for high-speed transmission of ISR data. Accordingly, further studies to enhance the performance of CDL are being performed around the world, and our government has also developed self-reliant CDL, MPI-CDL. However, the maximum data rate and networking performance of current CDL still fall short of the objective to enable multiple systems to share the large ISR data. Therefore, in this paper, we analyze the development flow and international technical trends of CDL, and present an approach for enhancing data rate and networking capacity of the next generation CDL.

• Journal of the Korea Society of Computer and Information
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• v.22 no.8
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• pp.63-72
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• 2017

In this paper, we propose a security architecture for HDLC-based T4 class common data link. The common data links are composed of point-to-point, multi-to-point, and point-to-multi mode. For multi-to-point mode, one node has a bundle of point-to-point links with different end-point on the other side of the links. Thus multi-to-point mode can be considered as a bundle of point-to-point mode. Point-to-multi mode is broadcasting link. For point-to-point mode we adopted robust security network scheme to establish a secure data link, and for multi-to-point mode we use broadcast encryption scheme based on ID-based cryptography to distribute encryption key for broadcasting message encryption. We also included MACsec technology for point-to-point data link security. Computational and communicational complexity analysis on the broadcast encryption have been done.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.1
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• pp.162-168
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• 2018

The UAV(Unmanned Aerial Vehicle) system, including the drone of a variety of fields, which has become an issue and utilized in various fields, has begun to develop in military fields and is actively developed in the commercial field. In various types of UAV systems, which have been developed recently, the communication system that is responsible for the connection between the ground control unit and the UAVs is called the data link. Especially, common data link used in military UAVs is required stability of communication to transmit surveillance and reconnaissance intelligence information and UAV's status. In this paper, the requirement for a modem was defined to secure the communication stability of the common data link used in surveillance UAVs. And, the design of the data link modem to satisfy applicable specifications was proposed. The proposed modem design was verified through the performance measurement of the implemented systems.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.7
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• pp.1425-1431
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• 2005

In this paper, we consider the ISR(Intelligence, Surveillance, and Reconnaissance) system which collects the imagery intelligence from an airplane and CDL(common data link) communication system which transports the information obtained by the ISR system. The IMINT(imagery intelligence) consists of MPEG-2 transport stream packets and they transmit through CDL. We have some simulations for communication performances of CDL and show performance improvements using convolutional coding. We have compared BER performances under AWGN channel and fading channel which is caused by the velocity of an airplane.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1876-1883
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• 2016

The new channel model for high data rate common data link(CDL) is proposed. The Two-ray channel, which is composed of the reflected signals on the front ground of the receiver, is considered in this paper. This channel arises due to the curvature of the earth when the altitude of the transmitter is tens of kilometers and distance between the transmitter and the receiver is hundreds of kilometers. The Two-ray channel is modeled by estimating the maximum delay profile and the power delay profile, depending on the transmitting and receiving beamforming angle and the radiation pattern of antenna. The power delay profile has a larger effect on the bit error rate(BER) over signal to noise ratio(SNR) than the maximum delay profile, because the distance range is too long in the proposed channel model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.4
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• pp.703-715
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• 2017

In this paper, we analyze the channel characteristics of the long distance air-ground wideband common data link and we propose a mathematical method to analyze the effect of narrowband and wideband interference of air-ground channel on the received signal of wideband data link. In this paper, we analyze the reception performance according to the communication distance using the proposed performance analysis method, and found out that the communication distance is limited by the narrowband and wideband interference of ground reflection wave. As a result of the performance analysis of the method of controlling the receiving antenna upward, not only the narrow band but also the wideband interference is effectively reduced, so that the communication distance is increased even in the existing wideband data link not including the equalizer.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.394-396
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• 2017

In various types of UAV systems, which have been developed recently, the communication system that is responsible for the connection between the ground control unit and the UAV is called the data link.Especially, in the data link used in systems for transmission of surveillance images from UAV in real time, stability of communication should be ensured. In this paper, the design of the data link modem was proposed for the purpose of applying for UAV for surveillance. And, the designed wad verified through the performance measurement of the implemented systems.