• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.12
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• pp.2839-2846
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• 2014

New VHF band for use in VDE is determined by WRC-12 due to the overload of AIS VDL, and the system characteristics of the VDE is recommended as ITU-R M. 1842-1. CS-TDMA, a multiple access method of AIS class B, is recommended as that of the VDE. It is inefficient for CS-TDMA just applying the report interval used in AIS class B to transmit high speed data with higher payload in the aspect of efficiency. In this paper, a simulation is executed in order to determine adequate report interval according to the number of active ships that affects directly network traffic. To this end, the performance of CS-TDMA, which includes the number of received packets, reception success rate, channel utilization, and collision rate, is investigated via a simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.7
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• pp.582-588
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• 2014

IMO and IALA have undertaken projects that GMDSS Modernization and E-navigation, which refer to "Future digital communications systems" for a more efficient transmission of voice and data communications in the VHF maritime mobile service. ITU has also resolved in WRC-07 Resolution 357 to study the use of spectrum-efficient technologies in order to provide for the operation of ship and port security and maritime safety systems. IALA and ITU WP5B have coordinated for the technical developments and the spectrum issues. Recommendation ITU-R M.1842-1 has approved by WP5B meeting. This revision provides a wideband data service both 50kHz and 100kHz in the VHF maritime mobile service. This paper has studied E-navigation, its needs for data exchange that includes explanations of the current methods for transmitting data by VHF that based in land mobile radio service. A further technologies trend is estimated for Recommendation ITU-R M.1842-1, that is based on the land mobile radio standards with some tailored to fit the needs of the maritime mobile service.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.344-346
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• 2022

본 연구는 우리나라에서 2020년부터 산업통상자원부와 해양수산부가 공동으로 추진중인 '자율운항선박 기술개발' '사업의 Ship2Ship2Shore 데이터 교환 및 통신기술 개발 과제의 연구현황과 향후 연구계획을 소개한다. 본 연구의 최종 기술개발 목표는 국제 해상업무용으로 운용되는 VDES 통신시스템 개발, 해상 광대역 통신시스템을 위한 요소기술 개발, 자율운항선박 통신기술의 국제표준화, Ship2Ship2Shore 통신시스템 검증 시나리오 개발이며, 2021년부터 연구에 착수하였으며, 2025년까지 기술개발을 진행할 예정이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.196-198
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• 2023

본 연구는 '자율운항선박 기술개발' '사업의 Ship2Ship2Shore 데이터 교환 및 통신기술 개발 과제의 연구현황과 시사점을 소개한다. 2024년 자율운항선박 실증선에서 개발된 시제품을 탑재하여 실증 할 예정이며, 이를 위해 시제품 개발 현황과 연구과정에서 식별된 문제점 분석을 통해 미래형 자율운항선박 개발을 위한 시사점을 살펴본다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.6
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• pp.681-688
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• 2016

Several VHF bands for the use in analog communications has been changed to those for the use in new maritime digital communications by WRC-12. ITU-R M. 1842-1 has been also standardized, recommending the characteristics of maritime digital communication systems. In addition, a Shipborne Ad-hoc Network (SANET) has been introduced by IMO in order to provide ships, which cannot be connected to a shore directly, with maritime digital data exchange services with the help of ad-hoc communication. In this paper, several functionalities of the SANET, including channel access, route determination to a shore, and data exchange, are verified via sea trials. It is expected that the SANET can be applicable to collecting and analyzing maritime information, facilitating the entry and departure of vessels, and the communication infrastructure of e-navigation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.406-407
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• 2022

자율운항선박, 무인선과 같이 전통적 선박 형태에 자율성이 부여되는 형태로의 발전과 함께 드론, 비행체 같은 비행 형태까지 포함하는 해상 모빌리티는 기존 통신 체계 대비 실시간성 향상 및 대용량 데이터 교환이 요구되는 새로운 해상 안전 운항 체계가 수반되어야 한다. 초고속해상무선통신망(LTE-Maritime) 송수신기를 장착한 국내 선박의 경우, LTE급의 통신 서비스를 연안 최대 100km까지 받을 수 있지만, 국제 항해를 하는 국적선과 외국적 선박을 포함하는 해상 모빌리티 안전 운항 체계 구축을 위해서는 VDES(VHF Data Exchange System)와 같은 국제협약에서 인정하고 해상이동서비스(Maritime Mobile Service)에 속하면서 기존보다 빠른 통신망의 보급이 필수적이다. 본 논문에서는 향후 해상 모빌리티 구현을 위해 필요한 해상무선통신망의 하나로 VDES의 필요성에 주목하여 그간의 개발 현황으로부터 향후 VDES 서비스 도입 및 활용방안에 관해 논한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.05a
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• pp.22-24
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• 2019

e-Navigation의 핵심 통신 시스템으로 사용되어질 VDES는 2015년 ITU-R M.2092-0가 발행된 이후로 2020년 개정된 표준을 발행하기 위해 IALA를 중심으로 활발히 기술규격에 대한 개발이 진행되고 있다. 우리나라도 한국형 e-Navigation사업을 통해 VDES의 기술 개발과 표준화에 기여하고 있다. 본 논문에서는 IALA G1139 Ed. 1을 기반으로 하여 개발된 VDES 해안국 장비의 제어부와 내장소프트웨어인 프로토콜처리 소프트웨어의 설계 및 구현에 대해서 기술하고자 한다. 먼저, IALA G1139에서 기술하고 있는 VDES에 대한 개요에 대해서 설명하고 VDES 해안국 장비의 설계 내용과 시험결과에 대해서 언급한다. VDES 해안국 제작을 통해 e-Navigation에서 요구하는 대용량 데이터 전송과 같은 통신 요구사항을 지원할 수 있을 것으로 확인 하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.339-343
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• 2022

In this study, a method for simplifying the structure of the VDES RF receiver, and the gain control method of the receiver to comply with the international standard in this structure was described. The input level of the wanted signal and unwanted signal to the receiver was defined, and when the two signals were input, the saturation state at the ADC was checked at the receiver output. As a result of the simulation by the circuit simulator, it was satisfied that the output power of the receiver was in the SFDR region of ADC with respect to the adjacent channel interference ratio, intermodulation, and blocking level. Through this study, it was found that the structure of th proposed RF receiver conforms to the international standard.

• Journal of Space Technology and Applications
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• v.2 no.2
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• pp.121-136
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• 2022

Automatic Identification System used in ship communication is required for marine control way, including monitoring of vessel operation in coastal and exchanging of information for safety navigation between them. But, it uses a very high frequency band of approximately 160 MHz, and at the same time, due to the curvature of Earth, there is a limit to the communication distance. Several demonstrations were made successfully over satellite, but not much work has been done yet through cube-satellite which has low-orbit at 500 km altitude. Here, we demonstrate a reception test of AIS (automatic identification system) receiver for a cube-satellites using software-defined radio (SDR). We collected AIS data from ship at port of Busan, Korea, using R8202T2 SDR and established to transmit them using Adam-Pluto and Matlab Simulink. The process of weakening the signal strength to a satellite was constructed using attenuator. Through above process, we demonstrated whether AIS data was successfully received from the AIS payload.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.266-271
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• 1999

The purpose in this study has to development the system on increasing operation of old-typed transceiver for solve the question that limited allocation frequencies and continuesly icreasment of traffic. Therefore, we are desigened the remote control system that has the function for variable channels, PTT and monitoring of transmission power and frequencies. Exchange of control data is to hold in common the twist two-wire or telephone line for the voice transmission. The H/W is consist of FSK and MCS-51 processor which are up-down control of channel, n control and monitoring display by serial data transmission. According to the simplex traffic operation is designed the algorithm of serial data transmission by sequential transmission sequence and protocol. The S/W of sequential transmission sequence is designed to usefully the intergrated communications system which is able to connection between the multi-transceiver and multi-terminal by master processor.