• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.1
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• pp.79-85
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• 1998

The 9-digit MMSI(Maritime Mobile Service Identity) in the NBDP is converted to the 7-digit identity signal, used to identify to the phase of and to synchronize to the clock of the ISS(Information Sending Station) automatically for phasing procedure between radio stations. In this paper, algorithms for the automatic identification phasing procedures and for conversions, calculations between 7-signals and 9-identity, those check-numbers in the phasing procedures for calling of the NBDP are discussed and designed. And a method of the faster locking and phasing for calling than that of recommended by ITU-R is suggested and implemented.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.252-255
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• 2005

In this paper, we analysed the new techniques for maritime mobile communications replacing NBDP in MF/HF bandwidth. Several countries already have contributed to new proposals for new digital systems through international standardization organizations as ITU, IMO and IEC. ITU-R SG8B in ITU reviews the contributed documents and discusses about radio regulations relating new systems. Also COMSAR in IMO reviews member's countries opinions and statues for introducing new techniques and replacing NBDP.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.4
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• pp.805-817
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• 1999

In this paper, the needs for introduction and adoption of MㆍHF DSC/NBDP system and for developments of its circuits and call sequences for use in the maritime mobile services for small-ships, leisure-ships and fishing ships are analyzed, discussed. Also design and implement for MㆍHF(1.6-4MHz) DSC/NBDP system is discussed. Most of casualties have been arisen from small-ships and fishing ships during last 5 years. So, the SAR schematic plans should been prepared to prevent casualties and facilitate the activities of SAR for those ships. DSC/NBDP for MㆍHF system is able to fulfill the roles of efficient SAR communication functions, and to advance the SAR system to small ships and fishing ships. This study is focused on the techniques of processing the DSC call sequences and the ARQ sequences of NBDP system. Especially ARQ sequences are expanded into processing of Korean letters, designed the call sequences and code conversion algorithm for Korean-code. It will be evaluated the availability of Korean-NBDP system. In designing the Transmitting circuits and Receiving circuits, for the carrier generation, DDS(Direct Digital Synthesizer) is used in stead of the Phase Locked Loop and frequency conversion by the mixer, BPF. And PSK modulation signals are directly generated by the controls of DDS, which show the characteristics of Spurious Free Dynamic Range are below -62dBc. Also, the monolithic U subsystem IC which provides various functional components, AD608 is used for designing the receiving circuitsㆍAnd the algorithm of Phasing methode for FSK demodulation are devised to process IF frequency 455kHz in the IF circuits.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.1 no.1
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• pp.113-121
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• 1997

The maritime mobile communication system has been changing to the new system that is facilitated by the radio telex, digital selective calling and maritime satellite communications from the old system by the radio telegraphy and telephone according to the GMDSS. The NBDP using the ITA No.2 code is a useful media in the maritime communications and provides the procedures of telex. Also it can provide the efficient and more useful functions and the solutions for the incremental traffic requirements by adopting the Hangul code. So, in this paper, we proposed the new Korean NBDP code for the ITA No.2 code, designed and implemented the algorithm which is the processing of the Hangul NBDP code using the microprocessor.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.3
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• pp.547-553
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• 2004

Linux is the one of various RTOS, also embedded linux has being studied with focus on technical stability and commercial utilities. In this paper, the technical trial was discussed on the development of real-time operating system that provides real time capability and extends the network communications ability and would be applied to the maritime mobile communication system through analysis the embedded linux kernel. Some techniques for Analyzing the embedded linux kernel and designing the target board, making the kernel image and porting the kernel are summarized in this paper.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1998.04a
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• pp.29-35
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• 1998

한국연안 NAVTEX서어비스를 하기 위한 방안을 제안하였다. EEX가 미정인 현실을 감안하여 서비스범위를 평화선내 전 구역으로 하였다. 해양수산부내에 운영실을 두고 , 무인으로 운영되는 동해안 송신소(죽변등대부지), 서해안 송신소(전북부안군 변산면 도청리)를 원격 감시운영하는 방안을 제안하였고, 안테나는 50m급 지선식철탑안테나이며 상부지선 일부를 정관으로 활용하고 접지선은 36본의 100m 급 래디알어어스를 제안하였다. 국문방송도 기존 시설을 겸용하여 방송하기로 하고 ITA No.2코드와 호환가능한 한글 NBDP코드를 제안하였다. 운영국 및 송신국의 시스템 구성과 장비규격, 통신회선등을 전부 제안하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.81-85
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• 2008

The INMARSAT is able to long range maritime communications that can not use for expensive charge in small ship. Additional an opinion of unuseful NBDP that is international discussion for replacement methods for the effective data communications by using HF band. A feature of HF band communication is ionospheric propagation that have not the distance question as A2, A3 and A4 sea areas. Therefore all navigation ship should has supplied service such as MSI, VMS, E-mail beside of distress and public communication that is demanded a design of communication sequence for using SSB transceiver. This paper has designed the new packet and communication sequence of truly and automatically radio link for maritime data communications by SSB in HF band.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.181-184
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• 2005

IMO(International Maritime Organization)에서는 최근에 AIS, LRIT, SSAS 등 현대화된 통신 기술이 융합된 시스템을 도입하고 있으며 HF 및 VHF 대역에서 e-mail 등 현대화된 데이터 통신 기술을 도입하려고 한다. 이에 따라서 ITU-R에서는 현대화된 해상이동통신시스템에서 사용되는 스펙트럼의 재조정 및 통신방식 권고안을 작성 중에 있다. 본 고에서는 최근 IMO COMSAR회의 및 ITU-R SG8B회의 그리고 IEC TC80회의에 기고되어 논의 중이 해상이동통신시스템의 기술 및 표준화 동향을 분석하고 기술하였다. 특히 본 고에서는 2005년 9월에 개최되었던 ITU-R SG8B에 제출된 기고서를 중심으로 기술을 분석하고, ITU-R, IMO 그리고 IEC의 향후 대응 방향을 기술하였다.