• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.87-89
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• 2017

In this paper, we propose a multi-band network selection (MNS) system, which determines and seamlessly connects to the desired available communication band based on user preferences and network environments. The MNS system employs MNS server in the middleware layer which communicates with clients in order to combine and manage heterogeneous networks efficiently. In addition, we define a system architecture and function modules of the MNS system. The MNS system monitors availability in each communication band and updates the network status information table which is applied to determining the best available network. It is expected that the MNS system can be applied to the next generation maritime networks and communication infrastructure of e-navigation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.297-300
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• 2012

Since the adoption of GMDSS, the band 495-505 kHz has no longer been globally used for maritime calling and distress and the designation of this band for calling and distress was suppressed at WRC-07. In accordance with provision RR, maritime mobile operations are presently limited to radiotelegraphy. Accordingly, use of the band has diminished.This frequency band 415 kHz to 526.5 kHz and high frequencies is ideally suited to broadcast from shore to ship. The surface wave propagation of a coast station using this band can provide a coverage area from the coast to 400 nautical miles off shore.

• 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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.652-655
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• 2017

As maritime information and communication technology has been developing and the demands for various kinds of application services has been increasing nowadays, the multi-band maritime networks combining available multiple radio networks has been introduced. We have previously proposed a multi-band network selection(MNS) system which operates in the middleware layer and selects the best available network seamlessly. In this paper we develop MNS server software, network interfaces, and application program. The functionalities of the MNS system, including updating network status, connecting to heterogeneous networks, and communicating in the best network are also verified via indoor test.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.143-144
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• 2023

해양수산부가 구축한 초고속 해상무선통신망(LTE-Maritime)은 연안으로부터 최대 100km 해역을 항해하는 선박들에게 지능형 해상교통정보서비스(e-Nav)를 제공하기 위한 기반 통신 인프라다. 선박에서 e-Nav 서비스를 제공받기 위해 LTE-M. 무선설비는 선내 고정 설치되어 유선으로 연결된 표시장치와 연동이 필요하다. 이는 공간이 협소하고 밀폐된 소형선박에 설치의 어려움뿐 아니라 선내 센서를 비롯한 다양한 IoT 기기 등과의 연결성에 제약을 줄 수 있다. 또한 선박이 육상의 LTE-M. 기지국과 멀리 떨어질 경우, 다운링크에 비해 업링크 통신품질이 상대적으로 취약해져 긴급 조난 신호를 비롯한 위험상황의 전달에 문제가 발생될 수 있다. 본 연구에서는 LTE-M. 망의 무선설비 다각화 사업으로 추진·개발된 소형선용 WiFi 및 업링크 향상용 무선설비의 실해역 성능 시험 방안을 고찰하여, 선내 WiFi 무선 품질을 평가하기 위한 성능 지표를 비롯해 업링크 통신속도 개선 등을 확인하기 위한 상호운용성 성능 시험 방안을 제시하고자 한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.77-78
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• 2022

Currently, communication at sea is more difficult than communication at inland due to the movement of route signs by waves. This paper conducts research on relay transmission and reception techniques to extend coverage in uplink situations. The uplink maritime communication environment between inland base stations and buoys located a certain distance inland was viewed as two hops, and a beam generated according to the number of antennas was selected and a performance analysis was conducted considering the movement of buoys measured by sensors.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.116-118
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• 2021

초고속 해상무선통신망(LTE-Maritime)은 바다 어민의 안전과 항해 중인 선박의 편의 서비스 제공을 위해 대한민국 연안으로부터 최대 100km 까지 해역을 LTE(Long Term Evolution) 통신 체계로 구축한 세계 최초의 해상 무선통신망이다. 본 논문은 초고속 해상무선통신망의 활용성을 높이기 위해 다용한 용도로 개발된 무선설비의 호환성, 신뢰성, 안정성을 확보하기 위한 상호운용성 시험 방안을 논의해보고자 한다. 본 논문은 이종 통신장비 및 이종 무선설비 간의 상호운용성을 단말(무선설비)과 시스템의 종단간 통신품질 측정을 통해 서비스 커버리지 성능, 무선데이터 전송 속도 및 전송성공률 등을 검토해 보고, 각 품질 지표를 검증할 수 있는 시험 구성 방안, 시험 항목 및 절차, 측정 결과 분석 방법 등을 다각도로 살펴보고자 한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.8
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• pp.1773-1779
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• 2015

Shore-to-sea visible light communication using color clustered multiple-input and multiple-output (MIMO) is presented. The proposed maritime visible light communication (MVLC) offers a low-cost, high-speed wireless link for shore-to-sea maritime communications. Each color cluster is comprised of 50 red, green and blue (RGB) light emitting diodes (LEDs) and is modulated using on-off-keying (OOK). Selection combining is performed at the receiver, producing diversity effect within that color cluster. In this paper, we employ sea states (wave height, wind speed, etc.) data from both Pierson-Moskowitz and JONSWAP spectrum models under atmospheric turbulence conditions. Based on the simulation model, the maritime link quality is analysed in terms of coverage distance and bit error rate performance. The results show that the proposed system provides an efficient MVLC, while satisfying International Association of Lighthouse Authorities (IALA) requirements for maritime buoyage system and also offering sufficient illumination from high power LEDs.

• 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.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.3
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• pp.542-547
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• 2018

Various countries around the world are conducting various studies to apply information and communication technology to marine safety. Based on this, the International Maritime Organization (IMO) has established the e-Navigation standard to apply the latest information and communication technology to marine services. In Korea, the Ministry of Maritime Affairs and Fisheries is promoting Korean e-navigation considering domestic marine environment and is trying to apply LTE communication method as a high-speed wireless communication method at sea. In this paper, we describe the development of an LTE based marine router system supporting 700Mhz frequency band allocated for high speed maritime wireless communication service. Experiments on the possibility of 100km distance communication from base station using LTE based ship router are shown. LTE - based high - speed maritime wireless communication router system can provide communication infrastructure necessary to develop various accident prevention technologies that may occur at sea.