• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.6
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• pp.1252-1260
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• 2017

As digital communication technology evolves, the diversity of maritime communication methods has benn increasing due to the emergence of new maritime communication technologies such as digital very high frequency (VHF) communication systems and LTE-M as well as traditional conventional maritime communication systems. At sea, all maritime communication methods may be available, but only some communication methods may be available depending on the location. In this paper, we propose a multi-band network selection (MNS) system that can provide seamless maritime communication service by switching to an optimal communication band among available communication systems, depending on network environment and user requirements. The proposed MNS system in the middleware layer is designed to be able to interface with two types of digital VHF communication systems that satisfy Annex 1 and Annex 4 of ITU-R M. 1842-1, LTE, and high frequency (HF) communication systems. We assign priority to each communication band, and design an optimal communication band determination algorithm based on this priority.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2001.10a
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• pp.61-64
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• 2001

We propose a message-based communication protocol for software agents. An emphasis is placed on the problems of sharing and exchanging information through agent communication. We adopt the Resource Description Framework (RDF) schema for information modelling in business domain. The eXtensible Markup Language (XML) serialization is used to generate messages for agent communication. The use of XML and RDF enables software agents to understand the contents of messages correctly and consistently. We believe that the approach can provide a promising way to the automation of business processes through seamless communication among the partners.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.778-780
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• 2004

This paper presents a computing system, called MEDICOS. that enables Multidisciplinary Design Optimization (MDO) technology for engineering design on distributed environments. In MDO, various legacy softwares have to be Integrated, so dynamic configuration and seamless coordination between these legacy softwares must be supported. MEDICOS is designed to address these issues by the Linda shared memory model-based design and the agent-based wrapper technology. A prototype system for engineering designs is developed and tested with designing a super high temperature vacuum furnace.

• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.251-264
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• 2008

One of the crucial elements to fully facilitate the various benefits of intelligent transportation systems (ITS) is to obtain more reliable traffic monitoring in real time. To date, point and section-based traffic measurements have been available through existing surveillance technologies, such as loops and automatic vehicle identification (AVI) systems. However, seamless and more reliable traffic data are required for more effective traffic information provision and operations. Technology advancements including vehicle tracking and wireless communication enable the acceleration of the availability of individual vehicle travel information. This study presents a UBIquitous PRObe vehicle Surveillance System (UBIPROSS) using vehicle-to-vehicle (V2V) wireless communications. Seamless vehicle travel information, including origin-destination information, speed, travel times, and other data, can be obtained by the proposed UBIPROSS. A set of parameters associated with functional requirements of the UBIPROSS, which include the market penetration rate (MPR) of equipped vehicles, V2V communication range, and travel time update interval, are investigated by a Monte Carlo simulation- (MCS) based evaluation framework. In addition, this paper describes prototypical implementation. Field test results and identified technical issues are also discussed. It is expected that the proposed system would be an invaluable precursor to develop a next-generation traffic surveillance system.

• ETRI Journal
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• v.35 no.5
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• pp.927-930
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• 2013

We propose a visible light communication system in which the color and brightness are controllable. Pulse width modulation and variable pulse position modulation (VPPM) schemes are used to control the color and brightness, respectively. A digital algorithm to decode VPPM signals is suggested and implemented. A seamless transmission is observed in a testbed experiment under various environmental conditions. The proposed scheme can be applied to emotional-lighting-based wireless optical communication.

• ETRI Journal
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• v.33 no.1
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• pp.18-26
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• 2011

The necessity for services of emergency communication systems to be uninterrupted and reliable has brought forward strict requirements for express software upgrades of base stations. Based on reconfigurability technology, this paper presents a protocol reconfiguration scheme for emergency communication base stations. By introducing the concept of 'local safe state,' the proposed scheme could make the updating and replacement of the protocol software flexible and maintain interactions during the updating procedure to achieve seamless system upgrades. Further, taking TETRA protocol stack and VxWorks operating system as an example, specific processes and realization methods of reconfiguration are proposed in this paper, along with the measurements of the factors impacting on the system performance. Simulation results show that, compared with traditional technology, the method proposed significantly improves the system efficiency and does not interrupt system services.

• Journal of information and communication convergence engineering
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• v.9 no.5
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• pp.523-529
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• 2011

In this paper an inter-layer protocol, referred to as a Multi-Network Selector (MNS) is proposed for multiband maritime networks. A MNS is located between the data-link layer and the network layer and performs vertical handover when a ship moves another radio network. In order to provide seamless data transfer to different radio networks, the MNS uses received signal strength (RSS) and ship's location information as decision parameters for vertical handover, which can avoid ping-pong effect and reduces handover latency. In addition, we present related issues in order to implement the MNS for a multiband maritime network.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.04a
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• pp.179-183
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• 2000

By spread of Internet, we become to use several of communication such as email, ICQ, VoIP etc. But as become convenient to use, user must be aware of variety of information regarding the media and partner user. The forecast is that this problem grows larger and larger as new media are brought in the expanding communications network. In this research, we suggest an agent MIA (Media Integration Agent) that manages the information instead of user. The MIA is an agent that obtains situation of user, and dynamically exchanged addresses and tendency of using medias in form of vCard. By use of this, user can choose better communication media. Accordingly seamless communication environment that user doesn't have to be aware of various information is formed.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.87-90
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• 2004

Telematics is an emerging industrial field made up of the convergence of technologies. The key technologies for Telematics are server-side technology, terminal-side technology, communication-related technology, and positioning technology. Standardization in Telematics is now getting more notice these days. Domestic situation is explained for several related facilities such as ETRI, TTA, and Telematics Standardization Forum. In this paper, we will focus especially on the standard reference model that is the most fundamental framework of Telematics technology standardization. In the reference model, the Telematics system is composed of Telematics client part, communication part, and Telematics server part. The Telematics client part consists of terminal, positioning device, and car electronic devices. Communication part can be composed of various telecommunication channels such as CDMA, WLAN, DMB, WiBro, etc. which can guarantee the seamless two-way communication. Telematics server part is composed of TSP(Telematics Service Provider) server and CP(Contents Provider) servers gathering and managing the various Telematics services. This Telematics reference model is expected to be utilized as the base architecture in developing the technology and standards from now on.

• Information and Communications Magazine
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• v.19 no.9
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• pp.77-85
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• 2002

In this paper, we introduce an ADSRC(hdvanced DSRC) OFDM packet communication system which has been developed by ETRI. The ADSRC system is targeted to provide high terminal mobility, high data rate and seamless service in roadside environment for mobile office services. We discuss the requirements of the ADSRC communication system for mobile office services, and the system design specification to meet them with regard to air interface. The ADSRC packet communication systems consist of the MAC processor block, the OFDM packet modem block and the RF block. The MAC processor block handles medium access control and the test. The OFDM packet modem transmits data packets at up to 24Mbps adaptively and recovers the data from RF block. We describe the ADSRC packet communication system architecture and the ADSRC system protocol.