• Journal of Satellite, Information and Communications
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• v.12 no.4
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• pp.42-49
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• 2017

Delay- and Disruption-Tolerant Network (DTN) has been considered as a key technology to overcome main challenges in interplanetary communications such as an intermittent connectivity and high bit error rates. The lack of end-to-end connectivity between source and destination results in long and variable delays and data loss, hence the Internet Protocols cannot operate properly in such environments because it requires an end-to-end connectivity. The DTN, which utilizes 'store-and-forward' message passing scheme between nodes, can overcome the lack of end-to-end connectivity in Interplanetary Network (IPN). In this paper, DTN is applied to 3-hop relay IPN, where messages are transmitted from Earth ground station to Lunar lander through Earth satellite and Lunar orbiter. ONE simulator is used to reflect the real environment of IPN and an efficient resource management method are analyzed to guarantee the message delivery by optimizing a message TTL (Time to Live), buffer size and message fragmentation.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.217-219
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• 2004

전자문서교환(EDI, Electronic Data Interchange)은 기업과 기업 간에 컴퓨터와 컴퓨터의 통신을 통하여 필요한 거래문서를 구조화된 형식으로 교환하여 업무를 처리하는 방식을 말한다. 이러한 전자문서의 유통은 절러 위험요소로부터 완전히 해방되지는 못한다. 본 연구에서는 향후 국내에서 발생 될 위협요소 중 우선적인 보호가 요구되는 것으로 메시지 노출로 인한 프라이버시 침해 및 중요 내용의 노출문제와 메시지 수정 문제 및 발신처 인증 문제. 그리고 수신자의 수신사실에 대한 부인을 위험요소로 선정하였다. 또한, 이를 막기 위한 보안서비스를 메시지 비밀보장. 무결성, 메시지 발신처 인증 및 수신내용 부인불능 등을 선정하여 이들의 구현방안을 제시하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.31-33
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• 2021

현재 진행 중인 '스마트 항로표지 현장시설 고도화 연구'는 '확장이 용이한 다목적 플랫폼 설계', '스마트 항로표지용 최적 통신장치 개발' 등이 포함되어 있다. 이 중 AIS-ASM은 AIS를 기반으로 특정 응용에 특화된 메시지를 보낼 수 있는 수단이며, ASM에 대한 활용 가능성이 증대됨에 따라, ITU-R M.2092-0에서는 두 개의 AIS 채널과는 별도로, 두 개의 ASM 채널을 새로 할당하였다. IALA-AISM에서는 각국의 ASM 메시지를 수집하여 제공하고 있는데, 본 논문에서는 이들을 분석하여 현재 운용하고 있는 항로표지 관련 메시지를 살펴보고, 향후 스마트 항로표지에서 활용 가능할 것으로 기대되는 메시지들을 정리한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.5
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• pp.93-99
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• 2013

We have used SMS to exchange messages between mobile phones. Since the network evolved to the ALL-IP network, the next generation messaging service, RCS, has emerged to the market. Because SMS and RCS coexist, we need to inter-work the messages between SMS users and RCS users. This paper introduces a message inter-working framework(MIWF) that can inter-work SMS and RCS without changing end user's UX. It defines the call flows between the network equipment and MIWF. Also, it shows how MIWF converts messages between 3 protocols. Performance evaluation proves that MIWF does not add loads to the existing network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.8B
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• pp.768-776
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• 2009

This paper analyses the message complexity of TDMA ad hoc MAC protocols. Since the network resource of ad hoc networks is limited due to the multiple interferences and the contention-based wireless channel, the scalability issue is one of the main research topics in developing ad hoc algorithms. Simulation demonstrates that SMACS protocol has the lowest message complexity, whereas TMMAC has the highest. In addition, it is found that since the effect of unicast dominates in the message complexity compared to other factors with an increasing number of nodes, Z-MAC tends to have the property of linearity, whereas BMA and TMMAC show exponential increases in their complexities.

• Journal of Broadcast Engineering
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• v.26 no.5
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• pp.592-598
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• 2021

Current cellular systems rely on a CBS protocol for emergency alert broadcast services. However, the CBS protocol just specifies the delivery of a limited text message. Therefore, foreigners, who are unfamiliar with local characters, may have some difficulties in understanding the received CBS text message. The CBS protocol also reveals a distinct restriction in delivering abundant information because of a limited number of text characters. In order to overcome the weak points of the current CBS protocol, we propose a display method of image information and URL on the screens of mobile terminals for the received CBS text message in this paper. The presented approach effectively utilizes the message structure of CBS for 5G cellular systems.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.280-283
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• 2013

최근 원자력 발전소, 의료 시스템, 항공 시스템 등과 같이 사람의 생명과 밀접하게 관련되어 있는 소프트웨어로 제어하는 시스템들이 점차 늘어나고 있다. 차량에서 또한 차량 제어 소프트웨어의 오작동으로 인한 잦은 사고로 인하여 운전자와 탑승자의 생명을 위협 받고 있다. 이러한 문제로 인하여 차량시스템 제어 소프트웨어도 안전성 확보를 위한 기술로 차량에 통신 기술을 접목한 차량 통신 기술에 대한 관심이 높아지고 있다. 차량 운전자 뿐 아니라 탑승자의 안전과 밀접하기 때문에 많은 연구가 진행되고 있다. 이러한 많은 연구 중 긴급메시지전송 시스템은 차량 간 통신(V2V)을 통한 운전자의 안전성 확보에 대한 연구다. 본 논문에서는 차량 긴급메시지 전송에 필요한 모듈을 구조적으로 나누고 이를 통하여 긴급메시지 전송시스템 구조의 안전성을 평가한다. 긴급메시지 전송시스템의 안정성을 검증하기 위하여 오토마타 모델링을 통한 시스템 구조를 설계하고 검증을 위해 CTL 논리식 정의, SMV(Symbolic Model Verifier)검증도구를 통한 시스템 안전성 모델 검사를 하였다.

• Journal of the Korea Society of Computer and Information
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• v.15 no.7
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• pp.41-47
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• 2010

The emergency between vehicles on the superhighway should be transmitted quickly to the following vehicles for safety of people. The message between them has been transmitted by broadcast method in an wireless environment of 802.11, so far. That causes the broadcast storm and a waste of the bandwidth of Wireless network owing to unnecessary process of sending messages to even vehicles that do not have to receive the information. The message collision is a main cause of the increase of message delay. In order to overcome the existing problem, this paper proposed a message broadcast scheme based on cell (MBC), which is the way to divide cars into different groups by cell unit and transmit messages to the members of the groups through the cell primary (cp) vehicles. This paper shows the proposed broadcast's performance in the same environment is much superior to other conventional broadcast schems for inter-vehicle communication, since the receiving ratio among the following vehicles is improved.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2169-2175
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• 2014

In this paper we have proposed a new distributed architecture of session-based instant message system, in which multiple servers can distribute loads effectively to improve system extendability. The server of session-based instant message system should manage SIP sessions to transfer instant message with multimedia data to each users, and it should process large amount of presence informations from each users. Therefore load of the server should be distributed as the number of users increases. In our system, when server load increases according to large user numbers, the load are distributed by selecting a server with the lowest load value, or new server is created to allocate the message processing. Therefore the overall load of instant message system can be dynamically distributed. A new presence information data format with added elements for controlling server load has been designed for this purpose, and SIP messages exchanging procedure between servers and users has been also suggested. The performance of our proposed system has been analysed by simulation, and showed improvement of performance.

• Journal of KIISE:Information Networking
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• v.36 no.2
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• pp.137-142
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• 2009

In traditional message ferrying schemes, only ferries carry messages between partitioned networks. In this paper, we propose a new approach to make both ferries and mobile nodes carry messages so that we reduce message delivery delay in disruption tolerant networks. We evaluate our scheme against conventional message ferrying in terms of message delivery delay, throughput, ferry buffer usage and mobile nodes buffer usage.