• The Journal of the Korea Contents Association
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• v.10 no.8
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• pp.59-65
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• 2010

This paper proposes an implementation of a hardware module for transmitting MPEG-2 TS data over the internet protocol (IP)-based network. This implementation consists of two modules; one is an encapsulation module which bridges between n TS packets, where $1\;{\leq}\;n\;{\leq}\;7$, and an IP packets, the other is a packet conversion module which extracts an DSM-CC PS packet from consecutive TS packets and then reconstructing an IP packet. So, these IP packets are carried over 150 megabits per second. Although overall work flow of the proposed DeMUX is based on the reference design of ALTERA, the DeMUX is enhanced by modifying it and performs more functions by adding a packet conversion module. The DeMUX is described by Verilog-HDL (hardware description language) and shows the faithful functionality and throughput through the simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.12
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• pp.2635-2642
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• 2012

MOST(Media Oriented Systems Transport) is a network protocol for vehicle multimedia, where it guarantees large bandwidth and reliability. However, previous MOST device utilized I2C or I2S communication method to data manage or transfer, Bandwidth of MOST have increased and additional equipments are added to one device, requiring a larger form of bandwidth communication method. Therefore, this research suggests of the methods in improving the efficiency of asynchronous data transfer, and suggest an algorithm, which will improve the reliability.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06d
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• pp.230-235
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• 2008

현재 대부분의 무선랜은 유선 분산 시스템을 통하여 백본에 연결되어 있다. 그러나 지역회담이나 재해재난 지역 그리고 군사용등은 유선 백본을 사용할 수 없다. 따라서 무선으로 액세스 포인트를 연결하여 일시적으로 네트워크 서비스를 원하는 곳이나 케이블을 연결하기 힘든 지역에서 빠르고 쉽게 네트워크 구성을 제공하기 위한 무선 메쉬 네트워크의 요구가 늘어나고 있다. 본 논문에서는 이러한 무선 메쉬 네트워크의 기반 기술인 무선 분산 시스템 환경에서 TCP와 UDP 프로토콜의 성능에 대하여 연구하였다. 시스템 성능 측정은 IEEE 802.11g 인터페이스를 가지고 있는 액세스 포인트에서 체인 토폴로지를 기본으로 측정되어졌고, 홉수와 트래픽 종류 그리고 트래픽 흐름의 방향에 따라 수율(throughput)과 전송시간(transaction time) 그리고 전송실패율(loss rate) 등을 비교 분석하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.1225-1228
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• 2007

무선 네트워크와 모바일 기술의 발달로 무선상에서의 통신뿐만 아니라, 모바일 기기의 이동성에 대한 요구가 점점 더 커지고 있다. 모바일 기기의 이동성을 지원하기 위해Fast Mobile IPv6 (FMIPv6), Hierarchical Mobile IPv6 (HMIPv6)와 같은IPv6기반의 네트워크 계층 프로토콜이 제안되어 왔으며, 최근에는 트랜스포트 계층에서 동작하는 mobile Stream Control Transport Protocol (mSCTP) 가 제안 되었다. 네트워크 계층에서의 이동성을 지원하기 위한 방안 중 하나인 FMIPv6 의 핸드오프 과정은 엑세스 라우터간 양방향 터널링을 설정 함으로서 엑세스 라우터의 버퍼링 오버헤드가 발생하고, 터널링 과정을 위한 메시지 교환으로 인해 핸드오프 지연이 발생하게 된다. 본 논문에서는 FMIPv6 의 이러한 단점을 해결하기 위해 트랜스포트 계층의 이동성 지원 방안인 mSCTP 를 이용한 통합 핸드오프 기법을 제안한다. 양단의 세션을 유지한 채 새로운 IP 주소를 등록 할 수 있는 mSCTP 를 사용 함으로서 FMIPv6 의 터널링으로 인해서 발생하는 엑세스 라우터의 오버헤드와 핸드오프 지연 시간을 줄이고 전체적인 핸드오프 성능을 향상 시킨다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.12
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• pp.3144-3153
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• 1996

ATM switching system is made up of transport network and control newrk according to its functions. The control device, basic part of control network must be developed before developing any other functions, and control device must be stable and need high reliability. Out distributed ATM switching system consists of several ALSs that provides variable local call services, and an ACS that interconnect among several ALSs. Eech ALS has CCCP that takes charage of call and connection control functions, and ACS has an OMP that takes charge of OA&M(Operation, Administration and Maintenance) functios. In this paper, we analyzed the performance evaluation of control device that manipulate subscriber's call based on ITU-T Q.2931 standard protocol messages and Interprocessor communication messages. As a result of simulation when the number of ALS is under 22, as the call arrival rate increase the processor utilization of CCCP increase rapidly than that of OMP. When the number of ALS is incremented to 22, the processor utilization of CCCP is balanced with the of OMP, and when the number of ALS exceeds 22, the processor utiliztion of OMP increase rapidly. Also if messary processing time of OMP is 1.35 times that of CCCP, processor utilizations of CCCP and OMP is equal.

• Journal of Communications and Networks
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• v.2 no.1
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• pp.35-45
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• 2000

this paper presents the concept of "mobile ATM', a proposal for third-generation (3G) mobile communication network infrastructure capable of supporting flexible evolution of radio technologies from today's cellular and data services towards future wireless multimedia services. Mobile ATM provides generic mobility management and QoS-based transport capabilities suitable for integration of multiple radio access technologies including cellular voice. wireless data, and future broadband wireless services. The architecture of a mobile ATM network is outlined in terms of the newly-defined "W-UNI" interface at the radio link and "M-UNI"and "M-UNI" interface which supports unified access for WATM and non-ATM mobile terminals through corresponding interworking functions (IWF) is explained. leading to an understanding of how different radio access technologies are supported by the same ATM-based core network infrastructure. Generic mechanisms for handoff and location management within the core mobile network are discussed. and related protocol extensions over the "W-UNI" and "M-UNI/NNI"interfaces are proposed. the issue of "crossover switch (COS)" selection in mobile ATM is considered, and a unified handoff signaling syntax which supports flexibility in COS selection is described. Typical signaling sequences for call connection and handoff using the proposed protocols are outlined. Experimental results form a proof-of-concept mobile ATM network prototype are presented in conclusion.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.12B
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• pp.800-808
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• 2007

With the development of wireless data communication technology, all IP-based network will become compositions of wired and wireless networks. TCP is a connection-oriented, reliable transport protocol and has been used as de facto standard in most wired networks. Because TCP's congestion control algorithm could not distinguish congestion from BER, link failure and frequent route changes, TCP shows a poor performance over mobile ad-hoc networks. In this paper, the theoretical feature of TCP was studied and the performance of TCP over mobile ad-hoc networks was analyzed with ns2.

• International journal of advanced smart convergence
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• v.5 no.3
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• pp.61-65
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• 2016

In the TV broadcasting, movie production and business the transportation of video between creators (programmers, studios) and distributors (broadcast and cable networks, cable and satellites companies) is still a mix of File Transfer Protocol (FTP), physical delivery, and expensive multicast satellite. Cloud-based file sync-and-share providers like Dropbox and box are playing an increasing role, but the industry's unique demands for speed and multicasting have fueled the growth of IP Video transport. This paper gives a solid grasp of the major elements of IP video technology, including content preparation, system architecture alternatives and network performance management.

• Journal of Digital Convergence
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• v.13 no.12
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• pp.193-202
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• 2015

The development of the security solutions that can provide a variety of security services is needed urgently. For development of the security solutions, analysis of international standard security technology is the key. In this paper, international organizations' standardization(ISO/IEC JTC1 SC27, ITU-T SG-17, IETF Security Area, etc.) and the current trend of the standard security technology are mainly analyzed. The core of the latest security technology(Application Bridging, DNS-based Authentication, HTTP Authentication, IP Security, Javascript Security, Authentication Technology Next Generation, Managed Incident, Web Authorization Protocol, Security Automation, Transport Layer Security, etc.) is analyzed focusing on 18 working groups of the IETF.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1312-1316
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• 2009

Growing interest in $CO_2$ capturing from industrial processes and storage in underground formations is emerging from commitments in reducing $CO_2$ emissions manifested in the Kyoto Protocol. In this paper, $CO_2$ liquefaction system is treated in focus of liquefaction efficiency & production rate. Presently $CO_2$ is transported in ships or trucks at a pressure of 14-20 bar. Considering this, the liquefaction pressures of 20, 15, 6.5 bar are selected. Compressor work and cooling capacity are calculated and compared. In order to investigate the effect of intercooling, the compressed gas after compressor work is cooled by ambient air or seawater. In case of applying the intercooling to the system, consuming energy can be saved larger than 20%. In the lower liquefaction pressure, the more $CO_2$ can be obtained due to higher density. In the liquefaction pressure of 6.5 bar, its $CO_2$ production is about 35% higher than that of the system with the liquefaction pressure, 20 bar.