• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.57-60
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• 2004

오늘날 정보통신 기술의 급속한 발전과 함께 인터넷은 그 용도를 점차 넓혀가고 있으며 기존의 유선망에서 무선망을 이용한 무선데이터 서비스가 점차 활성화되고 있다. 현재 무선망에서 사용되는 프로토콜은 WAP(Wireless Application Protocol)이 가장 널리 사용되고 있다. 그런데 이 무선망에서 사용되는 무선 단말기의 낮은 데이터 전송속도 및 연산능력에 의하여 기존의 소프트웨어로 구현된 WAP으로는 기존 무선단말기의 성능 향상에 한계가 있다 특히 WAP의 한 계층인 WTLS(Wireless Transport Layer Security)는 보안의 기능을 담당하는 계층으로 복잡한 연산 과정을 수행한다 본 논문에서는 WTLS 프로토콜 중에서 실질적인 보안 서비스를 제공하는 레코드 프로토콜(record protocol)) 을 하드웨어 모듈로 구현함으로써 기존의 시스템과 비교하고 앞으로의 방안을 제안하고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.648-652
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• 2003

In the GPRS(General Packet Radio Service) network, the transport layer between SGSN(Serving GPRS Support Node) and GGSN (Gateway GPRS Support Node) is based on IP-Over ATM Network. which means that the connectionless IP traffic is transmitted through connection oriented ATM transport layer. Efficient resource management is needed to perform connection and disconnection of the pertinent VC because of the connectionless IP traffic being passed through ATM transport layer In this paper, Internet Web service traffic model in the GPRS network is applied to the various VC holding Cost Pricing Model. each method is compared through analyzing each VC utilization and setup rate.

• Information and Communications Magazine
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• v.14 no.6
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• pp.123-132
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• 1997

• 한국ITS학회:학술대회논문집
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• 2002.11a
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• pp.31-34
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• 2002

• ETRI Journal
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• v.32 no.2
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• pp.204-213
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• 2010

In this paper, we investigate the possible security threats to downloadable conditional access system (DCAS) host devices. We then propose a DCAS secure micro (SM) and transport processor (TP) security protocol that counters identified security threats using a secure key establishment and pairing management scheme. The proposed protocol not only resists disclosed SM ID and TP ID threats and indirect connection between TA and TP threats, but also meets some desirable security attributes such as known key secrecy, perfect forward secrecy, key compromised impersonation, unknown key-share, and key control.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.5
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• pp.434-445
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• 1990

Protocol testing techniques are expanded from the traditional simple function- testing based on the OSI model, to sophisticated performance testing, conformance testing and interoperability testing. In addition, both point-to-point and point-to-multipoint protocols are to be covered. This paper presents a new multiple-purpose protocol test system where the common platform includes the test sequence generation and test result analysis, and the modular test execution part is selectively adjusted according to the test purposes and protocols under test. This paper describes test system for network routing protocol and test system for transport protocol, designed upon the ideas of the multiple-purpose protocol test system.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.52 no.3
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• pp.95-99
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• 2003

In this paper, the power system automation based on CAN communication protocol is introduced. Along with digitalization of electrical device, the various on-line services such as remote control, remote monitoring, remote parameter setting, fault data recording and remote diagnostic have been realized and become available. Therefore, it is necessary for those electrical devices to have real-time and reliable communication protocols. Author proposes DNPC(Distributed Network Protocol with CAN) which is proper to the power system SCADA (Supervisory Control And Data Acquisition) and DCS (Distributed Control System). The physical and datalink layer of DNPC protocol consists of the CAN2.0B which has the real-time characteristics and powerful error control scheme. As the transport and application layer, DNP3.0 is adopted because of its flexibility and compatible feature. Using the DNPC protocol, the power system automation is realized.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.6
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• pp.92-100
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• 2008

Ad-hoc network is a collection of wireless mobile hosts forming a temporary network without the aid of any centralized administration or reliable support services such as wired network and base stations. Recently, Ad-hoc networks are evolving to support multimedia contents according to expansion of ad hoc multi-hop communication system. Wireless ad-hoc network is different from the conventional wired network by frequent changes in network topology, number of routers and resources, there are a number of problems in applying conventional routing protocol to ad-hoc network. The AODV routing protocol is proposed for mobile node in ad-hoc networks. AODV protocol that provides to guarantee QoS for data transmission in ad hoc networks that link break frequently occurs. In this paper, AODV routing protocol based NDIS(Network Driver Interface Specification) is implemented. We design high performance image transmission that can operate with software(AODV) for ad-hoc networks without degradation. and verify operation of AODV routing protocol on the test bed.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.5
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• pp.116-124
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• 2016

This paper proposes a medium access control protocol for collision detection and resolution when a large number of sensor nodes transmits data in vehicle. The proposed protocol selects a random collision detection (CD) slot after data transmission, suspends its transmission and senses the channel to check whether a collision occurs by the detection of both energy level and jam signal. The proposed scheme uses multiple CD phases and in each CD phase, colliding stations are filtered and only surviving stations compete again in the next CD phase; thus, the collision resolution probability significantly increases. Simulation results show that the proposed protocol using the multiple CD phases has significantly better throughput than the conventional protocol. In addition, according to the number of CD phases and the number of CD slots per phase, the throughput aspect of the proposed scheme is investigated and the optimal parameters are derived.

• Journal of the Korea Society of Computer and Information
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• v.12 no.1 s.45
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• pp.137-144
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• 2007

Advances in networking technology digital media, and codecs have made it possible for the Internet evolves into a Broadband convergence Network (BcN) and provides various services including Voice over Internet Protocol (VoIP) and IPTV over their high-speed IP networks. In order for the Internet to make a profit as traditional Public Switched Telephone Network (PSTN), it must provide high qualify VoIP services. Therefore, real time qualify measurement framework is the most important requisite to provide VoIP service. For this, IETF (Internet Engineering Task Force) defined RTCP-Extended Reports (RTCP-XR) that extend RTCP (Real-Time Transport Protocol Control Protocol). However, procedure and method tot actually VoIP qualify measurement did not recommended nothing but defined item to measure voice quality. Our objective in this paper is to describes a practical measuring framework for end-to-end QoS of switched voice packet in an IP environment. It includes concepts as well as step-by-step procedures for measuring packetized voice streams. It also proposes new formats that extend RTCP-XR's concept.