• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.582-585
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• 2001

Requirements for device networks differ greatly from those of data(business) networks. Consequently, any control network technology which uses a fieldbus protocol is, in general, different from IP network protocol TCP/IP. One needs to integrate fieldbus protocol and TCP/IP to realize distributed control over IP network or internet. This paper suggests a basic concept that can be applied to distributed control over IP network or internet. Specifically, LonWorks technology that uses LonTalk protocol is reviewed as device network. LonWorks technology provides networked intelligent I/O and controllers which make it a powerful, expandable solution. It is also addressed that many hardwired PLCs can be replaced by LonWorks devices. Connecting these remote LonWorks networks to the Internet can provide a powerful, integrated, distributed control system.

• 제어로봇시스템학회논문지
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• 제6권8호
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• pp.666-671
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• 2000

With the current advances in optical WDM (Wavelength Division Multiplexing) networking technologies and the increasing demand for network bandwidth the Next Generation Internet is expected to be a network that runs IP(Internet Protocol) directly over WDM-based optical networks. The network control architecture for the IP over WDM networks is different from that of traditional Internet since the underlying WDM devices have more constraints than electronic IP routers such as the lack of optical buffers and wavelength continuity property etc. In this paper we introduce several architectural models for implementing IP over WDM networks and propose an integrated network control framework for the IP over WDM networks. This framework leverages the traffic engineering control architecture for the MPLS (Multi-Protocol Label Switching) networks and is mainly developed for the IP over packet-switched WDM networks. We also report several preliminary simulation results of contention resolution schemes in the packet-switched WDM networks.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.82.4-82
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• 2001

Requirements for device control networks differ greatly from those of data (business) networks. Consequently, any control network which uses a filedbus protocol is, in general, different from If network protocol TCP/IP. One then needs to integrate both fieldbus protocol and TCP/IP to realize distributed control over IP network or internet. LonWorks technology provides networked intelligent I/O and controllers which make it a powerful, expandable solution. Connecting these remote Lon Works networks to the Internet can provide a powerful, integrated, distributed control system. This paper suggests a basic concept that be applied to distributed control over IP network or internet. Specially, Lonworks technology that used LonTalk protocol is reviewed as device network and ...

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.107-109
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• 2005

BACnet(Building Automation and Control networks) is a standard data communication protocol designed specifically for building automation and control systems. BACnet provides BACnet/IP Protocol for data communication through the internet. BACnet device transmits BACnet broadcast messages and BACnet/IP messages using conventional IP technologies. Specially, BBMD(BACnet Broadcasting Management Device) is used to deliver BACnet broadcast messages. In this study, we propose a mechanism of fault tolerant BBMD in the BACnet/IP protocol. The Fault Tolerant BBMD mechanism(FTBM) improves the connectivity of BACnet/IP networks by inheriting the operation of BBMD in the networks. The FTBM is implemented with added functions to the original BACnet/IP protocol so that it can be applied together with original BACnet/IP devices. We also prove the FTBM's backward compatibility with original BACnet/IP protocol using experimental analysis.

• 대한전기학회논문지:시스템및제어부문D
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• 제55권12호
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• pp.534-543
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• 2006

BACnet(Building Automation and Control networks) is a standard data communication network protocol designed specifically for building automation and control systems. BACnet provides BACnet/IP Protocol for data communication through the Internet. BACnet device uses BBMD(BACnet Broadcasting Management Device) to deliver BACnet broadcast messages. In this study, we propose a fault tolerant BBMD in the BACnet/IP protocol. The fault tolerant BBMD improves the connectivity of BACnet/IP networks by inheriting the operation of original BBMD in the networks. The fault tolerant BBMD is implemented with added functions to the original BACnet/IP protocol so that it can provide backward compatibility with the original BACnet/IP devices. We examined the validity of the fault tolerant BBMD using an experimental model.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제9권1호
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• pp.47-59
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• 2003

인터넷 전화 서비스는 현재 상업적으로 성공한 인터넷 기반 응용 서비스 가운데 하나이다. 이 서비스를 위한 기반 기술은 YoIP이다. 이는 QoS 보장이 되지 않는 인터넷에서의 분산 멀티미디어 서비스를 위한 표준 프로토콜인 H.323 또는 SIP를 활용한다. 여기서 음성 데이타를 전송하기 위한 프로토콜로써 RTP/UDP/IP 프로토콜 스택을 채택하였다. 그러나 UDP 전송 프로토콜을 이용하는 인터넷 응용은 비공인 IP 주소를 이용하는 사설망 또는 일부 초고속인터넷망 서비스 접속자들에게 불완전하게 데이타를 전송하는 결과를 초래한다. 인터넷 전화 서비스 경우, 음성 수신이 불가능하여 상대방의 목소리가 들리지 않는 현상이 발생한다. 특히 본 논문에서 다룬 인터넷 전화 서비스에서는 음성 데이타 수신을 위해 모든 세션에 대해 동일한 하나의 UDP 포트 번호를 사용하는 특성을 가지고 있어 문제를 더욱 어렵게 하였다. 이 문제를 해결하는 방식으로 단말 프럭시, 게이트웨이 프럭시 프로토콜 변환 방식 등을 제시하고, 그 가운데 실제 구현한 게이트웨이 프럭시 방식을 기반으로 한 NAT 프럭시 서버에 대해 자세하게 설명한다.

• Journal of Communications and Networks
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• 제9권4호
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• pp.394-401
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• 2007

High speed all optical network is a viable option to satisfy the exponential growth of internet usage in the recent years. Optical networks offer very high bit rates and, by employing technologies like internet protocol over wavelength division multiplexing(IP-over-WDM), these high bit rates can be effectively utilized. However, failure of a network component, carrying such high speed data traffic can result in enormous loss of data in a few seconds and persistence of a failure can severely degrade the performance of the entire network. Designing IP-over-WDM networks, which can withstand failures, has been subject of considerable interest in the research community recently. Most of the research is focused on the failure of optical links in the network. This paper addresses the problem of designing IP-over-WDM networks that do not suffer service degradation in case of a single link failure. The paper proposes an approach based on the framework provided by a recent paper by M. Kurant and P. Thiran. The proposed approach can be used to design large survivable IP-over-WDM networks.

• Journal of Communications and Networks
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• 제16권6호
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• pp.645-655
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• 2014

Latency, an identified element of Internet protocol (IP) mobility protocol execution, can reduce handover performance in mobile networks. Although the performance can be improved by applying an effective network-based IP mobility scheme in place of the traditional host-based alternatives, the existing inter-domain extensions of network-based IP mobility continue to suffer from an extended handover latency. This paper proposes a new inter-domain network-based IP mobility scheme based on node movement prediction. The proposed scheme accelerates the handover by preparing the future domain of the mobile node in a proactive manner. Analytical and simulation-based evaluations confirm improved performance of the proposed scheme in terms of handover latency and packet loss compared with existing schemes.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.150.3-150
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• 2001

Requirements for Distributed Monitoring and Control Networks (DMCN) differ greatly from those of typical data networks. Specifically, any DMCN technology which employs a fieldbus protocol is different from If network protocol TCP/IP. In general, one needs to integrate fieldbus protocol and TCP/IP to realize DMCN over IP network or internet Interoperability between devices and equipments is essential to enhance the quality and the performance of predictive maintenance (PM). This paper suggests a basic framework for LonWorks-based DMCN over IP network and a method to guarantee interoperability between devices and equipments.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권1호
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• pp.305-321
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• 2012

Since Internet Protocol (IP) is the most important protocol in Next Generation Networks (NGNs), 3rd Generation Partnership Project (3GPP) utilizes Session Initial Protocol (SIP) based on IP as the base protocol for negotiating sessions in IP Multimedia Subsystem (IMS). Different from traditional circuit-switched network, in IMS, the media traffic and signaling are delivered through IP transport. The media traffic may affect the signaling efficiency in core network, due to traffic collisions and best effort packets delivery. This paper proposes a novel path-migration mechanism for enhancing the traffic efficiency in integrated NGN-IMS. The simulation results show that the interference and traffic collision can be reduce by applying proposed path-migration mechanism and the signaling efficiency in core network can be improved with higher system capability and voice quality.