• Journal of Korea Society of Digital Industry and Information Management
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• v.4 no.3
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• pp.9-18
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• 2008

Mobile devices do not need the fixed network infrastructure in ad-hoc network, these devices communicate each other through the distributed control. Accordingly, mobile devices can discover several services using dynamic searching method and provide safely public ownership of these services. Ad-hoc network needs the distributed control and topology of dynamic network because the limited power for processing and network communication. This paper is devoted to provide the secure protocol that provides efficient services discovery using SDP(Service Discovery Protocol) and considers the security requirements. Proposed protocol provides the distributed control based on PKI without central server, the discovery of trusted service, secure telecommunication, the identification among mobile devices, and service access control by user authority.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.7
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• pp.76-91
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• 1996

In this paper, we proposed the new medium access control protocol for the virtual token bus netowrk. The network is applied to inter-processor communication network of large capacity digital switching system and digital mobile system with distributed control architecture. in the virtual token bus netowrk, the existing medium access control protocols hav ea switchove rtime overhead when traffic load is light or asymmetric according ot arbitration address of node that has message to send. The proposed protocol optimized average message delay using cyclic bus access chain to exclude switchover time of node that do not have message to send. Therefore it enhanced bus tuilization and average message delay that degrades the performance of real time communication netowrks. It showed that the proposed protocol is more enhacned than virtual token medium access control protocol and virtual token medium access control protocol iwth reservation through performance analysis.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.11
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• pp.1676-1681
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• 2012

In network-based control system, measurement and control information is delivered by the network messages. Therefore, the performance of control system is directly affected by the performance of network system. System engineers need to evaluate the performance of network system to maintain the entire system in stable condition. BACnet is an international standard data communication protocol especially designed for building automation and control systems. In this study, experimental performance evaluation methodologies of BACnet MS/TP protocol and their practical evaluation results are presented.

• ETRI Journal
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• v.24 no.2
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• pp.69-81
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• 2002

This paper reviews the existing research activities on signaling and control procedures for IP over optical networks. We focus on the IP-centric signaling and control architecture based on the generalized multi-protocol label switching (GMPLS) protocol and analyze various scenarios and technical issues for deploying the IP over an optical network. We analyze the signaling and operations and administration and maintenance requirements for integrating an IP network and an optical network in order to cope with the high bandwidth and poor resource granularity of the optical network, including the optical cross-connect system. On the basis of network architecture and a reference configuration model, we investigate the GMPLS-based control architecture and interconnection model appropriate for controlling IP bandwidth and optical lambda resources. The signaling and control procedure based on GMPLS on optical user-network interface and network-network interface are comparatively investigated to provide the optical lightpath. We also study protection and restoration procedures to protect link failure when it applies to generalized MPLS signaling.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1581-1585
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• 2005

This paper describes the design and implementation of a XCP (Xeline Control Protocol) network system. XCP is an information oriented protocol which delivers information with high reliability according to the predefined rule. The XCP network system is implemented with partly hardware and partly software based on the power line communication(PLC) environment. A network management tool which interacts with devices is also developed. In order to verify the feasibility of the proposed architecture, the implemented XCP network system is evaluated using a lighting control system.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.175-180
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• 2002

In order to satisfy the requirements of time reduction and cost saving for development of electronic control systems(ECU) in automotive industry, the applications of a standardized real-time operating system(RTOS) and a communication protocol to ECUs are increased. In this study, a body control module(BCM) that employs OSEK/VDX(open system and corresponding interfaces for automotive electronics/vehicle distributed executive) OS tour the RTOS and a controller area network(CAN) fur the communication protocol is designed, and the performances of the system are evaluated. The BCM controls doors, mirrors, and windows of the vehicle through the in-vehicle network. To identify all the transmitted and received control messages, a PC connected with the CAN communication protocol behaves as a CAN bus emulator. The control system based upon in-vehicle network improves the system stability and reduces the number of wiring harness. Furthermore it is easy to maintain and simple to add new features because the system is designed based on the standards of RTOS and communication protocol.

• 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.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.996-999
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• 1996

This paper introduces prototype design of 765kV Substation control system based on fiber optics LAN and distributed network protocol. Two major important facts, immunity of any surge which frequently occurs in Ultra High Voltage Substation and the most suitable communication protocol for substation control system, are considered on the system design conception. To meet the first fact, use of fiber optics cable and isolation transformer are considered, and to satisfy the second fact, DNP3.0(Distributed Network Protocol) which is IEC870-5 compatible is adopted.

• International Journal of Control, Automation, and Systems
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• v.5 no.5
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• pp.584-593
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• 2007

BACnet is a standard data communication protocol especially designed for building automation and control networks. BACnet uses the Master-Slave/Token-Passing (MS/TP) protocol as one of its field-level networks. In this study, the performance of the BACnet MS/TP protocol is evaluated using an experimental model. The network performance is investigated and evaluated in terms of token rotation time and round trip time. The experimental results show that the performance of the MS/TP network is heavily influenced by the network traffic load, the assignment of MS/TP node address and the network configuration parameter called $N_{max_info-frames}$. Based on the experimental results, simple practical designing guidelines for BACnet MS/TP network systems are also proposed.

• Journal of the Korean Operations Research and Management Science Society
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• v.24 no.2
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• pp.95-108
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• 1999

The CDMA mobile system consists of several subsystems and each subsystem has many processing elements that handle voice messages and control messages for performing CDMA call processing functions through CDMA Interconnection Network(CIN). For assuring a high throughput and a short delay in the CIN, an efficient medium access control protocol should be provided. In this paper, we propose a new access control protocol of CIN for providing real time communications in CDMA mobile system. Also, we evaluate the delay performance of the proposed access control protocol and compare it with that of the existing access control protocol. Through a set of numerical examples, we show that our proposed protocol provides a better delay performance than the existing protocol.