• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2121-2123
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• 2003

Distributed Control Systems(DCS) arc used in a wide range of process applications such as power plants. This paper presents calculated network capacity of a DCS that developed for nuclear power plant. The network hierarchies are 3 layed of information network, control network and field network. The assumed total node number of maximum DCS network is 64. Worst case network utilization of the DCS is simulated and analyzed.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.3
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• pp.29-38
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• 1998

This ppaer suggests a congestion control scheme for CL(ConnectionLess) overlay network using the feedback loops getween CL werver, between CL servers, and the header translation table of CL server. The CL overlay network for CBDS(Connectionless Broadband Data Service) defined by ITU0T(International Telecommunication Union-Telecommunication) consists of CL servers which route frames and links which connect between CL user and CL server or between CL servers. In this CL overlay network, two kinds of congestions, link congestion and CL server congestion, may occur. We suggest a scheme that can solve the congestion using ABR(Available Bit Rate) feedback control loop, the traffic control mechanism. This scheme is the link-by-link method suing the ABR feedback control loops between CL user and CL server or between CL servers, and the header translation table of CL server. As CL servers are always endpoints of ABR connections, the congestion staturs of the CL server can be informed to the traffic sources using RM(Resource Management) cell of the ABR feedback loops. Also CL server knows the trafffic sources making congestion by inspecting the source address field of CLNAP-PDUs(ConnectionLess Network Access Protocol - Protocol Data Units). Therefore this scheme can be implemeted easily using only both ABR feedback control loop of ATM layer and the congestion state table using the header translation table of CL server because it does not require separate feedback links for congestion control of CL servers.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10c
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• pp.199-201
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• 2003

Ad hoc network은 stationary infrastructure의 도움 없이 이동 노드들이 필요 시 network 형태을 구성하여 통신이 이루어지게 하는 network으로 ad hoc network 환경에 맞는 다양한 라우팅 프로토콜들이 개발되었고 크게는 table­driven, on­demand 방식으로 나눌 수 있는데 on­demand 방식의 AODV 프로토콜은 routing overhead가 적다는 장점이 있는 반면 single path로 data forwarding을 진행하여 중간노드의 이동에 의한 path가 broken되는 경우 local routing을 하거나 새로이 source­initialed route rediscovery을 수행하여 전송 delay 및 control traffic overhead 등을 높이는 결과를 발생 시켰다. 본 논문은 single path로 구성되는 AODV 프로토콜의 route failures시 문제점을 보완한 Associativity Based Redundancy path Routing(ABRR) 및 Alternate Redundancy path Routing(ARR) schemes을 제안한다. 첫째, ABRR은 main path상에 있는 각 노드들은 associativity based stable node 정보를 이용하여 path broken 이전에 local redundancy path을 구성하여 path broken시 local routing없이 route을 복구할 수 있게 하고 둘째, ARR은 source­initialed route discovery에 의해 alternate path을 구성하여 ABRR 그리고 local routing에 의해 main route recovery 실패 시 alternate path을 main path로 전환하여 control traffic overhead 및 전송 delay을 줄이게 한다.

• Journal of Korea Multimedia Society
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• v.12 no.6
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• pp.824-832
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• 2009

Multi-radio multi-channel Wireless Mesh Network requires an effective management policy to control the assignment of channels to each radio. We concentrated our investigation on modeling method and solution to find a dynamic channel assignment scheme that is adapted to change of network traffic. Multi-path routing scheme was chosen to overwhelm the unreliability of wireless link. For a particular traffic state, our optimization model found a specific traffic distribution over multi-path and a channel assignment scheme that maximizes the overall network throughput. We developed a simple heuristic method for channel assignment by gradually removing clique load to obtain higher throughput. We also presented numerical examples and discussion of our models in comparison with existing research.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.1B
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• pp.39-46
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• 2005

As the multimedia application traffic takes more portion in the internet traffic, it is necessary to control the network congestion through the congestion control protocol. In addition, the QoS-enabled networks such as DiffServ become an indispensable technology when running the multimedia applications. However, the previously proposed end-to-end congestion control algorithms take the round trip time to react the network congestion. Thus, as the RTT becomes larger, the reaction against the congestion gets delayed further, while the network congestion gets worse. In addition the performance of end-to-end congestion control algorithm is degraded if the QoS-enabled network runs the congestion control mechanism in the network level without any coordination between them. In this paper, we propose the early rate adaptation protocol for the DiffServ network which effectively linke the congestion control algorithm at the host and the congestion mechanism in the network together. By taking advantage of early congestion notification from the network it is possible to react the network congestion more quickly and effectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.4
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• pp.99-104
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• 2010

We introduce Internet TCP/IP control system to monitor the traffic volume on the traffic network system. To check the traffic volume on traffic road, we use the traffic detector system shppe of circle or diamond or rectangular. Nevertheless we use traffic detector, we will use internet addressin TCP/IP system. If we use TCP/IP control system, we acquire many good point, we achive high sircurity and low costness traffic monitoring system coming difficulty and high level position. But internet system is very easy and low cost direction. Traffic control system is very more depending on the high techinquesion and very complexity. Therefore we introducing TCP/IP internet addressing control system schemetic point.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2017.05a
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• pp.55-56
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• 2017

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.274-279
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• 2008

In this paper, we will presents the join procedure for efficient network performance in the ZigBee Sensor Network. In existing network, new devices join procedure is performed base on the participating in the already Coordinator and Router beacon information. However, beacon has insufficient information network. Thus, the concentration of traffic and inefficient use of resources, address the problem that occurs. To solve these problems, the Coordinator and router on the network, depending on their location and the ability to transfer a beacon. This algorithm is proposed in the paper, the transmission time by using the beacon, network configuration control of the network to improve performance.

• The KIPS Transactions:PartC
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• v.14C no.1 s.111
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• pp.45-54
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• 2007

As one of the most threatening attacks, DDoS attack makes distributed multiple agents consume some critical resources at the target within the short time, thus the extent and scope of damage is serious. Against the problems, the existing defenses focus on detection, traceback (identification), and filtering. Especially, in the hierarchical networks, the traffic congestion of a specific node could incur the normal traffic congestion of overall lower nodes, and also block the control traffic for notifying the attack detection and identifying the attack agents. In this paper, we introduce a DDoS attack tolerant network structure using a hierarchical overlay for hierarchical networks, which can convey the control traffic for defense such as the notification for attack detection and identification, and detour the normal traffic before getting rid of attack agents. Lastly, we analyze the overhead of overlay construction, the possibility of speedy detection notification, and the extent of normal traffic transmission in the attack case through simulation.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.10
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• pp.1018-1023
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• 2010

The CAN (Controller Area Network) system is the most dominant protocol for in-vehicle networking system because it provides bounded transmission delay among ECUs (Electronic Control Units) at data rates between 125Kbps and 1Mbps. And, many automotive companies have chosen the CAN protocol for their in-vehicle networking system such as chassis network system because of its excellent communication characteristics. However, the increasing number of ECUs and the need for more intelligent functions such as ADASs (Advanced Driver Assistance Systems) or IVISs (In-Vehicle Information Systems) require a network with more network capacity and the real-time QoS (Quality-of-Service). As one approach to enhancing the network capacity of a CAN system, this paper introduces a CAN system with dual communication channel. And, this paper presents a distributed message allocation method that allocates messages to the more appropriate channel using forecast traffic of each channel. Finally, an experimental testbed using commercial off-the-shelf microcontrollers with two CAN protocol controllers was used to demonstrate the feasibility of the CAN system with dual communication channel using the distributed message allocation method.