• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.6
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• pp.1065-1069
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• 2006

With a home network, a device can dynamically join a home network obtain an IP address, convey its capabilities, and learn about the presence and capabilities of other devices. Devices can subsequently communicate with each other directly. Device discovery protocol defines how network services can be discovered on the network. In this paper, we propose the secure discovery method of devices that uses mutual authentication with symmetric key between devices. This method that we present distributes symmetric-key to home network devices by the home server. Using this key, mutual authentication is performed between home appliances. It enables any appliance under any middleware's control to securely communicate any other appliances.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2005.11a
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• pp.306-309
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• 2005

We consider the multi-objective optimization of a multi-service arrayed-waveguide grating-based single-hop metro WDM network with the two conflicting objectives of maximizing throughput while minimizing delay. We develop and evaluate a genetic algorithm based methodology for finding the optimal throughput-delay tradeoff curve, the so-called Pareto-optimal frontier. Our methodology provides the network architecture and the Medium Access Control protocol parameters that achieve the Pareto-optima in a computationally efficient manner. The numerical results obtained with our methodology provide the Pareto-optimal network planning and operation solution for a wide range of traffic scenarios. The presented methodology is applicable to other networks with a similar throughput-delay tradeoff.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1745-1748
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• 2003

This paper presents a Train Communication Network simulator (TCNS) that can be used to evaluate the performance of TCN. TCN was accepted as the standard of the protocol for the communication network in trains. We carry out some simulation tests using the TCNS to show practical uses of the simulator. Results of some simulation tests are also reported

• ETRI Journal
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• v.37 no.1
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• pp.186-196
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• 2015

In resource-constrained, low-cost, radio-frequency identification (RFID) sensor-based mobile ad hoc networks (MANETs), ensuring security without performance degradation is a major challenge. This paper introduces a novel combination of steps in lightweight protocol integration to provide a secure network for RFID sensor-based MANETs using error-correcting codes (ECCs). The proposed scheme chooses a quasi-cyclic ECC. Key pairs are generated using the ECC for establishing a secure message communication. Probability analysis shows that code-based identification; key generation; and authentication and trust management schemes protect the network from Sybil, eclipse, and de-synchronization attacks. A lightweight model for the proposed sequence of steps is designed and analyzed using an Alloy analyzer. Results show that selection processes with ten nodes and five subgroup controllers identify attacks in only a few milliseconds. Margrave policy analysis shows that there is no conflict among the roles of network members.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.386-388
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• 2010

에드 혹 네트워크(Ad hoc network)의 각 노드는 베터리 기반의 한정된 베터리로 동작하기 때문에 에너지 효율을 높이기 위한 다양한 라우팅 알고리즘이 연구되고 있다. 에드 혹 네트워크는 많은 수의 노드들이 거리 등의 상호 속성정보에 의한 노드의 관리기법에 따라 노드의 에너지를 관리해야 한다. 또한 주어진 망에서 관리 노드 또는 중계 노드 등이 동작 불가능한 상태가 되었을 경우 라우팅 경로가 끊어짐으로서 통신이 불가능한 상태가 되는 문제점이 있다. 본 논문에서는 트리망에서 중계 노드로 사용되는 클러스터 헤드 노드가 동작 불가능 상태가 되었을 경우, 노드간 거리 정보를 바탕으로 새로운 헤드 노드를 선출하는 ECDC(Energy Conservation Distance Control) 알고리즘을 제안하였다. 특히 제안된 ECDC 알고리즘을 이용함으로 노드에 대한 라이프타임을 향상 시키고 전체 라우팅 경로가 오랜 시간 동안 지속되는 결과를 보여주었다.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.133.5-133
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• 2001

The real-time industrial network, often referred to as fieldbus, is an important element for building automated manufacturing systems. Thus, in order to satisfy the real time requirements of field devices such as sensors, actuators, and controllers, numerous standard organizations and vendors have developed various fieldbus protocols. As a result, IEC 61158 protocol including Profibus, WorldFIP, and Foundation Fieldbus is recently announced as an international standard. Many fieldbus protocols have an important advantage over the widely used protocols such as Ethernet (IEEE 802.3) in terms of the deterministic characteristics of the fieldbuses. However, the application of fieldbus has been limited due to the high cost of hardware and the difficulty in interfacing with multi-vendor products. In order to solve these problems, computer network ...

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.9
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• pp.1184-1201
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• 1995

Two multiple access protocols are proposed for a multichannel WDM optical fibre local area network or metropolitan area network in which users are interconnected using a passive star topology. Each user has a single tunable transmitter and a single tunable receiver. A transmitter sends a control packet before its data packet transmission so that its intended receivers can tune to the proper data channel wavelength. The maximum throughput of the proposed protocols are independent of the effective normalized propagation delay which may include the transmitter and receiver tuning times and the processing delays. The maximum throughputs of the protocols are analyzed and compared with those of the existing ones by numerical examples. The message delay of the R- Aloha/synchronous N-server switch protocol which is suitable for the queued users is also analyzed.

• Journal of Communications and Networks
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• v.5 no.3
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• pp.202-214
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• 2003

The central challenge in the design of ad-hoc networks is the development of dynamic routing protocol that efficiently finds route between mobile nodes. Several routing protocols such as DSR, AODV and DSDV have been proposed in the literature to facilitate communication in such dynamically changing network topology. In this paper, a Node Transition Probability (NTP) based routing algorithm, which determines stable routes using the received power from all other neighboring nodes is proposed. NTP based routing algorithm is designed and implemented using Global Mobile Simulator (GloMoSim), a scalable network simulator. The performance of this routing algorithm is studied for various mobility models and throughput, control overhead, average end-to-end delay, and percentage of packet dropped are compared with the existing routing protocols. This algorithm shows acceptable performance under all mobility conditions. The results show that this algorithm maximizes the bandwidth utilization during heavy traffic with lesser overhead.

• Journal of information and communication convergence engineering
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• v.5 no.3
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• pp.200-204
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• 2007

The release of IEEE 802.15.4 PHY-MAC standard represents a milestone in developing of commercial wireless sensor network pursuing low power and low cost. In this paper, IEEE 802.15.4 Medium Access Control (MAC) protocol was analysed at the point of power consumption. This analysis measured the amount of the rest of power after transmitting data with beacon enabled mode and the power consumption of each node in the time period. ns-2 simulation is used to verify the analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.6A
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• pp.1078-1088
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• 2001

ATM-PON (Asynchronous Transfer Mode Passive Optical Network)에는 두 가지 핵심 기술이 있는데 ranging 프로토콜과 MAC (Medium Access Control) 프로토콜이 그것이다. Ranging 프로토콜은 시간 분할 다중화(Time Division Multiple Access, TDMA) 방식을 사용하는 ATM-PON에서 상향으로 액세스할 때 타임 슬롯의 동기를 유지하게 하기 위해 ONU (Optical Network Unit)를 가상적으로 동일한 거리에 놓는 기술이다. 본 논문에서는 FSAN (Full Service Access Network)과 ITU-T를 중심으로 표준화된 G.983.1의 ranging 프로토콜에 관하여 연구하고 성능분석과 모의실험을 수행한다. 이를 통하여 ranging을 하는데 걸리는 소요시간이 표준안의 권고사항을 만족시키기 위한 필요조건을 도출할 수 있다. 특히 ranging을 할 때 윈도우의 길이를 줄일 수 있는 새로운 방식을 적용하여, 이미 서비스 중에 있는 ONU의 서비스 품질이 저하되는 것을 막을 수 있음을 보여준다.