• Title/Summary/Keyword: CSMA/CD

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Ethernet with Virtual Polling Algorithm for real-Time Industrial Communication Network (실시간 산업용 네트워크를 위한 가상 폴링 기반 이더넷 구현)

  • Kim, T. J.;Lee, K. C;Lee, S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.602-605
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    • 2001
  • This paper focus on a method to use Ethernet Network for Industrial Communication Network. Ethernet use the CSMA/CD MAC(Medium Access Control) Protocol at the Data-Link Layer, Which isn't suit for Industrial Communication Network requiring Real-Time Communication, periodic data processing, critical data processing characteristics. In this paper we proposed the Virtual Polling Algorithm at the Application Layer will be solution of using the Ethernet Network for the Industrial Communication Network, Proposed Algorithm terminate the Collision in the network thus Delay Time is reduced and Real-Time Communication will be implemented.

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A study on the Internet control and monitoring system using a microprocessor embedded controller (마이크로프로세서를 이용한 인터넷 원격감시제어 시스템에 관한 연구)

  • 서인호;문복산;김경엽;김영일;천행춘;유영호
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2000.11a
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    • pp.152-156
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    • 2000
  • Many industrial equipments use RS-232C interface. But Ethernet using CSMA/CD was widly spread recently. This interface is not compatible with RS-232C and requires PC based system. So In this Paper, We decribe a Internet control and monitoring system that control and watch plants without PC. We developed IP controller consisted of microprocessor and NIC and monitoring system using VC++ and SQL database. The protocol used this system is UDP/IP because it is applicable for real time system.

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Performance Analysis of a BRAM (The Broadcast Recognizing Aceess Method) Protocol in a Wireless LAN (무선 근거리 통신망에서의 BRAM(The Broadcast Recognizing Access Method) 프로토콜 성능 분석)

  • 김재현;이종규
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.1
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    • pp.1-8
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    • 1994
  • In this paper, we have analyzed the performance of a BRAM (The Broadcasting Recognizing Access Method) protocol, as a CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance) scheme, which is widely used in wireles LAN systems. We have selected a Fair BRAM protocol among CSMA/CA schemes, considering the fairness of channel usage and the simplicity of the protocol. We have compared the performance of BRAM protocol to that of CSMA/CD. to research the characteristics of BRAM in wireless LAN system. In order to analyze the performance of this system, we have set up an imbedded Markov chain and calculated state transition probabilities. Then we have calculated steady state probabilities and finally derived the throughput of a Fair BRAM moder. To verify our analysis, we have simulated practical models. Then, we have found that analytic results are very close to simulation ones. Our analysis of the BRAM protocol will be expected to be very helpful to design and evaluate a MAC (Media Access Control) protocol in wireless LAN systems.

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Performance Analysis of the fairmess MAC protocol under the CATV/LAN network (CATV/LAN 전송망에서 공정성을 고려한 MAC프로토콜의 성능해석에 관한 연구)

  • 우상철;윤종호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.1A
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    • pp.74-80
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    • 2000
  • In this paper, we proposed the MAC protocol and analyzed the performance for CATV/LAN network which was based upon HFC(hybrid optic coaxial) increased abruptly as alternative method of high speed network. Upstream channel which analyzed very deeply for CATV/LAN network have the preferential access property depending upon that position and unidirectional property. To solve this fairness problem, we propose the CSMA-CD/U/P protocol that transm it as $P_i$ probability although data packets is immediately transmitted when it was occurred. As the analytic result and simulation, we obtained $P_i$ value and its average delay time. Also, we get its variance value and queue length distribution. The mean delay time and queue length increase as the load and number of stations increase in the CATV/LAN network.

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A Multi-Service MAC Protocol in a Multi-Channel CSMA/CA for IEEE 802.11 Networks

  • Ben-Othman, Jalel;Castel, Hind;Mokdad, Lynda
    • Journal of Communications and Networks
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    • v.10 no.3
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    • pp.287-296
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    • 2008
  • The IEEE 802.11 wireless standard uses the carrier sense multiple access with collision avoidance (CSMA/CA) as its MAC protocol (during the distributed coordination function period). This protocol is an adaptation of the CSMA/CD of the wired networks. CSMA/CA mechanism cannot guarantee quality of service (QoS) required by the application because orits random access method. In this study, we propose a new MAC protocol that considers different types of traffic (e.g., voice and data) and for each traffic type different priority levels are assigned. To improve the QoS of IEEE 802.11 MAC protocols over a multi-channel CSMA/CA, we have developed a new admission policy for both voice and data traffics. This protocol can be performed in direct sequence spread spectrum (DSSS) or frequency hopping spread spectrum (FHSS). For voice traffic we reserve a channel, while for data traffic the access is random using a CSMA/CA mechanism, and in this case a selective reject and push-out mechanism is added to meet the quality of service required by data traffic. To study the performance of the proposed protocol and to show the benefits of our design, a mathematical model is built based on Markov chains. The system could be represented by a Markov chain which is difficult to solve as the state-space is too large. This is due to the resource management and user mobility. Thus, we propose to build an aggregated Markov chain with a smaller state-space that allows performance measures to be computed easily. We have used stochastic comparisons of Markov chains to prove that the proposed access protocol (with selective reject and push-out mechanisms) gives less loss rates of high priority connections (data and voices) than the traditional one (without admission policy and selective reject and push-out mechanisms). We give numerical results to confirm mathematical proofs.

An Implementation of Multiprotocol-Based Data Communication System Using (80C152를 이용한 멀티프로토콜의 구현)

  • Heo, Pil-U
    • 연구논문집
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    • s.25
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    • pp.137-146
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    • 1995
  • This paper deals with multi protocol based data communication system, which allows to improve the performances. The hardware and software of the data cmmunication system was implemented by using the CSMA/CD and Token bus access methods. The performance evaluation was also carried out and the results were verified to validate

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A Development of Data Acquisition and Recorder System for Factory Wasted Water Supervisor and Analysis (공장설비 방출폐수 감시를 위한 저가의 데이터 수집 및 저장장치 개발)

  • 김병진;문학룡;정을기;전희종
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.14 no.2
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    • pp.83-88
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    • 2000
  • A Development of a data logger for monitoring wasted water is introduced. A characteristics of the system with microcontroller are simple and cheaper. A portable RAM card is consisted for saving a monitored data. Serial communication is adopted to communicate with a remote monitoring computer. CSMA/CD, which is used widely as MAC(Medium Access Control) in ethernet, is modified to apply a RS485 serial communication. When the measured values run over a limit values, the data logger takes alarm.

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