• Title/Summary/Keyword: Protocol Performance

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A Study of TCP Performance with Snoop Protocol over Fading Wireless Links

  • Cho, Yang-Bum;Cho, Sung-Joon
    • Journal of information and communication convergence engineering
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    • v.2 no.4
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    • pp.214-218
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    • 2004
  • In this paper, we have analyzed TCP performance over wireless correlated fading links with and without Snoop protocol. For a given value of the packet error rate, TCP performance without Snoop protocol is degraded as the fading is getting fast (i.e. the user moves fast). When Snoop protocol is introduced in the base station, TCP performance is enhanced in most wireless environments. Especially the performance enhancement derived from using Snoop protocol is large in fast fading channel. This is because packet errors become random and sporadic in fast fading channel and these random packet errors (mostly single packet errors) can be compensated efficiently by Snoop protocol's local packet retransmissions. But Snoop protocol can't give a large performance improvement in slow fading environments where long bursts of packet errors occur. Concerning to packet error rate, Snoop protocol results in the highest performance enhancement in the channel with mid-high values of packet error rate. This means Snoop protocol cannot fully fulfill its ability under too low or too high packet error rate environments.

A Multiaceess Protocol for Packet Transmission in Mobile Satellite Systems (이동 위성 통신 시스템에서 패킷 전송을 위한 다원 접속 프로토콜)

  • 임광재;곽경섭
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.7
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    • pp.17-28
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    • 1994
  • A combined random/reservation multiple access protocol is proposed which can provide services for packet transmission in mobile satellite systems between mobile statons, or between mobile stations and fixed stations. Random multiple access protocol and reservation multiple access protocol which are currently employed in most satellite communication systems have some strengthes and some weeknesses in according to the kind of user and traffic. In this paper, a combined random/reservation multiple access protocol with better characteristics is proposed. The models of the modified random access protocol and the proposed access protocol is setted and analyzed. The performance of the PDAMA protocol, the random access protocol and the proposed access protocol is compared using simulation. For small packet arrival rate, the performance of the proposed access protocol is close at that of the modified random access protocol, and better than that of the PDAMA protocol. As the packet arrival rate is increased, the modified random access protocol is saturated and unstable at 0.23, and the performance of the proposed access protocol is better than that of the PDAMA protocol.

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Simulation Study on the Performance of the IEEE 802.4 Token Passing Bus Protocol (IEEE 802.4토큰 패싱 버스 프로토콜의 성능에 관한 시뮬레이션 연구)

  • Lim, Dong-Min;lee, Hwang-Soo;Un, Chong-Kwan
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.3
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    • pp.22-31
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    • 1989
  • In this paper, we analyze the performance of the IEEE 802.4 token passing bus protocol through a simulation model of the protocol. In order to analyze performance of the protocol in the initialization, transition and fault recovery states as well as in the steady state, the protocol functions are divided into five processes each of which can effectively simulate protocol behaviors according to the variations of protocol parameters. From the simulation study, we obtain protocol parameters which severely influence the protocol performance and find out that proper selection of the protocol parameter values for token passing is very important to obtain good performance of the protocol when the priority scheme is used.

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Transmission Performance Comparison and Analysis with Different Publish/Subscribe Protocol (발행-구독 프로토콜에서 전송 성능의 비교 및 분석)

  • Fan, Zujie;Kim, JaeSoo
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2020.07a
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    • pp.77-80
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    • 2020
  • In this paper, we analyze and compare the performance of different publish and subscribe protocols in the real application environment. This paper provides a horizontal comparison of current publish/subscribe protocols in terms of security, throughput, and delay performance. Thanks to the use of lightweight frameworks, the MQTT protocol has demonstrated excellent performance in terms of delay performance. However, the AMQP protocol has more advantages in security and throughput. Although the REST/HTTP protocol has the worst delay performance, it is excellent in terms of compatibility because it is based on the HTTP protocol.

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The Effect of Operating Room Nursing and Medical Staff Teamwork and Perception of Patient Safety Culture on the Performance of Surgical Patient Safety Protocol (수술실 의료진의 팀워크와 환자안전문화에 대한 인식이 수술환자안전 프로토콜 수행에 미치는 영향)

  • Ahn, Shin-Ae;Lee, Nam-Ju
    • Journal of Korean Critical Care Nursing
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    • v.9 no.1
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    • pp.27-39
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    • 2016
  • Purpose: The purpose of this study lies in investigating nursing and medical staff perceptions on the importance of surgical patient safety protocol, teamwork, and patient safety culture, and how their grasp of the factors affects the degree of their performance of the protocol. Methods: A survey was conducted on 249 nurses and medical staff participating in the operating rooms of one higher general hospital in Seoul, using a 5-point scale self-reported questionnaire. Logistic regression analyses were used. Results: Operating room nurses yielded the highest scores on both the importance of the patient safety protocol and its performance. In patient safety culture, the operating medical staff yielded significantly higher scores than those of operating room nurses. Perception of the importance of the patient safety protocol and teamwork had a significant effect on the nurses' complete performance of the protocol. Conclusion: It is important to create a safety culture, where all the staff can actively and freely communicate with one another through team-based training programs. By enhancing teamwork and patient safety culture, it will be possible to establish the surgical patient safety protocol and to improve the performance of the protocol by health professionals.

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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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Dynamic Key Lifetime Change Protocol for Performance Improvement of Virtual Private Networks using IPSec (IPSec을 적용한 가상사설망의 성능개선을 위한 동적 키 재생성 주기 변경 프로토콜)

  • 한종훈;이정우;박성한
    • Proceedings of the IEEK Conference
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    • 2003.11c
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    • pp.125-128
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    • 2003
  • In this paper, we propose a dynamic key lifetime change protocol for performance enhancement of virtual private networks using IPSec. The proposed protocol changes the key lifetime according to the number of secure tunnels. The proposed protocol is implemented with Linux 2.4.18 and FreeS/WAN 1.99. The system employing our proposed protocol performs better than the original version in terms of network performance and security.

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Performance Analysis and Validation of Railway Signalling Communication Protocol (철도신호용 통신 프로토콜 성능해석 및 검증)

  • Hwang Jong-Gyu;Lee Jae-Ho;Shin Duk-Ho
    • Proceedings of the KSR Conference
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    • 2003.05a
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    • pp.462-467
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    • 2003
  • According to the computerization of railway signalling system, necessity of communication protocol for interface between these equipments is increasing. Therefore the research on communication protocol structure that is required according to computerization trend of these signalling goes. In our research the existed protocol currently used was analyzed, and the simulation modeling for performance analysis is deduced. Based on this simulation model the performance analysis and comparison is carried out, and also validation test is executed about new suggested protocol.

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Performance Analysis and Testing of Railway Signalling Communication Protocol (열차제어용 통신프로토콜 구조분석 및 성능검증 시험)

  • Hwang, Jong-Gyu;Lee, Jae-Ho
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.1318-1320
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    • 2003
  • According to the computerization of railway signalling system, necessity of communication protocol for interface between these equipments is increasing. Therefore the research on communication protocol structure that is required according to computerization trend of these signalling goes. In our research the existed protocol currently used was analyzed, and the simulation modeling for performance analysis is deduced. Based on this simulation model the performance analysis and comparison is carried out, and also validation test is executed about new designed protocol.

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Throughput and Delay Analysis of a Network Coding-enabled Cooperative MAC Protocol for Ad Hoc Networks

  • Jang, Jae-Shin;Kim, Sang-Wu;Wie, Sung-Hong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.6
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    • pp.1668-1688
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    • 2012
  • Cooperative communications and network coding schemes have been proposed to increase system throughput for ad hoc networks. In this paper, we present throughput and delay analysis of the new network coding-enabled cooperative MAC protocol called NC-MAC, which has been proposed by us in order to significantly enhance system performance. This protocol introduces an approach that can accommodate both cooperative communication and network coding for wireless ad hoc networks by slightly increasing overhead and modifying standards. The protocol's performance is evaluated using mathematical analysis and computer simulation and two performance measures, system throughput and average channel access delay, are used for a performance comparison with previous schemes. It is assumed that all the frames exchanged over a wireless channel are susceptible to transmission errors, which is a new but more reasonable assumption differentiating this research from previous research. Numerical results show this protocol provides significantly enhanced system performance compared with conventional cooperative MAC protocols used in previous research. For instance, system performance is 47% higher using the NC-MAC protocol than when using the rDCF protocol.