• Title/Summary/Keyword: Time delay protocol

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Worst-case Delay Analysis of Time-Triggered 802.15.4 for Wireless Industrial Environments

  • Kim, Hyun-Hee;Lee, Kyung-Chang
    • Journal of the Korean Society of Industry Convergence
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    • v.20 no.3
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    • pp.205-212
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    • 2017
  • This paper focuses on worst-case delay analysis of the time-triggered IEEE 802.15.4 protocol to satisfy the industrial quality-of-service (QoS) performance. The IEEE 802.15.4 protocol is considered to be unsuitable for industrial networks because its medium access control method is contention-based CSMA/CA, which exhibits unstable performance with an unbounded delay distribution under heavy traffic. To avoid these limitations, this paper presents a time-triggered version of the nonbeacon-enabled network of IEEE 802.15.4 that relies on a time division multiplexing access (TDMA) method implemented in the application layer without any modification of specification. The timing analysis of this time-triggered IEEE 802.15.4 was executed, and the worst-case transmission delay was calculated. Based on this analysis, the time-triggered IEEE 802.15.4 is a promising alternative for wireless industrial networking.

Communication Delay Properties in Performance Model of PROFIBUS Token Passing Protocol (PROFIBUS 토큰 패싱 프로토콜의 성능모델에서의 전송지연 특성)

  • Kim, Hyun-Hee;Lee, Kyung-Chang;Lee, Seok
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.511-514
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    • 2002
  • In may automated systems such as manufacturing systems and process plants, an industrial network or fieldbus is a very important component for the exchange of various and sometimes crucial information. Some of the information has a tendency to rapidly lose its value as time elapses after its creation. Such information or data is called real-time data that includes sensor values and control commands. In order to deliver these data in time, the fieldbus network should be tailored to have short delay with respect to the individual time limit of various data. Fine-tuning the network for a given traffic requires the knowledge on the relationship between the protocol parameters such as timer values and the performance measure such as network delay. This paper presents a mathematical performance model to calculate communication delays of the Profibus FMS network when the timer value TTR and the traffic characteristics are given. The results of this model is compared to those from experiments to assess the model's validity.

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A dynamic transmission reservation protocol with non-zero tunig delay for high-speed mutliwavelength networks (고속 광통신망에서 스위칭 오버헤드를 고려한 동적 전송 예약 프로토콜)

  • 최형윤;이호숙;김영천
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.34S no.5
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    • pp.25-34
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    • 1997
  • Relatively slow tuning speed of optical device causes the unwanted delay in high speed single-hop multiwavelength networks. To lessen the overhead, we present a channel access protocol with dynamjic message scheduling. Th eframe structure of proposed protocol adopts hybrid multiaccess scheme in which WDMA is used as a basic multiaccess technique and TDMA is used to provide subchannels within a wavelength band. This architecture has two merits : the network extention is not limited by available number of wavelengths, and the transmission delay caused by optical device tuning time can to minimize the number of tunings. It schedules messages that require same wavelength channels sequencely, so the total transmission delay is reduced by decreasement of wavelength changes. The performance of proposed protocol is evaluated through numerical analysis based on probability and queueing theory. The peformance of proposed protocol is evaluated through numerical analysis based on probability and queueing theory. The numeric results show that the peformance of proposed protocol is better than that of previous one.

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Delay-Power Aware Routing Protocol for Multimedia Ad hoc Networks (멀티미디어 Ad hoc 네트워크에서 전달지연-전력인지 라우팅 프로토콜)

  • Huh, Jun-Ho;Kim, Yoon-Do;Seo, Kyung-Ryong
    • Journal of Korea Multimedia Society
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    • v.15 no.3
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    • pp.356-363
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    • 2012
  • Power Aware Routing Protocol of MANET(Mobile Ad-hoc Network) minimized the power consumption of each node and helped to extend the lifetime of the network. But due to the nature of the protocol, it tends to increase the transmission delay, so multimedia transmissions were difficult to be applied. In this paper, a delay-power aware routing protocol is proposed considering the delay transmission delay that can be applied to ad hoc network. The proposed protocol consider two conflicting index, transmission delay and power consumption at the same time, maintaining a certain level of delay transmission delay while minimizes the power consumption. It is observed from the simulation results compared to not-considering delay transmission delay that the proposed protocol decrease transmission delay by 30% while the power consumption less than 10% increase.

LTE Base Station Power Saving Mechanism using Delay Information (Delay 정보를 이용한 LTE 기지국의 Power Saving 메커니즘)

  • Lee, Seung-Hwan;Rhee, Seung-Hyong;Choi, Yong-Hoon;Park, Su-Won
    • Journal of KIISE:Information Networking
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    • v.37 no.3
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    • pp.243-248
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    • 2010
  • This thesis proposes a power saving MAC protocol for LTE base station which utilizes different graded DRX/DTX(Discontinuous. Reception/Transmission) that specified by 3GPP(Third Generation Partnership Project). Considering QoS in UE, proposed MAC protocol controls adaptive DRX/DTX cycle. When Packet delay of UE is less than normal time, LTE base station economize power by increasing DRX/DTX. When Packet delay of UE is more than normal time, delay of UE is decreased by guaranteed QoS. It depends on the traffic which is sent by UE. The proposed method is more improve power saving performance than another method which is unchanged DRX/DTX by conditions. Especially when set DRX/DTX up in conditions, it will meet the requirements of UE. In this thesis, I propose an power saving MAC protocol in an environment where LTE base station are communicated with UE and prove improvement in performance through simulations.

The medium access control protocol of virtual token bus network for real time communication (실시간 통신을 위한 가상토큰버스 통신망의 매체접근제어 프로토콜)

  • 정연괘
    • 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.

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Implementation of IEEE 1588v2 PTP for Time Synchronization Verification of Ethernet Network (이더넷 네트워크의 시간 동기화 검증을 위한 IEEE 1588v2 PTP 구현)

  • Kim, Seong-Jin;Ko, Kwang-Man
    • The KIPS Transactions:PartA
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    • v.19A no.4
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    • pp.181-186
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    • 2012
  • The distributed measurement and control system require technology to solve complex synchronization problem among distributed devices. It can be solved by using IEEE Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems to synchronize real-time clocks incorporated within each component of the system. In this paper, we implemented the IEEE 1588v2 PTP emulator on BlueScope BL6000A using a delay request-response mechanism to measure clock synchronization.

A new WDM/TDM protocol for very high speed optical networks (고속광통신망용 새로운 WDM/TDM 프로토콜)

  • 이상록;이성근;박진우
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.2
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    • pp.50-58
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    • 1996
  • This paper proposes the channel-access protocol suitable to a very high speed photonic WDM network with star configuration, which can provide a high channel utilization and insensitivity to the propagation delay. The proposed protocol employs a control channel and a simple status table to deal with the propagation delay which has been a major limiting factor in the performance of the very high speed optical communication networks. The control channel transmits control information in order to reserve access on data channels, and each node constitutes a status table after the reception of control pckets which holds information about the availbility of destination node and data channel. The proposed protocol is insensitive to the propagation delay time by removing necessity of the retransmission and by allowing parallel transmission of control packet and data packets. It is proved in analysis and discrete event simulation that the proposed protocol is superior in throughput and mean delay, especially at the high load conditions compared to the existing high speed channel-access protocols.

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Real-Time Performance Evaluation of Network in Ethernet based Intranet

  • Pae, Duck-Jin;Kim, Dae-Won
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.133.3-133
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    • 2001
  • This paper analyses the real-time performance of Ethernet based intranet whether it is applicable to the real-time network. Unpredictability of transmission delay by collision-delay-retransmission mechanism in CAMA/CD(Carrier Sense Multiple Access with Collision Detect) of Ethernet is the major reason making hard to apply to real-time system. Both retransmission mechanism of TCP(Transmission Control Protocol) for reliability and sliding windows algorithm for high utilization make hard to predict transmission delay. Because real-time control network require fast responsibility and bustle of short-periodic messages, global-clock for collision avoidance and UDP(User Datagram Protocol) for high utilization of network are used. The mathematical models for time-delay that can be occured between ...

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Performance Analysis of Synchronization Protocols for Underwater Acoustic Networks (수중 장거리 네트워크를 위한 동기화 프로토콜 성능분석)

  • Cho, A-ra;Lim, Yong-kon;Choi, Youngchol
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.05a
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    • pp.68-71
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    • 2018
  • In this paper, we propose a synchronization protocol for underwater acoustic networks which aims to minimize the effects of long propagation delay and uncertain delay variations and employs packet train scheme with considering low data rate. The proposed protocol uses an one-way delay measurement method by transmitting consecutive packets and acquires synchronization only considering propagation delay variations by calculating packet arrival time differences. We perform simulations under various network conditions, such as node mobility, time interval for packet transmission, network range, and elapsed time after synchronizing. The simulation results shows the superiority of our protocol, compared with a previously proposed protocol.

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