• Title/Summary/Keyword: bandwidth control

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A Study on the Implementation of CAN in the Distributed System of Power Plant (발전설비 분산제어 시스템에서 CAN 구축기술 연구)

  • Kim, Uk-Heon;Hong, Seung-Ho
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.6
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    • pp.760-772
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    • 1999
  • The CAN is a serial communication protocol for distributed real-time control and automation systems. Data generated from field devices in the distributed control of power plant are classified into three categories: real-time event data, real-time control data, non-real-time data. These data share a CAN medium. If the traffic of the CAN protocol is not efficiently controlled, performance requirements of the power plant system could not be satisfied. This paper proposes a bandwidth allocation algorithm that can be applicable to the CAN protocol. The bandwidth allocation algorithm not only satisfies the performance requirements of the real-time systems in the power plant but also fully utilizes the bandwidth of CAN. The bandwidth allocation algorithm introduced in this paper is validated using the integrated discrete-event/continuous-time simulation model which comprises the CAN network and distributed control system of power plant.

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Management and control of fieldbus network traffic by bandwidth allocation scheme (대역폭 할당 기법에 의한 필드버스 네트워크의 트래픽 관리 및 제어)

  • Hong, Seung-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.3 no.1
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    • pp.77-88
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    • 1997
  • Fieldbus is the lowest level communication network in factory automation and process control systems. Performance of factory automation and process control systems is directly affected by the data delay induced by network traffic. Data generated from several distributed field devices can be largely divided into three categories: sporadic real-time, periodic real-time and non real-time data. Since these data share one fieldbus network medium, the limited bandwidth of a fieldbus network must be appropriately allocated to the sporadic real-time, periodic real-time and non real-time traffic. This paper introduces a new fieldbus design scheme which allocates the limited bandwidth of fieldbus network to several different kinds of traffic. The design scheme introduced in this study not only satisfies the performance requirements of application systems interconnected into the fieldbus but also fully utilizes the network resources. The design scheme introduced in this study can be applicable to cyclic service protocols operated under single-service discipline. The bandwidth allocation scheme introduced in this study is verified using a discrete-event/continuous-time simulation experiment.

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A Practical TCP-friendly Rate Control Scheme for SVC Video Transport (SVC 비디오 전송을 위한 실용적인 TCP 친화적 전송률 제어 기법)

  • Seo, Kwang-Deok
    • Journal of KIISE:Computing Practices and Letters
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    • v.15 no.2
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    • pp.114-124
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    • 2009
  • In this paper, we propose a practical TCP friendly rate control scheme that considers the minimum channel bandwidth of the network when transporting SVC (scalable video coding) video over IP netowrks such as Internet. RTP and RTCP is mainly designed for use with UDP (User Datagram Protocol) for real-time video transport over the Internet. TCP-friendly rate control was proposed to satisfy the demands of multimedia applications while being reasonably fair when competing for bandwidth with conventional TCP applications. However the rate control model of the conventional TCP-friendly rate control scheme does not consider the minimum channel bandwidth of the network. Thus the estimated channel bandwidth by the conventional rate control model might be quite different from the real channel bandwidth when the packet loss ratio of the network is very large. In this paper, we propose a modified TCP-friendly rate control scheme that considers the minimum channel bandwidth of the network. Based on the modified TCP-friendly rate control, we assign the minimum channel bandwidth to the base layer bitstream of SVC video, and remaining available bandwidth is allocated to the enhancement layer of SVC video for the TCP friendly scalable video transmission. It is shown by simulations that the modified TCP-friendly rate control scheme can be effectively used for a wider range of controlled bit rates depending on the packet loss ratio than the conventional TCP-friendly control scheme. Furthermore, the effectiveness of the proposed scheme in terms of objective video quality is proved by comparing PSNR performance with the conventional scheme.

Scalable Quasi-Dynamic-Provisioning-Based Admission Control Mechanism in Differentiated Service Networks

  • Rhee, Woo-Seop;Lee, Jun-Hwa;Yu, Jae-Hoon;Kim, Sang-Ha
    • ETRI Journal
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    • v.26 no.1
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    • pp.27-37
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    • 2004
  • The architecture in a differentiated services (DiffServ) network is based on a simple model that applies a per-class service in the core node of the network. However, because the network behavior is simple, the network structure and provisioning is complicated. If a service provider wants dynamic provisioning or a better bandwidth guarantee, the differentiated services network must use a signaling protocol with QoS parameters or an admission control method. Unfortunately, these methods increase the complexity. To overcome the problems with complexity, we investigated scalable dynamic provisioning for admission control in DiffServ networks. We propose a new scalable $qDPM^2$ mechanism based on a centralized bandwidth broker and distributed measurement-based admission control and movable boundary bandwidth management to support heterogeneous QoS requirements in DiffServ networks.

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Channel-Adaptive Rate Control for Low Delay Video Coding

  • Lee, Yun-Gu
    • IEIE Transactions on Smart Processing and Computing
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    • v.5 no.5
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    • pp.303-309
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    • 2016
  • This paper presents a channel-adaptive rate control algorithm for low delay video coding. The main goal of the proposed method is to adaptively use the unknown available channel bandwidth while reducing the end-to-end delay between encoder and decoder. The key idea of the proposed algorithm is for the status of the encoder buffer to indirectly reflect the mismatch between the available channel bandwidth and the generated bitrate. Hence, the proposed method fully utilizes the unknown available channel bandwidth by monitoring the encoder buffer status. Simulation results show that although the target bitrate mismatches the available channel bandwidth, the encoder efficiently adapts the given available bandwidth to improve the peak signal-to-noise ratio.

A Study on the Bandwidth Frequency of Directional Control Valves based on the Amplitude of the Metering-Orifice Pressure (미터링 오리피스 압력 진폭을 이용한 방향제어밸브 대역폭 주파수에 관한 연구)

  • Kim, Sungdong;Jeon, Sehyeong;Shin, Daeyoung
    • Journal of Drive and Control
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    • v.14 no.2
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    • pp.1-8
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    • 2017
  • The spool displacement of a directional control valve can be considered as the standard signal for the measurement of its bandwidth frequency. When the spool displacement is not available, the metering-orifice system is suggested in this study as an alternative way to measure the - 3 dB amplitude-ratio bandwidth frequency of the hydraulic directional-control valve. The amplitude ratio of the metering-orifice pressure can be adjusted to equal that of the spool displacement through the controlling of the metering-orifice opening area. A series of experiments were conducted to verify the effectiveness of the metering-orifice system. The metering orifice was confirmed as adequate for the measurement of the - 3 dB amplitude-ratio bandwidth frequency.

A Study on the ABR Traffic Control Mechanism using Dynamic Bandwidth Allocation (동적 대역폭 할당을 이용한 ABR 트래픽 제어 방식에 관한 연구)

  • 류호용;박권철;박광채
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.12B
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    • pp.2275-2282
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    • 1999
  • In ATM networks, bandwidth allocation using available bandwidth is important to control ABR traffic efficiently. However, it is difficult to dynamically assign bandwidth on bursty traffic, because the tracking of the existing available bandwidth information uses statistical value. In this paper, we propose a output-bufferd ATM switch using Per-VC queueing scheme with timer and Controller. The controller determines whether each VC is in congestion state or not, and the timer can assign dynamically as determining the available bandwidth for the Present period by Backlogged time and total link capacity, and then transmitting the determined bandwidth to source. Instead of using statistical parameters, the proposed scheme can improve link efficiency as allocating the bandwidth of the next period, by use of measured bandwidth during the current period.

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A Performance Analysis for Bandwidth Allocation Algorithm Using Available Bandwidth Information in ATM Networks (ATM 네트워크에서 가용 대역폭 정보를 이용한 대역폭 할당 알고리즘에 대한 성능분석)

  • 한상옥;박광채
    • The Journal of the Acoustical Society of Korea
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    • v.19 no.1
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    • pp.89-96
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    • 2000
  • ABR service is defined by ATM Forum and ITU for the efficient use of link bandwidth, and 2-pass service policing is proposed for this service. 2-pass service policing is effective by the real-time measurement of the used bandwidth, and this scheme obtains multiplexing gam and control efficiently ABR traffic as dynamically allocating rate by residual bandwidth information. In this study, we propose the real-time bandwidth prediction scheme for ABR traffic control, as using dynamic rate allocation by available bandwidth information. This study can obtain the simple hardware structure by means of as predicting available bandwidth by the total link bandwidth and the sum of transmission rate on the backlogged state connections.

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Performance Analysis of Call Admission Control Scheme with Bandwidth Borrowing and Bandwidth Reservation in GEO based Integrated Satellite Network (GEO 기반 위성 네트워크에서의 대역폭 빌림 방법과 대역폭 예약 방법을 이용한 호 수락 제어 성능 분석)

  • Hong, Tae-Cheol;Gang, Gun-Seok;An, Do-Seop;Lee, Ho-Jin
    • Journal of Satellite, Information and Communications
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    • v.1 no.1
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    • pp.12-19
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    • 2006
  • In this paper, we propose the bandwidth borrowing scheme which improves the performance of the cal admission control of the integrated GEO satellite networks. In general, target transmission rates of communications and streaming services are fixed, but data services do not have the target transmission rates. Therefore, we can control the transmission rates for data services flexibly according to the system loading situation. When the available bandwidth of the system is insufficient, the bandwidth borrowing scheme gives the bandwidth to request real time services by the transmission rates control of data services through packet scheduler. We make the queueing model for our system model and demonstrate the results through simulations. The simulation results show that there is a 8.7-35.2 dB gain at the total blocking probability according to the use of bandwidth borrowing scheme.

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Adaptive Rate Control Scheme for Streaming-based Content Sharing Service

  • Lee, Sunghee;Chung, Kwangsue
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.7 no.4
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    • pp.784-799
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    • 2013
  • This paper presents an adaptive rate control scheme for streaming-based content sharing service. This scheme delivers multimedia contents from a user device to another device or seamlessly redirects streaming service across heterogeneous user devices. In the proposed scheme, a streaming server adjusts video quality level according to the network and client status. Our scheme is different from other rate control schemes, because the video quality at the server is decided not only based on the available bandwidth, but also based on the device characteristics and bandwidth requirement at the access network. We also propose a bandwidth estimation method to achieve more equitable bandwidth allocations among streaming flows competing for the same narrow link with different Round Trip Times (RTTs). Through the simulation, we prove that our scheme improves the network stability and the quality of streaming service by appropriately adjusting the quality of the video stream. The simulation results also demonstrate the ability of the proposed scheme in ensuring RTT-fairness while remaining throughput efficient.