• Title/Summary/Keyword: HOL virtual queue

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Performance study of the priority scheme in an ATM switch with input and output queues (입출력 큐를 갖는 ATM 스위치에서의 우선순위에 관한 성능 분석)

  • 이장원;최진식
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.2
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    • pp.1-9
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    • 1998
  • ATM was adopted as the switching and multiplexing technique for BISDN which aims at transmitting traffics with various characteristics in a unified network. To construct these ATM networks, the most important aspect is the design of the switching system with high performance and different service capabilities. In this paepr, we analyze the performance of an input and output queueing switch with preemptive priority which is considered to be most suitable for ATM networks. For the analysis of an input queue, we model each input queue as two separate virtual input queues for each priority class and we approximage them asindependent Geom/Geom/1 queues. And we model a virtual HOL queue which consists of HOL cells of all virtual input queues which have the same output address to obtain the mean service time at each virtual input queue. For the analysis of an output quque, we obtain approximately the arrival process into the output queue from the state of the virtual HOL queue. We use a Markov chain method to analyze these two models and obtain the maximum throughput of the switch and the mean queueing delay of cells. and analysis results are compared with simulation to verify that out model yields accurate results.

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Performance Analysis of a Dynamic Priority Control Scheme for Delay-Sensitive Traffic (음성 트래픽을 위한 동적우선권제어방식의 성능분석)

  • 김도규;김용규;조석팔
    • The Journal of the Acoustical Society of Korea
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    • v.19 no.8
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    • pp.3-11
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    • 2000
  • This paper considers the performance of a dynamic priority control function (DPCF) of a threshold-based Bernoulli priority jump (TBPJ) scheme. Loss-sensitive and delay-sensitive traffics are applied to a system with a TBPJ scheme that is a general state-dependent Bernoulli scheduling scheme. Loss-sensitive and delay-sensitive traffics represent sound and data, respectively. Under the TBPJ scheme, the first packet of the loss-sensitive traffic buffer goes into the delay-sensitive traffic buffer with Bernoulli probability p according to system states which represent the buffer thresholds and the number of packets waiting for scheduling. Performance analysis shows that TBPJ scheme obtains large performance build-up for the delay-sensitive traffic without performance degradation for the loss-sensitive traffic. TBPJ scheme shows also better performance than that of HOL scheme.

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