• Title/Summary/Keyword: 셀 버퍼

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A Study on the Performance Analysis of Broadband ISDN Traffic (광대역 ISDN의 트래픽 성능분석에 관한 연구)

  • 구창회;박광채;이재호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.18 no.7
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    • pp.980-988
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    • 1993
  • In this paper, performance of 8-ISDN traffic for the buffer size which is requested of important parameters in switch/multiplexer of B-ISDN with multimedia traffic is analyzed. Multimedia traffic is modeled as a traffic, which is composed of poisson distribution traffic and burst traffic with exponential/geometric ON time duration(Burst duration) Performance of traffic which is modeled as a multimedia traffic is analysed and buffer size, can provide the high quality service, is presented for the cell loss probability. It is simulated using event scheduling approach method which is provided by simulation package, PC SIMSCRIPT II.5. Simulation program is composed of PREAMBLE, MAIN, INITIAL, ARRIVAL, DEPARTURE and STOP·SIM modules. Specially, in case of mixed traffic simulation, ARRIVAL module is composed of ARRIVAL I and ARRIVAL II, and cells are generated independently by each module.

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Performance Analysis of an ATM Multiplexer Loaded by CBR and Bursty Traffic Sources (CBR과 버스티 트래픽원이 가해진 ATM 다중화기의 성능 분석)

  • 김승환;박진수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.4
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    • pp.633-638
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    • 1994
  • Asynchronous Transfer Model(ATM) has a fixed-length packet transport scheme. It is one of promising proposals in Broadband ISDN(B-ISDN). Since the packet length is fixed, it can be potentially to perform the various service to user. In this paper, a queueing model for an ATM Multiplexer loaded by the Continuous Bit Rate(CBR) traffic and the bursty traffic sources is analyzed. The queueing system has a finite buffer size. The cell loss probabilities with the simple and recurcive form for a performance measures of ATM multiplexer are derived, and are also evaluated through numerical examples. The results of this study may be used as guidelines in buffer design problems and performance analysis of ATM multiplexing system.

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Performance of GFR service for TCP traffic in ATM switches with FIFO shared buffer (FIFO 공유 버퍼를 갖는 ATM 스위치에서 TCP 트래픽을 위한 GFR 성능 평가)

  • Park Inyong
    • Journal of Korea Society of Industrial Information Systems
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    • v.10 no.1
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    • pp.49-57
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    • 2005
  • ATM Form has defined the guaranteed frame rate (GFR) service to provide minimum cell rate (MCR) guarantees for TCP traffic in ATM networks and allow it to fairly share residual bandwidth. GFR switch implementation consists of the frame-based generic cell rate algorithm (F-GCRA) and a frame forwarding mechanism. The F-GCRA identifies frames that are eligible for an MCR guarantee. The frame forwarding mechanism buffers cells at a frame unit according to information provided by the F-GCRA and forwards the buffered cells to an output port according to its scheduling discipline. A simple GFR mechanism with shared buffer with a global threshold is a feasible implementation mechanism, but has been known that it is insufficient to guarantee the MCR. This paper has estimated performance of GFR service for TCP traffic over ATM switches with the simple FIFO-based mechanism

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Neural Dynamic Slot Assignment Algorithm for QoS Guarantee of VBR Traffic in Wireless ATM Network (무선 ATM 망에서 VBR 트래픽 Qos 보장을 위한 새로운 동적 슬롯 할당 알고리즘에 관한 연구)

  • Kim, Yeong-Cheol;Jeon, Chan-Yong
    • The KIPS Transactions:PartC
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    • v.8C no.4
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    • pp.443-450
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    • 2001
  • 본 논문에서는 무선 ATM 망에서 VBR(Variable Bit Rate) 트래픽의 QoS(Quality of Service)를 보장하고 무선 채널의 효율성을 극대화 할 수 있는 새로운 동적 슬롯 할당 알고리즘인 NDSA(Neural Dynamic Slot Assignment)를 제안한다. 제안된 알고리즘에서는 ATM 셀 헤더 부분의 GFC(Generic Flow Control) 필드 상에 단말기의 버퍼 상태와 셀 발생률 변화를 부호화 하여 piggybacking 하는 in-band 방식을 채택하였으며 다음 프레임에 할당할 슬롯의 갯수를 기존 방식과는 달리 신경회로망을 이용하여 유동적으로 조절하여 할당함으로써 단말기의 셀 손실이나 지연에 대한 QoS를 보장하고 채널 이용 효율을 높일 수 있었다. 제안된 알고리즘은 BONeS tool을 이용한 시뮬레이션을 통하여 기존의 방식과 비교 분석한 결과 그 정당성을 확인하였다.

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A Multicast Handoff Algorithm Considering Mobility of User on IMT-2000 Mobile Communication Network (IMT-2000 이동통신망에서 사용자의 이동성을 고려한 멀티캐스트 핸드오프 알고리즘)

  • 신창하;백진영;고승천;오원근;조성언
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2000.11a
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    • pp.54-58
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    • 2000
  • 멀티미디어 서비스를 제공하기 위한 피코셀(Pico-cell)환경의 IMT-2000(International mobile Telecommunication-2000) 이동통신망 구조를 살펴보면, 셀의 크기가 작기 때문에 이동체의 셀간 이동이 상대적으로 증가해서 잦은 핸드오프 처리로 서비스 중단이 빈번히 발생할 수 있을 뿐만 아니라 자원의 낭비도 많아지게 된다. 이런 문제를 해결하기 위해 셀 간 이동체에 대하여 중단 없는 서비스를 제공하고 멀티미디어 서비스를 효율적으로 채공하기 위하여 멀티캐스트 그룹 선정 방법과 핸드오프 알고리즘을 제안하고 성능을 평가하였다. 제안한 방법은 이동체의 속도와 예상 진행 방향을 애측하여 멀티캐스트 그룹을 결정한다. 결정된 멀티캐스트 그룹을 이용하여 이동체의 속도 증\ulcorner감소에 따라 멀티캐스트 그룹을 조절하여 핸드오프 멀티캐스트로 인한 버퍼 오버헤드를 감소시킴으로서 핸드오프 호의 블러킹을 감소시켜 전체적인 QoS를 향상시킬 수 있다.

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VQS4 Mechanism for the Priority Control in ATM Traffic (ATM 트래픽 성능향상을 위한 대기행렬구조의 제안 및 평가)

  • 안정희
    • Proceedings of the Korea Society for Simulation Conference
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    • 1998.10a
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    • pp.147-150
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    • 1998
  • ATM 환경의 다양한 QOS를 갖는 트래픽의 우선순위제어를 위해, ATM 스위치의 출력 버퍼에 저장되는 셀의 큐메카니즘을 제안하였다. 제안한 큐 방식은 가변큐공유(VQS4 : Variable Queue Sharing with 4 queue)방식으로서 기존의 고정 큐 방식의 문제점인 버스트 트래픽으로 인한 큐 오버플로우의 문제점을 개선하기 위해 CBR 큐, VBR-rt큐, VBR_nrt 큐, ABR 큐의 영역을 가변적으로 공유하여 큐 자원의 이용율을 최대화시킴으로써 순간 버스트 트래픽 유입으로 인한 셀손실율을 최소화시킬 수 있는 특성을 제공한다. VQS4 방식의 성능을 평가하기 위해 버스트 특성이 강한 트래픽 패턴을 이용하여 고정 큐를 이용한 HOL과 제안 방식인 VQS4의 셀손실률 및 평균 지연률을 비교하였으며 시뮬레이터는 Visual Slam 2.0(AweSim)을 이용하여 작성했다.

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A Study on BSW Algorithm for WRR Implementation (WRR 구현을 위한 BSW 알고리즘 연구)

  • 조해성
    • Journal of the Korea Society of Computer and Information
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    • v.7 no.3
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    • pp.122-127
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    • 2002
  • The Weighted Round Robin(na) discipline which is a sort of scheduling algorithm is quite simple and straightforward for handling multiple queues, and by Putting a different weight on each queue. In this paper, we propose new BSW structure, which can execute the WRR scheduling algorithm efficiently. Also, we develop a cell scheduling algorithm which is adapt in the new BSW structure. The Proposed BSW structure and the algorithm is capable of maintaining an allocated VC's weight correctly and decrease of average cell delay and maximum buffer length by serving other VC cell when empty in each VC queue. The proposed algorithm is a structure suitable for na implementation.

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A cell distribution algorithm of the copy network in ATM multicast switch (ATM 멀티캐스트 스위치에서 복사 네트워크의 셀 분배 알고리즘)

  • Lee, Ok-Jae;Chon, Byoung-Sil
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.8
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    • pp.21-31
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    • 1998
  • In this paper, a new algorithm is proposed which distributes multicast cells in a copy network. The dual copy network is composed of running adder network, distributor, dummy address encoder, and broadcasting network. It is operated lower input address and higher one simultaneously by the distribution algorithm. As a result, for each input has a better equal opportunity of processing, cell delay and hardware complexity are reduced in copy network. Also, for it adopts the broadcasting network from an expansion Banyan network with binary tree and Banyan network, overflow probability is reduced to a half in that network. As a result of computer simulation, the copy network processed by the distribution algorithm is remarkably improved in cell delay of input buffer according to all input loads.

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Cell Marking Priority Control Considering User Level Priority in ATM Network (ATM 네트워크에서 사용자 레벨 우선 순위를 고려한 셀 마킹 및 우선 순위 제어)

  • O, Chang-Se;Kim, Tae-Yun
    • The Transactions of the Korea Information Processing Society
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    • v.1 no.4
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    • pp.490-501
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    • 1994
  • In this study the problems of cell marking method used in the field of ATM network traffic control are presented. Also an extended cell marking method considering the user level priority is proposed. The conventional traffic monitoring schemes set the CLP bit of a cell to 1 only under the circumstance of the violation of traffic contract. It causes that the number of low level cells increases and the levels of cells are lowered regardless of the user level priority. The three level priority control method combining FCI bit with CLP bit has also been proposed. It divides CLP=0 cells into two levels. Consequently, the proposed method preserves more cells in high level than the conventional one and the real loss of high level cells can be reduced. The performance of the proposed scheme has also been analyzed by the PBS(partial buffer sharing) with two thresholds for the proposed three levels. The result shows that the PBS with two thresholds can give more efficient control than the scheme with no priority, or the PBS with one threshold.

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Strategy for An Adaptive UPC Algorithm with Buffer Threshold in ATM Network (버퍼 지연을 고려한 ATM 망의 적응적 UPC 알고리즘의 기법)

  • An, Ok-Jeong;Chae, Gi-Jun
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.1
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    • pp.224-236
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    • 1997
  • In order to control the flow of traffic in ATM networks and optimize the usage of network resources, an appropriate control mechanism is necessary to cope with congestion or prevent degradation of network performance caused by congestion. While the conventional UPC algorithm provides only unstable preventive function unrelated with the state of networks and is unable to recover congestion, the proposed adaptive UPC algorithm supervises the situation of ATM networks using the information from OAM cell. Then the monitor of the proposed adaptive UPC algorithm controls leaky rate and buffer threshold value according to QOS. Therefore, the proposed algorithm can cope with congestion as well as prevent and react sensitively to buffer delay. In proportion to the diversity of traffic and the increase of transmission rate in networks, the adaptive UPC-BT algorithm proposed in this paper can be effectively used in ATM networks with wide applications. This paper shows that the proposed algorithm efficiently uses in ATM networks with application. This paper shows that the proposed algorithm efficiently use network resources and provides QOS to users for various kinds of traffics by comparing with conventional UPC algorithms.

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