• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.8
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• pp.2042-2051
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• 1998

VBR compressed, pre-recorded video is known to exhibit significant, multiple time-scale bit rate variability. To reduce the variability and burstiness of the aggregated transmission rate as low as possible, in this paper, we present an adaptive bandwidth smoothing algorithm, that can be effectively applicalble for VoD services over a shared-medium channel. For these environments where many clients are connected to a single server, by introducing the conventional MVBA(minimum variability bandwidth allocation) algorithm and controlling adaptively the conventional MVBA(minimum variability bandwidth asllocation) algorithm and controlling adaptively the aggregated transmission rate whenever a new clients request is arrived at the server side, the proposed algorithm effectively reduces the burstiness and variability of the aggregated transmission rate. Through computer experiments, it is shown that the proposed method perporms better than the convertional non-aggregated bandwidth smoothing schemes in terms of the peak rate, standard deviation, number of rate changes for the aggregated traffic.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.41
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• pp.51-60
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• 1997

In this paper, A Connection Admission Control(CAC) algorithm by Dynamic Bandwidth Allocation is proposed. The B-ISDN will be required to carry traffic generated by a various traffic sources. These source will have all traffic flow characteristics and quality of services requirements. When a connectionless message with burstiness arrives at a node during a renewal period, CAC will be dynamically determined connection request by using the predetermined connection admission bounds in estimating the number of input arriving cells. The proposed algorithm estimates the available bandwidth by observing cell streams of the aggregate traffic. A connection request is accepted if the available bandwidth is larger than declared peak rate, and otherwise rejected. The proposed CAC scheme is shown to be promising and practically feasible in obtaining efficient transmission of burst traffic with guaranteed quality of services.

• Journal of information and communication convergence engineering
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• v.9 no.5
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• pp.551-555
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• 2011

Optical packet switching is a promising technology, which can integrate both data and optical network. In this paper, we present a comparative study of various traffic arrival approaches in WDM packet switches. The comparison is made based on packet loss rate and average delay under uniform and self-similar Pareto traffic. Computer simulations are performed in order to obtain the switch performance metrics. Study shows that burstiness of data traffic has a strong negative impact in the performance of WDM packet switches.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10c
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• pp.210-212
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• 2000

In this paper, we propose an enhanced usage parameter control algorithm, which is one of the preventive traffic control method in ATM networks and implemented it with VLSI Proposed algorithm is based on the cell loss priority bit in the ATM cell header. This algorithm can solve the measurement phasing problem in cell conformance testing in ATM networks. Proposed algorithm can minimize the cell loss ratio of high priority cell(CLP=0) and resolve the burstiness of cells which may be introduced in traffic multiplexing and demultiplexing procedure. The result of performance evaluation shows that the performance of proposed algorithm is better than that of ITU-T usage parameter control algorithm.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05b
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• pp.1401-1404
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• 2003

현재 제공되는 인터넷 서비스들의 동작 특성은 기존에 고려되던 트래픽 특성과는 완전히 다른 자기 유사성(Self·similarity)이라는 성질을 가진다는 것이 증명되었다. 자기 유사성은 장기간 의존성으로 표현되는데, 이것은 단기간 의존성 성질을 갖는 기존의 모델인 포아송(Poisson) 모델과는 상반되는 개념이다. 따라서 차세대 통신망의 설계 및 디멘져닝을 위해서는 무엇보다도 데이터 트래픽의 주요 특성인 버스트성(Burstiness)과 자기유사성이 반영된 트래픽 모델이 요구된다. 여기서 자기유사성은 허스트 파라미터(Hurst Parameter)로 특성화 될 수 있다. 이러한 관점에서 본 논문에서는 데이터 트래픽 특성이 서로 다른 다수의 데이터 트래픽의 통합되어 통신망에 입력되는 경우 주요 파라미터인 Hurst Parameter의 변화를 다양한 환경 하에서 분석하였고 이를 시뮬레이션 결과와도 비교하였다.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.873-874
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• 2008

In this paper, we propose a packet loss concealment (PLC) algorithm for CELP speech coders, which is based on multiple adaptive codebooks by using comfort noise for the lost packet recovery. The multiple adaptive codebooks are composed of a conventional adaptive codebook to model periodic excitation of speech and another adaptive codebook to provide a better estimate of excitation when packets are lost in the speech onset region. The performance of the proposed PLC algorithm is evaluated by implementing it into the G.729 decoder and compared with that of the PLC algorithm employed in the G.729 decoder by means of perceptual evaluation of speech quality (PESQ). It is shown from the experiments under different burstiness of packet loss rates of 3% and 5% that the proposed PLC algorithm provides higher PESQ scores than the G.729 PLC algorithm.

• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.196-199
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• 2000

In this paper has studied an enhanced usage parameter control algorithm, which is one of the preventive traffic control method in ATM networks. The proposed algorithm is based on the CLP(Cell Loss Priority) bit in the ATM cell header. This algorithm can eliminate the measurement phasing problem in cell conformance testing in ATM networks. The proposed algorithm can minimize the cell loss ratio of high priority cell(CLP = 0) and resolve the burstiness of eel]s which may be generated in the multiplexing and demultiplexing procedure. For the performance evaluation, we have simulated the proposed algorithm with discrete time input traffic model and the results show that the performance of the proposed algorithm is better than that of ITU-T usage parameter control algorithm.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.469-472
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• 2003

음성 중심의 기존 2G CDMA/PCS의 성능 및 용량을 분석하기 위한 트래픽 모델링에서는 시간당 평균 호 발생률, 발생 간격의 분포, 호 유지시간(Holding Time), 그리고 최번시(Busy Hour)를 결정하는 것이 주요 과제였으며, 이를 이용한 트래픽 엔지니어링은 음성호의 Blocking 확률과 지연시간을 최소화 하기위한 충분한 호 자원 확보에 중심을 두었던 것이 사실이다. 그러나 CDMA2000 1X 및 1xEV-DO/DV와 같은 3G 고속 데이터 이동통신 시스템에서의 패킷 데이터 트래픽의 특성은 자기 유사성(Self-similarity)이라는 성질을 가진다는 것은 잘 알려진 사실이다. 이와같은 고속 데이터 이동통신 시스템에서 요구되는 효율적인 망의 설계 및 디멘져닝을 위해서는 무엇보다도 데이터 트래픽의 주요 특성인 버스트함과 자기유사성이 반영된 모델 분석이 요구된다. 이러한 관점에서 본 논문에서는 데이터 트래픽의 자기유사성 및 큐잉 지연을 고려한 유효대역폭 산출식을 유도하여 시뮬레이션 결과와 비교 분석하였다.

• Journal of applied mathematics & informatics
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• v.22 no.1_2
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• pp.523-533
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• 2006

We analyze two finite buffers queueing system with priority scheduling dependent upon queue length. Customers are classified into two types ( type-l and type-2 ) according to their characteristics. Here, the customers can be considered as traffics such as voice and data in telecommunication networks. In order to support customers with characteristics of burstiness and time-correlation between interarrival, the arrival of the type-2 customer is assumed to be an Markov- modulated Poisson process(MMPP). The service order of customers in each buffer is determined by the queue length of two buffers. Methods of embedded Markov chain and supplementary variable give us information for queue length of two buffers. Finally, performance measures such as loss and mean delay are derived.

• Communications of the Korean Mathematical Society
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• v.14 no.2
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• pp.405-423
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• 1999

We consider a statistical multiplexer model with finite buffer capacity and finite number of independent identical 3-state bursty voice sources. The burstiness of the sources is modeled by describing both two different active periods (at the rate of one packet perslot) and the passive periods during which no packets are generated. Assuming a mixture of two geometric distributions for active period and a geometric distribution for passive period and geometric distribution for passive period, we derive the recursive algorithm for the probability mass function of the buffer contents (in packets). We also obtain loss probability and the distribution of packet delay. Numerical results show that the system performance deteriorates considerably as the variance of the active period increases. Also, we see that the loss probability of 2-state Markov models is less than that of 3-state Markov models.