• Journal of applied mathematics & informatics
• /
• 제9권2호
• /
• pp.879-890
• /
• 2002

In this paper we consider open queueing system with a Poisson arrival process which have a finite upper bound on the arrival rate for which the system is stable. Interpolation approximations for quantities of interest, such as moments of the sojourn time distribution, have previously been developed for such systems, utilizing exact light and heavy traffic limits. These limits cannot always be easily computed for complex systems. Thus we consider an interpolation approximation where all of the relevant information is estimated via simulation. We show that all the relevant information can in fact be simultaneously estimated in a single regenerative simulation at any arrival rate. In addition to light and heavy traffic limits, both the quantity of interest and its derivative (with respect to the arrival rate) are estimated at the arrival rate of the simulation. All of the estimates are then combined, using a least squares procedure, to provide an interpolation approximation.

• 정보통신설비학회논문지
• /
• 제1권1호
• /
• pp.51-64
• /
• 2002

This paper analyzes performance measures of a Bluetooth_based mobile home network system. The home network system consists of terminals with Bluetooth interfaces, access points (AP), a home PC, and a gateway A mobile host in wireless terminals uses Mobile IP for supporting the mobility This paper considers four types of data traffic, which are new connection traffic, handoff traffic, Internet data traffic, and control data traffic and suggests a queueing system model of the home network system, where the AP and the home PC are modeled as M/G/1 with four priority queues and the gateway is modeled as M/G/1 with a single queue The generation rate and service time of individual traffic influence their performance measures. Based ell the suggested model, we propose the elapsed time of data traffic in terms of the number of cells, the number of Home PCs, arrival rates of four types of traffic and the service rates of AP/Home PCs/Gateway To analyze influences on the elapsed time with respect to arrival rate of four types of traffic, some examples are given.

• Journal of Electrical Engineering and information Science
• /
• 제2권6호
• /
• pp.56-63
• /
• 1997

Under most system assumptions, closed form solutions of performance measures for ATM switches with input queueing are not available. In this paper, we present expressions and bounds for the derivatives of cell loss probabilities with respect to the arrival rate evaluated at a zero arrival rate. These bounds are used to give an approximation by Taylor expansion, thereby providing an economical way to estimate cell loss probabilities in light traffic.

• Journal of information and communication convergence engineering
• /
• 제9권5호
• /
• pp.551-555
• /
• 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.

• 산업경영시스템학회지
• /
• 제20권41호
• /
• pp.103-112
• /
• 1997

In this paper, a nonhierarchial integrated information network with circuit switched and packet switched traffic is considered. It is assumed that circuit switched traffic is allowed to attempt an alternate path if the direct path is blocked, whereas packet switched traffic is not. The network uses a movable boundary scheme to allocate bandwidth dynamically. To analyze the performance of this type of network, EEBP(End to End Blocking Probability) is selected as a measure for circuit switched traffic and average time delay for packet switched traffic, respectively. EEBP and average time delay are derived analytically. Using the two proposed measure, the performance of the network under various bandwidth allocations and arrival patterns are observed. Moreover, the arrival rate of one link for circuit switched traffic is obtained from an approximation formula. Simulation results reveal the validity of the proposed approximation method.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2009년도 추계학술발표대회
• /
• pp.465-466
• /
• 2009

This paper investigates congestion detection and control strategies for multi-path traffic (CDCM) diss emination in lifetime-constrained wireless sensor networks. CDCM jointly exploits packet arrival rate, succ essful packet delivery rate and current buffer status of a node to measure the congestion level. Our objec tive is to develop adaptive traffic rate update policies that can increase the reliability and the network lif etime. Our simulation results show that the proposed CDCM scheme provides with good performance.

• 한국정보통신설비학회:학술대회논문집
• /
• 한국정보통신설비학회 2005년도 하계학술대회
• /
• pp.109-112
• /
• 2005

In this thesis, we recommend the method for VOD service traffic modeling. By the analysis of service traffic, we verify that the process of VOD service is the POISSON process. So it is important to determine the probability of the user's existence in the system. But, because it is difficult to measure, we recommend proper using of arrival rate and service rate.

• 한국통신학회논문지
• /
• 제35권1B호
• /
• pp.20-26
• /
• 2010

이동통신 환경에서 하향링크 스케줄링 기법은 무선 시스템의 성능을 크게 좌우할 정도로 매우 중요하다. 그러나 무선 시스템에서 가장 잘 알려진 기존의 비례 공평성 (Proportional Fairness: PF) 스케줄링 기법은 사용자 별 무선 채널 품질만을 고려하여 자원을 할당하기 때문에 전송해야할 하향 트래픽 유입량이 많은 사용자의 경우 원활한 전송이 불가능하다. 이를 해결하기위해 전송 대기 큐의 크기를 고려하여 자원을 할당하게 될 경우 전송 대기 큐의 누적으로 인해 낮은 채널 품질을 갖는 사용자에게 자원 할당이 집중되어 전체 시스템 전송률을 저하시킨다. 이에 본 논문에서는 하향 트래픽 유입량을 추가적으로 고려하여 기존 PF 스케줄링 알고리즘을 확장함으로써 낮은 채널 품질을 갖는 사용자의 전송이 지연되는 기존 PF 스케줄링 알고리즘의 문제점을 해결하는 동시에 이로 인해 발생할 수 있는 전체 시스템 전송률 저하 문제를 최소화 할 수 있는 트래픽 유입량 기반 하향링크 스케줄링 알고리즘을 제안한다. 모의실험을 통하여 제안한 알고리즘이 기존 스케줄링 알고리즘의 문제점을 해결하고 높은 성능을 보임을 확인하였다.

• 한국통신학회논문지
• /
• 제35권6B호
• /
• pp.895-900
• /
• 2010

다양한 통신 서비스가 개발되면서, 네트워크 설계자들은 시간상관성, 폭주성, 예측 불가능한 트래픽의 통계적 변동성 때문에 발생하는 혼잡을 제어하기 위한 방안을 모색하여 왔다. 본 논문에서는 패킷 도착률과 토큰 생성률을 통합하여 관리하는 리키버킷 방식을 이용하여 네트워크의 혼잡을 예방하는 모형에 대하여 분석한다. 본 논문에서 다루는 모형에서는 패킷 도착률과 토큰 생성 시간간격을 대기중인 패킷수에 따라 제어함으로써 네트워크 혼잡을 예방하게 된다. 모형의 분석을 위하여 임베디드 마코프체인과 부가변수 기법을 사용하며, 대기중인 패킷수 확률분포, 패킷손실확률, 평균대기시간 등의 특성치를 구한다.

• 대한산업공학회지
• /
• 제23권1호
• /
• pp.23-37
• /
• 1997

In this paper, performance analysis of video traffic shaper for Motion Picture Experts Group (MPEG) video traffic in on ATM network are investigated. Traffic shaping for MPEG video traffic is proposed as a traffic control function in ATM networks. The proposed shaper smoothes video traffics by controling the output rate of the buffer, which is placed in an MPEG source, according to I,B,P frame sequences of MPEG. In performance analysis of an video traffic shaper, a periodic botch arrival model is suggested to describe cell streams in a frame of MPEG video traffic. The queueing model which has periodic independent botch arrival and periodic deterministic service time is used to obtain the cell loss ratio, the mean cell delay, and the measure of smoothing effect. Simulation results are used to validate this queueing model. The cell loss performance of ATM multiplexer is measured by simulation study with real MPEG-1 data. From the viewpoint of traffic load, the cell loss ratio is observed to be considerably high, which is considered to result from the burstiness of MPEG video traffic. As a result, it is shown that the shaping decreases cell loss ratio of multiplexer. The results of this paper can be employed to establish a basic guideline in the implementation of a traffic control scheme and the design of ATM multiplexer for MPEG video traffic.