• Title, Summary, Keyword: Throughput

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An Analysis of Effective Throughput in Distributed Wireless Scheduling

  • Radwan, Amr
    • Journal of Korea Multimedia Society
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    • v.19 no.2
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    • pp.155-162
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    • 2016
  • Several distributed scheduling policies have been proposed with the objective of attaining the maximum throughput region or a guaranteed fraction throughput region. These policies consider only the theoretical throughput and do not account the lost in throughput due to the time complexity of implementing an algorithm in practice. Therefore, we propose a novel concept called effective throughput to characterize the actual throughput by taking into account the time complexity. Effective throughput can be viewed as the actual transmitted data without including the control message overhead. Numerical results demonstrate that in practical scheduling, time complexity significantly affects throughput. The performance of throughput degrades when the time complexity is high.

Throughput Capacity of a Wireless Multi-hop Relay Network using Cognitive Radio (Cognitive Radio 무선 다중홉 릴레이 네트워크의 Throughput 용량)

  • Hassan, Md. Imrul;Song, Ju-Bin;Kim, Young-Il
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.44 no.5
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    • pp.33-39
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    • 2007
  • In this paper, we investigate the throughput capacity of a multi-hop relay with cognitive radio (CR) enabled relay stations (RS). We suggest a TDMA/FDMA based frame structure where RSs dynamically select unused channels to communicate with the base station (BS) using CR techniques to analyze the throughput capacity. We develop the throughput capacity model for the proposed system based on utilization factor. The analytical results based on those equations show significant improvement in throughput capacity for CR enabled multi-hop relay system.

Packet Scheduling Algorithms for Throughput Fairness and Coverage Enhancement in TDD-OFDMA Downlink Network (TDD-OFDMA 하향 링크에서의 수율 공평성과 서비스 커버리지 보장을 위한 패킷 스케줄링 알고리즘 연구)

  • Ki, Young-Min;Kim, Dong-Ku
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.7A
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    • pp.611-619
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    • 2005
  • The present paper proposes two different packet scheduling algorithms in the IEEE 802.16e type TDD-OFDMA downlink, which are the weighted fair scheduling(WFS) and the throughput guarantee scheduling(TGS). The performance of proposed scheduling algorithms are compared to some of conventional schedulers such as round robin(RR), proportional fair(PF), fast fair throughput(FFTH), and fair throughput(FH) in terms of service coverage, effective throughput and fairness at 64 kbps and 128 kbps minimum user throughput requirements. For a relatively smaller throughput(64 kbps) requirement, the proposed algorithms provide higher improvement in the number of users per sector within 95$\%$ service coverage while satisfying the lxEV-DV fairness criterion. For a relatively larger throughput(128 kbps) requirement, the proposed algorithms provide higher coverage enhancement while maintaining the same effective aggregate throughput over PF scheduler.

Throughput Accounting: Comparision of Management Accounting Systems (Throughput 회계 : 관리회계 시스템과 비교)

  • Sung woon, Choi
    • Proceedings of the Safety Management and Science Conference
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    • pp.323-327
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    • 2003
  • The four types of management accounting systems(traditional full costing, direct costing, activity-based costing, throughput accounting) are compared in this study. This paper reviews the differences between throughput and contribution margin. The paper concludes that the definition of totally variable cost(TVC) to calculate throughput is situational specific.

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Throughput Analysis for Dual Blade Robot Cluster Tool (듀얼블레이드 로봇 클러스터툴의 생산성 분석)

  • Ryu, Sun-Joong
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.12
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    • pp.1240-1245
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    • 2009
  • The throughput characteristics of the cluster tool with dual blade robot are analyzed. Using equipment's cycle time chart of the equipment, simple analytic form of the throughput is derived. Then, several important throughput characteristics are analyzed by the throughput formula. First, utilization of the process chamber and the robot are maximized by assigning the equipment to the process whose processing time is near the critical process time. Second, rule for selecting optimal number of process chambers is suggested. It is desirable to select a single process chamber plus a single robot structure for relatively short time process and multi process chambers plus a single robot, namely cluster tool for relatively long time process. Third, throughput variation between equipments due to the wafer transfer time variation is analyzed, especially for the process whose processing time is less than critical process time. And the throughput and the wafer transfer time of the equipments in our fabrication line are measured and compared to the analysis.

The Asymptotic Throughput and Connectivity of Cognitive Radio Networks with Directional Transmission

  • Wei, Zhiqing;Feng, Zhiyong;Zhang, Qixun;Li, Wei;Gulliver, T. Aaron
    • Journal of Communications and Networks
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    • v.16 no.2
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    • pp.227-237
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    • 2014
  • Throughput scaling laws for two coexisting ad hoc networks with m primary users (PUs) and n secondary users (SUs) randomly distributed in an unit area have been widely studied. Early work showed that the secondary network performs as well as stand-alone networks, namely, the per-node throughput of the secondary networks is ${\Theta}(1/\sqrt{n{\log}n})$. In this paper, we show that by exploiting directional spectrum opportunities in secondary network, the throughput of secondary network can be improved. If the beamwidth of secondary transmitter (TX)'s main lobe is ${\delta}=o(1/{\log}n)$, SUs can achieve a per-node throughput of ${\Theta}(1/\sqrt{n{\log}n})$ for directional transmission and omni reception (DTOR), which is ${\Theta}({\log}n)$ times higher than the throughput with-out directional transmission. On the contrary, if ${\delta}={\omega}(1/{\log}n)$, the throughput gain of SUs is $2{\pi}/{\delta}$ for DTOR compared with the throughput without directional antennas. Similarly, we have derived the throughput for other cases of directional transmission. The connectivity is another critical metric to evaluate the performance of random ad hoc networks. The relation between the number of SUs n and the number of PUs m is assumed to be $n=m^{\beta}$. We show that with the HDP-VDP routing scheme, which is widely employed in the analysis of throughput scaling laws of ad hoc networks, the connectivity of a single SU can be guaranteed when ${\beta}$ > 1, and the connectivity of a single secondary path can be guaranteed when ${\beta}$ > 2. While circumventing routing can improve the connectivity of cognitive radio ad hoc network, we verify that the connectivity of a single SU as well as a single secondary path can be guaranteed when ${\beta}$ > 1. Thus, to achieve the connectivity of secondary networks, the density of SUs should be (asymptotically) bigger than that of PUs.

An Autonomous Power Control Scheme of Femto Cells for Throughput Improvement and Overhead Reduction in Heterogeneous Networks (이종망 환경에서 오버헤드 감소와 수율 향상을 위한 자율적인 펨토셀 전송 전력 조절 기법)

  • Jo, Younghoon;Lim, Jaechan;Hong, Daehyoung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38B no.1
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    • pp.26-33
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    • 2013
  • Femto-cells are low power/cost, micro-base stations and are main components in heterogeneous networks. However, some of technical issues arise when femto-cells are initially installed. One approach to resolve the problems is to control the transmission (TX) power autonomously via SON(Self-Organized Network) scheme. By controlling the femto-cell TX power, the system throughput performance can be improved or the system overhead is highly reduced. Generally, the TX power for maximizing the system throughput and that for reduced system overhead may not be identical. Therefore, we propose a TX power control scheme by which we can improve the system throughput and reduce the system overhead, simultaneously. When we apply the proposed method, the simulation results show that the system overhead can be reduced by up to 41% compared to the performance of the method which maximizes throughput performance only, and the throughput performance can be improved by up to 63% compared to that of the method which only optimizes the coverage area.

A Cost-Effective Simulation Procedure for Achieving Target Throughput of New Production Lines (신규제조라인의 목표생산용량 달성을 위한 비용효과적 시뮬레이션 절차)

  • Kim, Seung-Nam;Rim, Suk-Chul
    • Journal of Korean Institute of Industrial Engineers
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    • v.32 no.2
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    • pp.104-110
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    • 2006
  • When a new facility such as automobile assembly line is designed, computer simulation is often used to estimate its actual throughput level. If it falls short of the target throughput level, then the design must be modified to increase the throughput capacity. For complex facilities having parallel processes and network of material flows, the modification procedure is not trivial. Even if the capacity of a particular bottleneck process is increased, the target throughput may not be achieved because the bottleneck may move to another process. Furthermore, each process has a different set of options with different cost to increase the capacity. In this study, we present a systematic procedure of determining the cost-effective set of options which achieves the target throughput.

The Throughput Order of Multicast Traffics with Physical-Layer Network Coding in Random Wireless Ad Hoc Networks

  • Chen, Chen;Bai, Lin;He, Jianhua;Xiang, Haige;Choi, Jin-Ho
    • Journal of Communications and Networks
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    • v.13 no.3
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    • pp.214-220
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    • 2011
  • This paper attempts to address the effectiveness of physical-layer network coding (PNC) on the throughput improvement for multi-hop multicast in random wireless ad hoc networks (WAHNs). We prove that the per session throughput order with PNC is tightly bounded as ${\Theta}((n\sqrt{m}R(n))^{-1})$ if $m=(R^{-2}(n))$, where n is the total number of nodes, R(n) is the communication range, and m is the number of destinations for each multicast session. We also show that per-session throughput order with PNC is tight bounded as ${\Theta}(n^{-1})$, when $m={\Omega}(R^{-2}(n))$. The results of this paper imply that PNC cannot improve the throughput order of multicast in random WAHNs, which is different from the intuition that PNC may improve the throughput order as it allows simultaneous signal access and combination.

Assessing Throughput and Availability based on Hierarchical Clustering in Wireless Sensor Networks (계층적 클러스터링을 기반으로 하는 무선 센서 네트워크의 Throughput 과 Availability 평가)

  • Lee Jun-Hyuk;Oh Young-Hwan
    • Journal of Applied Reliability
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    • v.5 no.4
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    • pp.465-486
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    • 2005
  • A unreliable network system results in unsatisfied performance. A performance criterion of a network is throughput and availability. One of the most compelling technological advances of this decade has been the advent of deploying wireless networks of heterogeneous smart sensor nodes for complex information gathering tasks, The advancement and popularization of wireless communication technologies make more efficiency to network devices with wireless technology than with wired technology. Recently, the research of wireless sensor network has been drawing much attentions. In this paper, We evaluate throughput and availability of wireless sensor network, which have hierarchical structure based on clustering and estimate the maximum hroughput, average throughput and availability of the network considering several link failure patterns likely to happen at a cluster consisted of sensor nodes. Also increasing a number of sensor nodes in a cluster, We analysis the average throughput and availability of the network.

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