• Title, Summary, Keyword: Bandwidth

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A Hybrid Upstream Bandwidth Allocation Method for Multimedia Communications in EPONs

  • Baek, Jinsuk;Kwak, Min Gyung;Fisher, Paul S.
    • IEIE Transactions on Smart Processing and Computing
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    • v.1 no.1
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    • pp.27-33
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    • 2012
  • The Ethernet Passive Optical Network (EPON) has been considered to be one of the most promising solutions for the implementation of the Fiber To The Home (FTTH) technology designed to ameliorate the "last mile" bandwidth bottleneck. In the EPON network, an efficient and fair bandwidth allocation is a very important issue, since multiple optical network units (ONUs) share a common upstream channel for packet transmission. To increase bandwidth utilization, an EPON system must provide a way to adaptively allocate the upstream bandwidth among multiple ONUs in accordance to their bandwidth demands and requirements. We present a new hybrid method that satisfies these requirements. The advantage of our method comes from the consideration of application-specific bandwidth allocation and the minimization of the idle bandwidth. Our simulation results show that our proposed method outperforms existing dynamic bandwidth allocation methods in terms of bandwidth utilization.

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An Adaptive Bandwidth Selection Algorithm in Nonparametric Regression (비모수적 회귀선의 추정을 위한 bandwidth 선택 알고리즘)

  • Kyung Joon Cha;Seung Woo Lee
    • The Korean Journal of Applied Statistics
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    • v.7 no.1
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    • pp.149-158
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    • 1994
  • Nonparametric regression technique using kernel estimator is an attractive alternative that has received some attention, recently. The kernel estimate depends on two quantities which have to be provided by the user : the kernel function and the bandwidth. However, the more difficult problem is how to find an appropriate bandwidth which controls the amount of smoothing (see Silverman, 1986). Thus, in practical situation, it is certainly desirable to determine an appropriate bandwidth in some automatic fashion. Thus, the problem is to find a data-driven or adaptive (i.e., depending only on the data and then directly computable in practice) bandwidth that performs reasonably well relative to the best theoretical bandwidth. In this paper, we introduce a relation between bias and variance of mean square error. Thus, we present a simple and effective algorithm for selecting local bandwidths in kernel regression.

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Opportunistic Routing for Bandwidth-Sensitive Traffic in Wireless Networks with Lossy Links

  • Zhao, Peng;Yang, Xinyu
    • Journal of Communications and Networks
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    • v.18 no.5
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    • pp.806-817
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    • 2016
  • Opportunistic routing (OR) has been proposed as a viable approach to improve the performance of wireless multihop networks with lossy links. However, the exponential growth of the bandwidth-sensitive mobile traffic (e.g., mobile video streaming and online gaming) poses a great challenge to the performance of OR in term of bandwidth guarantee. To solve this problem, a novel mechanism is proposed to opportunistically forwarding data packets and provide bandwidth guarantee for the bandwidth-sensitive traffic. The proposal exploits the broadcast characteristic of wireless transmission and reduces the negative effect of wireless lossy links. First, the expected available bandwidth (EAB) and the expected transmission cost (ETC) under OR are estimated based on the local available bandwidth, link delivery probability, forwarding candidates, and prioritization policy. Then, the policies for determining and prioritizing the forwarding candidates is devised by considering the bandwidth and transmission cost. Finally, bandwidth-aware routing algorithm is proposed to opportunistically delivery data packets; meanwhile, admission control is applied to admit or reject traffic flows for bandwidth guarantee. Extensive simulation results show that our proposal consistently outperforms other existing opportunistic routing schemes in providing performance guarantee.

A Novel Bandwidth Estimation Method Based on MACD for DASH

  • Vu, Van-Huy;Mashal, Ibrahim;Chung, Tein-Yaw
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.3
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    • pp.1441-1461
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    • 2017
  • Nowadays, Dynamic Adaptive Streaming over HTTP (DASH) has become very popular in streaming multimedia contents. In DASH, a client estimates current network bandwidth and then determines an appropriate video quality with bitrate matching the estimated bandwidth. Thus, estimating accurately the available bandwidth is a significant premise in the quality of video streaming, especially when network traffic fluctuates substantially. To cope with this challenge, researchers have presented various filters to estimate network bandwidth adaptively. However, experiment results show that current schemes either adapt slowly to network changes or adapt fast but are very sensitive to delay jitter and produce sharply changed estimation. This paper presents a novel bandwidth estimation scheme based on Moving Average Convergence Divergence (MACD). We applied an MACD indicator and its two thresholds to classifying network states into stable state and agile state, based on the network state different filters are applied to estimate network bandwidth. In the paper, we studied the performance of various MACD indicators and the threshold values on bandwidth estimation. Then we used a DASH proxy-based environment to compare the performance of the presented scheme with current well-known schemes. The simulation results illustrate that the MACD-based bandwidth estimation scheme performs superior to existing schemes both in the speed of adaptively to network changes and in stability in bandwidth estimation.

The Bandwidth from the Density Power Divergence

  • Pak, Ro Jin
    • Communications for Statistical Applications and Methods
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    • v.21 no.5
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    • pp.435-444
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    • 2014
  • The most widely used optimal bandwidth is known to minimize the mean integrated squared error(MISE) of a kernel density estimator from a true density. In this article proposes, we propose a bandwidth which asymptotically minimizes the mean integrated density power divergence(MIDPD) between a true density and a corresponding kernel density estimator. An approximated form of the mean integrated density power divergence is derived and a bandwidth is obtained as a product of minimization based on the approximated form. The resulting bandwidth resembles the optimal bandwidth by Parzen (1962), but it reflects the nature of a model density more than the existing optimal bandwidths. We have one more choice of an optimal bandwidth with a firm theoretical background; in addition, an empirical study we show that the bandwidth from the mean integrated density power divergence can produce a density estimator fitting a sample better than the bandwidth from the mean integrated squared error.

Video Quality Control Scheme for Efficient Bandwidth Utilization of HTTP Adaptive Streaming in a Multiple-Clients Environment (다중 클라이언트 환경에서 HTTP 적응적 스트리밍의 효율적인 대역폭 활용을 위한 비디오 품질 조절 기법)

  • Kim, Minsu;Kim, Heekwang;Chung, Kwangsue
    • Journal of KIISE
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    • v.45 no.1
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    • pp.86-93
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    • 2018
  • When multiple clients share bandwidth and receive a streaming service, HTTP Adaptive Streaming has a problem in that the bandwidth is measured inaccurately due to the ON-OFF pattern of the segment request. To solve the problem caused by the ON-OFF pattern, the proposed PANDA (Probe AND Adapt) determines the quality of the segment to be requested while increasing the target bandwidth. However, since the target bandwidth is increased by a fixed amount, there is a problem in low bandwidth utilization and a slow response to changes in bandwidth. In this paper, we propose a video quality control scheme that improves the low bandwidth utilization and slow responsiveness of PANDA. The proposed scheme adjusts the amount of increase in the target bandwidth according to the bandwidth utilization after judging the bandwidth utilization by comparing the segment download time and the request interval. Experimental results show that the proposed scheme can fully utilize the bandwidth and can quickly respond to changes in bandwidth.

Adaptive Call Admission and Bandwidth Control in DVB-RCS Systems

  • Marchese, Mario;Mongelli, Maurizio
    • Journal of Communications and Networks
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    • v.12 no.6
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    • pp.568-576
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    • 2010
  • The paper presents a control architecture aimed at implementing bandwidth optimization combined with call admission control (CAC) over a digital video broadcasting (DVB) return channel satellite terminal (RCST) under quality of service (QoS) constraints. The approach can be applied in all cases where traffic flows, coming from a terrestrial portion of the network, are merged together within a single DVB flow, which is then forwarded over the satellite channel. The paper introduces the architecture of data and control plane of the RCST at layer 2. The data plane is composed of a set of traffic buffers served with a given bandwidth. The control plane proposed in this paper includes a layer 2 resource manager (L2RM), which is structured into decision makers (DM), one for each traffic buffer of the data plane. Each DM contains a virtual queue, which exactly duplicates the corresponding traffic buffer and performs the actions to compute the minimum bandwidth need to assure the QoS constraints. After computing the minimum bandwidth through a given algorithm (in this view the paper reports some schemes taken in the literature which may be applied), each DM communicates this bandwidth value to the L2RM, which allocates bandwidth to traffic buffers at the data plane. Real bandwidth allocations are driven by the information provided by the DMs. Bandwidth control is linked to a CAC scheme, which uses current bandwidth allocations and peak bandwidth of the call entering the network to decide admission. The performance evaluation is dedicated to show the efficiency of the proposed combined bandwidth allocation and CAC.

Speedup in Measuring the Effective Bottleneck Bandwidth of an End-to-End Path in Internet (인터넷에서 종단간 경로의 유효 병목 대역폭 측정 속도 개선)

  • Yoo, Han-Seung;Jang, Ju-Wook
    • Journal of KIISE:Information Networking
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    • v.28 no.2
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    • pp.236-241
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    • 2001
  • A new scheme is proposed to speed up a known bandwidth measuring method which employs potential bandwidth for filtering out noiscs (in cstirna60nl from time compression caused by a packet queueing ahead of two probe packets. Instead of inerementing the potential bandwidth by a fixed amount as in the original method we increase the potential bandwidth exponentially for faster convergence. To retain its filtering capability as well as its agility to adapt to new bottleneck bandwidth, each trial potential bandwidth(PB) is adjusted using MAX and MIN as upper bound and lower bound. An experiment using known bandwidths shows 45~g9% improvement in conVergence time.

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Adaptive Bandwidth Algorithm for Optimal Signal Tracking of DGPS Reference Receivers

  • Park, Sang-Hyun;Cho, Deuk-Jae;Seo, Ki-Yeol;Suh, Sang-Hyun
    • Journal of Navigation and Port Research
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    • v.31 no.9
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    • pp.763-769
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    • 2007
  • A narrow loop noise bandwidth method is desirable to reduce the error of raw measurements due to the thermal noise. However, it degrades the performance of GPS initial synchronization such as mean acquisition time. And it restricts the loop noise bandwidth to a fixed value determined by the lower bound of the allowable range of carrier-to-noise power ratio, so that it is difficult to optimally track GPS signal. In order to make up for the weak points of the fixed-type narrow loop noise bandwidth method and simultaneously minimize the error of code and carrier measurements, this paper proposes a stepwise-type adaptive bandwidth algorithm for DGPS reference receivers. In this paper, it is shown that the proposed adaptive bandwidth algorithm can provide more accurate measurements than those of the fixed-type narrow loop noise bandwidth method, in view of analyzing the simulation results between two signal tracking algorithms. This paper also carries out sensitivity analysis of the proposed adaptive bandwidth algorithm due to the estimation uncertainty of carrier-to-noise power ratio. Finally the analysis results are verified by the experiment using GPS simulator.

Local Bandwidth Selection for Nonparametric Regression

  • Lee, Seong-Woo;Cha, Kyung-Joon
    • Communications for Statistical Applications and Methods
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    • v.4 no.2
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    • pp.453-463
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    • 1997
  • Nonparametric kernel regression has recently gained widespread acceptance as an attractive method for the nonparametric estimation of the mean function from noisy regression data. Also, the practical implementation of kernel method is enhanced by the availability of reliable rule for automatic selection of the bandwidth. In this article, we propose a method for automatic selection of the bandwidth that minimizes the asymptotic mean square error. Then, the estimated bandwidth by the proposed method is compared with the theoretical optimal bandwidth and a bandwidth by plug-in method. Simulation study is performed and shows satisfactory behavior of the proposed method.

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