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当因特网上的分组过多超过了网络的处理能力时,出现的网络性能下降的问题称为拥塞.使用流量/拥塞控制技术可以避免或缓解拥塞状况.本文对当前网络上运行的TCP/IP拥塞和流量控制算法进行了综述,分析和比较了各种算法的基本性能与可行性,指出了流量/拥塞控制技术将来发展方向. 相似文献
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Congestion in the Internet is the main reason for reduced performance and poor quality of service; therefore, a good congestion
control system is essential. The current work proposes that the congestion control problem in the Internet can be inspired
from natural population control tactics. Toward this idea, the congestion window size of each connection is viewed as population
size of a species and then congestion control problem is redefined as population control of these windows species (W). This
paper defines a three-trophic food chain and gives a model to control population size of W species within this food chain.
Simulation results show that the proposed algorithm leads to a fair, stable and high-performance congestion control scheme.
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Shahram Jamali (Corresponding author)Email: |
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近几年来,网络通信量的迅猛增长使得主干网日益拥塞;新业务的涌现对网络提出更高的服务质量要求,为了满足这些需求,主干网路由器就必须采取一定的策略来避免和控制网络拥塞,从而保证网络畅通并提供一定的服务质量(如端到端延时等),这些策略就是通常所说的拥塞避免/控制策略,本文分析了三种拥塞控制机制的优缺点,以及路由器中常用的4种拥塞控制的策略,重点介绍了在实际中运用最广泛的拥塞控制策略-RED(随机早期检测)的实现机制。 相似文献
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Yu-Ping Tian Author Vitae 《Automatica》2005,41(7):1255-1262
A unified duality model is proposed for describing the current Internet congestion control algorithms. Based on this model, the problem of the local asymptotic stability of the congestion control with heterogeneous propagation delays is formulated and solved. A general stability criterion is proved by using the stability theory for quasi-polynomials. 相似文献
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Internet路由器中的拥塞控制策略 总被引:4,自引:0,他引:4
近年来 ,Internet变的日益繁忙 ,为了减轻当前 Internet的拥塞程度 ,路由器中就必须采取某种有效的拥塞避免 /控制策略 .本文分析了三种拥塞避免 /控制方案 ,并比较了它们的优缺点 相似文献
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《Robotics and Autonomous Systems》2007,55(3):205-215
This paper proposes a stable control structure for the bilateral teleoperation of robots through Internet. The problem is motivated by the increasing use of the Internet as a communication channel. Internet has a time-varying delay which depends on factors such as congestion, bandwidth and distance. In this work, we propose a control structure for the teleoperation of a manipulator robot with force feedback. Such a control structure includes state controllers (placed on the local and remote sites) and a time-delay compensation, which modifies the delayed position command generated by the human operator using the force that he feels in such a delayed moment and the current force between the slave and the remote environment. In addition, the proposed control scheme is designed considering a model of the communication channel. Finally, experiments of bilateral teleoperation of robots through Intranet and Internet are shown to test the performance and stability of the designed teleoperation system. 相似文献
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随着互联网的发展,网络拥塞问题越来越严重,如何改进现有的拥塞控制算法成为一个重要课题。为了解决网络拥塞问题,目前已有很多拥塞控制算法,大体可分为端到端的拥塞控制和基于网络的拥塞控制,本文主要关注基于端到端的拥塞控制。在众多的TCP拥塞控制算法中,Vegas算法以其主动避免拥塞的思想,具有较好的效果。但是,Vegas与目前主流的Reno算法兼容性差,存在带宽被挤占的问题。本文分析了拥塞问题的多重原因,并从博弈的角度分析了Vegas的缺点,提出了一种改进的拥塞控制算法G-Vegas。通过在NS2平台仿真,验证了算法的有效性。 相似文献
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DIAN Shi-mei 《数字社区&智能家居》2008,(22)
随着互联网规模的增长,互连网上的用户和应用都在快速的增长,拥塞已经成为一个十分重要的问题。近年来,在拥塞控制领域开展了大量的研究工作。此文介绍了基于TCP协议的拥塞控制算法的研究现状,分析了对算法改进的研究,并提出一些改进的建议。 相似文献
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Zaichen Zhang Li V.O.K. 《Parallel and Distributed Systems, IEEE Transactions on》2007,18(9):1332-1344
Multicast is very efficient in distributing a large volume of data to multiple receivers over the Internet. Layered multicast helps solve the heterogeneity problem in multicast delivery. Extensive work has been done in the area of layered multicast, for both congestion control and error control. In this paper, we focus on network-supported protocols for streaming media. Most of the existing work solves the congestion control and error control problems separately and does not give an integrated efficient solution. In this paper, after reviewing related work, we introduce our proposed protocols, namely, router-assisted layered multicast (RALM) and router-assisted layered FEC (RALF). The former is a congestion control protocol, whereas the latter is an error control protocol. They work under the same framework and provide an integrated solution. We also extend RALM to RALM-II, which is compatible with transmission control protocol (TCP) traffic. We analyze the complexity of the proposed protocols in the network and investigate their performance through simulations. We show that our solution achieves significant performance gains with reasonable additional complexity. 相似文献
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随着互连网业务量的剧增,网络拥塞已经成为一个十分重要的问题。网络拥塞控制极大的促进了Internet的发展。本文指出了目前TCP/IP拥塞控制技术的不足,利用控制理论分析现有拥塞控制算法,并提出了解决拥塞控制的新思路,指出将来的工作方向。 相似文献
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XCP与TCP的拥塞控制算法比较分析 总被引:1,自引:1,他引:0
互联网用户数量激增,使得网络的拥塞问题变得越来越严重,拥塞控制是确保Internet鲁棒性的关键因素,因此拥塞控制问题成为目前关于Internet研究的难点问题.分析了传统的TCP拥塞控制算法存在一些不足,并对比分析了一种新的XCP拥塞控制算法.试验结果表明,XCP协议算法具有链路利用效率高、公平性好、可扩展性强、排队时延小的优点,并且路由器的开销也非常小. 相似文献
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网络的拥塞甚至崩溃是经常遇到的问题,它将严重影响网络的通信以至网络的应用。文章分析了在Internet上TCP/IP报文拥塞的原理,根据拥塞形成原理提出了通过拥塞控制抑制崩溃的策略,并提出了进一步的研究方向。 相似文献
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The Internet routers employing the random early detection (RED) algorithm for congestion control suffer from the problem of chaotic queue oscillation. It is well known that the slowly varying nature of the average queue size computed using an exponentially weighted moving average (EWMA) used in the RED scheme causes this chaotic behavior. This paper presents a new mathematical function to model the weighting parameter used in the EWMA. The proposed weighting function incorporates the knowledge of the dynamic changes in the congestion characteristics, traffic characteristics and queue normalization. Using this pragmatic information eliminates the slowly varying nature of the average queue size. It is evident from our simulations that the proposed approach not only reduces the chaotic queue oscillation significantly but also provides predictable low delay and low delay jitter with high throughput gain and reduced packet loss rate even under heavy load of traffic conditions. 相似文献
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TCP友好拥塞/速率控制算法及其在多媒体数据传输中的应用 总被引:4,自引:0,他引:4
基于Intenret的以UDP为传输协议的实时多媒体数据传输,需要在保证 实时性和可靠性基础上,能够与Internet其它服务所使用的TCP协议共享有限的带宽,基于这种需要,该文在研究了多种拥塞控制算法的基础上,提出了一种简单实用的TCP友好拥塞/速率控制算法,并将该算法应用在一个实用的Internet IP电话软FreePhone中,通过试验证明,该方法实用有效,并取得了预期的效果。 相似文献
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LI Yongli LIU Guizhong ZHANG Zhongwei & WU Chenggui . Department of Electronic Information Engineering Xi’an Jiaotong University Xi’an China . Beijing ZhongChuang Telecom Test Co. Ltd Beijing China Correspondence should be addressed to Li Yongli 《中国科学F辑(英文版)》2005,48(3):273-284
1 Introduction In the current Internet, not all applications use TCP and they do not follow the same concept of fairly sharing the available bandwidth. The rapid growing of real-time streaming media applications will bring much UDP traffic without integrating TCP compatible congestion control mechanism into Internet. It threats the quality of service (QoS) of real-time applications and the stability of the current Internet. For this reason, it is desirable to define appropriate rate rule… 相似文献
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奠石镁 《数字社区&智能家居》2008,(8):619-620
随着互联网规模的增长,互连网上的用户和应用都在快速的增长,拥塞已经成为一个十分重要的问题。近年来,在拥塞控制领域开展了大量的研究工作。此文介绍了基于TCP协议的拥塞控制算法的研究现状,分析了对算法改进的研究,并提出一些改进的建议。 相似文献
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《Computer Networks》2007,51(6):1684-1704
In this paper, we aim at developing an H∞ approach, from control-theoretic viewpoint, to the design of an active queue management (AQM) based congestion control algorithm for wireless networks supporting the Internet Protocol. We study networks in which the backbone is a traditional wired network supporting Internet TCP, while end user access is via wireless. First, a dynamic model for the congestion control problem of wireless networks is built up, which enables the application of modern control theory on time-delay systems to this problem. Second, an H∞ design approach for general time-delay systems is presented. Finally, the proposed approach is applied to the congestion control algorithm design of wireless networks, yielding an effective and systematic way for the design problem. Simulation results are provided to illustrate the design procedure and the effectiveness of the proposed method. Our design method is described by linear matrix inequalities (LMI), which can be solved very efficiently by LMI toolbox in Matlab. 相似文献