共查询到19条相似文献,搜索用时 156 毫秒
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基于TCP的拥塞控制技术研究 总被引:1,自引:0,他引:1
就数据流在拥塞控制方面的发展进行了研究,在介绍TCP基本机制的基础上,对TCP拥塞控制的改进机制进行了讨论,探讨了网络拥塞出现的原因及TCP拥塞控制的基本策略,论述了TCP拥塞控制的改进方案,并提出了其进一步的研究方向。 相似文献
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在网络拥塞控制的重要参数中,RTT(Roundtriptime)尤为突出,因为它能对网络所发生的拥塞作出较早的反映。所以对RTT的精确预测程度,无论是对网络拥塞控制还是流量、带宽估计都很有意义。分析了RTT的特性,发现其有很强的高频噪声,因而采用低通滤波和MBP网络相结合的RTT预测策略。实验表明,即使在网络状况较忙的情况下,也能获得很好的预测结果。 相似文献
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在学校的选课系统中,如果多名学生同时选择同一门课程,这种瞬时增大的数据流量流动的倾向会造成数据的分布均匀性较差。传统的校园网络选课系统多是基于CS结构,如果服务器数据源节点动态传输数据过于集中,会造成瞬时数据量猛涨,导致选课网络信道发生拥塞现象,选课数据无法及时传输到终端,造成选课系统存在较大延迟。为了解决上述问题,提出了一种基于流量预判算法的校园网络选课系统的拥塞控制策略,通过获取数据流量分布情况,进行流量参数估计;通过流量预测,判断信道流量拥塞程度,从而实现校园网络的拥塞分流控制。实验证明,这种基于流量预判算法的拥塞控制方式提高了校园网络选课速度,取得了令人满意的效果。 相似文献
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随着计算机网络技术的发展,用户对网络资源访问速度的要求越来越高.特别是近些年语音、图像以及视频等多媒体数据大量出现在互联网上,网络的拥塞问题也变得日益严重,拥塞控制对于保证网络的稳定性也具有非常重要的作用.本文提出了一种改进的MPTCP自适应拥塞控制算法,将权值动态调整策略融入拥塞控制中.算法的核心思想是当某一路径接收到数据包则增加其权值,相反如果丢失了数据包则降低其权值,修改权值时综合考虑了前一个时刻该路径的权值及其拥塞窗口的大小.仿真实验结果表明,本文提出的MPTCP拥塞控制算法改进方案有效地提高了系统的吞吐量,并且能够使得网络资源得到公平的利用. 相似文献
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无线传感器网络的拥塞控制技术是这一领域研究的重要方向之一.传感器网络的特点决定了网络容易发生拥塞.传统有线网络的拥塞控制技术不适用于传感器网络.本文对于当前的拥塞避免,拥塞检测和拥塞解除策略进行了分析和比较,并且对于拥塞控制技术的研究和发展方向进行了展望. 相似文献
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在网络拥塞算法研究中,IP层实现的主动队列管理已经成为一个研究的热点。将无模型自适应方法应用到主动列队管理中,并进行了与PI控制的比较研究,仿真结果说明,无模型自适应控制比PI控制更快更稳定地达到平衡点,说明无模型自适应控制在网络拥塞控制具有较好的适应性。 相似文献
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《Journal of The Franklin Institute》2022,359(14):7233-7261
This paper addresses the tracking control problem of TCP/AWM network systems in presence of nonresponsive data flows of category user datagram protocol (UDP) flows. Firstly, a modified network system model is established by a certain suitable variable transformation, and then a fuzzy logic system (FLS) emulator is used to approximate the nonlinear terms in the network dynamics representation system. Secondly, inspired by the idea of the prescribed performance control (PPC), a novel finite-time performance function (NFTPF) is proposed. In turn, an adaptive finite-time congestion control strategy is designed by compatible usage as appropriate of a barrier Lyapunov function (BLF), the backstepping control synthesis, and an event-triggered mechanism. The proposed control strategy can not only make the tracking error to satisfy the pre-assigned transient and steady-state performance, but also ensure that all the closed-loop signals remain semi-globally uniformly ultimately bounded (SGUUB). In addition, the designed congestion control strategy eliminates potential occurrence of Zeno behavior. A set of simulation results are presented to clarify the feasibility and effectiveness of proposed methodological approach and the designed congestion controller. 相似文献
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主动队列管理(Active Queue Management,AQM)拥塞控制领域的研究热点,对提高网络服务质量很重要。为了解决现有AQM算法在稳定性、环境敏感性等缺陷和对网络模型的复杂性难题,研究者纷纷尝试把控制理论引入到主动队列管理技术中。主要围绕基于模糊控制的AQM应用研究进行了分析。 相似文献
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王峻 《科技成果管理与研究》2008,(12):75-77
移动网络视频传输控制技术的关键问题是如何避免拥塞,并在丢包存在的情况下尽可能提高视频质量。文章基于无线网络平台,为了保证解码端的正确执行,使用了一些传输控制技术来减少传输错误造成的影响,并基于RTCP/RTP协议研究一些视频传输中的关键问题如误差掩盖、差错控制和速率控制等,针对视频传输中的速率控制问题分析了几种方法和思路。 相似文献
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《Information processing & management》2023,60(2):103236
Pedestrian congestion can negatively impact how visitors perceive tourist destinations, as well as turn local residents against the tourism industry. In this sense, urban planning and management principles derived from smart tourism can be enriched by applying suitable spatial analytical tools to monitor flows and congestion. This study puts forward a methodology integrating emerging geospatial data sources into a GIS environment to analyze pedestrian flows through the city of Palma. The information was obtained from devices’ geolocation data captured by the free Wi-Fi network (Smart Wi-Fi) during 2019 in the city of Palma, Spain. In order to calibrate the method, fieldwork was undertaken to count individuals in situ; this information was then contrasted with the raw data provided by the network. The study also assesses congestion in areas based on walkable space and the number of recorded devices. The results show different mobility patterns, which highlight several overloaded and congested areas within the city. The developed methodology demonstrates the usefulness of the method in providing support to decision-making in tourism management, as well as promoting sustainability in tourist destinations. 相似文献
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《Journal of The Franklin Institute》2022,359(11):5302-5321
This paper investigates the resilient sliding mode control problem for cyber-physical systems (CPSs) with multiple transmission channels under denial-of-service (DoS) attacks. A set of finite-time observers is designed, and a switched integral-type sliding surface is introduced. Thus, the impact of unreliable state estimating channels is reduced, and the disturbance rejection performance is also improved. The number of linear matrix inequalities (LMIs) decreases compared with some existing results in designing the observer-based controller, and the input-to-state stability (ISS) is guaranteed. Moreover, the input saturation and event-triggering scheme are considered in the controller and handled by an auxiliary system. The network congestion in the control channel is thus relieved, and the Zeno behavior is excluded simultaneously. Finally, an example of an unmanned stratospheric airship is given to demonstrate effectiveness of the proposed resilient control approach. 相似文献
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网络购物模式在我国已趋于成熟,购物网站在平日的运作、服务中也已游刃有余。但是在遇到节庆促销活动中的集中购物时段,或是特殊时期购物用户集聚性出现时,还是会呈现出网络拥挤、系统配置不合理、消费者权益得不到保障、快递配置不均衡等问题。只有解决了这些问题,才能保障我国网络市场的健康繁荣发展。 相似文献