基于带宽估计的ad hoc网络拥塞控制机制

针对ad hoc网络提出了一种基于带宽估计的拥塞控制机制.该机制通过实时的监测无线节点链路的工作状态,来估计节点的可用带宽,从而获得节点的拥塞程度指标,根据包的类型进行拥塞控制.由于带宽估计不需要与其他节点进行状态信息交换,降低了系统开销.同时拥塞控制机制缓解了无线网络的拥塞状态,提高了网络性能.     

一种基于市场模型的网络带宽分配方法

价格手段最近被用来控制网络拥塞和管理网络资源的分配,而价格手段的一个重要特点是可以促进资源的合理分配和利用。本文提出一种基于市场模型的网络带宽分配方法,该方法根据用户的宽带需求和网络系统带宽的使用状况,计算出网络带宽的市场价格,并通过用户有的价格参数进行带宽资源的协凋与分配,分析表明,该方法可以达到优化系统效率和提高用户满意度的目标。     

基于可用带宽测量的分层组播拥塞控制机制

针对现有的组播拥塞控制机制对接收端可用带宽估计精度较低的问题,提出了一种基于可用带宽测量的分层组播拥塞控制机制ABM-LMCC.在分析了现有可用带宽估计方法不足的基础上,提出一种适用于组播的可用带宽测量算法,并设计了分层组播拥塞控制机制的具体操作规程.通过调节组播数据包的发送间隔,使其呈现降速率的指数分布,从而实现各接收端对可用带宽的准确测量,并根据其测量值迅速调节期望速率,从而达到组播拥塞控制的目的.仿真表明,ABM-LMCC能够有效避免拥塞,提高链路利用率,显著降低丢包率,具有良好的响应性、稳定性.     

流媒体技术(8)

Intemet上使用最广泛的传输控制协议TCP最初并没有集成拥塞控制（congestion control）的功能。1986年，Intemet首次爆发了一系列“拥塞崩溃（congestion collapses）”事件。发生“拥塞崩溃”的链路可用带宽几乎降低为正常情况下的千分之一，TCP协议的设计者开始考察为什么会发生这样的情况。1988年，Jacobson和Karels在其经典论文《拥塞避免和控制》中首先提出了拥塞控制的概念，     

北京帧中继网上的Foresight技术

本文简介北京帧中继网中Foresight技术，内容包括Foresight的设计思想，前向拥塞控制和公平分配带宽原理。     

北京帧中继网上的Foresight技术

本文简介北京帧中继网中Ｆｏｒｅｓｉｇｈｔ技术，内容包括Ｆｏｒｅｓｉｇｈｔ的设计思想，前向拥塞控制和公平分配带宽原理。     

流媒体拥塞控制协议的研究

介绍了流媒体拥塞控制协议。一种分组传输速率按照连接的动态带宽分配进行调整的拥塞管理协议。并对协议的性能进行了较为全面的分析。     

TCP拥塞控制研究综述

系统深入地研究了TCP协议中的拥塞控制机制,TCP改进协议中研究最多的就是对TCP拥塞窗口调节机制的改进.从这个方面来看主要可以分为三种改进类型,即基于分组丢弃反馈的拥塞窗口调节方式;基于路径延时反馈的拥塞窗口调节方式;基于显式反馈和带宽测量的拥塞窗口调节方式.另外还针对无线网络的固有特性讨论了无线网络上TCP协议的一些改进方案.深入地分析了一些典型的算法,对它们的优劣做了详细的分析和总结,并提出了今后的一些研究方向.     

网格计算中的TCP拥塞控制

目前IP网络所应用的TCP拥塞控制机制是基于1988年Jacobson所设计的算法(慢启动和拥塞避免),虽然TCP在许多不同类型的网络中应用得很好,但在网格计算中,现有的TCP拥塞控制算法已不能有效工作。本文分析了TCP传统算法在网格计算中的缺陷,并提出在网格计算中使用新的TCP拥塞控制算法——一个新的带宽增减算法。     

一种基于带宽估计的战术互联网TCP改进机制

无线的战术互联网通常面临复杂的电磁环境,高误码率、终端的频繁移动等恶劣的通信环境使得针对有线网络设计的TCP协议传榆性能急剧下降.针对战术互联网提出了一种基于带宽估计的TCP改进机制,该机制利用TCP确认帧携带的数据包到达时间来估算带宽,并用动态的低通滤波器来平滑带宽的估计值.在此基础上用带宽的估计值更新拥塞窗口,避免在发生链路错误时启动拥塞控制机制,由此提高TCP在战术互联网中的性能.实验结果表明,该算法能减少链路差错对TCP性能带来的影响,提高TCP在战术互联网上的传输性能.     

Congestion detection based on rate and buffer occupancy measurements

Based on traffic simulation studies at an FDDI/BISDN gateway, this paper evaluates the relative merits of using rate and buffer occupancy measurements in the detection of congestion and the use of such measures to provide simple bandwidth management. In addition, a detection scheme based on using both rate and buffer occupancy measurement is recommended as it combines the advantages of both schemes and provides more reliable performance over a range of bursty traffic.     

A Bandwidth Control Method Providing Entrance QoS for Multimedia Communication

1 Motivation Nowadays , the QoS provided by the wideband IPnetwork starts at an edge-router and ends at anotheredge-router .Therefore ,the trunk QoSisfinished,suchas RSVP[1]and DiffServ[2].In order to complete theend-to-end QoS,the mechanism of entrance QoS (thebandwidth controller) is introduced. As Fig.1 shows ,if the bandwidth controller circledby the dashed frame is not used,the Ethernet is con-nected with the router directly through 100 Mbit/sbandwidth. Then this router is connect…     

Using TCP rate control for queue input‐output rate matching

In explicit TCP rate control, the receiver's advertised window size in acknowledgment (ACK) packets can be modified by intermediate network elements to reflect network congestion conditions. The TCP receiver's advertised window (i.e. the receive buffer of a TCP connection) limits the maximum window and consequently the throughput that can be achieved by the sender. Appropriate reduction of the advertised window can control the number of packets allowed to be sent from a TCP source. This paper evaluates the performance of a TCP rate control scheme in which the receiver's advertised window size in ACK packets are modified in a network node in order to match the generated load to the assigned bandwidth in the node. Using simulation and performance metrics such as the packet loss rates and the cumulative number of TCP timeouts, we examine the service improvement provided by the TCP rate control scheme to the users. The modified advertised windows computed in the network elements and the link utilization are also examined. Copyright © 2002 John Wiley & Sons, Ltd.     

无线多媒体网络中自适应拥塞控制算法的研究

提出了一种适用于采用无线接入多媒体流的拥塞控制算法,简称adaptive-MQWB(adaptivemediaQoSandwirelessbandwidth)。该算法依据当前带宽的动态变化率,在满足多媒体传输的最大时延的前提下,以最佳目标队长为实现目标,寻求最优的主动队列管理方案。仿真结果表明,与目前已有的MADR、tuned-RED算法相比,adaptive-MQWB算法在带宽动态变化的自适应性和多媒体传输时延的QoS保证方面都表现出更好的性能优势。     

DVB-RCS系统网络管理的分析与研究

简要介绍DVB-RCS卫星通信系统,着重讨论了网络管理在DVB-RCS系统中的作用,分析了卫星通信系统高效动态带宽资源分配、提高链路服务质量以及简化小站管理等方面的技术问题,以及网络管理系统在通信系统带宽利用率、服务质量保障等方面性能改善上的特殊贡献。     

Ant‐inspired level‐based congestion control for wireless mesh networks

The ever increasing presence of services over wireless networks utilizing large bandwidth necessitates the constant quest for developing efficient and dependable services, capable of providing support to a wide and variety of applications. Wireless mesh networks can provide such reliable and scalable solutions addressing the requirements of the services utilizing large bandwidth. The current focus is on the interesting and challenging issue of channel access for different services with assured bandwidth guarantees. The problem of bandwidth, constantly encountered by the wireless mesh networks, is studied in this paper with due thrust on the issues pertaining to congestion control mechanisms. A novel ant colony‐based approach called ant‐inspired level‐based congestion control (AILCC) is developed in order to effectively manage the issues of bandwidth. The versatility of the AILCC includes its capacity for service differentiation in addressing a range of requests, such as applications of real‐time and nonreal‐time. The primary focus of AILCC is on providing an efficient congestion control mechanism that can meet numerous bandwidth demands of various applications. The performance of AILCC in terms of the ratio of packet delivery and end‐to‐end delay is evaluated through relevant simulations. The results obtained demonstrate greater levels of performance of AILCC over the other methods in existence. Copyright © 2014 John Wiley & Sons, Ltd.     

基于星上处理的卫星ATM中ABR 业务拥塞控制算法研究

卫星ATM是近年来通信领域的研究热点,拥塞控制是其中很关键的一个问题.本文主要研究基于星上处理的卫星ATM网的ABR流量控制,它通过对流量的长时预测来达到控制目的.由于卫星信道的大延时,无法实现精确的长时预测,因而将预测结果直接用于ABR的拥塞控制效果不甚理想.将长时预测同动态利用因子控制的方法结合之后,在链路效率、信元丢失率、不同连接数目和暂态响应等方面都取得很好的结果.     

基于显式速率的TCP友好的UDP拥塞控制策略

本文提出了一种基于显式速率的UDP拥塞控制策略：通过源端和网络中的路由器相互配合，使得实时UDP应用能够根据网络的反馈以瓶颈链路的公平带宽为速率发送数据。此种控制策略对TCP应用是友好的，并且提高了网络的吞吐量和利用率。仿真结果表明：基于显式速率的UDP拥塞控制策略与采用TFRC(TCP—Friendly Rate Control)的UDP拥塞控制策略相比，在吞吐量、TCP友好性等方面性能有较大提高。     

Adaptive ABR congestion control with active buffer control

ATM Forum has defined that the ABR service is designed mainly for data traffic. The design of a simple and efficient congestion control scheme is a problem that network managers have to face. In this paper, we propose a control scheme for ABR service for better scalability and response. The scheme uses both the load level and an increase in queue length to detect the presence of congestion. Continuous control functions are designed for the bandwidth allocation. A better buffer control is achieved by incorporating the percentage of buffer occupancy into the control function. All of the control functions are designed in such a way that they are sensitive to the change of the system states when they are far from the optimal level to get a fast response, but insensitive and change slowly when the states are close to the optimal level to keep the system around the steady state. Our simulation results show that the algorithm is fair to all the connections and it converges fast when the network's condition changes. Copyright © 2001 John Wiley & Sons, Ltd.     

可用带宽的变时隙探测算法研究

目前基于自拥塞理论的网络可用带宽主动探测方法,一般都要发送大量的探测包串,在对网络可用带宽进行探测的同时,可能会干扰网络的正常通信。这一方面增加了网络负载,另一方面也增加了算法的复杂性。针对此问题,提出使用幂级数变时隙探测包替代等时隙探测包,期望通过新的探测方法在不失估测精度的前提下,用更少的探测流量获得更快的自拥塞集聚时间,从而提高可用带宽的探测效率。实验表明新的探测算法可以达到比传统算法更好的效率。