一种基于效用最大最小公平性的QAM资源分配算法

介绍一种基于IPQAM的接入网下行带宽扩容系统,并针对该系统中的QAM资源分配问题展开研究.将业务的带宽需求描述为带宽上下限和效用函数,以UMM(Utility Max-min,效用最大最小)公平性为研究目标,设计了一种新的单链路UMM公平分配算法.该算法与基于分段线性函数的算法相比,具有更高的计算精确度,而时间复杂度相似.基于该算法,在兼顾带宽利用率和效用公平性的原则下,设计了QAM频点选择算法和单频点带宽分配算法.仿真结果表明,本文的单链路UMM公平分配算法具有较高的精确度,并且,QAM频点选择算法使得多频点间公平性较好.     

基于Fibonacci的动态带宽分配算法

针对WiMAX系统中混合业务的特点,提出一种基于Fibonacci的动态带宽分配算法。介绍Fibonacci数列以及带宽调度的体系结构,对于实时轮询业务,在达到其能容忍的最大时延之前完成带宽分配。实验结果表明,与亏空公平优先队列算法相比,该算法能满足不同类型业务的QoS需求,提高系统吞吐量,且具有较好的服务公平性。     

基于区分服务的分组标记及队列调度策略研究

本文针对区分服务技术的原理和实现,对其体系结构进行分析,包括区分服务的基本原理、体系结构及其支持的服务,研究其实现IPQoS的各种控制策略,通过对分组标记算法的带宽分配公平性分析,提出相应的解决方案,分析SRTCM标记器的工作原理以及标记算法带宽分配公平性问题,通过仿真测试得到WRR调度各业务时,其带宽分配公平性问题。     

一种区分服务网络边缘路由器动态阈值的公平性标记算法

针对区分服务分组标记算法没有考虑到流特性,从而导致不同的流在带宽竞争中出现公平性较差的问题,提出了应用在网络边缘路由器上的一种基于动态阈值的三色标记算法DTTCM。该算法通过调整流速阈值minth和maxth,按照一定的策略对数据包进行标记,从而保证数据流在带宽不足时能公平地享受带宽。理论分析和仿真结果表明,DTTCM在UDP流与TCP流的带宽分配上,以及目标速率对于聚流间剩余带宽分配的影响上,均有着较好的公平性。     

支持用户SLA的高效DBA算法设计原则

EPON系统的动态带宽分配算法应当达到较高的信道利用率,同时保证业务的服务质量及公平性.分析了影响信道利用率的各种因素,提出将ONU分批交织以消除信道闲置,授权基于以太帧边界以消除授权时隙末的空闲,采用尽量大的轮询周期等三项措施,提高信道利用率.提出三种层次的公平性,主张保证用户间的公平性.提出为用户的各优先级业务分别授权、按SLA协议带宽比例授权,支持QoS的同时实现用户之间和优先级业务之间的公平性.遵照这些原则设计的算法可实现信道利用率的最大化,同时保证各种用户的服务质量.     

矿区EPON系统的DBA算法研究

文章在分析矿区EPON系统的特殊性和传统的动态带宽分配(DBA)算法不足的基础上,提出了一种适用于矿区EPON系统的改进DBA算法,详细分析了该算法的实现过程。实验结果表明,该算法实现了面向业务类型的动态带宽分配功能,同时兼顾了分配的公平性,保证了不同优先级业务的时延要求。     

TFRC与TCP流数之比对协议间公平性影响的研究

简要介绍了TCP Friendly的速率控制（TFRC）协议,通过仿真分析首次研究了TFRC与TCP流数之比对协议间公平性的影响。分析表明：在链路带宽较小时,无论比例如何,TFRC与TCP协议间的公平性都比较差,随着比值增大,协议间公平性得到改善;在链路带宽较大时,无论比例如何,协议间的公平性都较好,但随着比值增大,公平性能下降。     

平流层通信平台MAC层的调度方案建模及仿真

平流层升空平台能够满足可提供战时服务、能快速部署,适用于区域性覆盖.为满足平台支持的多用户、多优先权、综合业务的接入策略并解决资源动态分配问题.提出了一种可以满足平台MAC层的服务质量(QoS)和动态带宽分配的调度架构,架构包括移动中心站(MCS)对移动站(MS)的带宽分配和移动站内上行业务的二级带宽调度架构,并根据不同业务需求采用不同的调度算法.仿真结果表明:调度方案能很好的满足所有类型业务的服务质量需求.并提供了较好的公平性,保证了架构的可行性.     

Internet带宽分配的公平性研究

依据带宽分配的公平性原则可以实现网络资源的合理分配和利用，从而提高网络的服务质量。根据一广域网模型，介绍了带宽分配的最大－最小公平性和比例公平性，并采用效用函数方法设计了一种带宽分配的最优速率迭代算法。     

一种分层多描述编码的动态带宽分配策略

针对无线流媒体业务带宽资源有限的特点,提出一种基于分层多描述编码的动态带宽分配策略LMDBA.该策略利用了分层多描述编码的特性实现动态带宽分配,并采用QoS升降级策略,在保证用户QoS的前提下,尽可能地降低系统阻塞,提高系统带宽资源利用率.并对QoS升降级策略进行了公平性分析.仿真实验结果表明,在提供一定用户QoS保证下,提出的新策略比传统固定带宽分配策略在带宽资源利用率和系统阻塞上有显著的改善.     

一种ATM网络拥塞控制算法的仿真研究

该文讨论了一种基于随机控制理论的ATM网络拥塞控制算法,将该算法应用于带宽变化状态下ABR的拥塞控制问题研究。仿真结果表明：对于带宽变化的情况,该算法对交换机处排队长度有很好的控制效果,并且有很高的带宽资源利用率,同时能在各VCS间实现速率的公平分享。同时将该算法和ATM论坛的ERICA 算法进行了仿真和比较,仿真结果证明：采用该算法使得交换机队列长度、源速率、交换机输出能力波动平缓。该算法在控制队列长度及震荡、提高带宽的利用率以及实现速率公平性原则方面优于ERICA 算法。     

End-to-end bandwidth guarantees through fair local spectrum share in wireless ad-hoc networks

Sharing the common spectrum among the links in a vicinity is a fundamental problem in wireless ad-hoc networks. Lately, some scheduling approaches have been proposed that guarantee fair share of bandwidth among the links. The quality of service perceived by the applications however depends on the end-to-end bandwidth allocated to the multihop sessions. We propose an algorithm that provides provably maxmin fair end-to-end bandwidth to sessions. The algorithm combines a link scheduling that avoids collisions, a fair session service discipline per link, and a hop-by-hop window flow control. All the stages of the algorithm are implementable based on local information, except the link scheduling part that needs some network-wide coordination.     

Feedback-Based Adaptive Packet Marking for Proportional Bandwidth Allocation

Differentiated service (DiffServ) networks have been proposed to assure the achievable minimum bandwidth to aggregate flows. However, analyses in the literature show that the current DiffServ networks are biased in favor of ah aggregate flow that has a smaller committed information rate (CIR) when aggregate flows with different CIRs share a bottleneck link. In order to mitigate this unfairness problem, we propose an adaptive marking scheme which provides the relative bandwidth assurance in proportion to the CIRs of the aggregates. By introducing a virtual target rate (VTR) and adjusting it depending on the provision level of the network, each aggregate can obtain its fair share of the bandwidth, regardless of traffic load. This scheme is based on a feedback approach. It utilizes only two-bit feedback information conveyed in the packet header and can be implemented in a distributed manner. Furthermore, the proposed scheme does not require calculating fair shares of aggregates or any additional signaling protocol. Using steady state analysis and extensive simulations, we show that the scheme can provide aggregate flows with their fair shares of bandwidth, which is proportional to the CIRs, under various network conditions     

CSFQ算法的分析与改进

随着 Internet的迅猛发展 ,在 Internet中实现高效、公平、可扩展的业务流控制正变得日趋重要 .CSFQ ( Core-Stateless Fair Queueing)算法无需核心路由器为每一业务流保存状态但仍可实现相当程度的资源公平共享 .本文首先归纳总结了 CSFQ算法 ,然后给出了最大最小公平准则下公平共享速率的理想值、分析并揭示了 CSFQ算法存在的病态情形 ,最后对 CSFQ进行了改进 ,使得改进后的 CSFQ算法对公平共享速率的估算有了自适应机制及对因估算值偏小而丢弃的分组进行补救的机制     

分段式全带宽动态分配算法研究

为提高多业务分组系统的带宽利用效率,提出了一种分段式全带宽动态分配算法,该算法允许单业务流最大可用带宽超出其公平共享范围。分析和实践结果表明,在保持常规算法的带宽利用率、公平性和满足用户QoS指标的同时,该算法使有需求链路在系统处于非饱和状态时可占用全部剩余带宽(直至全带宽),显著提高系统的总带宽利用率。     

自适应带宽的最大-最小公平性拥塞控制

带宽共享和拥塞控制对于Internet的健壮性和公平性是很重要的研究课题.对交换设备中流量共享拥塞链路的带宽公平分配进行研究,提出一个优化交换设备带宽的设置算法:根据出端口接收速率自适应设置入端口带宽门限,对入端口的带宽进行动态重新分配,提高资源利用率.模拟实验表明,此算法有以下优点:1)高适应性;2)最大最小公平性;3)快速响应网络变化;4)高可靠性;5)稳定性.     

一种实用化接入段全带宽动态分配方案

针对接入段多业务非均匀突发性特点,提出了一种实用的全带宽动态分配方案,该方案允许单业务最大可用带宽超出其公平共享范围。分析和实践结果表明,在保证带宽利用率、公平性和满足用户QoS指标的同时,该方案可使有需求链路在系统处于非饱和状态时占用全部剩余带宽(直至全带宽),大大提高系统的总带宽利用率。     

Fair service for mice in the presence of elephants

We show how randomized caches can be used in resource-poor partial-state routers to provide a fair share of bandwidth to short-lived flows that are known as mice when long-lived flows known as elephants are present.     

Target bandwidth sharing using endhost measures

Recent congestion control protocols such as XCP and RCP achieve fair bandwidth sharing, high utilization, small queue sizes and nearly zero packet loss by implementing an explicit bandwidth share mechanism in the network routers. This paper develops new quantitative techniques for achieving the same results using only end-host measures. We develop new methods of computing bottleneck link characteristics, a new technique for sharing bandwidth fairly with Reno flows, and a new approach for rapidly converging to bandwidth share. A new transport protocol, TCP-Madison, that employs the new bandwidth sharing techniques is also defined in the paper. Experiments comparing TCP-Madison with FAST TCP, BIC-TCP and TCP-Reno over hundreds of PlanetLab and other live Internet paths show that the new protocol achieves the stated bandwidth sharing properties, is easily configured for near-optimal performance over all paths, and significantly outperforms the previous protocols.     

Integrating Priority with Share in the Priority-Based Weighted Fair Queuing Scheduler for Real-Time Networks

The Weighted Fair Queuing (WFQ) scheduler has been closely studied due to its desirable properties of bandwidth guarantee and bounded delay. However, the queuing delay bound of a communication session is tightly coupled with the session's allocated service share. To receive a low queuing delay, a session must reserve a high share. In this paper, we study a new fair queuing algorithm called Priority-based Weighted Fair Queuing (PWFQ). PWFQ combines a session's allocated share to achieve the bandwidth guarantee and the session's priority to adjust the delay bound inside a sliding window. The new algorithm decouples the delay from the service share so that a session with a low share but a high priority may still receive a small delay. We analyze the worst-case delay bound of PWFQ and propose a simple algorithm to assign session priorities.