802.11WLAN中一种基于循环队列的分布式公平队列调度算法

该文在无线局域网现有的802.11 MAC层访问机制的基础上,运用循环队列的思想提出了一种完全分布式的队列调度算法,该算法通过修改802.11的MAC层中的DCF(Distributed Coordination Function)子协议,实现了在分布式环境下控制802.11节点的公平访问无线链路资源的目的。文中通过仿真对算法进行了分析和研究,仿真结果表明该方法可以在一定范围内实现公平队列调度。     

IFQ:一种新的ATM网络业务调度算法

本文提出了插空公平公队列（ＩＦＱ）调度算法。由于该方法考虑了ＡＴＭ网络中不同种类连接的特性,能充分利用网络资源。理论分析和仿真实验表明,ＩＦＱ算法能为Ｇ连接提供预约带宽保证和确定的时延上界,满足业务的实时传输要求。同时ＩＦＱ调度算法还具有连接独立性特点,能灵活地分配带宽资源。     

一种基于帧的快速包调度算法

本文提出了基于帧的近似排序包调度新算法（FASFQ）,该算法用帧排序代替传统的包排序来处理G连接（预约带宽的连接）数据,并在帧与帧之间的空隙传送E型（best offort型）数据。理论分析和实验结果都表明,FASFQ算法与传统算法相比,在大大降低了排序复杂的同时,还能为G连接提供预约带宽,保证连接的独立性和公平性,避免E连接对G连接的冲击。     

一种改进的公平分享调度算法

调度算法是操作系统处理的核心任务之一.在仔细分析Linux调度算法以及公平分享调度算法FSS的基础上,针对Linux现有调度算法的不足,结合原有公平分享调度算法提出了一种改进的公平分享调度算法UTRS,并通过实验数据证明了算法在用户公平调度上的有效性.     

一种支持服务类别的无线公平调度算法

本文提出了一种支持服务类别的无线公平调度算法:CoSB－WFS(基于服务类别的无线公平调度).算法区分不同的服务类别并可根据其业务需要进行不同的调度.考虑到无线信道的特殊性,算法引入了补偿和再分配模式.在仿真工具OPNET上模拟了算法并得到了性能改良的结果.     

一种基于预测式公平队列调度算法的802.11e MAC层机制

在共享媒体的通信系统中,队列调度的公平性是很重要的。该文在研究了IEEE WLAN已有的各种队列调度算法的基础上,提出了一种预测式公平队列调度算法 (Predict Fair Queuing, PFQ),并结合IEEE 802.11e的EDCF(Enhanced Distributed Coordination Function)机制提出一种基于PFQ的新的MAC层协议P-EDCF(PFQ-based EDCF)。该协议通过引进PFQ算法来修改EDCF的优先级控制方式,提供一种公平、高效的接入机制。仿真结果表明,该机制很好地改善了EDCF的性能,为各种类型业务提供了公平的服务。     

一种基于延迟的队列调度实现

PQBEDF算法是一种将优先级和时延相结合的动态优先级调度算法,具有快速高效的特点。对PQBEDF算法进行了研究,对其实现过程进行了改进,并给出了具体实现方法,同时对队列长度和优先级之间的关系作了分析。改进后的算法简化了操作,避免了PQBEDF算法中优先级可能相同的不合理现象,提高了算法的鲁棒性。另外,改进后的算法在公平性上也有所提高,不仅满足高优先级业务对带宽和时延的要求,对低优先级业务也有一定的保障,为各业务提供既有一定保证又有所区别的服务,具有一定的公平性和合理性。     

一种按比例补偿的无线公平调度算法

该文提出了一种按比例补偿的无线公平调度算法,算法区分不同的服务类别并可根据其业务需要进行不同的调度。考虑到无线信道的特殊性,算法引入了补偿和再分配模式。其中补偿模式采用了针对滞后流按照其预约速率的固定比例进行补偿的方式。     

基于离散预约速率与分组长度组结构的高速路由器公平队列调度算法实现

本文提出一种基于离散预约速率与分组长度组单元的公平隐列调度器实现结构,该结构可根据不同预约速率需求,为其方便灵活的提供不同的预约带宽实现精度。组单元的模块化设计结构与流水线设计技术使得硬件逻辑资源得到更有效的利用。文中同时提了一种适用于结构的定点时标重构技术,利用该技术可有效节约存储流时标的所需的外部存储空间,算法仿真与FPGA综合结果表明,该结构可支持1．2Gbit/s 的输出链路,通过有效的集成方式,该设计可进一步应用到端口速率为OC－48（2．4Gbps)的高速路由器中。l     

一种HSDPA系统中依赖负载的正比公平调度算法

研究和仿真了HSDPA系统中分组调度算法(RR,Max C/I和PF)的系统吞吐量和用户公平性,仿真结果与理论分析表明在HSDPA系统中RR算法调度结果的公平性略逊于PF算法.为了补偿正比公平调度算法公平性,提出了依赖负载的正比公平(LDPF)调度算法.该算法旨在通过低负载时牺牲系统吞吐量换取用户间公平性.然后用扩展了爱立信EUPLANE模块的NS2网络仿真软件对LDPF算法进行了仿真.仿真结果表明LDPF调度算法在系统低负载时有效地补偿了先前的低速率用户,通过这种低负载和高负载时的时间分集,改善用户间的长时公平性.     

A Distributed Fair Queueing (DFQ) Architecture for Wireless ATM Local Access Networks

The application of Asynchronous Transfer Mode (ATM) to a Wireless Local Area Network (WLAN) environment is an undertaking that poses many problems not encountered in either wireline ATM or data-only WLAN. Wireline ATM networks do not have to transmit over multiple-access, unreliable transmission media while data-only WLANs do not have to satisfy heterogeneous Quality of Service (QoS) contracts for multimedia services. To address this issue, we propose in this paper a DFQ-based WLAN architecture, designed as a centrally controlled network where a complex base station polls simpler mobile terminals for channel access.DFQ is an implementation of Fair Queueing (FQ) algorithm to schedule the access to the transmission channel among the mobile terminals. The implementation of DFQ introduces new design challenges, mainly in the packet scheduler. A DFQ scheduler is designed to allow fast and efficient processing of scheduling data. The DFQ algorithm is introduced and simulated for delay-sensitive connections, and the hardware implementation of the packet scheduler is discussed.The Centre for Wireless Communications is a national R&D Centre funded by the Singapore National Science and Technology Board     

A Unified Architecture for the Design and Evaluation of Wireless Fair Queueing Algorithms

Fair queueing in the wireless domain poses significant challenges due to unique issues in the wireless channel such as location-dependent and bursty channel errors. In this paper, we present a wireless fair service model that captures the scheduling requirements of wireless scheduling algorithms, and present a unified wireless fair queueing architecture in which scheduling algorithms can be designed to achieve wireless fair service. We map seven recently proposed wireless fair scheduling algorithms to the unified architecture, and compare their properties through simulation and analysis. We conclude that some of these algorithms achieve the properties of wireless fair service including short-term and long-term fairness, short-term and long-term throughput bounds, and tight delay bounds for channel access.     

The Effects of Filtered Channel Quality Feedback on Throughput of Proportional Fair Algorithm

1　IntroductionSchedulingalgorithmsarewidelystudiedforwirelesspacketdatasystems,whichgenerallyhavetwobasiccategories,oneisoptimizedforsystemthroughputandfairness[1～ 2 ] ,andtheotherisforthequalityofservice[3～6] .Forsystemswherepack etdataaretimedivisionmultiplexedacrossusersonthedownlink ,orfromBaseStation (BS)tomultipleMobileStations(MS) ,theBSusesschedulingalgo rithmstodecidewhichuseristransmittedto .ItisindicatedinRefs.[7,8]thatschedulingonlyoneus eratatimeisoptimalfromthepointofviewo…     

ATM公平排队服务算法

异步转移模式ＡＴＭ作为一种新的交换和复接体制，已经被国际电联ＩＴＵ挑选为宽带综合业务数字网Ｂ－ＩＳＤＮ的核心技术。ＡＴＭ技术的主要目的是使数据业务、视频业务、话音业务等能在统一的全数字网络中实现传输和交换，同时提供灵活简捷有效的动态资源分配。文章在说明通信业务各自千差万别特征的基础上，进行业务归类，并给出几种公平排队服务算法。     

Improved proportional fair dynamic subcarrier allocation with frugality constraint for SC-FDMA system

With the objective of taking full use of channel resource, we proposed two utility based dynamic subcarrier allocation (DSA) algorithms for the single carrier frequency division multiple access (SC-FDMA) system, which are the proportional fair frugality constrained (PF-FC) algorithm and the weighted proportional fair frugality constrained (WPF-FC) algorithm. The two proposed algorithms are designed under the frugality constraint (FC) control consideration so as to avoid service rate waste and improve the spectrum efficiency. Moreover, the queuing buffer model in this paper is established on a finite size structure rather than the traditional infinite queuing manner, which is more consistent with the practical transmission condition. Simulation results indicate that the two proposed algorithms can both achieve significantly better system rate-sum capacity and quality of service (QoS) performance than their primary algorithms, and are more applicable for the heterogeneous traffic.