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.     

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.     

QoS maintenance for fair queueing algorithms in wireless mobile networks

In order to extend fair queueing algorithms to wireless networks, we propose a channel error and handoff compensation scheme. A compensation is performed by a compensation server and a priority swapping mechanism. The proposed compensation scheme provides a short‐term fairness guarantee for an error‐free session, long‐term fairness guarantee for an erroneous session, fast handoff and traffic‐specific quality of service control. Copyright 2002 John Wiley & Sons, Ltd.     

A new scheduling algorithm to provide proportional QoS in optical burst switching networks

A new scheduling algorithm, which aims to provide proportional and controllable QoS （Quality of Service） in terms of burst loss probability for OBS （Optical Burst Switching） networks, is proposed on the basis of a survey of QoS schemes in current OBS networks. With simulations, performance analysis and comparisons are carried out in detail. The results show that, in the proposed scheme, burst loss probabilities are proportional to the given factors and the control of QoS performance can be achieved with better performance. This scheme will be beneficial to the OBS network management and the tariffpolicy making.     

Joint relay selection and power allocation algorithm in two-way relay networks with proportional fair constraint

In this paper,we consider the joint relay selection and power allocation problem for two-way relay systems with multiple relay nodes.Traditionally,relay selection schemes are primarily focused on selecting one relay node to maximize the transmission sum rate or minimize the outage probability.If so,it is possible to cause certain relay nodes overloaded.In addition,the joint relay selection and power allocation problem is a mixed integer program problem and prohibitive in terms of complexity.Therefore,we pro...     

改进的正比公平调度算法

3GPP从R6版本开始,开展了对高速上行分组接入(HSUPA)技术的研究和标准制定工作。基于基站(NodeB)的调度算法是HSUPA的三大技术之一,对它的研究能有效地改善HSUPA系统性能,使系统的上行资源得以更充分的利用。在简述HSUPA中基于NodeB的典型调度算法的基础上,它针对用户的公平性给出了三种改进的正比公平调度算法,并在吞吐量和公平性上与典型调度算法进行仿真对比,仿真验证了当各个信道的衰落特性差别很大时,与正比公平调度算法相比,改进的正比公平调度算法有效地提高了用户的公平度,改善了系统性能。     

Solving the trade-off between fairness and throughput: Token bucket and leaky bucket-based weighted fair queueing schedulers

In this article, we present two efficient weighted fair queueing (WFQ) scheduling algorithms leaned on the well-known token bucket and leaky bucket shaping/policing algorithms. The performance of the presented algorithms is compared to those of the state-of-the-art WFQ approximations such as weighted round robin (WRR) and the recently proposed bin sort fair queueing (BSFQ). Our simulation results show that the proposed algorithms provide a better fairness at a lower implementation complexity while simultaneously achieving a comparable network utilization.     

Distributed proportional fair frequency allocation across multiple base stations

The problem of distributed proportional fair inter-cell frequency allocation for flat-structured cellular systems is studied in this paper. We firstly propose a framework of the frequency allocation in which the whole frequency allocation process is decomposed into many consecutive stages, then identify that for each stage the key is to find the Maximum Weight Independent Set (MWIS) in a given weighted conflict graph in the distributed manner. A new distributed algorithm for MWIS is described in which each node iteratively exchanges messages with neighbors. With this distributed MWIS algorithm, a new distributed proportional fair frequency allocation scheme is presented. The performance of the proposed algorithm is tested in computer experiments simulating the Long Term Evolution (LTE) cellular systems. Simulation results show the performance of the proposed distributed proportional fair frequency allocation scheme is comparable with the centralized ones.     

Distributed two‐hop proportional fair resource allocation in Long Term Evolution Advanced networks

In Long Term Evolution Advanced networks with Type I in‐band half‐duplex decode‐and‐forward relay nodes, proportional fair (PF) resource allocation is aiming at guaranteeing two‐hop match and optimising global proportional fairness. The two‐hop match is defined as equal data rates in the access links and the corresponding backhaul links. The global proportional fairness is between all the user equipments served by the evolved nodes B and the relay nodes. Existing centralised schemes achieve these targets at the cost of enormous channel state information (CSI) exchange. Existing distributed schemes focus on resource partitioning and employ a traditional single‐hop PF scheduling algorithm in access links, with less CSI exchange. The traditional PF scheduling algorithm maximises single‐hop proportional fairness between the data rates in the access links rather than two‐hop proportional fairness between the end‐to‐end data rates in the two hops. In order to reduce CSI exchange and at the same time to maximise the two‐hop proportional fairness, a distributed two‐hop PF resource allocation scheme is proposed. The proposed scheme includes two‐hop PF resource scheduling algorithms and adaptive resource partitioning algorithms, applied in different two‐hop transmission protocols. Simulation results demonstrate the proposed scheme is better than the existing distributed schemes in obtaining better proportional fairness and larger cell‐edge user equipment throughputs. Copyright © 2014 John Wiley & Sons, Ltd.     

Class‐based weighted fair queueing: validation and comparison by trace‐driven simulation

World‐wide web as well as proxy servers rely for their scheduling on services provided by the underlying operating system. In practice, this means that some form of first‐come‐first‐served (FCFS) scheduling is utilized. Although FCFS is a reasonable scheduling strategy for job sequences that do not show much variance, for the world‐wide web it has been shown that the requested‐object sizes do exhibit heavy tails. Under these circumstances, job scheduling on the basis of shortest‐job first (SJF) or shortest remaining processing time (SRPT) has been shown to minimize the total average waiting time. However, these methods have the disadvantage of potential job starvation. In order to avoid the problems of both FCFS and SJF we present in this paper a new scheduling approach called class‐based interleaving weighted fair queueing (CI‐WFQ). This scheduling approach exploits the specific characteristics of the job stream being served, that is, the distribution of the sizes of the objects being requested, to set its parameters such that good mean response times are obtained and starvation does not occur. In that sense, the new scheduling strategy can be made adaptive to the characteristics of the job stream being served. In this paper we compare the new scheduling approach (using trace‐driven simulations) to FCFS, SJF and the recently introduced α‐scheduling, and show that CI‐WFQ combines very good performance (as far as mean and variance of response time and blocking probability are concerned) with a scheduling complexity almost as low as for FCFS (and hence, lower than for SJF and α‐scheduling). The use of trace‐driven simulation is essential, since the special properties of the arrival process makes analytical solutions very difficult to achieve. Copyright © 2005 John Wiley & Sons, Ltd.