WiMAX系统的自适应实时带宽调度策略

提出一种自适应的实时轮询业务带宽分配机制,SS依据当前带宽需求和以往的实际分配带宽,提前预测实时业务数据包所需求的确切带宽,文中给出了数学分析模型和仿真,仿真结果表明,与传统的带宽分配机制和Mukul提出的自适应算法相比,该自适应带宽分配算法能更好地改善系统性能,提高吞吐量,减少时延和减少缓冲区需求.     

多重链路时延优化动态可用带宽分配算法

为了优化多重链路多业务环境下的时延,首先分析了带宽分配及链路中数据传输时延计算方法,提出一种时延优化的动态可用带宽分配算法(DODBA)。该算法基于不同优先级业务的时延比较实现了剩余可用带宽的重新分配。仿真实验证明了DODBA的有效性,能控制各链路不同业务的时延,并提高了系统带宽资源的利用率。DODBA可用于解决大型宽带网络接入控制中的实际问题。     

业务质量约束下最大化收益的HFC频点带宽分配方法

HFC频点带宽的分配是广播电视网络业务提供系统的一项关键技术,直接决定了系统的整体收益.描述了HFC频点带宽资源分配面临的问题,提出基于业务收益函数的频点带宽分配方法.在分析广电网络视频点播、时移电视和高速下载三种典型业务特性的基础上,给出了它们的收益函数,提出了一种基于边际效益的贪婪算法以完成资源的分配.该算法在保证业务质量满足最低要求的基础上,按照各类业务的实际需求分配可用的频点带宽,使系统的收益最大.仿真试验验证了该算法的有效性.     

考虑波束间干扰的多波束卫星功率带宽联合分配算法

多波束卫星通信系统由于频率复用导致波束间存在干扰。为此,通过引入干扰系数,构建带宽功率联合分配模型,将该资源分配问题拆分为功率分配、带宽分配和对偶变量更新3个子问题,并提出相应的分配算法。算法在初次完成功率以及带宽分配后,利用子梯度算法更新对偶变量,对功率和带宽进行再分配,如此进行迭代计算,直至满足对偶变量收敛条件,由此实现分配结果的最优。仿真结果表明,与功率和带宽均匀分配算法及按比例分配算法相比,该算法在明显降低系统二阶业务拒绝量的同时,提高了系统容量。     

WLAN与EPON融合接入网上行带宽分配算法

为了提高带宽的利用率,提出一种WLAN与EPON融合接入网上行带宽分配算法。该算法将无线终端接入的业务分为不同的服务等级,以实现不同业务Qo S保证。首先,ONU-AP给各个无线终端STA分配带宽,采用IEEE 802.11E协议的简单调度算法给语音业务和一般数据业务分配带宽,利用视频流的平均速率估算视频业务的传输带宽。其次,光线路终端OLT给各个ONU-AP分配带宽,OLT根据语音业务速率和当前视频业务流量分别估算语音、视频业务在下一个轮询周期的带宽,并将剩余带宽在重负载终端中二次分配,最后给一般数据业务分配带宽。通过仿真实验,结果表明:与传统算法相比,该算法的网络时延和丢包率明显降低,实现了带宽资源的合理分配。     

基于WiMAX的实时业务带宽优化调度策略

WiMAX是一项无线城域网(WMAN)技术,支持实时与非实时等多种业务,SS可以向BS动态申请所需求的带宽,由IEEE 802.16协议定义.但协议中没有具体定义实时服务QoS所需要的带宽调度策略.因此,如何高效地分配使用带宽,成为一个亟需解决的问题.本文提出一种自适应的实时轮询业务带宽分配策略,SS依据当前带宽需求和以往的实际分配带宽,提前预测实时业务数据包所需求的确切带宽.文中给出了数学分析模型和仿真.仿真结果表明,与传统的带宽分配机制和其他自适应算法相比,该自适应的带宽分配算法能更好地改善系统性能,提高吞吐量,减少时延和减少缓冲区需求.     

SDN架构下基于优先级的带宽保障算法研究

针对SDN构建的数据中心,互联网出口带宽无法同时满足所有业务的带宽需求,提出一个基于优先级的带宽保障算法,在满足高优先级业务带宽需求的情况下再满足低优先级业务的带宽需求,保障带宽资源的合理分配。测试结果表明,相比于没有采用带宽保障算法的模拟数据中心,基于优先级的带宽保障算法能确保高优先级业务在总体带宽资源不充足情况下保障业务质量。     

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。     

一种面向业务的动态带宽分配方法

在分析传统QoS业务模型以及传统动态带宽分配方法（DBA）的基础上,提出一种面向业务的动态带宽分配算法。该算法吸取了各种QoS业务模型及传统动态带宽分配方法的优点,充分考虑了不同业务服务质量对带宽分配要求的差别以及带宽资源的利用率,仿真结果表明这种方法更加有效。     

一种优化的EPON动态带宽分配算法

EPON是基于以太网的无源光网络技术,目前以太网技术在局域网技术中应用最广泛。动态带宽分配算法作为EPON的关键技术之一,对提高系统服务质量,改进EPON系统时延等性能指标有着重要意义,为研究的热点。本文对已有DBA算法进行优化,算法思想为先将数据流进行分组,在两层动态带宽分配算法的基础上迭加根据各分组业务的权重优先级进行比例分配算法,并尝试引入预估计机制。仿真结果可以看出改进后的算法在系统带宽利用率、等待时延和服务质量上都能得到一定程度的优化。     

基于公平服务多维加权轮询调度的IPTV组播流量控制策略

根据大规模接入汇聚路由器（ACR)的总体技术规范,IPTV组播复制在ACR的以太网分合路器（EMD)中进行,而IPTV组播业务的增长会对其他业务造成冲击,因此需要对IPTV组播流量进行控制,以保证其他业务的带宽分配,针对IPTV流量控制中的关键环节──队列调度,提出了一种公平服务多维轮询调度策略(FSMWRR),性能仿真的结果表明该调度策略能够满足IPTV业务的低时延、时延抖动的需求,同时保证各个业务带宽分配的公平性。     

云环境下基于SLA的优化资源分配研究

针对云计算环境下如何高效分配资源,实现资源供应者利润最大化这一难题,提出了一种基于服务级别协议（SLA）的动态云资源分配策略。该策略通过将SLA中的计算力、网络带宽、数据存储等属性作为优化参数,构造了一种服务请求与资源的映射模型,同时设计相应的效用函数,并结合改进的与模拟退火算法相融合的混合粒子群算法（SA-PSO）,实现云环境下的优化资源分配。实验分析结果表明,基于SLA参数的SA-PSO算法具有更好的全局最优值,在给定虚拟资源相同情况下,调用该算法完成用户任务实现的利润更高。     

A new approach to dynamic bandwidth allocation in Quality of Service networks: Performance and bounds

Efficient dynamic resource provisioning algorithms are necessary to the development and automation of Quality of Service (QoS) networks. The main goal of these algorithms is to offer services that satisfy the QoS requirements of individual users while guaranteeing at the same time an efficient utilization of network resources.In this paper we introduce a new service model that provides per-flow bandwidth guarantees, where users subscribe for a guaranteed rate; moreover, the network periodically individuates unused bandwidth and proposes short-term contracts where extra-bandwidth is allocated and guaranteed exclusively to users who can exploit it to transmit at a rate higher than their subscribed rate.To implement this service model we propose a dynamic provisioning architecture for intra-domain Quality of Service networks. We develop a set of dynamic on-line bandwidth allocation algorithms that take explicitly into account traffic statistics and users’ utility functions to increase users’ benefit and network revenue.Further, we propose a mathematical formulation of the extra-bandwidth allocation problem that maximizes network revenue. The solution of this model allows to obtain an upper bound on the performance achievable by any on-line bandwidth allocation algorithm.We demonstrate through simulation in realistic network scenarios that the proposed dynamic allocation algorithms are superior to static provisioning in providing resource allocation both in terms of total accepted load and network revenue, and they approach, in several network scenarios, the ideal performance provided by the mathematical model.     

基于QoS和吞吐量公平的信道分配算法

高密度接入点(AP)部署会导致AP工作信道重叠,从而较大地影响无线局域网的吞吐量。为此,在IEEE 802.11e分析模型的基础上,考虑AP受相邻AP干扰造成的吞吐量衰减,引入Jain指标衡量基础服务集(BSS)间系统吞吐量的公平性,在满足最大公平性和最小信道干扰的限制条件下,提出一种基于最小生成树的信道分配算法CAQFT。数值分析结果表明,CAQFT算法能满足BSS内业务的服务质量需求,提高整个系统吞吐量并兼顾BSS间系统吞吐量的公平性。     

Dynamic bandwidth allocation for 3G wireless systems—A fuzzy approach

3G Wireless systems are to support multiple classes of traffic with widely different characteristics and quality of service (QoS) requirements. A major challenge in this system is to guarantee the promised QoS for the admitted users, while maximizing the resource allocation through dynamic resource sharing. In the case of multimedia call, each of the services has its own distinct QoS requirements concerning probability of blocking (P_B), service access delay (SAD), and access delay variation (ADV). The 3G wireless system attempts to deliver the required QoS by allocating appropriate resources (e.g. bandwidth, buffers), and bandwidth allocation is a key in achieving this. Dynamic bandwidth allocation policies reported so far in the literature deal with audio source only. They do not consider QoS requirements. In this work, a fuzzy logic (FL)-based dynamic bandwidth allocation algorithm for multimedia services with multiple QoS (P_B, SAD, ADV, and the arrival rate) requirements are presented and analyzed. Here, each service can declare a range of acceptable QoS levels (e.g. high, medium, and low). As QoS demand varies, the proposed algorithm allocates the best possible bandwidth to each of the services. This maximizes the utilization and fair distribution of resources. The proposed allocation method is validated in a variety of scenarios. The results show that the required QoS can be obtained by appropriately tuning the fuzzy logic controller (FLC).     

HFC网络的缓冲区管理和分组调度联合算法

以HFC网络为背景,针对嵌入式设备的存储资源有限性、网络带宽有限性以及宽带网络中多业务流的特点,提出一种缓冲区管理和分组调度联合算法.该算法通过控制业务流队列长度和设置业务流优先级方程的方式来管理缓冲区和带宽的分配,使内存管理和分组调度协调配合,从而为不同类型的网络数据提供区分服务.通过测试,在本文的仿真设置下,当网络资源紧张时,使用该算法后,可以达到实时业务流的超时数据比未使用该算法时的超时数据少89.6%的效果;而非实时业务流也可以达到平均丢包率比不使用该算法时的平均丢包率低90%的效果.     

Seamless channel transition for slotted generalized fibonacci broadcasting

Periodic Broadcasting schemes are cost- effective methods of implementation of Near Video on Demand systems. While the schemes enjoy the advantage of reducing the demand on server bandwidth, they suffer from the problem of insensitivity to the popularity of videos. However, the popularity of a video does not remain constant in the real world; it varies with time, social events, and so on. From a service provider’s viewpoint, given a set of popular videos and limited server bandwidth, it would be desirable to adjust the bandwidth allocated to each of the videos dynamically and seamlessly according to the level of its hotness. In this paper, we first re-formulate the Generalized Fibonacci Broadcasting as the Fixed-Length Segment- Scheduling problem and name the re-formulated scheme the Slotted Generalized Fibonacci Broadcasting (SGFB). We then propose a seamless channel transition enhancement on top of the SGFB scheme so that the service provider is capable of adjusting the channel allocation policy to make the most benefit out of the available bandwidth. The correctness of SGFB together with its performance analysis will be presented. Furthermore, we shall provide mathematical analysis to demonstrate its channel transition behavior. This work is partially supported by NSC-94-2213-E-260-024.     

A Scalable Pricing Model for Bandwidth Allocation

In this paper, we present a scalable pricing model for dynamic bandwidth allocation. Using simulation we demonstrate that service providers can achieve increased revenue as well as better resource utilization without compromising user specified levels of Quality of Service (QoS). Our model allows for increasing the revenue while maintaining an acceptable level of QoS, this is done by selecting an appropriate bandwidth allocation policy, to reduce the number of blocked users.     

ATM网络中ABR业务的带宽分配算法研究

在ATM网络(异步转移模式)中,ABR(可用比特速率)业务主要面向数据通信服务,ABR带宽利用率的高低与所采用的带宽分配算法有密切的关系。文中介绍了ABR业务中带宽分配的一般性原则,并讨论了一种新的带宽分配算法。