多业务IP网络呼叫接纳控制模型和算法

呼叫接纳控制(CAC)是多业务IP网络QoS的关键技术。文章主要研究在采用多协议标记交换(MPLS)传送机制的区分服务(DiffServ)网络中引入带宽代理(BB)资源管理实体条件下的呼叫接纳控制模型和算法。文章在分析比较三类常用呼叫接纳控制技术的基础上,提出了基于参数模型和网络测量相结合的控制模型,给出了该模型的核心控制算法,设计了算法实现流程,并在ns-2.26上进行了仿真实验。仿真结果表明,该文提出的控制模型和算法既能确保各类业务所需的QoS,又能有效地提高网络资源利用率。     

QoS接纳控制算法的研究与比较

在下一代因特网中,网络服务质量的提供将成为人们关注的热点。要高效、高质量地传输各类业务,就必须通过一个有效的接纳控制机制来保证。本文介绍目前存在的两类QoS接纳控制算法：基于模型的接纳控制算法(Model Based Connection Admission Control)和基于测量的接纳控制算法(Measurement-Based Connection Admission Control),分析比较了它们的优缺点,并在此基础上提出了一个基于测量的接纳控制算法基本框架。     

一种基于测量的动态公平接纳控制算法

接纳控制算法是接纳控制的核心,在基于参数和基于测量的这两类接纳控制算法中,基于测量的接纳控制无需知道应用的流量模型,其次它能动态适应网络的负载变化,提高网络资源的利用率;然而最新的研究表明,仅仅追求高接纳率的接纳控制算法会造成对不同带宽QoS需求的连接的接纳非公平性,并且历经多跳的流更不易被接纳;文章的目的是解决基于测量的接纳控制算法的非公平性问题,文中分析了基于测量的接纳控制的基本思想和非公平性产生的原因,并在此基础上提出和实现了一种基于测量的HR接纳控制算法;仿真结果表明,该算法在以降低很小的接纳率的代价下,能有效地克服基于测量类接纳控制算法的非公平性问题。     

通用分组无线业务中基于测量的接纳控制算法

GPRS(generalpacketradioservice)通过使用类似于ATM中采用的QoS管理算法来为用户提供预留服务。许多学者的研究表明：基于测量的链接接纳控制算法与其他链接接纳控制算法相比,对GPRS网络具有更好的适应性和更高的效率。利用优先级队列的最坏延迟计算模型、等效漏桶近似和延迟标准化,在充分分析GPRS特性的基础上,提出了一种适合于GPRS的基于测量的接纳控制算法。通过仿真发现,该算法能在满足GPRS的QoS要求的同时获得80％的资源利用率。     

区分服务网络基于测量的接纳控制方案的设计与应用

提出了一种分布式可扩展的接纳控制方案，其目的是为区分服务网络提供端到端服务质量（Quality of Services,QoS)保证，该方案主要由以下部分构成：（1）连接接纳控制协议，主要负责主机和网络节点以及网络节点和带宽代理之间的信息传送，实现对连接请求的串行操作；（2）位于网络核心节点的可用带宽估计算法；（3）位于网络边缘节点的接纳控制算法；给出了该方案在视频传输方面的应用实例；利用多种网络拓扑结构和QoS指标评价该方案的性能，实验结果表明该方案能准确地控制可接纳区域和提高网络资源的利用率。     

MPLS接纳控制技术的研究与发展

接纳控制技术作为一种有效的、预防性的流量控制手段,是避免网络拥塞、实现网络QoS保障的重要技术。MPLS是ITU-T和IETF共同推出的支持QoS的宽带技术,因此研究基于M PLS的接纳控制技术有着十分重要的意义。本文总结了接纳控制技术的研究现状,提出了各种接纳控制技术在MPLS网络中的应用及其实现方式,并预测了MPLS接纳控制技术未来研究和发展的主要方向和热点问题。     

一种改进的基于探测的接纳控制机制

接纳控制作为一种预防性的流量控制手段是实现网络服务质量（QoS）保障的重要手段。本文在研究基于测量的接纳控制技术原理的基础上，着重分析了基于探测的接纳控制方法存在的问题，并对其中的“链路带宽重复评测”问题的解决方法进行了改进，提出了基于资源预留标签探测机制并给出了探测流程，最后通过仿真验证了该探测机制的有效性。     

适合于移动多媒体网络的呼叫接纳控制算法

移动多媒体网络应该能够同时支持传统的数据业务和实时交互式多媒体业务,并能够为用户提供QoS保证.在无线移动网中提供QoS保证,呼叫接纳控制扮演着重要的角色.通过对呼叫接纳算法中资源预留方案进行了分析总结,提出了一种适合于移动多媒体网络的自适应呼叫接纳控制算法.     

域内QoS控制研究

针对目前在实际的IP网络中部署QoS面临的技术和政策等各方面的困难,本文在DiffServ的服务框架下,提出了一种分层的QoS实现机制,即将全网的QoS控制分为域间的QoS控制和域内的QoS控制.域内的QoS以Internet上的自治系统为一个相对独立的QoS"域"(如某个ISP、政府或学校的网络)来实现QoS控制,以满足QoS的增量部署要求,以及保持QoS机制的可扩展性(适应网络规模的变化)和技术进化要求.本文着重考虑了在域内实现基于带宽代理的QoS体系结构,这种体系结构综合考虑了QoS路由、接纳控制、网络政策管理等因素,因此能实现良好的QoS保证并在网络域内部实现整体优化.     

多媒体信息网络QoS的控制*

文章综述了多媒体信息网络在服务质量(QoS)研究方面的一些最近的工作,着重论述了接纳控制和信源整形、QoS选路和资源预留、基于QoS的传输调度、综合服务网的QoS控制等问题.文章还描述了多媒体信息网络QoS控制的技术以及所面临的问题和进一步的研究方向.     

Dynamic radio resource allocation for 3G and beyond mobile wireless networks

Next generation of wireless cellular networks aim at supporting a diverse range of multimedia services to mobile users with guaranteed quality of service (QoS). Resource allocation and call admission control (CAC) are key management functions in future 3G and 4G cellular networks, in order to provide multimedia applications to mobile users with QoS guarantees and efficient resource utilization. There are two main strategies for radio resource allocations in cellular wireless networks known as complete partitioning (CP) and complete sharing (CS). In this paper, theses strategies are extended for operation in 3G and beyond network. First, two CS-based call admission controls, referred to herein as queuing priority call admission control (QP-CAC) and hybrid priority call admission control (HP-CAC), and one CP-based call admission control referred to as complete partitioning call admission control (CP-CAC) are presented. Then, this study proposes a novel dynamic procedure, referred to as the dynamic prioritized uplink call admission control (DP-CAC) designed to overcome the shortcomings of CS and CP-based CACs. Results indicate the superiority of DP-CAC as it is able to achieve a better balance between system utilization, revenue, and quality of service provisioning. CS-based algorithms achieve the best system utilization and revenue at the expense of serious unfairness for the traffic classes with diverse QoS requirements. DP-CAC manages to attain equal system utilization and revenue to CS-based algorithms without the drawbacks in terms of fairness and service differentiation.     

移动Ad hoc网络中基于稳定性的QoS路由算法综述

简要回顾了移动Ad hoc网络的基本概况,分析了在移动Ad hoc网络中提供QoS保障的重要性。简单介绍了移动Ad hoc网络中路由层QoS保障研究的现状和进展。在此基础上,系统地介绍了基于稳定性的QoS路由算法的各组成部分,并对其进行了细致的分类和科学的性能比较。最后,给出了研究方向。     

无线视频传输服务质量研究

在下一代无线通信网络中，以视频传输为主的流媒体业务将成为主要业务之一。着眼于无线视频流服务质量的研究，首先简要介绍了以网络为中心的服务质量控制策略，然后重点分析以终端为中心的速率控制机制，并介绍了目前常用的分组调度算法。     

QoS based multicast routing algorithms for real time applications

In recent years, there has been a lot of interest in providing real-time multimedia services like digital audio and video over packet-switched networks such as Internet and ATM. These services require certain quality of service (QoS) from the network. The routing algorithm should take QoS factor for an application into account while selecting the most suitable route for the application. In this paper, we introduce a new routing metric and use it with two different heuristics to compute the multicast tree for guaranteed QoS applications that need firm end-to-end delay bound. We then compare the performance of our algorithms with the other proposed QoS-based routing algorithms. Simulations were run over a number of random networks to measure the performance of different algorithms. We studied routing algorithms along with resource reservation and admission control to measure the call throughput over a number of random networks. Simulation results show that our algorithms give a much better performance in terms of call throughput over other proposed schemes.     

Utilizing call admission control for pricing optimization of multiple service classes in wireless cellular networks

In this paper, we utilize admission control algorithms designed for revenue optimization with QoS guarantees to derive optimal pricing of multiple service classes in wireless cellular networks. A service provider typically adjusts pricing only periodically. Once a “global” optimal pricing is derived, it would stay static for a period of time, allowing users to be charged with the same rate while roaming. We utilize a hybrid partitioning-threshold admission control algorithm to analyze a pricing scheme that correlates service demand with pricing, and to periodically determine optimal pricing under which the system revenue is maximized while guaranteeing that QoS requirements of multiple service classes are satisfied.     

IP网端到端接纳控制策略研究*

接纳控制解决一个流是否被接纳,以及如何在具有不同需求的流之间分配带宽和时延的问题。优良的接纳控制模型能够在提供有保证的服务质量的同时,提高网络资源的利用率,降低成本。首先简介接纳控制的基本概念、研究意义;然后对现有的接纳控制模型进行分类、归纳和总结,对每一种接纳类型进行详细介绍,分析其性能优劣,指出存在及需要改进的问题;最后,讨论了接纳控制面临的挑战并对其研究前景进行了展望。     

EMSC: a joint multicast routing,scheduling, and call admission control in multi–radio multi–channel WMNs

This paper deals with the problem of joint multicast routing, scheduling, and call admission control in multiradio multi-channel wireless mesh networks. To heuristically solve this problem, we propose a cross-layer algorithm named “extended MIMCR with scheduling and call admission control phases (EMSC)”. Our model relies on the ondemand quality of service (QoS) multicast sessions, where each admitted session creates a unique tree with a required bandwidth. The proposed scheme extends the MIMCR algorithm to fairly schedule multiple non-interfering transmissions in the same time slot. It also exploits a call admission control mechanism to protect the QoS requirements of the multicast traffics. EMSC reduces the number of occupied time slots, with consideration of spatial reuse, both Intra-flow and Inter-flow interferences, and selecting the minimuminterference minimum-cost paths. This subsequently leads to better radio resource utilization and increases the network throughput. Simulation results show that the proposed algorithm outperforms the other algorithms and improves the network performance.     

多媒体信息网络

This is a review paper on recent works about quality of service (QoS) of multimedia information networks. A brief of the technologies considered in the literatures is given in this paper. These technologies include admission control, traffic shaping, QoS routing, resource reservation, QoS based scheduling, and QoS control for integrated services. A few of methodologies, research directions and open problems in this area are discussed in this paper.