新环境下SDH传输网络的特点与基本构成分析

随着网络技术的迅速发展,通信网络规模不断扩展,SDH传输网络逐渐发展起来并不断在实践中走向成熟。SDH传输网络具有很强的网管能力和统一比特率,其应用对于提高网管效率、提高网络资源利用率、降低网络维护成本具有重要作用,能够保证网络操作的便捷性、高效性和灵活性。     

SDH技术的组网应用及其发展前景

ＳＤＨ技术的一个重要特点就是组网的灵活性和安全性，并可以有效地提高网络资源的利用率。文章介绍了ＳＤＨ技术的组多特点及其应用，并探讨了ＳＤＨ技术的发展前景和国产ＳＤＨ设备的发展方向。     

软件化网络：一场即将开始的网络变革

SDN技术将会逐渐埘电信网络的发展和演进起到重要作用。该技术将使传统电信嘲络发生变化，我们应密切关注其进展，研究和分析其对网络元索的影响，使其提高网络资源的利用率年11业务部署的灵活性，不断增强刚络能力，提升用户体验。     

开放创新 Nuage Networks SDN解决方案

Nuage Networks SDN解决方案是开放的,围绕这一解决方案,阿尔卡特朗讯正在为数据中心及其他网络的SDN综合解决方案打造一个合作伙伴生态系统。随着,企业和个人用户不断推动云计算和存储业务需求增长,数据中心设备性能日益强大,但由于网络资源调配的灵活性不足,无法有效利用网络容量。目前,网络资源的提供仍需详细的技术规划、手工设置和复杂的系统及处理流程,才能使用户连接到所需的计     

数据中心光网络资源分配方法与优化

数据中心采用光网络传输模式有利于提高系统的灵活性和拓展性,进而降低整体的能耗水平,但在实践中发现光网络资源存在分配不合理、应用效率较低等问题,不利于数据中心应对流量增加、宽带资源紧张等挑战。通过机器学习建立流量分类算法模型,并将其设计为流量分类器,使其融入光网络的流量传输环节,实现流量自动分类。借助遗传算法模型重构光网络的拓扑结构,从而优化传输路径。通过以上两项措施改进光网络的资源分配方式,并借助软件模拟检验算法模型的性能,结果显示经过以上算法处理的光网络缩短了传输路径的长度,提高了网络资源的利用率。     

云南广电网络资源管理系统设计及工作流引擎应用

主要从系统目标、系统构架、系统性能、系统功能等方面阐述了云南广电网络资源管理系统的设计方案,并将工作流引擎技术引入到该系统中进行实现,实际运行结果较好.可为其他广电运营商的网络资源管理系统建设提供一定的参考依据.在广电其他IT系统的建设中,建议进一步考虑将规则引擎技术和消息引擎技术也引入进来,以更好地提高系统的灵活性和可扩展性.     

基于NFV和SDN的无线网络虚拟化关键技术研究

随着无线网络应用的进步,人们对于无线网络性能要求越来越高,如何能够实现网络的灵活性、可编程性、可扩展性成为研究热点。本文利用 NFV 和 SDN 进行了网络功能和网络资源的虚拟化,提出了一种基于神经网络 PID 算法的虚拟资源分配方法,利用网络切片技术实现网络按需定制。     

天地异构网络资源融合管理与智能调度技术

针对天地网络资源跨域分散、快速配置调度难、综合利用率低等问题,开展天地异构网络资源特性及融合模式分析,以网络性能优化为目标设计天地异构网络资源融合管理架构。针对资源的异质异构性进行网络资源的分类与虚拟化,针对不同的网络服务需求进行资源多维描述和子网构建,针对业务的动态变化进行虚拟化资源的智能分配与动态调整。采用上述技术实现了网络资源的协同运用与自主调优,通过全网资源的统一调度和智能分配提高了网络资源利用率,提升了网络服务质量。     

基于OpenFlow的负载均衡研究

Open Flow网络将控制平面与数据平面解耦,通过集中式的控制器来控制整个网络,能够更有效地实现对网络流量的管控。基于Open Flow的负载均衡通过对链路流量进行调度和分配,实现对整个网络流量的负载均衡,能防止网络拥塞、提高网络资源利用率等。但是传统的负载均衡方案难以满足Open Flow网络的全局式、灵活性的要求。因此,需要对Open Flow网络中的负载均衡进行进一步研究,文章提出一种全新的负载均衡解决方案。     

使用分类改进标签推荐系统准确度的研究

由于标签的灵活性及其概念可理解性,使用标签可以提高推荐系统的推荐性能.协同标签系统在网络资源推荐服务中取得了巨大的成功.分类为用户显示了不同的利益群体的不同喜好.基于此,提出了基于分类的标签推荐系统—TRSUC,将它作为内分类推荐,使分类标签成为全球用户和项目之间的中介实体.通过对MovieLens中数据集进行实验,结果表明,TRSUC的推荐准确度明显优越于传统推荐算法.     

一种改进的宽带卫星网络MAC协议

为了提高宽带卫星网络上行信道资源的利用率,同时保障多媒体业务的不同服务质量要求,需要采用合适的媒体接入控制协议。BTDAMA可以显著减少自相似业务的等待时延,并且提高了资源利用率。但它没有区分业务类型,不能保证高优先级业务的服务质量,也造成了一定程度上资源的浪费。在BTDAMA的基础上提出了一种基于业务优先级的带宽分配算法,针对不同的业务类型采用不同的分配方案,不仅保证了各类业务的服务质量,同时提高了资源利用率。     

A joint resilience scheme with interlayer backup resource sharing in IP over WDM networks

The survivability of IP over WDM networks gains importance as network traffic keeps growing. Recovery at the lowest layer is fast and scalable. However, it is usually considered to provide poor network utilization. In this article we propose a resilience scheme based on recovery at the lowest layer in which intralayer and interlayer backup resource sharing is utilized to improve the network utilization. By applying interlayer backup resource sharing, we can totally depend on the reserved backup resources for fiber link failures to guarantee 100 percent recovery of IP router failures. In addition, by applying intralayer backup resource sharing, the network utilization improvement of recovery at the lowest layer is much more significant than at the highest layer. Simulations results show that the proposed scheme can efficiently improve network utilization and be even more capacity-efficient than resilience schemes based on recovery at the highest layer.     

数据中心的网络虚拟化技术研究

文中以数据中心的网络虚拟化技术为研究对象，探讨了在现代数据中心环境下如何优化网络资源利用、提高网络性能和灵活性的问题。首先，引入了软件定义网络（Software Defined Networking，SDN）的基本概念与架构，分析了SDN与网络虚拟化的关系。在此基础上，设计了一个综合性的网络虚拟化总体架构，以支持多租户的虚拟网络隔离和灵活配置。随后，详细介绍了虚拟局域网（Virtual Local Area Network，VLAN）技术在该总体架构中的实现方法。为验证VLAN技术在数据中心网络中的效果，文中设计了实验环境并进行了实验评估。结果表明，VLAN技术有效提高了数据中心网络的资源利用率，提升了网络的灵活性和性能，验证了其在数据中心网络中的实用性和优越性。     

基于电力光纤到户的网络切片资源管理方案

为解决电力光纤到户项目中网络管控不灵活、业务种类繁多且QoS复杂等问题,提出了基于电力光纤到户的网络切片资源管理方案和基于网络切片感知的多业务融合动态资源分配算法。仿真结果表明,所提方案能够有效实现不同切片的QoS保障,并显著提升网络资源利用率。     

Probabilistic burstiness-curve-based connection control forreal-time multimedia services in ATM networks

In this paper we present a method to establish real-time connections with guaranteed quality of service (QOS), based on a per-session probabilistic burstiness curve (PBC). Under two distinctive service disciplines, role proportional processor sharing and fixed rate processor sharing, we derive useful probabilistic bounds on per-session end-to-end loss which is caused by either buffer overflow in the path or excessive delay to the destination. One remarkable feature of the bounding solutions is that they are solely determined by the PBC of each session itself, independent of the network environment and other connections. To improve network resource utilization, our method is extended to allow statistical sharing of buffer resources. The admission control scheme presented in this paper has a great flexibility in connection management since bandwidth and buffer allocations can be adaptively adjusted among incoming and existing sessions according to present network resource availability. We also present a novel method to compute the PBC of multimedia traffic based on the measurement of two important statistics (rate histogram and power spectrum). Our study of MPEG/JPEG video sequences reveals the fundamental interrelationship among the PBC, the traffic statistics, and the QOS guarantee, and also provides many engineering aspects of the PBC approach to real-time multimedia services in ATM networks     

一种新的对称CDMA系统中非对称业务下的呼叫允许控制策略

未来无线多媒体网络将以分组技术为基础,支持多种业务的传输,业务的QoS保证将受到一定的挑战.各运营商也将针对自己所服务的对象特点,定义各类业务的QoS等级,来提供具有不同QoS要求的业务.因此,呼叫允许控制(Call Admission Control,CAC)策略将要以分组业务为主要对象,即既要在充分利用系统资源的基础上保证各业务的QoS要求,又要适应各运营商之间的不同需求.因此本文提出一种新的对称CDMA系统中非对称业务下基于动态QoS保证的CAC策略.各运营商可根据自己的要求定义各业务的QoS等级.由于业务的不同特性,使得网络中上行链路和下行链路的业务呈现不对称性,为避免资源的浪费,将根据网络中的资源占有情况动态的地分配上行和下行链路中的资源.仿真结果表明,该策略可以自适应地保证各业务的QoS要求,提高了业务间的公平性和系统资源的利用率.     

Dynamic inter-SLA resource sharing in path-oriented differentiated services networks

This paper proposes novel resource sharing schemes for differentiated services (DiffServ) networks, to achieve both high resource utilization and quality of service (QoS) guarantee. Service level agreements (SLAs) are negotiated at network boundaries and supported by path-oriented resource mapping within the network. The recently proposed SLA management scheme based on virtual partitioning (Bouillet et al., 2002) allows overloaded SLAs to exploit the spare capacity of underloaded SLAs for efficient resource utilization, however, at the the cost of possible SLA violation of the underloaders. In the bandwidth borrowing scheme proposed here, the dedicated bandwidth for underloaded SLAs is determined and adaptively adjusted at network boundaries according to the actual traffic load and QoS policies; the available spare capacity is then properly distributed to related links for lending to others. On the other hand, the traffic flows admitted with borrowed bandwidth are tagged and may be preempted later when the original bandwidth owner needs to claim back the resources. Through a detailed implementation design and extensive computer simulation results we show that, by bandwidth borrowing, both SLA compliance and high resource utilization can be achieved in various load conditions, with some side benefits such as call-level service differentiation, small admission overhead, and convenience for policy-based management. In addition, we propose a distributed bandwidth pushing scheme that can dynamically adjust the spare bandwidth distribution over the network. Combining bandwidth pushing with bandwidth borrowing, the resource utilization can be further improved.     

A fuzzy modeling based dynamic resource allocation strategy in service grid

One of the major challenges in service grid is to guarantee the promised quality of service (QoS) for all the admitted users or applications, while maximizing the resource utilization through dynamic resource sharing. An efficient resource allocation method should ensure the service QoS and balance the load among service grid nodes which are often highly dynamic, heterogeneous and linked by wide-area network. In this paper, a new dynamic resource allocation method is presented and analyzed based on fuzzy modeling to solve the adaptation between heterogeneous applications with multiple QoS requirements and grid resource. Simulations in service grid with heterogeneous QoS requirements reveal that the proposed dynamic resource allocation method can distribute most suitable resource among the different service quickly and sensitively as the service QoS demand varies under the constraint of achieving maximum utilization of grid resources.     

Radio resource management for cellular CDMA systems supporting heterogeneous services

A novel radio resource management (RRM) scheme for the support of packet-switched transmission in cellular CDMA systems is proposed by jointly considering the physical, link, and network layer characteristics. The proposed resource management scheme is comprised of a combination of power distribution, rate allocation, service scheduling, and connection admission control. Power distribution allows individual connections to achieve their required signal-to-interference-plus-noise ratio, while rate allocation guarantees the required delay/jitter for real-time traffic and the minimum transmission rate requirement for non-real-time traffic. Efficient rate allocation is achieved by making use of the randomness and burstiness; of the packet generation process. At the link layer, a packet scheduling scheme is developed based on information derived from power distribution and rate allocation to achieve quality of service (QoS) guarantee. Packet scheduling efficiently utilizes the system resources in every time slot and improves the packet throughput for non-real-time traffic. At the network layer, a connection admission control (CAC) scheme based on the lower layer resource allocation information is proposed. The CAC scheme makes use of user mobility information to reduce handoff connection dropping probability (HCDP). Theoretical analysis of the grade of service performance, in terms of new connection blocking probability, HCDP, and resource utilization, is given. Numerical results show that the proposed RRM scheme can achieve both effective QoS guarantee and efficient resource utilization.     

A Cooperative Differential Game Model for Multiuser Rate-Based Flow Control

Flow control is one typical resource management tool. Its objectives are to adjust the traffic in the network, and resolve data traffic congestion, maximize the utilization of available bandwidth resource and realize fairness among different sources. Taking more consideration on the interaction and the dynamic characteristics of the flow, in this paper, we propose a cooperative differential game of flow control. Our goal is to assign sources with appropriate transmission rate levels so as to the queue length in the bottleneck link is optimal for the network performance and their benefits are maximal. We derive a payment distribution mechanism that would constitute a time-consistent solution and guarantee individual rationality.