层次化软件定义光网络原型系统开发与试验演示

针对OTN的组网需求,提出了一种层次化的软件定义光网络控制结构,并采用商用OTN设备进行了试验测试和验证。本次试验在业界首次基于OpenFlow协议扩展实现了对多厂商OTN设备的统一控制管理,这种能力对于运营商在多厂商/多域网络环境中提供低成本、性能可控的端到端业务具有重要的价值。     

基于SDN的宽带接入网用户认证方式研究

通过介绍SDN的层次结构和OpenFlow的工作原理,分析了现有宽带接入业务的2种典型认证方式,讨论了它们在SDN技术构建的宽带接入网中的实现方式、网络结构和优缺点,证明了IPoE认证方式更适合应用于未来的SDN宽带接入网络。     

SDN Based Next Generation Mobile Network With Service Slicing and Trials

Software-Defined Network （SDN） empowers the evolution of Internet with the OpenFlow, Network Virtualization and Service Slicing strategies. With the fast increasing requirements of Mobile Internet services, the Internet and Mobile Networks go to the convergence. Mobile Networks can also get benefits from the SDN evolution to fulfill the 5th Generation （5G） capacity booming. The article implements SDN into Frameless Network Architecture （FNA） for 5G Mobile Network evolution with proposed Mobile-oriented OpenFlow Protocol （MOFP）. The Control Plane/User Plane （CP/UP） separation and adaptation strategy is proposed to support the User-Centric scenario in FNA. The traditional Base Station is separated with Central Processing Entity （CPE） and Antenna Element （AE） to perform the OpenFlow and Network Virtualization. The AEs are released as new resources for serving users. The mobile-oriented Service Slicing with different Quality of Service （QoS） classification is proposed and Resource Pooling based Virtualized Radio Resource Management （VRRM） is optimized for the Service Slicing strategy with resource-limited feature in Mobile Networks. The capacity gains are provided to show the merits of SDN based FNA. And the MiniNet based Trial Network with Service Slicing is implemented with experimental results.     

基于SDN与NFV的移动核心网演进

随着LTE接入技术的广泛部署,移动核心网在支撑移动通信业务快速发展的同时,也面临着爆炸式增长的数据流量和快速变化的业务模型的不断冲击。传统的移动核心网架构将难以满足未来移动通信实现海量数据高效转发的核心需求,对移动核心网演进方案的研究已经在业界展开。本文分析了移动核心网进一步演进的目标,并对基于SDN和NFV技术的移动核心网演进方向进行了分析。     

面向软件定义核心网的OpenFlow分组转发优先制排队模型研究

软件定义网络（Software-Defined Networking,SDN）作为一种数据转发与控制逻辑相解耦、并开放底层编程接口的创新网络架构,为降低核心网的部署运营成本、提升应用业务性能提供了全新的解决思路.然而,在SDN架构下,逻辑上集中的控制平面容易出现性能瓶颈,进而加大分组转发时延,因此有必要理解其分组转发性能特性.为此,本文首先介绍了软件定义核心网的典型部署场景,分析了控制平面的Packet-in消息到达过程和数据平面的分组到达过程,进而应用M/M/n/m和M/M/1/m排队模型分别刻画控制器集群的Packet-in消息处理过程和OpenFlow交换机的分组处理过程.在此基础上,建立OpenFlow分组转发优先制排队模型,进而推导出不同优先级的分组转发时延及其累积分布函数CDF.最后,借助控制器性能测量工具OFsuite_Performance进行实验评估,结果表明：与现有模型相比,本文所提的M/M/n/m模型更能准确估计控制器集群的实际性能.同时,采用数值分析的方法对比了多种情况下不同优先级的分组转发时延及CDF曲线,为软件定义核心网的实际应用部署提供有效参考.     

蜂房式无线数据网及其应用

本文对无线数据网的体系和蜂房式无线数据网络系统的构成作了简要的分析，指出了蜂房式无线数据网络的主要关键性技术、特点及应用领域。     

基于SDN的量子密码通信网络设计与研究

软件定义网络(SDN)采用OpenFlow技术分离网络设备的数据平面和控制平面,实现灵活控制网络资源的目的。基于此,设计了量子密码通信网络模型,实现灵活控制密码通信网络整体量子密匙资源,确保了信息的安全传输。此外,提出了综合到端可用密匙和跳数的路由算法,提高了QKD生成密匙的有效利用率。由测试结果可知,通过基于SDN的量子密码通信网络及路由算法,可提高量子密匙资源利用率,提高网络性能。     

基于OpenFlow的虚拟网实现研究

软件定义网络是一种数据和控制平面分离、软件可编程的新型网络架构及技术,控制平面使用以OpenFlow为代表的协议对转发平面进行集中式控制。SDN架构的这些特点能很好地满足了云计算对虚拟网络的集中化、标准化、自动化的配置管理要求。针对传统虚拟网络技术支持云计算平台的不足,提出基于OpenFlow的SDN技术设计虚拟网络的思路,论述了几种虚拟网络实现的原理与处理流程,并给出了模块化的软件设计及部分关键代码功能描述。     

On Generality of the Data Plane and Scalability of the Control Plane in Software-Defined Networking

The control and data planes are decoupled in software-defined networking （SDN）, which enables both planes to evolve independently, and brings about many advantages such as high flexibility, programmability, and rapid implementation of new network protocols. However, in order to improve the scalability of the control plane at present, some control functionalities are added to the data plane, which is probably to impact on the generality of the data plane. The key challenge of adding control functionalities to the data plane is to strike a careful balance between the generality of the data plane and the scalability of the control plane. We propose some basic principles that both control and data planes should comply with, based on the evolutionary trend of SDN. Moreover, we take two approaches for reference according to the principles, viewed from the control messages in OpenFlow-based SDN. Our evaluations demonstrate that the approaches can maintain the generality of the data plane and improve the scalability of the control plane.     

基于SDN的智能接入网关键技术及其标准化进展

在云计算时代,开放化、虚拟化的需求不断增加,将FTTx技术与SDN结合,构建软件定义的架构．是下一代接入网发展的方向。本文研究了基于SDN的接入网架构设计及关键技术,并对基于SDN的接入网的标准化现状进行了介绍。     

On Bandwidth Allocation for Data Dissemination in Cellular Mobile Networks

Wireless bandwidth is a scarce resource in a cellular mobile network. As such, it is important to effectively allocate bandwidth to each cell such that the overall system performance is optimized. Channel allocation strategies have been extensively studied for voice communications in cellular networks. However, for data dissemination applications, studies on bandwidth allocation have thus far been limited to a single-cell environment. This paper investigates the problem of bandwidth allocation for data dissemination in a multi-cell environment, which, to the best of our knowledge, has not been investigated before. The performance objective is to minimize the overall expected access latency given the workload for each cell in a data dissemination system. Two heuristic techniques, called compact allocation and cluster-step allocation, are proposed to effectively allocate bandwidth for a cellular network. Simulation experiments are conducted to evaluate the performance of the proposed bandwidth allocation schemes. Experimental results show that the proposed schemes substantially outperform the uniform allocation and proportional allocation schemes.     

软件定义网络安全研究

软件定义网络（SDN）采用控制和转发的分离架构,使研究者可以通过软件实现任意的网络控制逻辑,而不需对网络设备本身进行修改,具备极强的灵活性,已经在路由决策、网络虚拟化、无线接入、云计算数据中心网络等领域得到研究和应用,成为一项热点技术。但SDN在蓬勃发展的同时,也引入了新的安全风险,带来新的安全问题。另一方面,SDN也给传统安全技术以冲击,带来创新的网络安全应用发展的机会。鉴于此,结合SDN网络架构的特点综述了SDN安全的研究现状,包括SDN安全风险分析和安全技术及应用,并思考了SDN对信息安全的意义。     

Modeling a Mobile Cellular Network Using a Discrete-Event Simulator

In this paper we introduce a discrete-event-based simulation technology suitable to model cellular mobile radio systems with respect to their dynamic behavior. The latter results in the need for simulation tools which support mutable system configurations. The problems encountered when modeling mutable system configurations using conventional discrete-event simulators are discussed. In order to show a possible solution to this problem we introduce configuration events and configuration objects into the theory of discrete-event simulations. We demonstrate how configuration objects can be implemented in a discrete-event simulator using a dynamic map-function, hereby extending a definition of higher order functions. We apply the configuration objects in a Multiple Layer Model for modeling an entire mobile cellular radio network in a discrete-event simulator as an application for the extended theory. In this model we use the configuration objects to change the network's configuration during runtime. We show that this solution—combined with an object-oriented software design and, possibly, a visual programming language—is a powerful tool for the simulation of the dynamic aspects of mobile cellular radio networks. The software technology presented will be applied by the German cellular network operator Mannesmann Mobilfunk to model dynamic features applicable to the radio resource management of mobile radio networks and to access their performance by simulation.     

4G无线接入网拓扑结构展望

第四代移动通信(4G)系统的无线接入网如果沿用传统蜂窝结构,很难满足设计要求.为此文章介绍了可能用于4G系统的改进蜂窝结构,如光纤无线电(RoF)、分布式接收站、多跳无线接入蜂窝、簇-蜂窝,以及全新设计的非蜂窝结构,如Ad hoc和分布无线通信系统.在对这些结构进行了分析对比后,文章认为采用分布式处理/控制和多跳技术的无线接入网比传统蜂窝接入网更符合4G系统的要求.     

一种基于传感器网络的认知蜂窝网模型

文中针对未来的蜂窝通信服务提出了一种具体的基于传感器网络的认知蜂窝网模型，并对网络各部分的功能进行了深入分析．该模型能充分的利用现有蜂窝网的基础设施并发挥认知无线电解决频谱资源紧张的特点，具有广泛的应用价值．     

基于SDN的光纤无线混合接入网络架构研究

在分析 SDN (软件定义网络)组网的国内外相关工作的基础上,提出了一种新型融合宽带接入网络架构,该架构遵从OpenFlow协议,实现了光纤无线接入网络的智能管控,相关的资源分配算法、路由选择协议和节能机制可以在该架构下有效实施并提升网络性能。     

移动蜂窝物联网无线网络规划的探讨

时代在进步,物联网已深入应用到社会产业体系,强化了我国各个社会产业体系的联系,且向服务行业渗透。我国的经济建设目标聚焦在物联网上,移动通信网络在物联网建设发挥了关键的作用。基于此,本文介绍了移动蜂窝物联网技术,详细研究了蜂窝物联网规划,希望为有关企业提供合理建议。     

Research on software-defined network and the security defense technology

Software-defined network (SDN) separated the traditional control plane from the data plane,formed a centralized controller,opened up the network programming interface,simplified network management,promoted network innovation and optimized network operation.However,SDN's “three-layer two-interface” architecture increased the network attack surface,resulting in many new security issues.The development,characteristics and working principle of SDN were first introduced,and the existing security problems from the application layer,the northbound interface,the control plane,the southbound interface,the data plane were summarized respectively.Secondly,the latest research progress and existing solutions were discussed.Finally,SDN current and future security challenges were summarized,and the future SDN security development direction was looked forward to.     

软件定义网络关键技术及其实现

提出了一种SDN控制器——ZENIC,并给出了其架构。在控制、转发两个层面上,ZENIC架构主要包括转发抽象层及驱动层、网络操作系统内核层、北向应用编程接口。ZENIC采用了统一的转发抽象层加特定转发驱动、接入和内联网络分层控制的特色架构设计,解决了多种设备接入和复杂网络控制的问题。     

集成Ad Hoc和移动蜂窝网络系统的切换算法

传统切换算法不能适应多准则切换的要求,基于多准则切换算法的实现越来越重要,必须发展新的技术来提高切换算法的有效性,在用户满意度和网络效率间形成平衡。智能和优化切换算法对像集成自组网(Ad hoc)和蜂窝网络结构的混合网络具有很好的适应性和鲁棒性,能够根据未来混合网络中的各种业务类型的服务质量需求、网络状态以及移动节点条件等多种因素的变化进行自适应切换,可以运用这些智能优化算法来进行更加有效的切换判决,从而提高系统的性能。更进一步的研究方向是在集成Ad hoc和蜂窝网络的环境下,使用智能或优化技术设计垂直切换算法来提高系统整体性能。