软件定义无线传感器网络研究综述

无线传感器网络（Wireless Sensor Network, WSN）经过长时间的发展,技术上已经有了很大进步,并广泛应用于很多领域,但其仍存在一些技术难点,影响应用效果。软件定义网络（Software-Defined Network, SDN）是一种新的网络架构,它采用了数据平面与控制平面解耦的思路,提供了网络架构发展的新方向。为了提升WSN的技术有效性,SDN架构被引入到WSN领域中,形成了新的软件定义无线传感器网络（Software-Defined Wireless Sensor Networks, SDWSN）。在分析软件定义无线传感器网络现有研究成果的基础上,阐述了WSN及SDN的发展现状;结合目前的研究进展,综述了SDWSN可行的技术方案;探讨了SDWSN未来的研究方向及发展趋势。     

基于RMI的EPON EMS北向接口设计与实现

FTTH是国际公认的终极接入网解决方案，被专家们誉为是一种一劳永逸的网络接入方式，EPON作为FTTH的一种解决方案，就必须有网络管理系统对其进行管理；同时为了实现综合网络管理系统的集中式管理，EPON EMS必须为上层网管提供北向接口。文中根据北向接口的基本功能，深入分析了Java RMI的基本原理，提出了基于Java RMI技术的北向接口体系结构，并对实现过程中的一些关键难点提出了可行的解决方案。由于北向接口基于Java RMI技术，所以继承了Java的安全性和可移植性等强大功能。     

软件定义网络研究综述

现有网络设备支持的协议体系庞大, 导致高度复杂, 不仅限制了IP网络的技术发展, 更无法满足当前云计算、大数据和服务器虚拟化等应用趋势。软件定义网络（SDN）作为一种最新网络架构, 对网络设备控制面、转发面和应用层功能进行重新定义抽象, 使得网络设备软件可编程, 有望改变上述局面。介绍了OpenFlow技术的产生背景、特点及发展现状, 分析了基于OpenFlow的SDN体系结构和平台设计的关键技术, 并探究了SDN技术在网络管理自动化、光网络传输与IP承载的统一控制、无线网络的平滑切换、网络虚拟化和QoS保证等方向的应用。     

软件定义网络:安全模型、机制及研究进展

软件定义网络(software defined networking,简称SDN)初步实现了网络控制面与数据面分离的思想,然而在提供高度开放性和可编程性的同时,网络自身也面临着诸多安全问题,从而限制了SDN在很多场景下的大规模部署和应用.首先对SDN的架构和安全模型进行分析;其次,从"SDN特有/非特有的典型安全问题"和"SDN各层/接口面临的安全威胁"两方面,对SDN中存在的典型安全威胁和安全问题进行分析和归纳;随后从6个方面对现有SDN安全问题的主要解决思路及其最新研究进展分别进行探讨,包括SDN安全控制器的开发、控制器可组合安全模块库的开发和部署、控制器Do S/DDo S攻击防御方法、流规则的合法性和一致性检测、北向接口的安全性和应用程序安全性;最后对SDN安全方面的标准化工作进行了简要分析,并对SDN安全方面未来的研究趋势进行了展望.     

软件定义网络(SDN)研究进展

网络抽象促使软件定义网络(software-defined networking,简称SDN)的产生.SDN将数据平面与控制平面解耦合,简化了网络管理.首先从SDN诞生发展的背景入手,梳理了SDN的体系结构,包括数据层、控制层和应用层,并按照SDN的层次结构深入阐述其关键技术,特别分析了一致性、可用性和容错性等特性.然后,论述了SDN在不同应用场景下的最新研究成果.最后,展望未来研究工作.     

无线软件定义网络研究前景展望

软件定义网络是一种新型网络创新架构,其核心技术OpenFlow通过将网络设备控制面与数据面分离开来,从而实现了网络流量的灵活控制,为核心网络及应用的创新提供了良好的平台。软件定义网络能够改变现有的数据发送规则,由转发设备决定的僵硬模式能够显著提高数据发送的服务质量。目前软件定义网络的无线网络条件下应用的研究还处于起步阶段,本文分析了无线网络中实现软件定义网络可能遇到的困难与机遇。     

软件定义网络中资源消耗型攻击及防御综述

在传统网络中,集成多种网络功能的控制平面和负责转发数据包的数据平面是紧密耦合的,并且通常嵌入在一个专用设备中,这严重限制了网络管理的灵活性和网络服务的创新性。软件定义网络（Software-Defined Networking,SDN）作为一种新型的网络范式,通过将控制平面与数据平面解耦克服了传统网络架构的不足。研究人员凭借全网视图可见性以及对网络设备直接编程的能力提出了诸多SDN应用场景,如数据中心网络、云和广域网。然而SDN带来的灵活性、可管理性以及可编程性等优点是以引入新的安全挑战为代价。本文聚焦SDN网络中的资源消耗型攻击,首先分层整理了SDN网络中的关键资源以及攻击目标,然后对控制平面、控制通道和数据平面存在的多种资源消耗型攻击以及现有防御机制做出了详细的分析和归纳,最后对未来的研究工作进行了展望,并提出了一些潜在的研究方向。     

软件定义网络数据平面安全综述

软件定义网络将数据平面与控制平面解耦,旨在更快地引入网络创新,并从根本上实现大型网络的自动化管理。架构创新带来了挑战与机遇,安全问题限制了软件定义网络的广泛采用。针对数据平面的攻击可能会损毁整个软件定义网络,首先介绍了数据平面结构与发展趋势;然后分析了数据平面安全风险,指出漏洞,确定潜在的攻击场景,并给出2种具体解决方案,讨论其意义与局限性;最后展望未来的安全研究方向。     

软件定义网络架构下的安全问题综述

随着网络业务的多元化与网络基础服务能力的不断提升,企业网、云计算、数据中心等大量新兴应用场景迅速丰富,传统网络已不能满足其不断涌现的可扩展性、可管理性及安全保障等新需求,这一现状有力地推动以SDN为代表的当代网络架构的发展。然而随着学术界与产业界对SDN技术的研究及其设备的普及,安全问题逐渐成为制约其进一步发展的关键因素之一。针对SDN架构的技术发展背景进行分析,然后简析SDN技术的核心架构原理及目前的发展现状;结合SDN架构特点,针对其安全特性及其所面临的安全威胁进行详细分析,并深入讨论SDN网络安全研究的范畴与新兴发展方向。     

Dependability modeling of Software Defined Networking

Software Defined Networking (SDN) is a new network design paradigm that aims at simplifying the implementation of complex networking infrastructures by separating the forwarding functionalities (data plane) from the network logical control (control plane). Network devices are used only for forwarding, while decisions about where data is sent are taken by a logically centralized yet physically distributed component, i.e., the SDN controller. From a quality of service (QoS) point of view, an SDN controller is a complex system whose operation can be highly dependent on a variety of parameters, e.g., its degree of distribution, the corresponding topology, the number of network devices to control, and so on. Dependability aspects are particularly critical in this context. In this work, we present a new analytical modeling technique that allows us to represent an SDN controller whose components are organized in a hierarchical topology, focusing on reliability and availability aspects and overcoming issues and limitations of Markovian models. In particular, our approach allows to capture changes in the operating conditions (e.g., in the number of managed devices) still allowing to represent the underlying phenomena through generally distributed events. The dependability of a use case on a two-layer hierarchical SDN control plane is investigated through the proposed technique providing numerical results to demonstrate the feasibility of the approach.     

Software defined cloud: Survey,system and evaluation

Next generation cloud systems will require a paradigm shift in how they are constructed and managed. Conventional control and management platforms are facing considerable challenges regarding flexibility, dependability and security that next generation systems must handle. The cloud computing technology has already contributed in alleviating a number of the problems associated with resource allocation, utilization and management. However, many of the elements of a well-designed cloud environment remain “stiff” and hard to modify and adapt in an integrated fashion. This includes the underlying networking topologies, many aspects of the user control over IaaS, PaaS or SaaS layers, construction of XaaS services, provenance and meta-data collection, to mention but few. In many situations the problem may be due to inadequacy of service abstraction. Software Defined Systems (SDSys) is a concept that help abstract the actual hardware at different layers with software components; one classical example of this abstractions are hypervisors. Such abstraction provides an opportunity for system administrators to construct and manage their systems, more easily, through flexible software layers. SDSys is an umbrella for different software defined subsystems including Software Defined Networking (SDN), Software Defined Storage (SDStorage), Software Defined Servers (Virtualization), Software Defined Data Centers (SDDC), Software Defined Security (SDSec) etc. and ultimately Software Defined Clouds (SDCloud). Individual solutions and seamless integration of these different abstractions remains in many respects a challenge. In this paper, the authors introduce Software Defined Cloud (SDCloud), a novel software defined cloud management framework that integrates different software defined cloud components to handle complexities associated with cloud computing systems. The first part of paper presents, for the first time, an extensive state of the art critical review of different components of software defined systems, constructing the proposed SDCloud. The second part of the paper proposes the novel concept of SDCloud, which is implemented and evaluated for its feasibility, flexibility and potential superiority.     

财务软件中XML接口的设计

针对目前财务软件和其它软件数据交换问题，本文尝试用XML技术来解决此问题。本文首先简单地介绍了XML技术，在此基础上提出了财务软件XML接口的作用、目标和设计。     

Optimized traffic engineering in Software Defined Wireless Network based IoT (SDWN-IoT): State-of-the-art,research opportunities and challenges

Wireless networks have been in focus since the last few decades due to their indispensable role in the future generation networks like the Internet of Things (IoT). However, the associated challenges in wireless network implementation such as distance, line-of-sight, interference, weather, power issues, etc., affect the performance adversely. Software Defined Networking (SDN) is a future generation networking technology and has been proven to alleviate the performance challenges in the existing wireless IoT networks. It helps to evolve the wireless IoT domain in the form of Software Defined Wireless Network based IoT (SDWN-IoT). Traffic Engineering (TE) has been part of traditional network designs since long back, to improve the performance of the communication networks. However, its more optimized forms and their usefulness in SDWN-IoT networks have been under active investigation. This work explores the existing literature related to the major types of SDWN-IoT networks namely, Software Defined Wireless Sensor Network based IoT (SDWSN-IoT) and Software Defined Wireless Mesh Network based IoT (SDWMN-IoT). Additionally, the article also draws some useful inferences, and compares respective contributions and shortcomings. Finally, various research opportunities and challenges have been discussed with respect to the SDWSN-IoT and SDWMN-IoT networks.     

软件无线电台实时数据采集软件设计

针对软件无线电台接收机工作流程的特点与要求,在Windows XP环境下开发中频信号实时数据采集软件。与使用单线程相比,多线程编程技术可以保障数据采集的实时性和效率。采用操作系统提供的事件内核对象作为线程同步机制,协调线程间操作的正确次序和对共享资源的正确访问。应用微软基础类库使代码在一定程度上可重用。该软件设计灵活、方便、易于维护,可以提高开发效率。     

软件界面的交互设计

本文讨论了交互设计在软件界面中的作用,并通过对交互设计与界面设计之间的关系、软件界面特点等概念的探讨,说明了交互设计师在软件界面设计中的任务和其应该发挥的作用,指出了软件界面发展的方向以及将交互设计引入软件界面设计的意义。     

软件定义网络安全问题研究综述

软件定义网络是一种新型的网络体系结构,其通过OpenFlow技术来实现网络控制面与数据面的分离,从而达到对网络流量的灵活控制,目前已成为下一代互联网的研究热点.随着SDN的发展及广泛应用,其安全问题已成为亟待解决的重要研究内容.近年来,国内外学者在SDN安全研究领域取得了一定的成果,文中针对SDN的3层架构分别对各层所...