Network Function Virtualization Technology： Progress and Standardization

Network innovation and business transformation are both necessary for telecom operators to adapt to new situations,but operatorsface challenges in terms of network bearer complexity,business centralization,and IT/CT integration.Network function virtualiza-tion(NFV)may inspire new development ideas,but many doubts still exist within industry,especially about how to introduceNFV into an operator’s network.This article describes the latest progress in NFV standardization,NFV requirements and hottechnology issues,and typical NFV applications in an operator networks.     

异构重叠网络下MIP移动检测方法性能比较

未来的通信网络将融合、协同多种异构网络。IETF提出的移动IP(MIP)能够将各种网络统一到单一的IP信息平台。本文重点分析了影响MIP切换时延的移动检测机制：LCS,ECS。提出了异构重叠网络下跨层优化快速检测机制。理论分析和仿真均表明由于得到了来自链路层信息的辅助,该方法能有效地降低切换时延,减少丢包,提高通信服务质量。     

运营商级SD-WAN综合网管系统的创新实践

由于软件定义广域网(SD-WAN)能够降低成本、提升效率,还具有易管理、高安全的特点,因此成为了广域网(WAN)服务的主流方向.针对SD-WAN产品具有跨厂商、多维度的管理需求,研究了运营商级SD-WAN综合网管系统建设实践,创新建立了多厂商的统一数据编排平台,实现了overlay+underlay统一纳管能力,同时将...     

一种自组织时间同步网

基于NTP协议构建大规模网络的时间同步网时，必须在网络每一节点上事先进行参数配置，如同步源地址等。这种网络拓扑是静态的，时间同步操作必然会受到网络环境变化的制约和影响。扩展定义两个新的NTP包SRP和SAP，将同步源抽象为一种资源，应用网格计算中的分布式资源发现方法，动态的根据网络环境变化以及节点的能力差异配置参数，进而构成了一种自组织时间同步覆盖网。该方法不仅对于NTP协议的进一步完善研究有参考价值，而且使时间同步更可靠、经济、灵活。     

生物陶瓷表面生长细胞扫描电镜观察

应用扫描电镜观察了羟基磷灰石(HA),生物压电陶瓷(HABT、BT),PZT(加Li)和PZT(加Mn)等材料表面生长细胞的形态变化。结果表明:HA、HABT和BT等三种陶瓷无细胞毒性,陶瓷表面适宜于细胞生长,而PZT(加Li)和PZT(加Mn)等含铅压电陶瓷的细胞形态改变明显,其表面不利于细胞附着、生长。用细胞生长抑制法和琼脂覆盖法考察了HA、HABT和TC_4—Al_2O_3等陶瓷的细胞毒性作用。证明HA、HABT两种陶瓷对细胞生长无抑制作用,TC_4—Al_2O_3和PZT陶瓷则明显地抑制细胞生长。     

IP网络组播技术的新发展

本文综述了IP网络中组播实现体制和技术的新发展。首先．对在IP层实现组播的体系结构——IP组播进行了深入的探讨，分析、比较了IP组播两种业务模型——标准业务模型和确定源节点业务模型，讨论了IP组播存在的问题和发展趋势。接着，对应用层实现组播的体系结构进行了讨论，描述了应用层组播体制的主要功能和机制，对主要的几个应用层组播方案进行了比较，探讨了应用层组播体制的优缺点。最后对未来Internet中组播业务的实现提出了一些看法。     

Performance of cognitive relay network with novel hybrid spectrum access schemes with imperfect CSI

Two novel spectrum access schemes, a hybrid spectrum access scheme (HSAS) and a modified HSAS combining underlay mode and overlay mode, are proposed for a relay based cognitive radio (CR) network. The CR employs the underlay mode with imperfect channel state information of the interfering link between CR transmitter and primary user receiver if primary user is sensed to be present else it employs overlay mode. In both the schemes, transmission of CR is assisted by relay working in amplify and forward scheme by maintaining interference below an interference threshold in underlay mode and a collision constraint in overlay mode. In HSAS, CR transmits either in underlay mode or in overlay mode only during the transmission slot of a detection cycle, whereas in modified HSAS, the CR transmits for the entire frame including the sensing time. The outage probability of CR user is considered as the performance metric. Novel expressions of outage probability for both the schemes have been developed. Impact of several sensing parameters such as sensing time, correlation coefficient, and tolerable interference threshold has been investigated. Copyright © 2016 John Wiley & Sons, Ltd.     

云计算环境下支持多属性查找的混合对等网络

针对云计算环境下,云资源的多属性查找问题,设计了一种混合结构的对等网络。该网络采用多星形拓扑结构,将云资源以统一的编码方式规范化之后部署到该网络上,可较好地实现多属性查找。文中描述了多属性查找算法,分析了网络性能,该网络旨在降低资源查找的跳数,因此文中主要分析网络查找跳数。实验表明,资源查找跳数得到优化,达到了预期效果。     

Microwave permittivity of leaf using an Ag thick-film microstrip resonator

The X-band microwave dielectric constant, dielectric loss and the conductivity of the leaves of four different plants were measured from even and odd mode resonance characteristics of an Ag thick-film microstrip straight resonator, due to the perturbation caused by leafy vegetation as an overlay. Using the changes in the frequency response, the moisture-dependent X-band microwave properties of the leaves of Ficus Bengalensis, Ficus Religiosa, Acalypha Wilkensiana, and Acalypha Hispidia have been calculated. The permittivity obtained depends on the position of the overlay and moisture content. A partial overlay method might be a low-cost alternative for dielectric characterisation of biomaterials since a very small size of leaf is needed.     

基才百度地图JavaScriptAPI的通信地图展示

基于为通信公司提供一个可视化、精确化、直观化显示公司通信站点及线路的地图展示功能的目的,采用由baidu提供的JavaScript地图API技术,通过JavaSeript脚本语言设计对地图的坐标覆盖以及覆盖物操作方法的实现,结合对底层数据库机房站点和通信线路拐点数据表的设计,完成了一个优良的地图可视化系统。