Differentiated multi-layer integrated routing algorithms in optical internet

We investigate the problem of efficiently provisioning connections of arbitrary bandwidth granularities in integrated optical Internet model, and propose a novel dynamic weighted fair routing algorithm (DWFA) that employs QoS-aware flexible adaptive unified routing strategies according to the priority and granularity of the traffic connection request. Performance simulation results of DWFA show that our adaptive approach performs better in terms of traffic blocking ratio, traffic blocking fairness and traffic average logical hop counts than traditional overlay sequential routing scheme such as optical-layer-first routing (OFR) and electrical-layer-first routing (EFR). DWFA is very suitable for solving QoS-based multi-layer integrated routing (MLIR) problem in the next generation multi-granularity integrated optical Internet.     

IPv6中的流标签分析及有关问题——对RFC3697,RFC1809的分析补充

通过对RFC3697协议的分析研究,参考RFC1809、RFC2460、RFC2474协议的有关内容,提出了基于IPv6 flow label域的流分类后续协议和应用开发需要解决的相关问题.而后在参考IPv4现有设计的基础上,提出了部分问题的定性解决思路.同时作为RFC 3697的补充说明供其他研究者参考.     

基于MPLS流量工程的流量保护自动处理机

简述了MPLS(多协议标签交换)和MPLS流量工程的基本原理,提出了流量工程实现的思路和流程;在以RSVP TEDaemonforDiff servoverMPLSunderLinux软件包构建的MPLS实验平台上,设计了一个基于MPLS流量工程的流量保护自动处理机———实现了自动重路由、自动流量切换,以及自动弹性恢复。     

转基因生物标识立法：价值、经验及改进

目前,域外转基因生物标识立法存在自愿标识和强制标识两种类型,我国立法属于后者.我国已建立起转基因生物标识的规范体系,但需要从扩大转基因生物物种的标识区间,细化转基因生物标识的准确度,加强转基因生物负标识使用规范,以及健全转基因生物标识管理体系等角度予以进一步完善.     

Label-free selective sensing of Pb2＋ lead（II） sensors based on the aggregation of a pyrene fluorescent probe

In the present work, we report a label-free fluo- rescence turn-on approach for the sensitive and selective sensing of Pb2＋. Pyrene with one positive charge was used as the fluorescent probe, and thrombin aptamer （TBA）, which was a G-rich oligonucleotide, was employed to form G-quadruplex with lead（II）. When TBA and Pb2＋ were mixed with lead（II） in an aqueous solution, it was folded into a stable G-quadruplex. Subsequently, a single-stranded nucleic acid-specific nuclease S1 was added. The G-quad- ruplex stabilized by Pb2＋ lead（II） had markedly a significant resistant ability to nuclease S1 digestion. However, in the absence of Pb2＋ lead（II）, no quadruplex or less stable quadruplex was formed and TBA was digested by nuclease S1 in 3 min under the optimized experimental conditions. Finally, pyrene probe was Pb2＋ lead（II）. Electrostatic mixed with oligonucleotide in interactions between oligonu- cleotide （a polyanion） and the probe induced the aggregation of the probe, which in turn produced strong emission of the strong pyrene excimer emission. The intensity of the induced excimer emission was directly proportional to the amount of Pb2＋ added. Our approach shows good selectivity and sen- sitivity for the detection of Pb2＋ with a limit of detection limit as low as 800 nmol/L.     

MPLS中基于着色线程的环路预防/检测机制

首先简要介绍了 4种解决MPLS(多协议标签交换 )中瞬态环路的方法和MPLS技术 ,接着以着色线程机制为重点 ,详细介绍了其涉及的基本术语和算法 ,并通过一个实例讨论了该算法 ,最后对线程算法和路径矢量进行了简单比较 ,指出了线程算法的优点 ,分析了它的不足之处。     

基于IP/MPLS的多标记最小干涉路由算法

针对多标记路由机制的“干涉”问题和最小干涉路由算法有的“震荡”问题,对这两种算法的优缺点进行分析后,提出了多标记最小干涉路由机制算法,它既能解决前者的“干涉“问题,又能解决后者的”震荡“问题.本算法采用集中模式和分布模式来计算相关的参数值和建立相应的LSP,其在线计算和预计算模式既能适应网络需求的变化,又能在一定程度上减轻网络的开销.     

宽带通信技术发展过程、现状和趋势

文章分别从宽带骨干网和宽带接入网两个层面，介绍了宽带网的基础知识和一些关键技术，并展望了宽带通信网络的发展趋势。     

一种面向实时业务的Ad Hoc网络MAC协议

为降低Ad Hoc网络中实时业务的端到端时延,提出了基于802.11 DCF的改进协议.协议采用3种机制降低实时业务的时延:面向路径的连续转发机制将RTS中的转发信息携带在ACK中发送,给实时业务提供较高的接入优先级;标签交换机制使得中间节点可以在MAC层获取转发信息,加快了实时业务数据包的转发速度;重传控制机制减少了无效传输的超时数据包.仿真结果表明,在重负载条件下,改进协议中实时业务的时延比802.11 DCF有大幅度的下降,网络吞吐量也有所提高.     

多协议标记交换

多协议标记交换（ＭＰＬＳ）技术是ＡＴＭ交换与Ｉｎｔｅｒｎｅｔ路由／转发技术相结合最具代表性的一种模式。ＭＰＬＳ技术半网络层分组的网络层转发和链路层交换相结合,不仅有助于提高中继系统的分组转发能力,而且可以对提高网络路由系统的可扩展性起到一定的作用。本文简要分析了ＭＰＬＳ的网络模型,标记分配、路由技术以及ＡＴＭ骨干网上采用ＭＰＬＳ的技术方案。