ADLE:一种Ad hoc网络分布式领导者选取算法

Ad hoc网络的动态拓扑结构和节点自组织给分布式算法的实现带来了诸多困难.Ad hoc网络分布式领导者选举算法:ADL.该算法基于广播机制,采用逻辑时戳保证消息的时序性,避免了节点饿死.同时,它通过缩小算法执行范围降低了消息复杂度,而且不需要节点了解系统中所有节点的信息,因而能够适应Ad hoc网络的动态拓扑结构和节点频繁出入.分析与仿真结果表明该算法具有较低的消息复杂度、小响应延迟和公平性.     

分布式紧耦合虚拟专用网可靠性计算方法

为了评估构建在互联网络基础上,具有多个服务质量约束要求的分布式紧耦合虚拟专用网可靠性能,该文提出一套可靠性指标计算方法。首先,在赋有权值参数的互联网络中,计算出所有满足约束条件的分布式紧耦合节点之间路由。然后,根据这些路由建立满足服务质量要求的网络邻接矩阵,对邻接矩阵进行分解与整合等变换,求得满足约束条件的不交化网络状态集。最后,根据不交化网络状态集得到可靠性指标的计算式,进而完成可靠性指标计算。由于所有过程都实现了代数化或逻辑代数化计算,所以易于计算机编程实现。论述了算法关键环节的正确性。通过算例、实验以及与传统算法结果比较等方式,说明新算法能够非常贴切地反映出分布式紧耦合虚拟专用网的可靠性。     

主动网络技术下分布应用的性能优化

本文独立地提出了基于插件技术的主动网络的体系结构,通过插件技术使业务的引入以及业务功能的扩展更加快速、灵活.在此基础上建立了一种新的网上定票业务模型.仿真表明,主动网络在网络中加入计算的能力可以大大优化网络的性能,网络在对用户的平均响应时间、服务器负载等方面都明显有所改善.     

主动网络技术下分布应用的性能优化

本文独立地提出了基于插件技术的主动网络的体系结构,通过插件技术使业务的引入以及业务功能的扩展更加快速、灵活,在此基础上建立了一种新的网上定票业务模型,仿真表明,主动网络在网络中加入计算的能力可以大大优化网络的性能,网络在对用户的平均响应时间、服务器负载等方面都明显有所改善。     

Architectural Design,Improvement, and Challenges of Distributed Software-Defined Wireless Sensor Networks

Wireless Personal Communications - Software-defined networking (SDN) is widely perceived to simplify network management and monitoring. The introduction of the SDN model into wireless sensor...     

Load Balancing in Software-Defined Networks Using Spider Monkey Optimization Algorithm for the Internet of Things

In the Internet of Things (IoT), the number of devices connected to the internet, and they can collect and exchange information at any time. IoT is helpful for the progress of a smart city and different applications. Software-Defined Network (SDN) offers programmability and flexibility in the IoT network. Nevertheless, the adoption of the number of gadgets will increase the transmission delay and this will lead the network to heavy loaded. To overcome this issue, an efficient load balancing technique has to be presented in the SDN network. By considering this solution as an aim, spider monkey optimization algorithm based load balancing (LB-SMOA) is presented in this paper. Using this technique, the controller with minimum load is selected and this selected controller balances the load of the heavily loaded controller. Simulation results show that the performance of the proposed LB-SMOA outperforms the existing load balancing techniques in terms of average response time, packet loss rate, and throughput.

     

An Algorithm for the Reliability Evaluation of Redundant Networks

An algorithm is presented for evaluation of reliability of any redundant network. It uses the properties of digraphs and is especially suitable for the computer analysis of large complex networks. A method for deriving the reliability expression for any type of network is also described along with a Fortran computer program for the reliability evaluation of series-parallel networks.     

A New Algorithm for the Weighted Reliability of Networks

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网状WDM网中支持区分可靠性的共享通路保护算法

光纤链路由于共享了某些物理资源(如光缆、管道、通路等),因此存在一定的故障相关性,术语“共享风险链路组(SRLG)”就是用于描述链路之间的这种风险共享关系的。SRLG分离成为保护设计的重要约束。该文研究了支持区分可靠性的SRLG分离共享通路保护设计问题。结合SRLG条件故障概率的概念,提出了部分SRLG分离的共享保护算法PSD-SPP(PartialSRLG-DisjointShared-PathProtection),有效地解决了SRLG分离约束下的区分可靠性设计问题。仿真结果表明该算法既满足了用户的区分可靠要求,又能有效利用资源。     

软件定义光网络研究进展与创新应用探讨

以软件定义网络(SDN)控制平面技术为特征的软件定义光网络(SDON)代表着未来传送网演进趋势,是新型超大容量光网络实现高度智能化的重要发展方向。认为通过在光层引入基于软件定义组网的控制平面解决方案,利用软件编程的方式对光网络的结构和功能进行动态定制,完成光网络设备配置、传输参数调整和带宽灵活分配,能够更好地适应新型光网络智能化发展的要求。认为开发软件定义光网络创新应用成为SDON领域新的研究热点。     

软件定义光网络的编码方法与应用

提出了一个新的产生光矢量偏移正交相移键控(OQPSK)信号方法,该方法仅使用一个强度调制器(MZM)和载波抑制技术,利用光电二极管的平方律检测特性,对强度调制器驱动信号的幅度和相位进行预编码处理,而且采用Turbo均衡技术提高了矢量正交移相键控(QPSK)信号系统的传输性能。实验证明,传输40 km单模光纤后,当误码率(BER)为10-4时,1/2和2/3码率的Turbo均衡QPSK信号的接收机灵敏度比原始QPSK信号分别提高了4 d B和3 d B。实验结果说明,Turbo均衡技术在光矢量信号传输系统中具有较好的纠错和抗色散能力。     

A New Algorithm for the Reliability Analysis of Multi-Terminal Networks

In a probabilistic network, source-to-multiple-terminal reliability (SMT reliability) is the probability that a specified vertex can reach every other vertex. This paper derives a new topological formula for the SMT reliability of probabilistic networks. The formula generates only non-cancelling terms. The non-cancelling terms in the reliability expression correspond one-to-one with the acyclic t-subgraphs of the network. An acyclic t-subgraph is an acyclic graph in which every link is in at least one spanning rooted tree of the graph. The sign to be associated with each term is easily computed by counting the vertices and links in the corresponding subgraph. Overall reliability is the probability that every vertex can reach every other vertex in the network. For an undirected network, it is shown the SMT reliability is equal to the overall reliability. The formula is general and applies to networks containing directed or undirected links. Furthermore link failures in the network can be s-dependent. An algorithm is presented for generating all acyclic t-subgraphs and computing the reliability of the network. The reliability expression is obtained in symbolic factored form.     

多域光网络中一种支持区分可靠性的通路保护算法

区分可靠性的通路保护方案既能为光网络中具有不同可靠性需求的业务提供有效的故障保护,又能优化网络资源的利用,是一种高效的生存性机制。但目前此类问题的研究主要是集中于传统的单域光网络中,所得的研究成果无法直接运用于具有多域特点的下一代光网络中。针对这一问题,在对以往通路保护算法进行改进的基础上提出了一种适用于多域光网络中的支持区分可靠性的通路保护算法,并对其性能进行了计算机仿真研究。仿真结果表明,该算法不仅能满足多域光网络中不同业务的可靠性需求,而且能提高网络资源的利用率、降低业务连接的阻塞率。     

A Power-Efficient Distributed TDMA Scheduling Algorithm with Distance-Measurement for Wireless Sensor Networks

This paper describes a power-efficient distributed TDMA slot scheduling algorithm which the slot allocation priority is controlled by distance measurement information in details. In our former proposed scheme, L-DRAND+, an extension of Lamport’s bakery algorithm for prioritized slot allocation based on the distance measurement information between nodes and a packet-based transmission power control had been applied. In this paper, we propose its enhanced scheme with a weighted rule control and state machines refinements of L-DRAND+, named L-DRAND++. This aims at the achievement of media access control methods which can construct a local wireless network practically by limiting the scope, and eliminate the redundant power consumption in the network. The proposed scheme can be shown as a possible replacement of DRAND algorithm for Z-MAC scheme in a distance-measurement-oriented manner. In addition, to evaluate the ordered node sequence determined by the algorithm, node sequence metric is proposed. By using the metric, we can evaluate protocol behaviors according to the environmental situation around the node.     

无向通信网端对端可靠性通用算法

针对无向通信网的节点和链路都存在失效的问题,提出了端到端可靠性的通用算法。对无向网络基于概率论的分解定理进行证明,介绍了无向网络的简化与分解算法及流程,并分析了端到端可靠度的计算准则,针对3种复杂程度无向网络进行了分析比较,最后提出一种无向通信网端对端可靠性通用算法。分析结果表明提出的通用算法适合节点和链路都不可靠的情...     

Collaborative Detection and Mitigation of Distributed Denial-of-Service Attacks on Software-Defined Network

Mobile Networks and Applications - This paper presents a collaborative technique to detect and mitigate Distributed Denial-of-Service (DDoS) flooding attacks on Software-Defined Network (SDN). This...     

Secure Distributed Routing Algorithm with Optimizing Energy Consumption for Cognitive Radio Networks

In cognitive radio networks, the non-cooperative behavior is an inherent security issue. Then it is important to guarantee the support of the cooperation among nodes. In this paper, first the distributed routing problems with optimizing energy use are translated into a 0–1 integer programming problem by analyzing the dynamical power interference among nodes. Secondly, the key allocation about end nodes is devised to realize the confidentiality about data transmission. Thirdly, a secure distributed routing algorithm (SDRA) with energy use is proposed to ensure the security on end-to-end communication. The simulation and analysis show that the energy use for the SDRA is lower than that of the spectrum and energy aware routing protocol. Moreover, the trust mechanism based on Bayesian theorem is more compatible than that of Beta function for distributed routing algorithm in the actual situation.     

Genetic Algorithm for Improving the Lifetime and QoS of Wireless Sensor Networks

Wireless Personal Communications - Wireless sensor networks (WSNs) has recently drawn lots of attention due to its application in multiple domains. The sensors have limited power sources and in...     

无线传感器网络分布式迭代定位误差控制算法

针对无线传感器网络分布式迭代定位中误差的传播和累积问题,该文首先分析了锚节点几何形状对定位误差的影响,提出了基于几何精度因子的误差控制算法,巧妙设计了加权策略,将锚节点几何形状对定位精度的影响以权值的形式定量体现在迭代定位过程中,在每一轮迭代中有效控制了误差的传递,进而提高了整个网络的分布式定位精度。与传统的最小二乘定位算法和基于轮数的误差控制算法进行了仿真比较,结果表明,基于几何精度因子的误差控制算法定位性能最优,网络定位精度分别提高了25%和15%。