无线传感器网络拓扑的容错度与容侵度

研究传感器网络拓扑对节点失败的容忍能力,必须解决三个基本问题,容忍节点失败的定义是什么,如何评价拓扑的这种容忍能力,什么样的拓扑具有较高的容忍能力.当前有关无线网络容错拓扑的研究均将图的多连通性看成拓扑的容错性,以图形多连通度的大小来衡量拓扑容错性的高低.本文通过实例分析指出图的多连通性与容错性是不同的,并结合网络的可用性,给出拓扑对失败节点容忍的定义,在此基础上,根据随机故障和恶意入侵两类节点失败形成原因,给出了拓扑容错度和容侵度作为拓扑对节点失败容忍能力高低的评价标准,并利用这两个标准分析了传感器网络分层拓扑,得出其拓扑容错度随簇头节点比例提高递减、而容侵度随之递增的理论结果.     

基于网格结构无线传感网络故障诊断算法

无线传感网中节点的数据信息具有空间相关性,可以通过邻居节点数据的比较来完成网络的故障诊断。网络中有时会出现瞬时故障,影响网络的诊断精确度。文中提出了一种基于网格结构的无线传感网络故障诊断算法,算法通过相邻节点历史数据信息之间的比较来确定节点最终状态,有效地避免了瞬时故障对节点诊断的影响。仿真结果表明,文中算法可保证较高地诊断精确度并能节省一定的能量。     

仿血管路径的无线传感器网络故障容错路由算法

为提高无线传感器网络故障容错性和传输稳定性,实现网络负载均衡,提出了一种仿血管路径的无线传感器网络故障容错路由算法.研究了人体血管路径特性及属性关联,对网络节点分区域等级标定并以不同概率值进行静态分簇,运用改进的蚁群算法BWAS(最优最差蚂蚁系统)生成节点路径,以路径信息素值作为传输路径的选择概率建立仿血管拓扑结构路由...     

一种无线传感器网络节点故障的检测方法

To reduce excessive computing and communication loads of traditional fault detection methods, a neighbor-data analysis based node fault detection method is proposed. First, historical data is analyzed to confirm the confidence level of sensor nodes. Then a nodes reading data is compared with neighbor nodes which are of good confidence level. Decision can be made whether this node is a failure or not. Simulation shows this method has good effect on fault detection accuracy and transient fault tolerance, and never transfers communication and computing overloading to sensor nodes.     

An Inter-cluster Communication based Energy Aware and Fault Tolerant Protocol for Wireless Sensor Networks

The ambient intelligence paradigm is built upon Ubiquitous Computing (UC), in which the computing devices are embedded in the environment with the purpose of enhancing the human experience at home, workplace/office, learning, health care etc. The UC applications aim at providing services to the users anywhere, anytime in an unobtrusive, seemingly invisible way. Wireless sensor networks (WSNs) have great potential for UC applications and are envisioned to revolutionize them. This paper presents a clustering routing protocol for event-driven, query-based and periodic WSNs. The protocol aims at optimizing energy dissipation in the network as well as providing network’s fault tolerance and connectivity. Message propagation is accomplished by using short distance transmissions by employing nearest neighbor nodes between neighboring clusters. Moreover, the algorithm proposes using an energy efficient approach by alternating the nodes responsible for inter-cluster communication inside one cluster. The algorithm also aims at even energy dissipation among the nodes in the network by alternating the possible routes to the Sink. This helps to balance the load on sensor nodes and increases the network lifetime, while avoiding congested links at the same time. We discuss the implementation of our protocol, present its proof of correctness as well as the performance evaluation through an extensive set of simulation experiments. This work is partially sponsored by Grants from the NSERC, Canada Research Chairs Program, ORNEC, the Ontario Distinguished Researcher Award and the EAR Award.     

面向目标跟踪的无线传感器网络动态分簇

在考虑节点剩余能量和节点探测信号强度的基础上,提出了一种面向目标跟踪的无线传感器网络动态分簇方法。由于在簇首选择时考虑了节点的剩余能量,因此可以有效地避免簇首节点能量不足导致的跟踪失败。方法既能保证各个节点均衡地担任簇首节点,又能避免簇首切换过于频繁,因此可以延长网络的使用寿命。计算机仿真结果表明,在满足簇首节点能量需求和簇内节点大部分能观测到目标的情况下,应该取尽量小的能量阈值和尽量大的距离阈值。     

工业无线层次传感器网络的动态TDMA算法

Industrial wireless sensor networks adopt a hierarchical structure with large numbers of sensors and routers. Time Division Multiple Access (TDMA) is regarded as an efficient method to reduce the probability of confliction. In the intra-cluster part, the ran-dom color selection method is effective in reducing the retry times in an application. In the inter-cluster part, a quick assign algorithm and a dynamic maximum link algorithm are proposed to meet the quick networking or minimum frame size requirements. In the sim-ulation, the dynamic maximum link algorithm produces higher reductions in the frame length than the quick assign algorithm. When the number of routers is 140, the total number of time slots is reduced by 25%. However, the first algorithm needs more control messages, and the average difference in the number of control messages is 3 410. Consequently, the dynamic maximum link algorithm is utilized for adjusting the link schedule to the minimum delay with a relatively high throughput rate, and the quick assign algo-rithm is utilized for speeding up the network-ing process.     

可生存光纤—无线融合宽带接入网规划方法

光纤—无线融合（fiber-wireless,FiWi）宽带接入网的出现不仅为随时随地的灵活宽带接入提供了新的技术参考,同时也为可生存宽带接入网的低成本设计增加了研究契机。研究了可生存FiWi接入网的网络规划问题,提出一种基于无线重路由保护的可生存网络规划方法。当任意光纤链路断裂时,失效的光网络单元可通过无线重路由将业务转移到其他可用的光网络单元承载。重点解决了无线路由器部署、备份射频接口配置及光网络单元容量分配的联合优化问题,目标是通过最小化网络部署成本实现业务的完全保护。采用整数线性规划方法获得了小规模网络规划问题的最优解,同时提出了适用于大规模网络规划问题的启发式算法。仿真结果证实了所提方法在降低网络部署成本方面的有效性。     

基于Web的无线传感器网络可视化管理系统的设计与实现

无线传感器网络广泛部署于工业、农业、医疗及多种场景。面向网络应用的信息管理需求,设计并实现了一种基于Web的无线传感器网络可视化管理系统。传感器节点采集用户感兴趣的对象信息,通过多跳方式汇聚至网关,网关利用以太网或GPRS／CDMA等多种Internet接入方式将信息传送给网络服务器。用户利用终端设备,可跨平台访问此管理系统,执行对IPv6无线传感器网络状态信息和传感信息的动态实时检测,并可对节点设备进行远程控制与管理。     

混合式无线传感器网络动态调度及功率控制方法的研究

无线传感器网络是资源受限网络,研究其动态调度与功率控制对于提高网络性能具有重要意义.基于此,提出了一种无线传感器网络中混合式动态调度与功率控制方法.该方法采用集中式时隙调度与分布式功率控制相结合的思想,避免了介质访问控制(MAC)层传输冲突,并支持各传感器节点综合利用各自的队列状态信息和无线信道信息进行跨层优化传输.该...     

一种基于双密钥的无线传感网络动态密钥管理方案

针对无线传感网络节点的存储空间、能量等的限制,以及动态密钥管理的无身份认证的安全问题等,提出一种类似一次一密的双密钥管理方案.该方案增加了身份认证模块,以及新节点的认证机制.同时在更新动态密钥时引入盐值,这一特性又进一步增强了无线传感器网络的抗毁性能.最后分析了方案的存储量、连通性以及安全性：在超过6 000个节点的网络环境下,该方案单个节点的密钥存储量大幅降低,仅有E-G方案的一半左右;在连通性方面,E-G方案是基于概率的,一般为0.9,而该方案的连通率为1;在安全性方面,该方案降低了密钥环的数量,未捕获节点的密钥暴露概率比E-G方案低很多.     

A New Scheme for Seamless Inter-Cluster Handoffs in Wireless ATM Networks

Many schemes to reduce the inter-cluster handoff delay in wireless ATMnetworks have been proposed, but the previous schemes waste relativelylarge network resources to decrease the path rerouting delay. In thispaper, we propose the 2-layered cluster concept, where the seamlessinter-cluster handoff can be supported regardless of path reroutingtime. As a result, the waste of wired resources and the rate of theinter-cluster handoff can be reduced. From the performance analysisand simulation, the inter-cluster handoff rate for non-real-timetraffic is only about 1/3 of the conventional result. Suchadvantageous features of the proposed scheme neither incur anyincrease of the total handoff rate nor require additional ATMswitches.     

无线传感器网络中一种高能效低延时的泛洪算法研究

提出了一种新的应用于无线传感器网络的泛洪传播算法——覆盖优先泛洪算法。算法采用覆盖优先策略为相邻节点分配不同的转发优先权,实现泛洪包快速覆盖整个网络;采用节点转发抑制策略和动态延时转发机制,尽可能抑制冗余包和减少冲突重传。仿真结果表明,该算法与同类算法相比,具有更高的能源有效性,更低的延时。     

一种基于ZigBee协议的动态数据采集系统的实现

动态数据采集有着采集范围大、采集点众多、数据通信困难、布线空间有限、自动作业等特点,传统的以总线方式组成网络的采集系统很难满足这种应用要求。在此动态数据采集系统的设计充分借鉴无线传感器网络设计思想,探讨一种基于ZigBee协议无线传输的设计方案,具有低功耗、灵活性强、可扩展好、体积小、成本低等特点,解决了传统的采集系统的设计瓶颈。并具有新的优异特性。     

一种改进的动态用户认证协议

针对用户快速认证问题,对动态用户认证协议作了介绍,并指出了其可能的安全隐患.提出了对动态用户认证协议的改进方案,并对改进协议的性能进行讨论,并论述了该协议在异构环境下无线传感器网络中的应用.     

基于SMAC的无线传感器网络MAC协议的分析与优化

首先对MAC协议进行了相关介绍。然后重点介绍了一种基于竞争的无线传感器网络MAC层协议S-MAC协议。其核心是提出了一种新的无线传感器网络的MAC协议设计方案。基于动态调整占空比的思想,提出了ATC-SMAC协议。该协议在S-MAC协议的基础上改进了固定占空比的劣势,根据每个节点上的数据包的平均延迟调整占空比。通过动态地调整每个节点的占空比,使不同流量的节点拥有不同的工作时间,协议根据不同节点的流量情况自适应地对其占空比进行调整。经过仿真试验,得到ATC-MAC在网络端对端延迟、能量消耗以及吞吐量方面较S-MAC协议都有比较明显的提高。