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1.
水下移动无线传感器网络是追踪水下目标的重要手段,由于水下环境复杂,传感器节点会因为损坏或能量耗尽等问题脱离WSN网络,造成目标追踪困难。针对该问题,在拓扑熵理论基础上建立移动WSN目标追踪算法模型,利用拓扑熵对空间中点集拓扑关系描述移动WSN节点的部署情况。当有节点脱网后,通过不断计算拓扑熵值的变化合理调度节点移动,实现节点移动过程中的分布式自适应部署。仿真结果表明,在传感器节点损耗的情况下,提出算法和现有WSN目标追踪方法相比,在优化移动传感器网络的部署和目标追踪方面,具有更高的算法性能和效率。  相似文献   

2.
由于传感器节点能量受限,如何优化无线传感器网络(WSN)寿命是一项重要任务。借助混合二元线性规划(MBLP)框架,对限制传入/传出链路数量的WSN寿命影响进行了研究。利用MBLP最大化WSN寿命,并给出对应约束条件;通过线性网络拓扑结构,分析了节点数量、节点面积对WSN寿命的影响。性能分析表明,如果传入/传出链路数量至少为3时,网络寿命降低小于1.0%,从而进一步证明了分割流量为三部分足以平衡传感器节点间的能耗。  相似文献   

3.
追踪精度与传感器节点能耗是无线传感网络WSN(Wireless Sensor Network)中主要考虑的两个性能指标,现有的许多目标追踪算法在提高追踪精度、降低传感器节点能耗的同时缺乏对传感器节点位置与数目的考虑.因此,提出一种基于误差椭圆的自适应节点选择目标追踪算法,以误差椭圆为基准计算目标最可能出现的区域,然后根据误差判决调整区域内所需激活的传感器节点数量,完成对目标的跟踪.仿真结果表明,该算法可以在保证追踪精度的同时有效降低激活传感器节点数量.  相似文献   

4.
面向主动防御的无线传感器网络安全框架   总被引:1,自引:0,他引:1  
无线传感器网络的部署和应用受通信信道开放、动态拓扑和节点资源严格受限等因素制约,其安全性面临着巨大的威胁和挑战。文中在分析了现有WSN安全防御的特点和难点的基础上,针对目前无线传感器网络安全技术处于被动防守、扩展性差、动态防护能力不强的问题,分析并设计了面向主动防御的WSN安全框架。通过各模块协同联动,运用“预防-〉入侵探测(预测)-〉防御响应-〉动态加固”多重手段,提供了一个全方位多层次的主动防御安防模式。  相似文献   

5.
为了保证在具有较高跟踪精度的条件下,实现WSN监测区域移动目标的动态跟踪,并尽可能地降低节点能耗和延长网络的生命周期,提出了一种基于改进粒子滤波算法的分布式移动目标跟踪算法;首先,对网络假设和目标移动模型均进行了描述,然后设计了实现对移动目标进行跟踪的节点组织策略,对网络进行动态分簇,在初始时刻簇头收集簇成员的目标估值并进行信息融合以获得目标的初始位置,然后在簇头处运行改进的粒子滤波算法并周期收集各簇成员的观测值进行目标跟踪;采用Matlab仿真工具进行仿真,结果表明文中方法能精确地实现WSN监测区域的移动目标跟踪,且与其它方法比较,具有较高的跟踪精度、较小的误差及较大的优越性。  相似文献   

6.
一种基于网格和移动代理的无线传感器网络数据融合算法   总被引:2,自引:1,他引:1  
能源有效性是无线传感器网络(WSN)路由算法设计要考虑的首要问题,数据融合可以通过合并冗余数据而有效地节约能耗.提出一种将网格和移动代理相结合的WSN数据融合算法,基于移动代理对Sink节点发出兴趣代理报文和目标节点发出数据代理报文进行转发.将移动代理路由归结为一个优化问题,通过把WSN均匀分割为多个大小适当的二维网格,形成自适应遗传算法(AGA)的初始群体,采用AGA求出移动代理的最优路由节点序列.仿真结果表明,随着网络规模增大,和局部最近邻优先算法(LCF)相比,该算法有更小的网络能耗和延时.  相似文献   

7.
面向特定区域的WSN组播路由协议   总被引:1,自引:0,他引:1       下载免费PDF全文
针对无线传感器网络(WSN)中节点分布不均和能量消耗较大的问题,提出一种面向特定区域的WSN组播路由协议.采用组头轮换机制,使能量储备较多和位置最优的节点担任组播节点承担转发任务,能量储备较少的节点负责数据采集任务.利用多转发组的模式建立稳定路由,提高网络健壮性,降低数据延迟.仿真结果表明,该协议可使整个区域内节点能量...  相似文献   

8.
针对大多数现有无线传感器网络(Wireless Sensor Network, WSN)目标覆盖方案没有考虑传感器功率(传感范围)可调的问题,提出一种基于学习自动机(Learning Automata, LA)和节点功率自适应调整的WSN的目标覆盖方案。利用LA算法根据节点能量自适应调整节点的发射功率,构建能够覆盖所有目标的覆盖集,并通过精简过程获得最小覆盖集,从而减低节点的能耗,提高网络的生命周期。通过实验研究了传感器数量和目标数量对网络寿命的影响,并将该方案与基于贪婪算法、遗传算法的方案进行比较,结果表明,该方案能够获得更多的覆盖集和更长的网络寿命。  相似文献   

9.
一种面向认知网络的QoS路由协议   总被引:2,自引:0,他引:2  
随着网络应用的快速发展,传统网络面临诸多挑战,难以满足新型应用的服务质量QoS(Quality of Service)需求,网络管理变得极其复杂,迫切要求网络具备认知能力.文中提出了一种面向认知网络的QoS路由协议.为了满足不同应用的QoS需求,路由请求对应不同业务类型和服务等级,映射到相应的QoS参数.文中赋予路由节点感觉、活动感、记忆、查找、决策、执行、推理、解释等认知行为,设计了与这些行为相对应的协议报文,支持节点之间通过这些报文进行交互,从而具备认知能力.节点只收集和维护局部邻居和链路状态信息,通过使用和维护经验路段信息提高路由效率.文中对所提出的路由协议在原型系统上进行了实现,对协议的多项性能指标进行了评价.实验结果表明,文中所提出的路由协议是可行和有效的.  相似文献   

10.
无线传感器网络的QoS体系结构   总被引:13,自引:1,他引:12  
不同于传统互联网,作为涵盖了数据感知、处理和传输的复杂任务型网络,无线传感器网络面向应用的特点给服务质量(QoS)研究带来了许多新的挑战,需要针对QoS体系结构以及QoS指标间复杂关系的系统工作.文中首先提出了无线传感器网络中QoS指标的分层模型以及相应的规范化描述,然后分析了QoS指标的映射关系,最后提出了一个层次化的QpS体系结构,希望为无线传感器网络中QoS保障技术的系统性研究提供参考.  相似文献   

11.
无线局域网MAC层QoS机制综述   总被引:1,自引:0,他引:1  
无线局域网WLAN已成为当下日益流行的无线接入方案,但现有的WLAN协议对QoS的支持极其有限,致使多媒体、实时交互等QoS需求高的应用的实施难以实现.无线局域网MAC层是控制和协调无线节点访问网络介质的关键协议子层.如何在有限的网络资源和不稳定的物理介质前提下在MAC层提供有效QoS服务,成了无线网络研究界的一个新的课题.本文分析并总结了当前在无线局域网提供QoS的技术难点和主要的QoS提供策略,对现存的QoS提供机制从两个角度进行了分类和概括,最后指明了MAC层QoS研究的发展方向.  相似文献   

12.
Yong  Jianping  Ke 《Computer Networks》2005,47(6):923-937
Quality-of-service routing (QoSR), seeking to find a feasible path with multiple constraints, is an NP-complete problem. We propose a novel precomputation approach to multi-constrained intra-domain QoS routing (PMCP). It is assumed that a router maintains the link state information of the entire domain. PMCP cares each QoS weight to several degrees, and computes a number of QoS coefficients uniformly distributed in the multi-dimensional QoS metric space. Based on each coefficient, a linear QoS function is constructed to convert the multiple QoS metrics to a single QoS value. We then create a shortest path tree with respect to the QoS value by Dijkstra’s algorithm. Finally, according to the multiple coefficients, different shortest path trees are calculated to compose the QoS routing table. We analyze linear QoS functions in the QoS metric space, and give a mathematical model to determine the feasibility of a QoS request in the space. After PMCP is introduced, we analyze its computational complexity and present a method of QoS routing table lookup. Extensive simulations evaluate the performance of the proposed algorithm and present a comparative study.  相似文献   

13.
Web services promise to become a key enabling technology for B2B e-commerce. One of the most-touted features of Web services is their capability to recursively construct a Web service as a workflow of other existing Web services. The quality of service (QoS) of Web-services-based workflows may be an essential determinant when selecting constituent Web services and determining the service-level agreement with users. To make such a selection possible, it is essential to estimate the QoS of a WS workflow based on the QoSs of its constituent WSs. In the context of WS workflow, this estimation can be made by a method called QoS aggregation. While most of the existing work on QoS aggregation treats the QoS as a deterministic value, we argue that due to some uncertainty related to a WS, it is more realistic to model its QoS as a random variable, and estimate the QoS of a WS workflow probabilistically. In this paper, we identify a set of QoS metrics in the context of WS workflows, and propose a unified probabilistic model for describing QoS values of a broader spectrum of atomic and composite Web services. Emulation data are used to demonstrate the efficiency and accuracy of the proposed approach.  相似文献   

14.
面向服务QoS模型中一种需求映射方法   总被引:1,自引:0,他引:1  
对如何在面向服务网格环境下进行QoS需求映射,做了较深入研究,提出了相应的QoS模型,并对模型进行了详细描述。该模型紧密结合网格系统管理架构和策略,突出了网格系统的特点。对应用程序QoS需求,提出使用QoS订单方式提交,在此基础上建立了一个QoS约束映射模型,并分析了映射参数之间的关系和确定方法。通过举例进行分析,给出了具体QoS映射过程,表明该模型在理论和应用两个方面都具有较高价值。  相似文献   

15.
QoS multicast routing in networks is a very important research issue in networks and distributed systems. It is also a challenging and hard problem for high-performance networks of the next generation. Due to its NP-completeness, many heuristic methods have been employed to solve the problem. This paper proposes the modified quantum-behaved particle swarm optimization (QPSO) method for QoS multicast routing. In the proposed method, QoS multicast routing is converted into an integer programming problem with QoS constraints and is solved by the QPSO algorithm combined with loop deletion operation. The QPSO-based routing method, along with the routing algorithms based on particle swarm optimization (PSO) and genetic algorithm (GA), is tested on randomly generated network topologies for the purpose of performance evaluation. The simulation results show the efficiency of the proposed method on QoS the routing problem and its superiority to the methods based on PSO and GA.  相似文献   

16.
基于蚁群算法的多路径多约束QoS路由研究   总被引:3,自引:1,他引:2       下载免费PDF全文
多路径多约束服务质量(Quality of Service,QoS)路由问题是无线传感器网络的核心问题之一,由于网络拓扑的不断变化及链路的固有的不精确性,解决这个问题具有很大的挑战性。首先给出无线传感器网络中QoS路由问题描述及调和蚁群算法(Ant Colony Optimization,ACO)的基本算法步骤及其特点。然后在分析了蚁群算法应用于QoS路由问题的可能性的基础上,给出了调和蚁群算法解决多路径多约束QoS问题的算法。最后通过仿真实例得到满意的结果。  相似文献   

17.
We present a QoS-aware recommender approach based on probabilistic models to assist the selection of web services in open, distributed, and service-oriented environments. This approach allows consumers to maintain a trust model for each service provider they interact with, leading to the prediction of the most trustworthy service a consumer can interact with among a plethora of similar services. In this paper, we associate the trust in a service to its performance denoted by QoS ratings instigated by the amalgamation of various QoS metrics. Since the quality of a service is contingent, which renders its trustworthiness uncertain, we adopt a probabilistic approach for the prediction of the quality of a service based on the evaluation of past experiences (ratings) of each of its consumers. We represent the QoS ratings of services using different statistical distributions, namely multinomial Dirichlet, multinomial generalized Dirichlet, and multinomial Beta-Liouville. We leverage various machine learning techniques to compute the probabilities of each web service to belong to different quality classes. For instance, we use the Bayesian inference method to estimate the parameters of the aforementioned distributions, which presents a multidimensional probabilistic embodiment of the quality of the corresponding web services. We also employ a Bayesian network classifier with a Beta-Liouville prior to enable the classification of the QoS of composite services given the QoS of its constituents. We extend our approach to function in an online setting using the Voting EM algorithm that enables the estimation of the probabilities of the QoS after each interaction with a web service. Our experimental results demonstrate the effectiveness of the proposed approaches in modeling, classifying and incrementally learning the QoS ratings.  相似文献   

18.
Kaan  Cem   《Performance Evaluation》2009,66(12):701
The tremendous amount of multimedia applications running across the wireless communication medium makes quality of service (QoS) a fundamental requirement for mobile ad hoc networks. However, it is not easy to incorporate QoS into these networks. Moreover, the growing number of group-oriented applications also necessitates the efficient utilisation of network resources. The multicast model is a promising technique which can achieve this efficiency by facilitating the inherent broadcast capability of the wireless medium. The mesh-evolving ad hoc QoS multicast (MAQM) routing protocol is developed to address the resource efficiency and QoS problems with one, integrated solution. MAQM achieves multicast efficiency by tracking the availability of resources for each node within its neighbourhood. The QoS status is monitored continuously and announced periodically to the extent of QoS provision. Using these features, MAQM nodes can make their decisions on joining a new multicast session based on the sustainability of their perceived QoS. MAQM also evolves the initial multicast tree into a mesh during the course of an ongoing session to achieve a more robust network topology. Thus, MAQM integrates the concept of QoS-awareness into multicast routing in mobile ad hoc networks. Since ad hoc networks require the protocol control overhead to be as small as possible, we analyse the multicast session establishment process of MAQM to see its impact on the protocol performance in terms of system control overhead. We also evaluate the performance of MAQM through computer simulations using various qualitative and quantitative criteria. The simulation results validate our mathematical analysis of the control overhead and show that MAQM significantly improves multicast efficiency through its QoS-aware admission and routing decisions with an acceptably small overhead. Thus, MAQM shows that QoS is not only essential for, but also applicable to mobile ad hoc networks.  相似文献   

19.
宋嵩  杜文  牛志升  李康 《计算机应用》2005,25(6):1471-1474
为了在无线网络中保证实时多媒体业务的服务质量(QoS),基于IPv6在无线局域网中设计并实现了差分QoS测试平台,实验测试各种支持QoS调度策略。测试平台核心部件为实现差分QoS调度的IPv6路由器。路由器由Linux操作系统来实现,采用可加载内核模块编程,使用Netfilter中钩子函数截获网络数据包,根据业务的不同优先级进行调度,合理分配网络资源,保证实时业务的服务质量。在此平台上,进行了多媒体业务差分QoS的演示和测试。实验表明,测试平台运行稳定,可以为QoS研究提供一个开放式开发测试环境。  相似文献   

20.
Multimedia group applications often operate in an environment where the various participants are located on systems and communication links with different capabilities. Mechanisms are required that ensure full-quality media for high-performance workstations but lower-quality media for playout at low-end systems. QoS filters have been proposed as a way to adapt QoS to the user specified level by changing the structure of a media stream in a well defined way. Resource reservation and QoS filter instantiation should be closely integrated since both represent one particular aspect of the provision of individualistic QoS for heterogeneous users in multipeer communications. The Internet reservation protocol RSVP is receiver oriented and allows each receiver to specify its resource requirements. However, no actual mechanisms are defined that adapt the data stream to the receiver specified QoS requirements.In this paper we present an enhanced version of RSVP (called RSVP++) that integrates resource reservation and QoS filter control. In order to achieve this integration we extend the RSVP functional model and define a new QoS service class. RSVP++ can coexist with common RSVP systems, thus, openness and interoperability of the system are ensured.  相似文献   

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