首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 218 毫秒
1.
机会网络是一种通过节点移动建立通信链路的无线自组织网络,一般通过消息复制的路由策略传递信息。但该方式将导致链路中存在大量消息副本,对节点缓存形成巨大压力,造成网络拥塞。针对该情况,结合Prophet算法,充分考虑节点缓存对链路状态及传输概率的影响,设计限制消息最大副本数量与及时删除节点缓存中不必要数据包的缓存管理机制,同时在Prophet算法中考虑了缓存比因素。仿真结果表明,该算法可以有效提高消息投递率,降低网络消耗。  相似文献   

2.
提出了一种无线传感器网络中基于蚁群算法的单向链路路由算法,该算法采用单向链路和双向链路相结合的方法,寻找源节点到目的节点的最优路径。仿真结果表明,该算法能够选择参数性能好的路径,最优路径上的总时延远远小于只支持双向链路的传统蚁群算法,而且最优路径的收敛速度明显加快,由此节省了无线传感器网络中的能耗。  相似文献   

3.
针对分簇无线传感器网络提出了一种基于虚拟天线阵列的协作算法.该算法通过节点间的协作来提高网络连通性,所有节点均按照泊松Voronoj网格模型进行分簇,簇首根据通信链路决定是否激活节点协作;若节点协作算法被激活,簇首从其成员中选择适合的节点作为协作节点共同组成虚拟天线阵列.通过协作,可扩展簇间的通信范围从而与远方节点直接...  相似文献   

4.
路由在机会网络(Opportunistic Networks,OPPNETs)中扮演着重要的角色.在机会网络中,大多数的路由方案都假定了数据传播过程不受恶意节点攻击.然而,在实践中,由于通信链路的频繁中断,机会网络会遭受到各种攻击.利用了连接状态、转发能力和共同属性作为衡量信任的指标,结合基于网络编码的数据传输模式,提出了基于信任的路由算法和缓存管理算法.提出的路由策略通过利用可信节点来传输数据,保证了数据传输的安全性,而且还可以通过受信任的路径来降低传输成本.仿真实验的结果表明,本文的算法在投递率、平均延迟和网络开销三方面均获得较好的性能.  相似文献   

5.
通过分析底层网络在物理网络固化、资源利用率低、系统稳定性差等方面存在的问题,提出了基于模糊逻辑的自适应虚拟网络映射算法。该算法能够有效地解决映射过程中节点及链路多个参数对映射路径的选择影响,并且能够提高底层资源负载均衡度、降低链路花费以及减少丢包率,从而提高底层资源的利用率和虚拟网络的可靠性。  相似文献   

6.
提出一种基于弧覆盖的节点调度算法来控制无线传感器网络的密度问题.利用节点感知区域所覆盖到的弧是否被邻居节点完全覆盖来判定节点的状态,通过节点之间的状态轮换与合作策略来延长网络寿命.仿真证明该算法具有良好的节能性能,而且有效延长网络的生存寿命.  相似文献   

7.
在Ad hoc网络中冲突控制问题一直是研究热点,本文首先对冲突进行定量的分析描述,然后从自适应按需加权的角度提出相应的冲突受限算法。该算法在保证网络连通性的前提下,兼顾节点移动性,节点度以及链路冲突尽量最小化,构建了一个冲突控制拓扑,用于实现整个网络的冲突控制,提高了网络性能。  相似文献   

8.
移动自组织网络具有无需基础设施,使用带宽受限的无线链路,并且拓扑结构频繁变化的特点。AODV(Ad-hoc On Demand Distance Vector Routing)是移动自组织网络中的一种典型路由算法。本文在其基础上提出一种改进方法,充分利用RREQ和RREP携带网络节点路由信息,存放到后续经过的中间节点的路由表中,从而抑制路由请求广播,提升协议性能。  相似文献   

9.
为解决无线通信链路状态不稳定、节点通信资源有限以及节点行为不可预知条件下节点信誉评价问题,提出一种无线Mesh网络信誉度评价模型。该方法通过可达骨干路由节点的最短跳数构建基础信任关系,并通过协同服务质量QoS评价建模分析,实现信誉度评价反馈。实验结果表明,信誉评价机制能够在空闲状态时反映路由链路特征,且收敛速度较快。该协同服务信誉评价机制能够有效反映不同链路状态和交互结果下节点间的信任关系,更有效地促进节点协作。  相似文献   

10.
目前很多无线Mesh网络(WMN)是以多信道、多接口环境搭建,如何进行有效的信道分配来提高网络性能是无线Mesh网络研究的重点之一.综合考虑了网络链路负载、节点可信度和链路干扰等因素,提出了一种基于节点可信度的无线Mesh网络信道分配策略(NTCA)对重要链路优先分配信道,从而降低链路冲突率.通过实验仿真表明,与随机信道分配策略相比,NTCA策略能有效降低网络冲突,提高网络性能.  相似文献   

11.
视频中的大部分文本,特别是标题字幕会与背景有较强的对比,另外,部分文本会做线性运行或不规则运动,针对上述两种情况,提出了基于主成分追踪的视频文本定位方法,将主成分追踪这种矩阵分解算法成功应用于视频文本的定位系统中,主要包含两个步骤,首先进行视频分解,通过主成分追踪算法将视频帧分解成低秩矩阵和稀疏矩阵两部分,稀疏矩阵中包含了大部分文本信息,接下来在稀疏矩阵中进行文本定位.该方法减少了后续的文本提取和识别的难度,算法简单可行,实用性强,具有一定的现实意义.  相似文献   

12.
Algorithm for Delay-Constrained Minimal Cost Group Multicasting   总被引:1,自引:0,他引:1  
Group multicast routing algorithms satisfying quality of service requirements of real-time applications are essential for high-speed networks. A heuristic algorithm was presented for group multicast routing with bandwidth and delay constrained. A new metric was designed as a function of available bandwidth and delay of link, And source-specific routing trees for each member were generated in the algorithm by using the metric, which satisfy member's bandwidth and end-to-end delay requirements. Simulations over random network were carried out to compare the performance of the proposed algorithm with that from literature. Experimental results show that the algorithm performs better in terms of network cost and ability in constructing feasible multicast trees for group members. Moreover,the algorithm can avoid link blocking and enhance the network behavior efficiently.  相似文献   

13.
无线传感器网络作为一种新型的以采集数据为目的、高密度、自组织、低数据率的短距离无线通信网络,在国外相关研究领域一直是热点.文章概要地介绍了无线传感器网络的特点、应用前景以及研究热点,强调了无线传感器网络的路由协议设计方式不同于现有的有线及无线网络.特别阐明了作为一个以环境监测为主要应用的自组织网络,在现有器件的条件下,网络寿命这一关键参数主要取决于对传感器节点的能耗有重大影响的路由协议,着重研究了如何从网络层的路由协议和算法设计着手实现功率控制,以达到节约能耗、延长网络寿命这一目的.  相似文献   

14.
余涵 《教育技术导刊》2009,8(8):149-151
无线Mesh网(wireless mesh networks,WMNs)是一种新兴的无线网络技术,支持节点多跳路由和转发功能。节点合作与否是实现通信的关键。在缺少预先约定的信任关系时,判断节点合作性的安全机制是解决恶意节点破坏网络通信的有效手段。在对WMNs中AODV协议安全分析的基础上,提出了一种基于局部声誉值的安全路由解决方案。  相似文献   

15.
Cross-layer design of energy-saving AODV routing protocol   总被引:1,自引:0,他引:1  
Since most ad hoc mobile devices today operate on batteries, the power consumption becomes an important issue. This paper proposes a cross-layer design of energy-aware ad hoc on-demand distance vector (CEAODV) routing protocol which adopts cross-layer mechanism and energy-aware metric to improve AODV routing protocol to reduce the energy consumption and then prolong the life of the whole network. In CEAODV, the link layer and the routing layer work together to choose the optimized transmission power for nodes and the route for packets. The link layer provides the energy consumption information for the routing layer and the routing layer chooses route accordingly and conversely controls the link layer to adjust the transmission power. The simulation result shows that CEAODV can outperform AODV to save more energy. It can reduce the consumed energy by about 8% over traditional energy-aware algorithm. And the performance is better when the traffic load is higher in the network.  相似文献   

16.
To find the optimal routing is always an important topic in wireless sensor networks (WSNs). Considering a WSN where the nodes have limited energy, we propose a novel Energy^*Delay model based on ant algorithms ("E&D ANTS" for short) to minimize the time delay in transferring a fixed number of data packets in an energy-constrained manner in one round. Our goal is not only to maximize the lifetime of the network but also to provide real-time data transmission services. However, because of the tradeoff of energy and delay in wireless network systems, the reinforcement learning (RL) algorithm is introduced to train the model. In this survey, the paradigm of E&D ANTS is explicated and compared to other ant-based routing algorithms like AntNet and AntChain about the issues of routing information, routing overhead and adaptation. Simulation results show that our method performs about seven times better than AntNet and also outperforms AntChain by more than 150% in terms of energy cost and delay per round.  相似文献   

17.
承载了大数据业务的复杂感知网络在满足业务接入的同时如何应对网络节点面临的业务失效风险,已成为业界研究的热门问题。风险控制算法克服了传统算法在实施风险评估时对节点较高的依赖性。风险控制算法通过构建数学模型为展开信息域参数的计算和更新,并制定筛选策略来锁定潜在风险的异常业务质量(QoS)目标节点。经验证,该算法具有良好的可行性。  相似文献   

18.
针对Adhoc网络中移动节点能量受限的问题,考虑节点剩余能量和节点能量消耗速率两方面因素,对AODV协议,在选路机制,hello机制几个方面作了改进,改进后的路由协议能够有效均衡负载,保护低能量节点,延长网络生存时间。  相似文献   

19.
There were two strategies for the data forwarding in the content-centric networking(CCN): forwarding strategy and routing strategy. Forwarding strategy only considered a separated node rather than the whole network performance, and Interest flooding led to the network overhead and redundancy as well. As for routing strategy in CCN, each node was required to run the protocol. It was a waste of routing cost and unfit for large-scale deployment.This paper presents the super node routing strategy in CCN. Some super nodes selected from the peer nodes in CCN were used to receive the routing information from their slave nodes and compute the face-to-path to establish forwarding information base(FIB). Then FIB was sent to slave nodes to control and manage the slave nodes. The theoretical analysis showed that the super node routing strategy possessed robustness and scalability, achieved load balancing,reduced the redundancy and improved the network performance. In three topologies, three experiments were carried out to test the super node routing strategy. Network performance results showed that the proposed strategy had a shorter delay, lower CPU utilization and less redundancy compared with CCN.  相似文献   

20.
In order to share multimedia transmissions in mesh networks and optimize the utilization of network resources, this paper presents a Two-stage Evolutionary Algorithm (TEA), i.e., unicast routing evolution and multicast path composition, for dynamic multicast routing. The TEA uses a novel link-duplicate-degree encoding, which can encode a multicast path in the link-duplicate-degree and decode the path as a link vector easily. A dynamic algorithm for adding nodes to or removing nodes from a multicast group and a repairing algorithm are also covered in this paper. As the TEA is based on global evaluation, the quality of the multicast path remains stabilized without degradation when multicast members change over time. Therefore, it is not necessary to rearrange the multicast path during the life cycle of the multicast sessions. Simulation results show that the TEA is efficient and convergent.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号