共查询到18条相似文献,搜索用时 62 毫秒
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一种Ad Hoc网络组移动模型 总被引:7,自引:2,他引:7
战术互联网是Ad Hoc网络的主要应用,在该网络环境下,节点由于作战使命及建制的约束,移动节点常呈现出“组移动”的特征且组内节点通常分布在相对狭长的地带。针对战术互联网中移动节点的移动特征,提出了一种符合战术互联网环境的组移动模型:狭长的组移动模型(CGM:Confined Group Mobility),并从网络拓扑结构和对路由协议性能的影响两个方面与目前广泛采用的参考点组移动模型(RPGM:Refefence Point Group Mobility)进行了比较。仿真表明,不同的组移动模型对Ad Hoc网络的性能仿真将产生较大的影响。 相似文献
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车载无线自组网络连通性分析 总被引:1,自引:0,他引:1
在智能交通系统中,车辆上常常安装无线adhoc节点,车辆间通过Adhoc方式进行点对点通信,针对这种车载无线自组网络在实际道路上的网络拓扑特点,抽象出合理的网络模型,利用渗流理论讨论该网络的连通性问题.首先证明了1维动态无线自组网络的"无渗流"特点,并通过仿真实验探讨实际交通网络中车载无线ad hoe节点的合理传输半径,提出通过合理部署静态节点的方法提高1维动态网络的连通性.针对2维车载无线自组网络的交通特性,提出适合车辆交通网的无线节点连通性策略-一基于定点覆盖的策略,从理论上给出了2维网络被定点覆盖的条件,之后通过仿真实验分析2维车载无线自组网在真实道路系统上的连通特点,并针对定点--五角场中心进行定点覆盖实验. 相似文献
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针对不同密级设备间的信息交互问题,基于移动存储设备,提出了一种安全交互模型。该模型利用移动存储设备分区建立安全通信通道,将多密级交互问题转化为有序操作请求序列的控制问题。通过设定安全等级条件、分区与操作类别可识别条件构造分区读写控制函数,控制分区对交互区的读写;在此基础上,设计交互设备间的操作控制规则,从而建立起有效的双向可控的多密级信息安全交互机制,并给出理论证明。仿真实验结果表明,该模型能够实现多密级设备间信息的双向安全交互。 相似文献
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Modern modes of transport, in the developed world, were designed to achieve higher mobility (or speed) and increased accessibility, all in the name of growth and human progress. However, in the course of providing for this higher mobility, through the rapid expansion of the transport system, we have ended up with a condition of imbalanced mobility, which we refer to as "hypermobility," particularly with reference to the automobile mode. Ironically, this very expansion of the transport network, with the objective of providing higher transport speeds, has resulted in traffic congestion that has drastically reduced mobility and accessibility, thereby lowering business productivity, increasing fuel consumption, increasing pollution, and robbing the public of billions of hours of valuable time. In light of the present unsustainable conditions, we examine and analyze the concepts of mobility through an inquiry of time, space, human freedom, and social justice from an ethical and systemic viewpoint. We conclude that if hypermobility is not dealt with both as an individual and as a collective responsibility, the challenge to transport ethics and its systemicity could be further impaired. 相似文献
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For wireless ad hoc networks simulation, node's mobility pattern and traffic pattern are two key elements. A new simulation model is presented based on the virtual reality collision detection algorithm in obstacle environment, and the model uses the path planning method to avoid obstacles and to compute the node's moving path. Obstacles also affect node's signal propagation. Considering these factors, this study implements the mobility model for wireless ad hoc networks. Simulation results show that the model has a significant impact on the performance of protocols. 相似文献
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在卫星星座通信系统中,往往通过降低位置更新频率或减少位置寻呼波束的方法达到减少系统开销的目的,这势必会造成位置寻呼成功率的降低及处理时延的增加,为此提出了采用位置寻呼补救策略的思想,通过仿真验证,补救策略可以用很小的信令开销,在移动终端相关位置区内完成小区重新定位,从而提高整个系统的呼叫成功率。 相似文献
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在无线网络架构中,移动性管理包括位置管理和寻呼过程,是为用户提供网络服务的一项重要保障.目前已有的位置管理中跟踪区列表部署方案大多数没有考虑到用户的实际运动轨迹,在网络架构中造成大量的位置管理信令浪费.本文构建了一个基于用户运动轨迹的二维随机移动模型,并基于常规马尔可夫链和带有吸收态的改进马尔可夫链预测方案分析移动性管... 相似文献