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AODV协议是目前比较成熟的应用于移动自组网(MANET)中的一种反应式路由协议,其缺点主要是协议开销比较大,运动情况下路由优化性能不理想。利用为RREQ消息设置时限和为中间节点根据自身队长设置回复RREP消息延迟的方法,提出了一种改进的AODV协议(AODV-DL),有效地提高了网络的投包率和路由优化性能,降低了网络的协议开销。提出了将路由优化性能作为协议的一项新的评价标准。描述了其实现策略,并给出了NS2下的仿真结果。 相似文献
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移动自组网MANET是由许多移动节点组成的无中心的、多跳的自组织网络,网络中的节点由于移动和能量耗尽可能会使得路径失效,因此传统的单路径协议效率并不高。本文介绍了自组网中最常用的AODV协议,重点对AOMDV多路径路由协议的路由机制和维护管理进行了探讨。最后使用NS2仿真软件对两种协议进行了比较,结果表明,在分组投递率和端到端延时方面,AOMDV比AODV更具优势。 相似文献
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移动自组织网络(MANET)的节点通常能量有限,为了均衡网络中节点的能量消耗并延长网络的生存时间,有必要针对MANET网络进行相关的能量感知均衡设计。文章在网络层对MANET进行能量感知研究,通过对AODV路由协议进行改进,提出具有能量有效的AODV路由发现机制,最终设计改进的AODV路由协议——EQ-AODV。仿真结果表明,本研究设计的路由协议在平衡能量消耗和延长网络生存时间方面较原始AODV协议有较大提升。 相似文献
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基于移动性的AODV路由协议改进 总被引:2,自引:0,他引:2
介绍了Ad Hoc网络路由协议(Ad Hoc On-Demand Distance Vector Routing,AODV)的路由机制和特点,提出了一种基于AODV的改进协议V-AODV。V-AODV改进了AODV的路由测度,用量化的节点移动性代替跳数作为路由代价的度量,在动态网络中能够选取到更加稳定的路由。仿真表明,V-AODV比AODV在时延和重传次数等性能上都有一定程度的提升。 相似文献
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针对移动Ad Hoc网络中节点任意移动、网络拓扑频繁变化导致以最小跳数作为路由选择机制的AODV路由协议面临频繁连接中断而造成网络QoS下降的问题,文章综合节点的剩余电量、剩余队列长度和源节点到目的节点的跳数三个跨层信息,提出一种基于灰色关联算法的改进AODV路由协议(GRA-AODV)。仿真结果显示:相比于改进前的AODV协议,改进之后的GRA-AODV(Gray Relevance AlgorithmAODV)协议在稍微增加路由开销的情况下,具有更低的平均端到端时延和更低的分组丢失率,在拓扑频繁变化的移动Ad Hoc网络中具有较好的鲁棒性。 相似文献
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本文在AODV路由协议的基础上提出了一种基于无环替代(LFA)的前摄性重路由机制,旨在提高无线Mesh网络的快速自愈的能力.文中首先介绍了AODV的改进AODV备份路由协议,并指出AODV备份路由协议的不足,然后提出了基于无环替代的AODV路由算法AODV-LFA,最后通过NS仿真实验,比较了AODV、AODV备份路由和AODV-LFA的丢包率、端到端时延等,表明AODV-LFA具有更强的自愈能力. 相似文献
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AODV路由协议的改进算法 总被引:2,自引:0,他引:2
无线Ad hoc网络拓扑结构动态变化的特点,决定了路径断裂是不可避免的。路径断裂会引起源节点路由重建,源节点频繁地发起路由重建过程会降低网络的性能。AODV协议中采用本地修复机制来减少源节点路由重建的次数。基于这一思想,文章提出了一种AODV路由协议改进算法SRP,旨在进一步提高本地修复的成功率。仿真结果表明,在拓扑结构变化迅速的Ad hoc网络中,SRP协议比AODV路由协议有更好的网络性能。 相似文献
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GMPLS技术引入的多层复杂性给源路由器带来了极大的压力,也造成了LSP建立的延时.为了缓解这种影响,文章提出了一种分布式的路由计算技术:域间和域内的路由选择分别由所辖范围的分层、分布路由器来完成.它能减少路径建立的时延,并能依据每个GMPLS域或者每层的路由选择机制做出较OSPF更为灵活的路由选择. 相似文献
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Spatial experiences in route finding, such as the ability of finding low‐traffic routes, exert a significant influence on travel time in big cities; therefore, the spatial experiences of seasoned individuals such as taxi drivers in route finding can be useful for improving route‐finding algorithms and preventing using routes having considerable traffic. In this regard, a spatial experience‐based route‐finding algorithm is introduced through ontology in this paper. To this end, different methods of modeling experiences are investigated. Then, a modeling method is chosen for modeling the experiences of drivers for route finding depending on the advantages of ontology, and an ontology based on the taxi drivers’ experiences is proposed. This ontology is employed to create an ontology‐based route‐finding algorithm. The results are compared with those of Google maps in terms of route length and travel time at peak traffic time. According to the results, although the route lengths of route‐finding method based on the ontology of drivers’ experiences in three cases (from nine cases) are greater than that based on Google maps, the travel times are shorter in most cases, and in some routes, the difference in travel time reaches only 10 minutes. 相似文献
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《Journal of Location Based Services》2013,7(2):98-120
A prediction of a vehicle's route would be useful for giving the driver advance warnings and alerts about upcoming situations and opportunities. This paper presents a new algorithm for predicting a driver's route based on a probabilistic prediction of the driver's destination. For each candidate destination, our route prediction algorithm plans a route to that destination. Roads on these routes accumulate the probabilities of their respective destinations, giving higher probabilities to roads along the way to higher probability destinations. The algorithm is based on a single parameter that characterises how efficiently a driver drives. Once this parameter is computed, it does not require storing a history of trips, and it works in places a driver has never visited. We test the algorithm on 100 routes recorded with the Global Positioning System (GPS) and show that the route prediction quickly narrows down the future route to a small fraction of the road network. We also compare our algorithm to two other algorithms to show how it performs better. 相似文献
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针对大部分现有替代路径共同存在的替代路径老化和构建效率问题,本文提出了一种基于跨层设计和蚁群优化的负载均衡路由协议(CALRA),利用蚁群优化算法特有的信息素挥发方法实现对替代路径的老化问题,将蚁群优化和跨层优化方法结合起来解决自组网中的负载均衡问题,通过双向逐跳更新的方式较好的解决了替代路径构建效率问题,并将蚂蚁在所经过的各中间节点为路由表带来的信息素增量映射为蚂蚁离开源节点的距离、移动过程中所遇到的节点拥塞程度、节点当前信息素浓度和节点移动速度等各协议层的统计信息的函数,通过对各种信息所对应的参数赋予不同加权值的方法对概率路由表进行控制,改善了自组网中现有基于蚁群优化的路由协议中普遍存在的拥塞问题、捷径问题、收敛速度问题和引入的路由开销问题.仿真表明,CALRA在分组成功递交率、路由开销、端到端平均时延等方面具有优良性能,能很好地实现网络中的业务负载均衡. 相似文献
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Yang Y.R. Haiyong Xie Hao Wang Silberschatz A. Krishnamurthy A. Yanbin Liu Li Erran Li 《IEEE network》2005,19(6):20-27
In this article we investigate a model of route selection for interdomain traffic engineering where routing to multiple destinations can be coordinated. We identify potential routing instability and inefficiency problems, and derive a set of practical guidelines to guarantee stability without global coordination. Using a realistic Internet topology, we show that route oscillations can happen even when a small number of ASes coordinate route selection for just a small number of destinations if the coordination does not follow our guidelines. Wc further extend our model so that ASes can adopt any route selection algorithms in a class of algorithms we call rational route selection algorithms; and the local ranking of routes of an AS can depend on ingress traffic patterns. We show that persistent route oscillations can happen in certain network settings even if the ASes strictly follow the constraints imposed by business considerations, and adopt any rational route selection algorithms. 相似文献
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为保证巡航导弹低空突防的成功率,在航迹规划时必须设计出以最小代价的可接受航程为目标的航迹。提出一种基于混合优化策略的航迹优化方法。该方法通过用退火机制来减轻遗传算法中的选择压力,将模拟退火和遗传算法相结合用于航迹优化,增强了航迹优化算法的全局收敛性和提高了算法的收敛速度。同时方法中还采用了聚类算法,将各条航迹按照其空间分布,化成不同的多个种群,进化后可得到不同区域的优化航迹,从而有效地保持了解的多样性,能一次生成多条航迹,可满足通常航迹优化过程中生成多条航迹的要求。最后的仿真结果表明了该方法的可行性和有效性。 相似文献