共查询到19条相似文献,搜索用时 171 毫秒
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AS级Internet拓扑分析 总被引:4,自引:0,他引:4
Interact拓扑结构的分析,对网络的进一步应用和发展具有重大意义.通过对AS(autonomous system)级拓扑海量授权数据的大跨度时间分析,得出网络多项主要特征与节点度值间的演化联系.进一步对时间切片数据的空间分析,发现了网络层次性相关的若干重要特征以及高层节点对网络拓扑的重大影响力,并通过一种层次建模方法,以实验数据论证了层次性质对网络拓扑的重要意义.结合两方面分析结果,得出AS级Interact拓扑在十分缓慢的均匀化的同时,以最高核为代表的高层节点控制着网络拓扑聚集性、幂律性、层次性等主要性质稳定的重要结论. 相似文献
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针对因特网(Internet)的复杂网络特征,通过计算Internet标准结构熵和时间的关系,揭示了Internet的拓扑结构向着更有序方向演化的规律,并利用协同学原理求出了影响其演化的序参量.另外,通过对Internet节点平均连接度时间序列进行相空间重构,计算了其分形维数、最大Lyapunov指数和Kolmologorov熵,从理论上分析了这组数据可预测的时间尺度.最后,根据分析的结果,通过对时间序列进行预处理,运用混沌预测方法对未来一段时间内Internet节点的平均连接度进行了预测. 相似文献
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首先通过海量数据统计,计算并分析了Internet的无尺度特性及小世界规律。然后在其基础上提出了一个新的面向Internet的资源查找算法——连接度优先路由查找算法(CFR,connection—coefficient first routing),充分利用其上节点间平均最短路径短以及存在少量连接度较高节点的特点,实现了在Internet上高效的资源查找。最后实现了Internet拓扑生成器,通过仿真实验,验证了该算法在超大规模的复杂网络环境下,具有查找效率及命中率较高,并且时间开销和造成的网络流量较小的优点。 相似文献
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如何描述了被仿真网络的拓扑结构是网络仿真的基础性问题.对于大规模异构性动态性发展的非集中性的Internet来说,描述其拓扑结构并不是一件容易的事情.Internet拓扑建模至今仍然是计算机网络研究领域中的热点问题.文中对几种Internet拓扑建模进行了研究与分析,比较了他们的优缺点,指出了存在的问题,最后给出Waxman算法的具体实现. 相似文献
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随着大规模交换网络的发展,网络拓扑发现的研究由网络层拓展到数据链路层.链路层的拓扑发现能够发现网络层拓扑发现无法发现的局域网内部的详细的物理连接情况.通过对数据链路层现状和存在的不足的研究,提出了一种基于STP树的数据链路层拓扑发现算法,该算法不要求各个网桥FDB表的信息是完备的,就能快速准确地计算出网络第二层的拓扑结构. 相似文献
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容迟网络中基于节点间亲密度的分组路由方法 总被引:1,自引:0,他引:1
借鉴MANET中通过分簇来减少冗余副本和社交网络中有关挖掘社交圈的思想,通过分析节点的移动规律,定义了基于节点间亲密度的拓扑结构,并将该亲密度在拓扑图中量化为可以比较的边的权值,依据边的权值大小进行拓扑裁剪,挖掘出相互亲密度较高的节点分组,并且针对源节点和目的节点所在的分组对spray and wait路由方法进行改进,来决定本身的报文副本的分配情况,进而提出了基于节点间亲密度的分组路由方法(PBI)。实验结果表明,该路由方法能够明显地提高投递成功率并且减小网络时延。 相似文献
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Habib M. Ammari 《International Journal of Communication Systems》2007,20(8):943-968
Connecting wired and wireless networks, and particularly mobile wireless ad hoc networks (MANETs) and the global Internet, is attractive in real‐world scenarios due to its usefulness and praticality. Because of the various architectural mismatches between the Internet and MANETs with regard to their communication topology, routing protocols, and operation, it is necessary to introduce a hybrid interface capable of connecting to the Internet using Mobile IP protocol and to MANETs owing to an ad hoc routing protocol. Specifically, the approaches available in the literature have introduced updated versions of Mobile IP agents or access points at the edge of the Internet to help MANET nodes get multi‐hop wireless Internet access. The main differences in the existing approaches concern the type of ad hoc routing protocol as well as the switching algorithm used by MANET nodes to change their current Mobile IP agents based on specific switching criteria. This paper surveys a variety of approaches to providing multi‐hop wireless Internet access to MANET nodes. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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《AEUE-International Journal of Electronics and Communications》2014,68(9):835-840
The topology control algorithms can improve the network capacity and network lifetime in location-aware networks. The topology control algorithms require accurate locations of mobile nodes or distances between each of the mobile nodes. The IEEE 802.15.4a-based location-aware networks can provide precise ranging distance between two mobile nodes. The mobile nodes can obtain their accurate locations by using accurate ranging distances. However, in the IEEE 802.15.4a networks, the ranging distance has a large measurement error in non-line-of-sight (NLOS) conditions. In this paper, we propose MST-based topology control with NLOS location error compensation algorithm to improve location accuracy and prevent mobile nodes from connecting to unstable links in NLOS condition. Performance evaluation shows the proposed algorithm constructs a topology map which has low location errors with considering the instability of NLOS links in NLOS condition. 相似文献
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In computer communication networks, routing is often accomplished by maintaining copies of the network topology and dynamic performance characteristics in various network nodes. The present paper describes an algorithm that allows complete flexibility in the placement of the topology information. In particular, we assume that an arbitrary subset of network nodes are capable of maintaining the topology. In this environment, protocols are defined to allow automatic updates to flow between these more capable nodes. In addition, protocols are defined to allow less capable nodes to report their topology data to the major nodes, and acquire route information from them. 相似文献
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移动自组网与Internet互连的动态网关策略 总被引:6,自引:0,他引:6
移动自组网(MANET)是自治的无基础设施的网络,它通过IP路由支持多跳无线通信。它与Internet 相比存在着许多差异,不仅有网络拓扑结构的不同,还存在通信方式的不同。因此,MANET与Internet组合成混杂网络(hybrid network)是一个具有挑战性的课题。移动自组网(MANET)的结点要进行Internet连接,就必须寻找Internet网关。如何寻找和维持与Internet网关的连接是这个问题的关键,再者,就是如何切换到一个更合适的相邻网关。在这篇文章中,首次提出动态网关的概念,动态网关作为MANET和Internet之间的接口起桥梁作用。通过模型分析,证明动态网关体系结构适合于自组网与Internet互联。仿真结果显示,利用动态网关的网络性能优于单一固定网关的体系结构的网络性能。 相似文献
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Topology discovery is a prerequisite when investigating the network properties; with the enormous number of Bitcoin users and performance issues, it becomes critical to analyse the network in a fashion that makes it possible to detect all Bitcoin's nodes and understand their behaviour. In massive, dynamic, and distributed peer‐to‐peer (P2P) networks like Bitcoin, where thousands of updates occur per second, it is hard to obtain an accurate topology representing the structure of the network as a graph with nodes and links by using the traditional local measurement approaches based on batches, offline data, or on the discovery of the topology around a small set of nodes and then combine them to discover an approximate network topology. All of which present some limitation when applying them on blockchain‐based networks. In this paper, we propose a topology discovery system that performs a real‐time data collection and analysis for Bitcoin P2P links, which assembles incoming nodes information for deeper graph analysis processing. The topology discovery system allows us to gain knowledge on the Bitcoin network size, the network stability in terms of reachable, churn, and well‐connected nodes, as well as some data regarding the effects of some countries' Internet infrastructure on Bitcoin traffic. 相似文献
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无线数据终端点对点数据传输是指终端之间通过网络相互进行数据传递的通信。提出了基于嵌入式系统和GPRS技术的DTU点对点数据传输的两种方案及其实现过程。方案一通过移动公司的CMNET接入Internet,DTU获得动态IP地址,进而进行终端间的数据传输;方案二使用移动公司根据用户需求为用户组建的APN专网,DTU根据需求可以固定IP地址,实现终端间的数据传输。DTU的组网方式采用TCP/IP典型的C/S模式。 相似文献