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一个自组网中基于局部状态位置已知的分布式QoS路由算法 总被引:4,自引:0,他引:4
在分析自组网的单播QoS路由问题的基础上,提出了一种位置信息已知的利用局部状态信息进行路由选择的的分布式QoS路由算法——LILAGR算法。LILAGR路由算法的基本思想是逐段优化费用和尽快到达目的节点,即在决定节点之间是选择带宽约束费用最小的路径而各个决定节点则是按照贪婪地尽快到达目的节点的原则进行选择。仿真结果表明:LILAGR算法能够以适度的路由消息开销取得较高的路由成功率。此外,LILAGR算法具有可扩展性,可以应用于较大规模的自组网中。 相似文献
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无线自组网节点定位算法综述 总被引:1,自引:0,他引:1
节点移动性使无线自组网络在军事、医学、环境保护等领域展现出广阔的应用前景。然而随着人们对移动节点位置信息的需求,节点定位问题也成为一个研究的热点问题,到目前为止,己有许多有关无线自组网的自定位系统和算法。在对这些定位算法进行分类的基础上,把节点定位过程分为4个基本步骤,着重分析阐述各类申具有代表性的定位算法的原理和各自特点,并提出一个对定位算-法I陛能评价的标准。 相似文献
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网络连通性是组网与路由研究的前提和基础,针对目前对固定航线航空自组网连通性研究较少的现状,提出一种连通性研究方法.该方法结合实际航线分层、双向的特点,通过建立飞机分布模型与航线模型,推导出了一维航线连通性表达式.在此基础上,运用基于概率矩阵的概率图求解方法对航线网的连通性进行理论研究,并用实验证明其正确性.随后,根据实际航班数据对我国部分空域内一维航线及航线网的连通性进行仿真,结果表明航空自组网在上述空域具备可行性.最后,从航班安排、航线规划等4个方面对提升连通性给出了合理性建议. 相似文献
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井下语音通信是煤矿安全系统的组成部分,随着电子通讯技术的发展,已陆续推出几代产品。无线自组织网络技术的自我配置、多跳式无线接力联接、不需要基础通信设施、低功耗和较低的成本等特性正好适应井下无线通信的特点,同时能够增加调度功能,这是传统无线通信系统所不具备的。 相似文献
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DV Based Positioning in Ad Hoc Networks 总被引:95,自引:0,他引:95
Many ad hoc network protocols and applications assume the knowledge of geographic location of nodes. The absolute position of each networked node is an assumed fact by most sensor networks which can then present the sensed information on a geographical map. Finding position without the aid of GPS in each node of an ad hoc network is important in cases where GPS is either not accessible, or not practical to use due to power, form factor or line of sight conditions. Position would also enable routing in sufficiently isotropic large networks, without the use of large routing tables. We are proposing APS – a localized, distributed, hop by hop positioning algorithm, that works as an extension of both distance vector routing and GPS positioning in order to provide approximate position for all nodes in a network where only a limited fraction of nodes have self positioning capability. 相似文献
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Fast resources discovery and high Quality of Service (QoS) guarantee are the key det-erminants for efficient Mobile P2P (MP2P) video sharing. In this paper, we propose a Cross- Layer and One-Hop Neighbour-Assisted Video Sharing (CNVS) solution in Mobile Ad Hoc Networks (MANETs). By making use of cross- layer approaches to bridge the overlay and the MAC layer and with the help of dissemination assisted by one-hop neighbours, CNVS intel-ligently builds the resource-centric self-organ-ization node cluster group. In order to meet the QoS requirement, by making use of video resources access cost model, each peer can disconnect a less efficient connection with the original supplier and choose a peer that pro-vides a low access cost as the new supplier. Simulation results also show how CNVS achi-eves lower average end-to-end delay, less ave-rage number of hops for video data delivery, lower routing overhead and packet loss rate, and higher network throughput than another state-of-the-art solution. 相似文献
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无线特定网络--Ad Hoc网络 总被引:5,自引:0,他引:5
Ad Hoc网络是一种没有固定结构的无线移动网络。介绍了移动Ad Hoc网络(MANETs)的主特点和与传统有线分组交换网相比的特性,讨论了应用于Ad Hoc网络的路由机制和所需面临的问题。 相似文献
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提出了一种新的Ad Hoc网络中对路由的维护方法,即基于局部多路径路由维护的路由软切换技术。在当前路由中某段或某几段链路出现问题时,通过建立局部的多路径路由,分担问题链路中的负载,维护网络保持通信连接不被中断;当路由稳定时,从局部多路径路由中寻找一条满足当前主路由通信需要的子路径,并且将数据传输切换到此子路径上,达到路由抢先维护和软切换的目的。该方法能够缩短路由重建的时间,延长单路径路由的寿命,使用多路径维护,避免了网络拥塞出现造成路由中断,能够很好地提高网络性能。 相似文献
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In a mobile ad hoc network, nodes that are geographically close may need to compete for exclusive access to a shared resource. This paper proposes an abstraction of this problem, called local mutual exclusion; it is an extension to mobile networks of the dining philosophers problem, which has been well studied in static networks. The desirable feature of an algorithm for this problem is having response time and failure locality independent of the total number of nodes, thus providing a scalable and robust solution. The paper presents two algorithms, exhibiting trade-offs between simplicity, failure locality and response time. The first algorithm has two variations, one of which has response time that depends very weakly on the number of nodes in the entire system and is polynomial in the maximum number of neighboring nodes; the failure locality, although not optimal, is small and grows very slowly with system size. The second algorithm has optimal failure locality and response time that is quadratic in the number of nodes. A pleasing aspect of the latter algorithm is that when nodes do not move, it has linear response time, improving on previous results for static algorithms with optimal failure locality. 相似文献
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服务质量保障是Ad Hoc网络环境中的一个复杂的急需解决的问题。首先论述了Ad Hoc网络的网络协议模型、QoS服务模型、QoS路由以及QoS保障策略等方面的问题,然后对其进行了综合分析,在此基础上,给出了Ad Hoc网络中不同层次的QoS路由方案以及其未来的研究方向。 相似文献
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Ad Hoc网络中的节能机制 总被引:4,自引:1,他引:3
Ad Hoc网络终端的连续工作时间是影响Ad Hoc网络实用化的关键因素,产业界也一直在寻求通过采用节能机制来延长终端工作时间的方法。本文对Ad Hoc网络中典型的节能机制进行了分类介绍和比较,对运用节能机制所面临的困难给予了阐述,最后给出了节能研究的发展方向。 相似文献
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We present a local distributed algorithm that, given a wireless ad hoc network modeled as a unit disk graph U in the plane, constructs a planar power spanner of U whose degree is bounded by k and whose stretch factor is bounded by 1 + (2sin{frac{pi}{k}})^{p}, where k geq 10 is an integer parameter and p in [2, 5] is the power exponent constant. For the same degree bound k, the stretch factor of our algorithm significantly improves the previous best bounds by Song et al. We show that this bound is near-optimal by proving that the slightly smaller stretch factor of 1 + (2sin{frac{pi}{k + 1}})^{p} is unattainable for the same degree bound k. In contrast to previous algorithms for the problem, the presented algorithm is local. As a consequence, the algorithm is highly scalable and robust. Finally, while the algorithm is efficient and easy to implement in practice, it relies on deep insights on the geometry of unit disk graphs and novel techniques that are of independent interest. 相似文献