共查询到19条相似文献,搜索用时 458 毫秒
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作为一种新型的端到端存储转发网络体系结构,容迟与容断网络(delay and disruption tolerant network)具有间歇连接、频繁割裂、时延极高、非对称的数据速率、较高的误码率、异构互连等特点,传统的Internet、移动Ad Hoc网络和传感网的路由协议难以有效应用在容迟与容断网络中,容迟与容断网络路由面临新的挑战.在简要介绍了容迟与容断网络的基本特性和路由协议设计挑战之后,提出了路由协议评估指标.然后从单播路由、组播路由和选播路由3个方面介绍了容迟与容断网络路由协议的研究进展,最后对主要路由协议进行了综合比较,并指出了未来的研究方向. 相似文献
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针对容迟与容断网络中的单播通信问题,提出了一种自适应感知路由协议(adaptive context aware routing protocol,ACRP);并引入卡尔曼滤波理论,给出最优的消息轮渡节点选取策略.仿真实验表明,与常见的单副本拷贝或多副本拷贝协议相比,提出的面向情境感知的自适应路由协议拥有更好的传输性能和稳定性. 相似文献
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容迟网络路由算法 总被引:13,自引:1,他引:12
容迟网络泛指那些由于节点移动、能量管理、调度等原因而出现频繁中断、甚至长时间处于中断状态的一类网络.它涵盖了由于节点调度而处于间歇式连通的无线传感网络、移动Ad hoc网络、周期性连通的卫星网络、乡村网络、野生动物追踪网络以及个人设备交换网络等等.具有十分广阔的应用前景,引起了广泛的关注.与传统网络相比,容迟网络没有稳定的端到端传输路径,因而其路由问题更为复杂.已有的研究工作也主要集中于这一问题.并提出了许多的容迟网络路由算法.对这些算法的最新进展进行了综述.首先,介绍了容迟网络路由算法的性能评价标准.其次.给出了容迟网络路由算法的分类方法.按照路由策略来分.客迟网络路由算法可以分为基于复制策略的算法和基于转发策略的算法.按照网络模型来分,容迟网络路由算法又可以分为面向主动移动模型的算法和面向被动移动模型的算法.然后,针对每一分类.重点综述了其中具有代表性的一些容迟网络路由算法,并总结了各算法的优缺点.最后,讨论了未来的研究方向. 相似文献
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容迟网络是一类由移动设备组成的新型网络体系,近年来的研究对其提出了许多路由方案。但是现有的路由方案大都缺乏有效的安全方案和激励机制。本文结合Spray&Wait路由算法,提出适用于容迟网络发布/订阅多播协议高效安全方案和激励机制。通过分析和仿真实验,本文证实该机制可以有效地激励网络中的节点遵照Spray&Wait路由算法为他人提供转发服务,同时可以有效地阻击泛洪攻击等多种网络中的恶意行为。 相似文献
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容迟网络DTN是一个新兴的研究领域,这种网络中节点之间的连接时常发生中断并且难以预测,目前一个常用的解决办法是使用多拷贝路由。但是,考虑到网络中多数节点能量供应受限的特点,大量额外的消息拷贝传输会使网络中部分节点能量迅速消耗,直至节点停止工作,导致整个网络的路由性能快速下降。针对容迟网络中的散发等待路由算法[1],利用网络中不同节点在能量供应方面不同的特点,本文提出了混合散发等待路由算法。仿真结果表明,与二分法散发与等待路由算法相比,这种路由算法通过不同程度地利用各节点上的能量供应,在递交成功率、平均延迟方面能够取得较大改善。 相似文献
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针对容迟移动传感器网络(Delay Tolerant Mobile Sensor Network,DTMSN)网络的容迟及节点的移动性特点,提出了一种新的基于概率预测的能量均衡组播路由算法(Energy-balanced Multicast Routing based Probability Probabilistic,EMRPP)。该算法采用到达概率选择路由下一跳的方式,且考虑了节点能量对算法性能的影响。仿真结果表明,EMRPP算法在数据传输率和平均传输延迟方面的性能要优于改进之前的PROPHET算法,是一种有效的容迟移动网络组播路由方案。 相似文献
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Some ad hoc network scenarios are characterized by frequent partitions and intermittent connectivity. Hence, existing ad hoc routing schemes that assume that an end-to-end path exists from a source to a destination do not work in such challenging environment. A store-and-forward network architecture known as the disruption tolerant network (DTN) has been designed for such challenging network environments. Several unicast and multicast routing schemes have been designed for DTNs. However, the existing multicast routing schemes assume a route discovery process that is similar to the existing ad hoc network routing approach. Thus, in this paper, we design an encounter-based multicast routing (EBMR) scheme for DTNs which uses fewer hops for message delivery. We first describe how the EBMR scheme works and then present an analytical framework to estimate the delivery performance of the EBMR scheme. Next, we present some comparisons of the analytical and simulation results to show that our analytical framework provides delivery performance estimates that match closely the observed simulation results. Last but not least, we present simulation results to study the delivery performance of EBMR in different scenarios, e.g. different mobility models, different multicast group size, different number of multicast groups and different node speed. We also compare the performance of the EBMR scheme with other DTN multicast strategies. Our simulation results indicate that the EBMR scheme can achieve higher delivery ratio while maintaining high data transmission efficiency compared to other multicast strategies. 相似文献
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由于容迟网络(DTN)为满足极端情况下的端到端服务,使得容迟网络的路由机制复杂而且有别于现存的各种网络。基于洪泛的蔓延(Epidemic)路由,由于其广播特性,网络容易拥塞,基于效用(utility)的单复制路由机制,开销小,但是递交率不高,延迟大。文中根据这两种路由机制的优点,结合数据包产生的初期应尽最大努力递交这一思想,提出了一种可变效用的路由机制。通过ONE仿真器仿真了蔓延路由,PRoPHET路由,Spray and Wait路由机制以及文中提出的可变效用路由机制,结果表明文中提出的可变效用路由机制在递交率、平均延迟两个指标上表现的非常出色。 相似文献
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容迟容断网络具有无中心化的特点,使得对其节点的监控和管理存在天然的困难。本文介绍了当前容迟容断网络路由算法的主要研究成果,如较早的基于洪泛的喷射路由等。接着介绍了最新的基于节点社会性的路由。随后分析了这两种路由的优缺点,包括引入节点社会性后带来的负载不均衡和资源分配不公问题。进一步,通过分析人类活动轨迹数据发现节点社会属性的相对稳定。利用这种稳定性提出了一种公平分配资源机制,使得各节点可以合理地共享网络资源。最后验证了该机制的有效性和实用性。 相似文献
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基于多队列自适应的DTN传染路由算法 总被引:2,自引:0,他引:2
传染路由是DTN中一类较简单的基本路由算法.针对DTN网络环境易变的特点及传染路由的不足提出多队列自适应传染路由,采用多队列方式管理存储空间,利用效用函数对队列内信息进行排序,针对不同队列及网络情况采用相异的转发机制,从而降低网络负载率、提高传输率并降低传输时延,同时可提供简单的QoS.仿真证明本算法优于路由算法Spray andw ait和MaxProp. 相似文献
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Mike P. Wittie Khaled A. Harras Kevin C. Almeroth Elizabeth M. Belding 《Computer Communications》2009,32(16):1699-1709
Delay Tolerant Network (DTN) routing addresses challenges of providing end-to-end service where end-to-end data forwarding paths may not exist. The performance of current DTN routing protocols is often limited by routing metric “staleness”, i.e., routing information that becomes out-of-date or inaccurate because of long propagation delays. Our previous work, ParaNets, proposed a new opportunistic network architecture in which the data channel is augmented by a thin end-to-end control channel. The control channel is adequate for the exchange of control traffic, but not data. In this paper we present Cloud Routing, a routing solution for the ParaNets architecture. We motivate the need for such a solution, not only because of stale routing metrics, but also because of congestion that can occur in DTNs. Unable to use up-to-date routing metrics to limit congestion, existing DTN routing solutions suffer from low goodput and long data delivery delays. We show how Cloud Routing avoids congestion by smart use of forwarding opportunities based on up-to-date routing metrics. We evaluate our solution using extensive OPNET simulations. Cloud Routing extends network performance past what is currently possible and motivates a new class of globally cognizant DTN routing solutions. 相似文献
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为了更加深入的研究容迟网络(delay tolerant networks,DTN)路由技术中决定性能表现的主要因素,以3种具有代表性的主流DTN路由为例,设计了一个典型的地区探测场景,利用ONE模拟器进行了仿真实验。实验结果表明,在相同的应用场景下,采用不同策略的DTN路由表现出很大的性能差异。实验数据的对比分析证明,路由算法的性能主要受网络中报文拷贝数量及其转发策略的限制,同时跟网络硬件性能也有很大关系。 相似文献
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There are major challenges in establishing effective communications between nodes in Vehicular Ad Hoc Networks (VANETs). In them the systems are subject to wireless interference and disconnections, thus hindering the availability and reliability of source-destination connections. Another major problem arises when VANETs are sparse, causing excessive retransmissions and delays due to long periods without maintaing connection between pair of vehicles. In these environments traditional routing protocols proposed for VANETs suffer from the absence of end-to-end connections. From intensive studies and analysis, it was found that these problems are best overcome by using Delay Tolerant Network (DTN) routing protocols that can endure huge delays, connection disruptions and embolden applications to use a minimum number of roundtrip response confirmations. DTN routing protocols are considered to be the most suitable alternative to traditional routing protocols in VANET environments. They are designed for storing and forwarding messages through a series of forwarders to maintain network connectivity. Thus, we present a systematic technical survey and a comparative analysis of a taxonomy of DTN routing protocols, which we extended and adapted it to include a new set of VDTN (VANET/DTN) routing protocol categories with results. 相似文献