共查询到20条相似文献,搜索用时 71 毫秒
1.
无线移动Ad Hoc网络作为可移动分布式多跳无线网络,没有预先确定的网络拓扑或网络基础设施以及集中控制。为了在这样的网络中促进通信,路由协议主要用于在节点之间发现路径。Ad Hoc网络路由协议的主要目的是网络拓扑的动态变化任意两个节点之间建立一个使得通信总费用和带宽消费最少的正确和有效的通信路径。使用OPNET仿真软件对AODV、DSR协议这两种典型无线移动Ad Hoc网络按需路由协议的参数和性能进行了详细比较和分析。 相似文献
2.
3.
Ad hoc网络两种按需路由协议性能分析 总被引:1,自引:0,他引:1
Ad hoc网络是一种无需依赖于事先布设的基础设施,而仅依靠网络内部节点之间的协作,就能够完成节点间通信的网络。比较了Ad hoc网络两种主流的按需路由协议:动态源路由协议,自组网按需距离矢量路由协议。使用基于ns-2的仿真模型进行仿真,并通过分组交付率、平均端到端时延、标准化路由负荷、对两种按需路由协议进行评估。实验结果表明即使DSR和AODV协议都是按需路由协议,但它们采取的路由机制的不同,导致它们的性能表现的巨大差异。 相似文献
4.
移动无线Ad Hoc网络中的路由安全问题 总被引:2,自引:0,他引:2
由于移动无线Ad Hoc网络具有动态拓扑结构、缺少中心鉴权等特点,面临多种安全问题,更导致路由安全性上升到重要的地位。其主要的三种路由协议(DSDV,AODV和DSR)对安全方面考虑不够。最后详细分析了常见的“黑洞”攻击问题,并介绍了一种基于按需距离矢量路由协议的解决方案。 相似文献
5.
移动Ad hoc网络路由协议标准 总被引:4,自引:0,他引:4
通过重点说明互联网工程任务组(IETF)已通过的两个移动Ad hoc网络路由协议标准,使得相关工程人员在对应用于此种网络的路由协议有一个整体认识基础之上,进一步加深对移动Ad hoc网络原理的理解. 相似文献
6.
移动Ad hoc网络中基于链路稳定性预测的按需路由协议 总被引:4,自引:0,他引:4
移动Ad hoc网络拓扑的高度动态变化是造成传统按需路由协议的路由频繁通断的主要原因,因此在传统按需路由协议的基础上进行链路稳定性预测扩展,增强路由稳定性具有十分重要的意义。该文利用分组的接收功率把节点间的相对运动划分为靠近和远离两种类型,然后在不同相对运动类型下根据节点间距离得到了的链路平均维持时间。在路由过程中,中间节点利用得到的链路平均维持时间设置请求报文的转发延迟,通过一定转发规则选择稳定性较强的链路构成路径。仿真结果表明进行链路稳定性预测扩展后的按需路由协议能够有效增强路由的稳定性,并提高网络性能。 相似文献
7.
盘莉莉 《微电子学与计算机》2010,27(11)
"线性结构"的Ad Hoc网络有很多的实际应用.采用OPNET建立"线性结构"的Ad Hoc网络,对典型的按需路由协议DSR和AODV的接收分组数量、路由负载、信道接入时延、吞吐量等参数进行了仿真比较,为"线性结构"的Ad Hoc网络选择路由协议提供理论依据. 相似文献
8.
主要比较了两种移动Ad hoc网络路由协议——动态源路由协议和Ad hoc按需距离矢量路由协议。这两种协议虽然有一些共性,不过它们协议本身的特点导致在不同的网络负荷、节点移动性等条件下有明显的性能差异。这些性能差异通过实验结果得到进一步分析,并对如何改进两种协议给出建议。 相似文献
9.
10.
Ad Hoc网络路由协议研究及其性能比较 总被引:4,自引:0,他引:4
介绍和分析了当前Ad Hoc网络中的主要路由协议算法,在Linux下使用网络仿真软件NS2评价Ad Hoc路由协议中的距离矢量路由协议、临时排序路由算法、动态源路由协议和Ad Hoc按需距离矢量路由协议,编写了用于仿真实现的脚本程序,并对仿真结果进行了分析比较和性能评价,由此得出不同协议的特性及其适用范围。 相似文献
11.
Performance of Multipath Routing for On-Demand Protocols in Mobile Ad Hoc Networks 总被引:25,自引:0,他引:25
Mobile ad hoc networks are characterized by multi-hop wireless links, absence of any cellular infrastructure, and frequent host mobility. Design of efficient routing protocols in such networks is a challenging issue. A class of routing protocols called on-demand protocols has recently found attention because of their low routing overhead. The on-demand protocols depend on query floods to discover routes whenever a new route is needed. Such floods take up a substantial portion of network bandwidth. We focus on a particular on-demand protocol, called Dynamic Source Routing, and show how intelligent use of multipath techniques can reduce the frequency of query floods. We develop an analytic modeling framework to determine the relative frequency of query floods for various techniques. Our modeling effort shows that while multipath routing is significantly better than single path routing, the performance advantage is small beyond a few paths and for long path lengths. It also shows that providing all intermediate nodes in the primary (shortest) route with alternative paths has a significantly better performance than providing only the source with alternate paths. We perform some simulation experiments which validate these findings. 相似文献
12.
Mobile ad hoc networks are characterized by multi-hop wireless links, absence of any cellular infrastructure, and frequent host mobility. Design of efficient routing protocols in such networks is a challenging issue. A class of routing protocols called on-demand protocols has recently found attention because of their low routing overhead. We propose a technique that can reduce the routing overhead even further. The on-demand protocols depend on query floods to discover routes whenever a new route is needed. Our technique utilizes prior routing histories to localize the query flood to a limited region of the network. Simulation results demonstrate excellent reduction of routing overheads with this mechanism. This also contributes to a reduced level of network congestion and better end-to-end delay performance of data packets. 相似文献
13.
14.
15.
Predictive Caching Strategy for On-Demand Routing Protocols in Wireless Ad Hoc Networks 总被引:1,自引:0,他引:1
Route caching strategy is important in on-demand routing protocols in wireless ad hoc networks. While high routing overhead usually has a significant performance impact in low bandwidth wireless networks, a good route caching strategy can reduce routing overheads by making use of the available route information more efficiently. In this paper, we first study the effects of two cache schemes, link cache and path cache, on the performance of on-demand routing protocols through simulations based on the Dynamic Source Routing (DSR) protocol. Since the path cache DSR has been extensively studied, we focus in this paper on the link cache DSR in combination with timer-based stale link expiry mechanisms. The effects of different link lifetime values on the performance of routing protocol in terms of routing overhead, packet delivery ratio and packet latency are investigated. A caching strategy incorporating adaptive link timeout is then proposed, which aims at tracking the optimal link lifetime under various node mobility levels by adaptively adjusting the link lifetime based on the real link lifetime statistics. The performance of the proposed strategy is then compared with the conventional path cache DSR. The results show that without a timeout mechanism, a link cache scheme may suffer severe performance degradation due to the use of broken routes, while the proposed adaptive link cache strategy achieves significantly improved performance by reducing the routing overhead when the network traffic load is high. 相似文献
16.
17.
18.
Ad hoc网络中的路由技术 总被引:6,自引:0,他引:6
Ad hoc网络是一些移动节点组成一个多跳的临时性无线自治系统,这种新型的通信网络具有动态变化的拓扑结构和分布控制的网络机制。文中针对Ad hoc网络作了简单的介绍并重点介绍了针对Ad hoc网络特性而提出的路由协议。 相似文献
19.
QoS是无线Ad Hoc网络中的一个重要问题,而QoS路由技术是解决这一问题的关键技术之一.假定无线AdHoc网络中的每个节点的MAC子层能够提供一个参量,这个参量可以量化地表示该节点的忙闲状态,在这个假设的基础上,本文提出一种以DSR路由协议为基础的改进路由,在新的路由协议中,路由请求包中增加一个参量,用这个参量来表示路由请求包所经过的所有节点的状态总和,当路由请求包到达目的节点就找到了源节点到目的节点的路径,并且可以得到每条路径的状况.通过这些信息可以使得发现的路径是状况最好的路径,从而来满足QoS. 相似文献
20.
Ad Hoc网络路由协议性能分析 总被引:4,自引:4,他引:0
介绍了移动自组网的表驱动和按需驱动两类路由协议.提出了定量评估网络路由协议性能的六个基本指标.利用网络仿真器NS-2,对四种典型的路由协议(DSR、DSDV、AODV和TORA)建立仿真模型,配置仿真参数,并进行了仿真.对仿真过程产生的文档进行处理,分析,比较它们的性能指标.试验结果表明,模型仿真结果接近理论分析和实际情况,该方法在路由协议研究,设计与仿真方面具有较强的实用性和通用性. 相似文献