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1.
移动自组网中路由协议对TCP性能的影响   总被引:2,自引:0,他引:2  
在NS2仿真环境下,通过对3种路由协议的TCP性能的仿真,分析了路由协议对TCP性能的影响,得出了结论,并提出了一个接收方通过ACK进行路由发现请求的改进方案。  相似文献   

2.
移动自组网路由协议DSR性能评价   总被引:5,自引:0,他引:5  
研究移动自组网的难点之一是开发能够跟随网络拓扑变化,在移动节点之间快速找到有效路径的路由协议。DSR协议作为一种简洁有效的按需机制路由协议,成为IETF的MANET工作组提出的草案之一。本文利用MANET工作小组推荐的Ns2仿真软件对DSR进行模拟,从源节点个数、分组发送频率、移动速度、节点密度、节点个数五个方面分析DSR的性能,指出对DSR性能影响最大的因素。分析随分组频率降低协议性能下降是由于它的路径缓存策略引起,提出将针对DSR路径缓存,搜索,抛弃策略进行改进。  相似文献   

3.
基于AODV优化的移动自组网路由协议   总被引:2,自引:0,他引:2       下载免费PDF全文
王新颖  吴钊 《计算机工程》2009,35(7):113-115
提出一种基于AODV优化的移动自组网路由协议AODVO,优化RREQ传播机制、HELLO机制和链路修复机制,提供节点不相关多径路由,降低网络路由开销,提高数据传输率,对网络负载平衡有明显帮助。仿真结果验证,相对于AOMDV,该协议在分组传输率、时延和路由开销方面有较大的优越性。  相似文献   

4.
本文讨论了泛播的基本概念,网络模型和路由选择标准,对移动自组网络中的泛播研究现状进行了回顾和分析,在此基础上,提出了泛播技术在移动自组网络中的应用前景。  相似文献   

5.
DSR动态源路由协议是一种典型的按需路由协议,它只在有需求的时候才启动路由发现过程,也是目前移动自组网网络的一种主要路由协议。本文阐述了DSR的工作原理并分析了多种基于DSR的移动自组网的多路径路由协议的工作原理与特点。  相似文献   

6.
本文就移动自组网的关键技术之一--路由协议做了性能上的分析.以往对路由协议的仿真,传输的是基于UDP的CBR数据流,其对在移动自组网中传输FTP数据流无指导意义.本文中给出了DSR、DSDV、AODV三种典型协议在节点不同移动速度下的基于TCP传输的仿真,对路由协议的主要性能参数:有效发送量、延时和丢包率进行了统计分析.仿真结果表明:有效发送量DSR好于DSDV,AODV最差;从延时方面分析,DSDV具有最小的端到端延时,而AODV又比DSR好;在对丢包率分析时,AODV的丢包率最大,DSDV的次之,DSR的丢包率最低.仿真结果验证了理论分析的正确性.  相似文献   

7.
移动自组网是一种特殊的无线移动通信网络,它由一系列带有无线收发装置的动态节点临时形成一个多跳的自治系统,因此传统网络中的路由协议不适合于移动自组网络.选播作为一类新的通信协议,能有效平衡网络负载分布和提高网络性能.本文首先描述了移动自组网络的特点及该环境下的路由协议,在此基础上提出了一种有效的选播路由协议.通过平均分组传送成功概率和平均控制字节数指标的测试表明了算法的有效性.  相似文献   

8.
刘涛  黄本雄 《计算机工程》2002,28(8):165-168
移动自组网在军用和紧急救援等特殊环境的应用前景非常广阔,其中的多播路由技术面临很迫切的挑战。文章介绍了当前的一些移动自组网的多播路由协议,将其分类比较,并详细介绍了比较优秀的按需多播路由协议(ODMRP)。最后探讨了泛洪在多播路由中的应用,以及多播路由的发展和面临的问题。  相似文献   

9.
介绍移动自组网络的基本概念,讨论在移动自组网络中存在的安全问题,分析几种路由安全协议.  相似文献   

10.
移动自组网中的恶意节点对路由协议的安全和隐匿具有严重威胁.现在针对安全路由协议的研究很多,但是很少有人涉及匿名性问题,匿名路由协议能够实现节点身份、位置和通信关系的隐匿,在军事和其它机密通信领域中具有重要意义.首先对匿名路由协议面临的攻击行为进行分析,介绍其定义、分类和匿名性评价方法,然后概括性的介绍已有的典型匿名路由协议,比较其匿名性和安全性,最后对以后研究的问题和方向作了总结和展望.  相似文献   

11.
移动ad hoc网络AODV协议的分析与改进   总被引:3,自引:0,他引:3  
由于移动ad hoc网络的AODV(Ad hoc on-Demand Distant Vector)协议仅维护1条到目的节点的路由记录,即使路由未失效,在超时后也会被删除,因此提出改进的AODV协议---HI-AODV协议.改进内容为:(1)借鉴DSR协议的特点,使其路由表维护多条路由记录;(2)在路由发现和路由维护中有效利用路由缓存信息和多路径路由,使得路由发现更加迅速.仿真结果表明HI-AODV协议可以提高数据吞吐量,减小平均延时.但由于移动ad hoc网络节点的移动性,采用HI-AODV协议容易导致路由信息失效,对路由协议产生负面影响.  相似文献   

12.
Mobile Ad Hoc Networks (MANETs), which provide data networking without infrastructure, represent one kind of wireless networks. A MANET is a self-organizating and adaptive wireless network formed by the dynamic gathering of mobile nodes. Due to the mobility of mobile nodes, the topology of a MANET frequently changes and thus results in the disability of originally on-the-fly data transmission routes. The dynamic properties of MANETs are therefore challenging to protocol design. To cope with the intrinsic properties of MANETs, Dynamic Backup Routes Routing Protocol (DBR2P), a backup node mechanism for quick reconnection during link failures, is proposed in this paper. DBR2P is an on-demand routing protocol and it can set up many routes to reach a destination node in a given period. Even when a link fails, those routes from the source node to the destination node can be analyzed to obtain backup routes to sustain quick reconnection. The information of backup routes can be saved in a specific on-the-route node and enables backup routes to be found immediately in situation regarding disconnection. As a result, DBR2P could more thoroughly improve the quality of routing protocol than those proposed in the past.  相似文献   

13.
An efcient hop count route fnding approach for mobile ad hoc network is presented in this paper.It is an adaptive routing protocol that has a tradeof between transmission power and hop count for wireless ad hoc networks.During the route fnding process,the node can dynamically assign transmission power to nodes along the route.The node who has received route request message compares its power with the threshold power value,and then selects a reasonable route according to discriminating algorithms.This algorithm is an efective solution scheme to wireless ad hoc networks through reasonably selected path to reduce network consumption.Simulation results indicate that the proposed protocol can deliver better performances with respect to energy consumption and end-to-end delay.  相似文献   

14.
讨论了层状移动AdHoc网络的一个信息传播路由算法和基于半马尔可夫过程的节点移动跟踪模型,通过该路由算法可以有效地解决层状子网络间的通信和信息交换。通过路由算法得到的中继节点的移动跟踪模型和计算机仿真,分析了层状移动AdHoc网络的传播性能和路由开销,并得出:当 0≤ρ≤ 1时,层状AdHoc网络的传播性能显著地受到移动呼叫率ρ的影响,当ρ>1时,层状AdHoc网络的传播性能主要取决于移动网络的节点总数、节点移动速度和加速度的结论。  相似文献   

15.
无线自组网与传统的有线网不同,它由一些可移动的结点组成,这些结点的带宽、计算能力和能量都受到一定限制。针对这种网络,研究者们提出了按需路由协议,这些协议非常适合无线自组网这种拓扑结构,但是由于缺乏对全局拓扑和结点移动性的了解,可能达不到最优。因此提出了一种高效的路由协议ERNC,该协议基于已提出的SHORT路由协议[13],并对以前所提出的NAOR协议[14]进行了扩展,即利用网络编码技术来进一步提高路由协议的性能。最后,使用NS-2模拟器来评估ERNC的性能,结果显示ERNC在分组投递率和平均端到端时延等方面获得了比已有协议更好的性能。  相似文献   

16.
Compared with traditional networks, ad hoc networks possess many unique characteristics. For example, ad hoc networks can drop a packet due to network events other than buffer overflow. Unfortunately, the current layered network architecture makes it impossible to pass the information specific to one layer to other layers. As a result, if a packet is lost due to reasons other than buffer overflow, TCP adversely invokes its congestion control procedure. Similarly, the routing algorithm may misinterpret that a path is broken and adversely invoke the route recovery procedure.This study addresses the limitations of the current layered network architecture by adopting a cross-layer protocol design for TCP and routing algorithms in ad hoc networks. The objective of this approach is to enable the lower-layered ad hoc network to detect and differentiate all possible network events, including disconnections, channel errors, buffer overflow, and link-layer contention, that may cause packet loss. Using the information exploited by lower layers, the upper layer-3 routing algorithm, and the layer-4 TCP can take various actions according to the types of network events. Simulation results demonstrate that the combination of the cross-layer optimized TCP and routing algorithms can effectively improve the performance of TCP and DSR, regardless of whether it is in a stationary or a mobile ad hoc network.  相似文献   

17.
A stable weight-based on-demand routing protocol for mobile ad hoc networks   总被引:3,自引:0,他引:3  
A mobile ad hoc network (MANET) consists of a set of mobile hosts that can communicate with each other without the assistance of base stations. In MANETs, the high mobility of mobile nodes is a major reason for link failures. In this paper, we propose a stable weight-based on-demand routing protocol (SWORP) for MANETs. The proposed scheme uses the weight-based route strategy to select a stable route in order to enhance system performance. The weight of a route is decided by three factors: the route expiration time, the error count, and the hop count. Route discovery usually first finds multiple routes from the source node to the destination node. Then the path with the largest weight value for routing is selected. Simulation results show that the proposed SWORP outperforms DSR, AODV, and AODV-RFC, especially in a high mobility environment.  相似文献   

18.
为了满足移动多媒体传输的需要,提出了一种新的移动模型——multimedia communication mobility model (MCM),该移动模型充分考虑了实际环境中存在障碍物和多媒体业务的特殊要求。利用MCM设计了针对多媒体业务的路由算法,并给出了算法的详细描述。由于该算法考虑到了现实障碍物的影响。并借鉴了无线自组网基本路由协议,因此其不仅能获得满足业务要求的路由。而且能避免链路中断的影响,以便通过及时开启备用节点来提供备用路由。与目前已经提出的路由算法相比。该协议更适合于移动多媒体业务的需求。  相似文献   

19.
AHBP: An efficient broadcast protocol for mobile Ad hoc networks   总被引:9,自引:0,他引:9       下载免费PDF全文
Broadcast is an important operation in many netowkr protocols.It is utilized to discover routes to unknown nodes in mobile ad hoc networks(MANETs) and is the key factor in scaling on -demand routing protocols to large networks.This paper presents the Ad Hoc Broadcast Protocol(AHBP)and its performance is discussed.In the protocol,messages,are only rebroadcast by broadcast relay gateways that constitute a connected dominating set of the network.AHBP can efficiently reduce the redundant messages which make flookding-like protocols perform badly in large dense networks.Simulations are conducted to determine the performance characteristics of the protocol.The simulation results have shown excellent reduction of broadcast redundancy with AHBP.It also contributes to a reduced level of broadcast collision and congestion.  相似文献   

20.
移动自组网的动态编址问题   总被引:2,自引:0,他引:2  
张治  戴冠中  陈旿  赵玉亭 《计算机应用》2005,25(7):1502-1505
作为实现移动自组网自动配置的一个关键问题,综述了节点地址的自动配置的最新进展,描述了设计移动自组网动态地址配置协议所面临的问题,对该问题研究开展以来所提出的各种主要方法和协议进行了详细对比、分析和分类阐述,为进一步的研究提出了新的建议。  相似文献   

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