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1.
MANET网络由可自主移动的无线节点组成。节点的自主移动导致了链路路由的改变,因此需要有一个机制维护和发现路由信息。目前人们已经针对MANET网络提出了几种路由协议,但这些路由协议都是基于IP的且路由维护的代价高,这严重影响了MANET网络的稳定性、可扩展性和用户有效带宽。本文提出了一种基于改进RTS/CTS的MANET高效报文转发策略。该策略对标准IEEE 802.11协议进行了修改,利用改进的RTS/CTS报文信息,进行报文转发,从而避免了使用MANET网络路由协议给网络性能带来的影响。使用改进的NS-2模拟了基于改进RTS/CTS的MANET高效报文转发策略。模拟结果表明:该策略可以有效地降低路由维护的开销并降低报文传输的延迟。  相似文献   

2.
MANET网关辅助抑制开销分群路由协议研究   总被引:2,自引:0,他引:2  
针对MANET现有分群路由协议中群首负担过重,群合并时引发全网泛洪甚至连锁反应等问题,提出一种MANET网关辅助抑制开销分群路由协议GORP。在该协议中,网关在路由维护与数据传送中分担群首的部分工作,以降低群首的负担,使得群首不再成为整个网络的瓶颈;当群首移动导致群合并时,让运动群首作为第二个群的普通成员,原来静止的群首担任新群的群首,最大限度保证群的稳定性。仿真结果表明GORP协议在节点移动或节点数少和多的情况下都能获得好的性能,能满足MANET路由需求。群结构的稳定还将有利于MANET基于群的路由安全策略的实施。  相似文献   

3.
节点间的信任关系对MANET网络路由协议的可靠性和安全性有重要意义,由于MANET网络的特性,难以通过传统的方式建立节点间信任关系。提出一个适用于MANET的信任评估模型CETM(Contribution and Evaluation Trust Model),用来度量MANET节点间信任关系,并将此模型应用于AODV协议中,提出了一种新的安全路由协议TAODV。仿真结果表明当网络中存在少于一半的恶意节点时,CETM能有效抵御如诋毁等恶意行为,从而显著地提高了交易的成功率。基于CETM的TAODV建立在可靠的节点信任关系之上,具有较好的安全性。  相似文献   

4.
MANET是一种无基础设施支持的动态、自组织、多跳无线移动网络,为之设计适当的路由协议是一大挑战。该文在分析MANET特性及应用需求的基础上,提出了一种的分区MANET路由协议,该协议基于到最小ID节点的距离形成分区并维护简化的全局网络拓扑,通过巧妙地利用节点的邻接点信息使得路由请求的时间和通讯复杂度均降为O(2R)。仿真结果表明,该协议具有路由请求时延低,控制开销少的特点。  相似文献   

5.
针对移动自组织网络(MANET)中优化链路状态路由(OLSR)协议路由稳定性差和端到端延时高的问题,提出一种改进的OLSR路由协议。考虑MANET拓扑的移动性,通过优先选择平均相遇率较小、稳定性较高的中继节点构建移动拓扑,避免路由震荡。基于跨层技术,利用链路层共享的链路速率优化路由权值,从而提高路由性能。实验结果表明,与OLSR协议相比,改进协议在MANET网络中具有更好的网络稳定性及更低的端到端延时。  相似文献   

6.
MANET网络是一种无线通讯的移动节点的集合。这种网络非常灵活,不需要固定的中央服务器。它适合于临时的通讯连接。这种网络的最大挑战是在通讯节点间寻找最佳的路径,路径不当会加重系统的负载。文章介绍一种新的按需多跳MANET网络的路由算法,该协议是基于智能蚁群,试图利用蚁群的数学及工程能力来解决MANET网络的路由算法问题。该协议具有高适应性、高效性及可扩展性,该路由算法可以大大地减少网络的路由开销。  相似文献   

7.
MANET中,现有的按需路有协议解决了包传送路由的问题。但是,因为节点的移动,这些协议都缺乏对全局节点拓扑的认识,因而不是最优的。路由是否优化影响着网络的性能,特别是当网络负载很重的时候。越长的路由耗费的带宽会更多,连不通的可能性就越大。提出了一种带自愈功能的路由优化机制(ORMS)来监视路由,如果一条较短的路由存在,就尽可能使其变短。ORMS在现有的带宽和反应时间内提高了网络的性能而没有增加任何额外的资源耗费.  相似文献   

8.
MANET是由一系列可以自由移动的节点主机聚集而成的一个临时性动态网络。它没有固定基站,也没有作为控制管理中心的节点主机。由于其拓扑的动态性,其路由协议不同于其它网络。为更有效支持MANET的应用,文章提出了一种基于移动预测下的Unicast路由。该协议采用GPS定位机制,通过预测路径有效连接时间来实现。模拟结果表明这种方案能获得较好的网络性能和较低的控制开销。  相似文献   

9.
马驰  孟锦  张宏 《计算机应用》2011,31(11):2883-2886
针对战场毁伤条件下移动自组网(MANET)普通路由算法性能下降的问题,在含有抗毁增强节点的混合MANET网络中,融合了普通MANET路由和容迟网络(DTN)路由设计了抗毁性增强路由协议STHR,并且为了降低网络负载和冲突对STHR中抗毁增强节点的选取算法进行了设计。在网络遭受毁伤甚至出现分割情况下,MANET路由扩展环无法到达目标节点,但借助具有区域覆盖特性的抗毁增强节点转入DTN路由,可以保证在一定时延容忍前提下,仍能保持较高的分组投递率。通过ONE仿真平台实验,结果表明在毁伤情况下,STHR的分组投递率要优于AODV路由,而路由时延低于DTN喷雾等待路由。  相似文献   

10.
Ad Hoc网络节点能量受限的路由协议的研究是目前的一个热点,IETF的MANET小组提出的几种经典的路由协议,属于最短路由,即最小跳数路由,没有考虑能量因素。由于Ad Hoc网络中的节点是由电池供电,整个网络是一个能量受限系统,如何节省节点的能量,尽可能延长网络的可操控时间逐渐成为衡量路由协议性能的重要指标。基于移动节点的能量级别,采取不同的转发概率,提出了一种Ad Hoc网络基于概率的路由协议——PBR,并与AODV协议进行了性能比较,仿真结果显示,PBR明显改善了系统的能量消耗,延长了网络的存活时间,并且具有较优的可扩展性。  相似文献   

11.
This paper proposes an efficient anonymous routing protocol for mobile ad hoc networks (MANETs). This protocol considers symmetric and asymmetric links during the wireless communication of MANETs. A MANET is one type of self-organized wireless network that can be formed by several wireless devices such as laptops, tablet PCs, and smartphones. Different wireless transmission ranges of different mobile devices lead to a special communication condition called an asymmetric link. Most research on this topic focuses on providing security and anonymity for the symmetric link without considering the asymmetric link. This paper proposes a novel distributed routing protocol beyond the symmetric and asymmetric links. This protocol guarantees the security, anonymity, and high reliability of an established route by avoiding unreliable intermediate nodes. The routes generated by the proposed protocol are shorter than previous research. The proposed protocol enhances MANET performance in assuring security and anonymity.  相似文献   

12.
随着UWB技术的出现,无线移动多媒体业务在自组网中的应用成为可能。为了满足无线移动多媒体传输的需要,设计了一种新的针对多媒体业务的QoS路由协议,给出了协议的详细描述。由于该协议充分利用了UWB技术的速率和距离互换特性,考虑了传输速率、时延和链路拥塞程度3个QoS参数,并借鉴无线移动自组网基本路由协议DSR和AODV,因此不仅能够获得满足业务要求的路由,且能提前预测链路的中断,以便及时切换替代路由。与目前已提出的基于UWB技术的路由协议相比,该协议更适合于无线移动多媒体业务的传输。  相似文献   

13.
The software-defined network (SDN) is one of the network architectures, in which the data plane and control plane is divided from each other, and the network can be handled using a sensibly centralized controller and this method is adopted to reconfigure the wireless sensor network automatically. In this article, to implement the SDN in MANET, in which control nodes can be chosen in SDN dynamically for the activation of MANET function to allocate the works to other mobile nodes to the base station. However, in the field of mobile ad hoc networks, the network lifetime, and battery lifetime is one of the major problems and the energy consumption can play a significant rule for the transmission of data in the SDN. Therefore, in this article, particle swarm optimization (PSO) based CGSR (cluster-head gateway switch routing protocol) algorithm with fuzzy rules is proposed to increase the network lifetime of battery powered mobile nodes by reducing the energy consumptions of each node in software-defined MANET. In this proposed method, a routing method that can permit various mobile nodes with low battery power to transmits the data from source node to base station. We design a PSO based CGSR routing protocol by selecting the routing mobile nodes using fuzzy rules for packet transmission. In CGSR process, the formation of cluster and selection of cluster head is executed depending on the particle swarm optimization method. This proposed routing protocol can be used to enhance the battery lifetime by extension of the network lifetime with numerical analysis for efficient route node selection.  相似文献   

14.
无线自组网是由一组无线移动主机组成的无基础设施的临时网络,在与其相关的网络协议的研究中常涉及到修改及扩展问题。文章分析了经典按需路由协议AODV的路由发现和建立过程,通过NS2仿真软件的内核扩展及重编译,在控制台输出相关的扩展内容,包括RREQ和RREP包的传送、正反向路由表的建立和节点路由表的更新等信息。结果表明,在NS2仿真软件下对无线自组网路由协议的研究和调试分析是一种科学有效的方法。最后对AODV协议本身提出了几种改进的思路和方法。  相似文献   

15.
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   

16.
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   

17.
一种基于邻居信任评估的虫洞防御机制   总被引:6,自引:0,他引:6  
洪亮  洪帆  彭冰  陈晶 《计算机科学》2006,33(8):130-133
移动adhoc网是一种新型无线移动网络,具有无中心、自组织、拓扑结构变化频繁以及开放式通讯信道等特性,因此adhoc网络下的路由协议所面临的安全问题比有线网环境中更为严重。虫洞攻击就是其中的一种,能够对adhoc网络产生致命的影响。在这种攻击下,网络的路由机制将会紊乱,特别是那些依赖通过接收对方的广播报文进行邻居探测的路由协议。本文首先从虫洞形成的根源上入手,重新定义了邻居的概念,强调了邻居作为节点信息转发第一站的功能。然后根据邻居定义,引入简化的Marsh信任模型,将邻居的以往表现作为信任评估的经验来源,再通过具体公式对邻居关系做出判定。在具体的路由过程中,节点根据信任评估值选取高可信度的邻居作为下一跳的转发节点,从而避免虫洞攻击的危害。为了验证方法的可行性,本文将模型应用于OLSR路由协议中并在NS2中进行了仿真。  相似文献   

18.
Wireless mesh networks can provide low-cost solutions for extending the reach of wireless access points by using multi-hop routing over a set of stationary wireless routers. The routing protocol for these networks may need to address quality considerations to meet the requirements of the user. In this paper, we present a quality based routing protocol for wireless mesh networks that tries to maximize the probability of successful transmissions while minimizing the end-to-end delay. The proposed routing protocol uses reactive route discoveries to collect key parameters from candidate routes to estimate the probability of success and delay of data packets transmitted over them. To achieve accurate route quality assessments, a new route quality metric is proposed that uses performance models of data packet transmissions as opposed to estimating route quality from the transmission of control packets, which have different transmission characteristics. These models are developed after careful evaluations of multi-hop wireless transmissions and validated by computer simulations. Relevant parameters that can be used to assess the route quality metric using these models are explained. Extensive performance evaluations of the proposed quality based routing protocol are presented and its benefits in comparison to some other known routing protocols are discussed.  相似文献   

19.
孙杰  郭伟 《软件学报》2011,22(5):1041-1052
在MANET中,通信节点的移动会造成端到端通信路由的时常中断.传统TCP协议只有拥塞控制机制,对由于节点移动造成的数据包传输丢失和超时也作为拥塞处理,使得端到端传输性能低下.为解决这一问题,采用跨层设计思想,将传输控制与链路稳定性路由结合,提出了一种基于链路生存时间概率的传输控制协议(transmissioncontrol protocol based on probability of link residual lifetime,简称TCP-PLRT).该协议通过在路由稳定时跨层收集路由层链路生存时间概率信息来实现对端到端连接稳定性的认知,并针对路由不稳定、路由中断、路由恢复,分别制定了路由切换、数据存储转发、ACK再确认三大机制.这使得TCP-PLRT协议具有对由移动造成的路由中断进行提前预判和有效处理的能力.仿真结果表明,TCP-PLRT协议能够极大地减小由节点移动带来的端到端传输性能的下降,减少分组重传,提高端到端的吞吐量.  相似文献   

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