一种基于动态概率转发的AODV路由协议

在Ad hoc网络(自组织网络)的路由建立过程中,由于AODV(Ad hoc按需距离矢量)路由采用洪泛方式转发RREQ(路由请求)消息会产生很多不必要的重传,很可能引发广播风暴而影响网络性能。文章提出了一种基于动态概率转发RREQ消息的改进方案,该方案根据邻居节点的个数选择不同的概率转发RREQ消息。仿真结果表明,在网络节点较多且网络比较稠密的情况下,改进方案能有效减少网络端到端时延,提高网络吞吐量和分组投递率。     

一种基于节点移动性的AODV改进协议

移动Ad hoc网络是移动节点动态临时组建的自组织网络,路由协议一直是Ad hoc网络研究的关键问题.文中提出了一种新的AODV改进协议AODV-NM,它能够根据节点速度自适应的调整RREQ泛洪频率,实现稳定路径的选取.仿真结果表明,AODV-NM能够有效降低网络路由负荷,同时改善了时延与分组投递率等性能.     

ADLE:一种Ad hoc网络分布式领导者选取算法

Ad hoc网络的动态拓扑结构和节点自组织给分布式算法的实现带来了诸多困难.Ad hoc网络分布式领导者选举算法:ADL.该算法基于广播机制,采用逻辑时戳保证消息的时序性,避免了节点饿死.同时,它通过缩小算法执行范围降低了消息复杂度,而且不需要节点了解系统中所有节点的信息,因而能够适应Ad hoc网络的动态拓扑结构和节点频繁出入.分析与仿真结果表明该算法具有较低的消息复杂度、小响应延迟和公平性.     

Ad hoc网络中的路由技术

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。     

Ad hoc网络中不相关多路由源端寻路算法

路由方案是Ad hoc网络中一个热点研究领域。其中,按需路由算法由于其有效性在带宽受限的Ad hoc网络中得到比较大的发展。然而大部分的按需路由算法,建立并只使用单条路由,当前使用的路径的链路断开时,路由算法必须执行一个路由修复过程。提出了不相关多路由源端路由算法（DMSR）,建立并利用多条最大不相关路由。算法中,中间节点等待一段时间以得到多个路由请求包（RREQ）,然后在这个RREQ中,选择相关性最小的多路径,并将这些信息写入一个RREQ中,并将它广播出去。从仿真结果可以看出本文的算法提高了数据包的正确传输率和业务均衡性。     

一种带有负载监听的多信道Ad hoc网络MAC协议

针对Ad hoc网络提出了一种新的媒体接入控制（MAC）协议——带有负载监听的多信道协议。它能够有效地解决多跳的Ad hoc网络中暴露节点的问题。在该协议中,每个节点都可以根据当前的信道负载来决定是否接入信道,并进行信道预留。在信道预留成功后,多速率的数据包就可以在指定的信道上不受干扰地进行同步传输。该机制允许一个节点同时占用多个空闲信道,不同节点间可以同时传递数据包。仿真结果显示,该机制要优于单信道的RTS／CTS模型,它提高了Ad hoc网络的吞吐量和抗干扰能力。     

Ad hoc网络安全与攻击探讨

介绍了Ad hoc网络的体系结构和特点,分析了其存在的网络安全问题,总结了对Ad hoc网络的多种攻击方法,并提出了几种改善Ad hoc网络安全的策略。     

认知无线Ad hoc网络的认知体系结构研究

对认知无线Ad hoc网络进行了阐述。对于认知无线Ad hoc网络,要考虑到无线Ad hoc网络的整体特点,来研究网络级认知结构。而由于认知无线Ad hoc网络是基于无线Ad hoc网络体系结构,同时鉴于无线Ad hoc网络本身特点,因此网络体系参数和网络本身特性参数共同被定义为认知信息,并在与跨层设计结合基础上进行节点级认知结构设计。认知信息的获取与传输方式将认知无线Ad hoc网络网络级与节点级结构有机地联合起来,使整个认知体系成为完整有机体。     

移动Ad hoc网络安全路由协议综述

Ad hoc网络的安全性问题越来越引起人们的关注,如何确保Ad hoc网络路由协议的安全成为Ad hoc研究的一项关键技术.本文介绍了安全协议的目标以及针对Ad hoc网络路由协议的恶意攻击,接着详细分析了目前比较典型的几种Adhoc网络安全路由的研究现状,在对他们进行综合比较的基础上指出了存在的问题.     

Ad hoc网络中ARAN路由协议的安全性分析

由于Ad hoc网络的特性,传统的串空间理论无法分析其路由协议的安全性,该文首先对串空间理论进行了扩展,添加了证明中间节点可信的条件。随后,使用扩展后的串空间理论分析了ARAN路由协议的安全性,提出了使用该理论分析Ad hoc网络中安全路由协议的新方法。分析和证明结果表明,ARAN路由协议中存在重放和合谋两种攻击,说明采用文中提出的分析方法对Ad hoc网络中的按需距离矢量路由协议的安全性进行分析是有效的。     

一种改进型Ad hoc网络安全路由协议

移动Adhoc网络的自组织、动态拓扑以及无线接入等特点使路由的安全性问题日益突出,而现有的Adhoc网络路由协议并没有提供安全的保护机制。论文首先论述了Adhoc网络几种常见的按需安全路由协议,指出有待解决的问题,在此基础上提出一种改进的、有效的安全路由协议（SEAR）,阐述了该协议的路由请求、响应和维护的路由方式和过程,并通过协议间的比较分析其安全性和网络性能。该方案采用对称密钥协商和公钥认证方式,在兼顾性能资源的同时也保证了Adhoc网络的路由安全。     

Ad hoc网络安全性分析

Ad hoc网络是一种特殊的多跳移动无线网络，具有广泛的应用场合。介绍了Ad hoc网络的脆弱性和安全威胁，然后在探讨Ad hoc网络安全目标的基础上。集中讨论了移动Ad hoc网络的路由安全、密钥管理等关键问题。     

Ad hoc网络安全综述

移动Adhoc网络是由一组自主的无线节点或终端相互合作而形成的网络,由于其动态拓扑、无线通信的特点,容易遭受各种安全威胁。从传输信道、移动节点、动态拓扑、安全机制、路由协议几方面,分析了移动AdHoc网络的安全弱点,然后结合其安全策略和机制,分析了FSR、SRP和AODV3种典型的路由协议的工作原理和优缺点。     

Direct trust-based security scheme for RREQ flooding attack in mobile ad hoc networks

The routing algorithms in MANETs exhibit distributed and cooperative behaviour which makes them easy target for denial of service (DoS) attacks. RREQ flooding attack is a flooding-type DoS attack in context to Ad hoc On Demand Distance Vector (AODV) routing protocol, where the attacker broadcasts massive amount of bogus Route Request (RREQ) packets to set up the route with the non-existent or existent destination in the network. This paper presents direct trust-based security scheme to detect and mitigate the impact of RREQ flooding attack on the network, in which, every node evaluates the trust degree value of its neighbours through analysing the frequency of RREQ packets originated by them over a short period of time. Taking the node’s trust degree value as the input, the proposed scheme is smoothly extended for suppressing the surplus RREQ and bogus RREQ flooding packets at one-hop neighbours during the route discovery process. This scheme distinguishes itself from existing techniques by not directly blocking the service of a normal node due to increased amount of RREQ packets in some unusual conditions. The results obtained throughout the simulation experiments clearly show the feasibility and effectiveness of the proposed defensive scheme.     

移动自组网中基于声誉机制的安全路由协议设计与分析

移动自组网是一种有特殊用途的对等式网络,具有无中心、自组织、可快速展开、可移动等特点,这些特点使得它在战场、救灾等特殊场合的应用日渐受到人们的重视.由于在移动自组网络中每节点既是主机又是路由器,所以容易遭受基于路由信息的攻击,而现今的路由协议基本没有考虑到该问题.本文在分析移动自组网络安全特性的基础上,综述了该方面的研究工作,建立了基于声誉机制评价体系,并给出了具体的评价方法和计算模型.在此基础上,提出了基于声誉机制的安全路由协议S-DSR.仿真结果表明在存在攻击节点的情况下S-DSR协议比DSR协议具有更好的包传输率、包丢失率等属性.     

Wormhole attacks in wireless networks

As mobile ad hoc network applications are deployed, security emerges as a central requirement. In this paper, we introduce the wormhole attack, a severe attack in ad hoc networks that is particularly challenging to defend against. The wormhole attack is possible even if the attacker has not compromised any hosts, and even if all communication provides authenticity and confidentiality. In the wormhole attack, an attacker records packets (or bits) at one location in the network, tunnels them (possibly selectively) to another location, and retransmits them there into the network. The wormhole attack can form a serious threat in wireless networks, especially against many ad hoc network routing protocols and location-based wireless security systems. For example, most existing ad hoc network routing protocols, without some mechanism to defend against the wormhole attack, would be unable to find routes longer than one or two hops, severely disrupting communication. We present a general mechanism, called packet leashes, for detecting and, thus defending against wormhole attacks, and we present a specific protocol, called TIK, that implements leashes. We also discuss topology-based wormhole detection, and show that it is impossible for these approaches to detect some wormhole topologies.     

An EDRI-based approach for detecting and eliminating cooperative black hole nodes in MANET

Mobile Ad hoc Network (MANET) is a self-configurable, self-maintenance network with wireless, mobile nodes. Special features of MANET like dynamic topology, hop-by-hop communications and open network boundary, made security highly challengeable in this network. From security aspect, routing protocols are highly vulnerable against a wide range of attacks like black hole. In black hole attack malicious node injects fault routing information to the network and leads all data packets toward it-self. In this paper, we proposed an approach to detect and eliminate cooperative malicious nodes in MANET with AODV routing protocol. A data control packet is used in order to check the nodes in selected path; also, by using an Extended Data Routing Information table, all malicious nodes in selected path are detected, then, eliminated from network. For evaluation, our approach and a previous work have been implemented using Opnet 14 in different scenarios. Referring to simulation results, the proposed approach decreases packet overhead and delay of security mechanism with no false positive detection. In addition, network throughput is improved by using the proposed approach.     

Simulation Based Comparative Study of Routing Protocols Under Wormhole Attack in Manet

A Mobile Ad hoc network (manet) has emerged as an autonomous, multi-hop, wireless and temporary type of network which works within the constraints like bandwidth, power and energy. Manet can be observed as an open type of network where nodes become a part of any network at any time that’s why it is susceptible to different types of attacks. Wormhole attack is most threatening security attack in ad hoc network where an attacker node receives packet at one location and replay them at other location which is remotely located far. In this paper, we study and compare the performance of AODV, DSR and ZRP under the impact of multiple wormhole attacker nodes. Diverse scenarios are characterized as like average of 50 runs and mobility. By statistical placement of multiple wormhole nodes across the network, we evaluate the performance in terms of throughput, packet delivery ratio, packet loss, average end to end delay and jitter. Finally based on the simulation we investigated the most affected routing protocol in terms of network metrics.     

基于泛洪约束的MANET按需组播路由协议

降低路由控制开销是MANET网络组播路由协议节省节点能量,提高带宽利用率的关键因素之一。本文研究了组播路径近邻节点对路由维护的作用以及链路的连通性,分别提出了一个新的泛k-洪约束算法和一个混合泛洪模式。基于泛k-洪约束算法和混合泛洪模式,提出一个新的按需组播路由协议ODMRP-CF,ODMRP-CF协议通过选择k-路由近邻节点转发泛洪分组来提高泛洪效率。ODMRP-CF协议不仅保持了ODMRP协议所具有的简单,对节点移动鲁棒性好的优点,而且有效地降低了ODMRP-CF协议的控制开销。