无线自组(Ad-Hoc)网及其路由算法

无弛自组(Ad-Hoc)网是一种不需固定路由器能够实现自治运行的无线多跳网络.在无线Ad-Hoc网中,每个节点既可以是主机又可以是路由器.本文介绍了无线Ad-Hoc网的特点、挑战,并介绍了路由技术实现协议.最后对无线Ad-Hoc网前景进行了展望.     

802.11 Mesh network中WBDMR分布式路由协议的研究

提出了一种适用于中等规模的802．11 Mesh network网络的无线分布式路由协议（WBDMR）。该协议借鉴了基于Ad-Hoc 的ADOV协议并进行了改造,实现了不同BSS（基本服务集）间无线客户端通过无线中继相互通信。利用节点间交换链路损耗信息实现了动态负载平衡、有效地抑制了冗余路由信息的传播、消除了路由环路、建立了备份路由。仿真结果表明,WBDMR协议具有较好的路由特性和时延特性。     

一种基于TXOP传输机制的多信道多址接入协议

址接入协议对无线网络的性能有极大影响,并已成为实现高效无线通信的关键因素。为了提升动态信道分配(DCA)协议的信道资源利用率,设计了一种基于传输机会(TXOP)传输机制的多信道介质访问控制(MAC)(T-DCA)协议。由于T-DCA协议实现简单,可适用于分布式无线网络,如Ad-Hoc以及无线局域网络(WLAN)等。最后,通过搭建NS-2网络仿真平台,验证了T-DCA协议的优越性。仿真结果表明,T-DCA协议有效抑制了协议的冲突概率,提升了网络吞吐量并降低了平均分组时延。     

基于感知的同构Ad-Hoc网络互联的实现

提出了一种基于IEEE802.11无线网卡和Linux操作系统平台的同构Ad-Hoc网络自适应地进行网络融合的实现方案。介绍了软、硬件开发平台,互联流程及采用的主要机制和算法,并通过组网测试验证了方案的可行性。方案具有良好的通用性和扩展性,为实现多个同构Ad-Hoc网络的互联提供了一定的参考,可在野外作业、战地通信、救灾现场等领域发挥独有的特色。     

基于跳频扩频技术的抗干扰Ad Hoc网络协议

将跳频技术与Ad Hoc网络结合以提高通信系统的抗干扰能力,针对跳频扩频通信的物理特点,设计一种相适用的Ad Hoc网络的MAC协议。对已有的多信道Ad-Hoc网络接入协议进行了分析,在MMAC协议的基础上经行了改进,引入了跳频码分多址与时分双工。最后对该系统的性能进行了分析,改进后的MAC协议加强了通信的抗干扰能力和网络的各项性能。     

AODV、AOMDV和AODV-UU路由协议性能仿真与分析

使用NS-2(Network Simulator Version 2)仿真软件,选取分组投递率、端到端平均时延、归一化路由开销和路由发现频率4个指标对按需距离矢量路由(AODV,Ad hoc On-Demand Distance Vector Routing)、多径按需距离矢量路由(AOMDV,Ad Hoc On-Demand Multipath Distance Vector Routing)和乌普萨拉大学开发的按需距离矢量路由(AODV-UU,Ad Hoc On-Demand Distance Vector Routing developed by Uppsala University)进行了性能仿真,通过改变节点最大运动速度和业务源连接对数分析比较这些参数对3个协议性能的影响,研究结果表明了AODV-UU协议的优越性。并提出了对AODV-UU协议的改进。     

Ad Hoc网络中一种新的多径路由机制研究

基于AODV(Ad Hoc on demand distanceVector)提出了一种新的按需多径矢量路由协议模型TRND-AODV(TreeRoot Node Disjoint Ad-Hoc On Demand distance Vector),旨在增强路由的健壮性,增强网络对拓扑变化的适应能力。通过对AODV路由协议发现过程的修改,能够在源节点和目的节点间提供多条节点分离的无环链路。仿真结果表明,该协议模型能有效地减少路由开销、加快数据包的转发速度。     

基于DSR协议的Ad-Hoc网络入侵检测分析

分析了Ad-Hoc网络可能存在的各种安全问题，提出了一种基于动态源路由（DSR）协议进行入侵检测分析的方法。该方法利用设置可疑因子对路由信息进行检测，标识可疑节点，在路由表中删除恶意节点，在一定程度上达到了对路由攻击的防范。     

Ad hoc网络安全综述

移动Ad hoc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Ad-Hoc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.     

ZigBee网络层的设计与实现

ZigBee是基于IEEE802.15.4的一种新兴的无线网络技术。详细介绍了ZigBee协议栈的架构、层协议的参考模型。分析了ZigBee协议网络层关键技术,提出了具体网络层实现方案,并给出了基于该技术的路由过程。在以TI公司的CC2430芯片搭建的硬件平台上,测试了基于ZigBee协议的路由实现。实验表明,基于ZigBee协议组建的无线网络,能够实现较复杂网络的路由功能,网络的可扩展性强,具有很好的实用效果。     

无线自组网中AODV路由协议的Linux实现

基于AODV(Ad hoc On-Demand Distance Vector)路由协议在无线移动自组网中应用的基本原理,针对Linux操作系统路由体系结构特点,深入分析了在这种路由体系结构中实现AODV路由协议的主要关键技术和难点,给出了解决问题的办法,提出了在Linux操作系统上实现AODV路由协议的方案并在实践中加以验证,证明这种方案切实可行。     

基于OPNET仿真平台的AODV协议的性能研究

AODV(Ad hoc On-demand Distance Vector Routing)路由协议是面向移动Adhoc网络的,在介绍了移动Ad hoc网络的特征、现有路由协议和AODV路由协议的发展过程之后,重点分析了AODV协议的特征、路由建立、维护过程,并基于OPNET平台仿真了AODV协议的性能(包括路由发现时间、协议效率、平均跳数、数据吞吐量),总结了目前AODV协议存在的问题及其改进的主要方法,最后对AODV协议改进的前景进行了预测。     

基于OPNET的AdHoc网络FSR路由协议的研究

本文阐述了基于OPNET仿真框架下,如何实现Adhoc网络中FSR路由协议的开发实现。针对Adhoc网络特点的分析,分析基于表驱动的路由协议FSR,并通过OPNET建模仿真工具来实现该协议。通过FSR与AODV、OLSR进行时延和负载方面的性能比较,得出FSR在Adhoc网络中应用前景。     

按需路由协议AODV的安全性改进与仿真

移动Ad hoc网络无基础设施仅靠网络节点之间的协作完成通信。其路由协议的安全性是研究热点之一。通过对按需路由协议AODV及其安全性进行分析,提出一种基于其安全性的改进方案。该方案采用隐藏身份寻找路由、唯一标识路由请求,对报文分组进行认证等方法,增强路由信息安全性。最后在NS2网络仿真平台上对该方案进行仿真和性能分析,结果表明改进方案的安全性有较大提高。     

Multi-Fractal Characteristics of Mobile Node’s Traffic in Wireless Mesh Network with AODV and DSDV Routing Protocols

The analysis of traffic characteristics can be used for performance evaluation, design and implementation of routing protocols in WMNs (Wireless Mesh Networks). Higher bursty traffic will cause larger queue size, which means more dropping packets, and thus affects other metrics. Because burstiness can be modeled by multi-fractal characteristics effectively, multi-fractal characteristics of mobile node’s traffic in WMNs are analyzed with typical proactive and reactive routing protocols, which are DSDV (Destination Sequenced Distance Vector) and AODV (Ad hoc On-demand Distance Vector), respectively. Three types of traffic models are used to generate traffic at application level, which corresponding to open-loop and closed-loop scenarios. With different configurations, the probability distribution of inter-arrival time and multi-fractal characteristics of traffic at mobile node and gateway are analyzed with DSDV and AODV protocols. Results show that inter-arrival time with AODV and DSDV protocols possesses heavy-tailed property. And traffic with DSDV protocol exhibits more multi-fractal characteristics than that with AODV protocol, which can explain the higher routing performance of AODV.     

Security and performance enhancement of AODV routing protocol

A mobile ad hoc networks (MANET) is a decentralized, self‐organizing, infrastructure‐less network and adaptive gathering of independent mobile nodes. Because of the unique characteristics of MANET, the major issues to develop a routing protocol in MANET are the security aspect and the network performance. In this paper, we propose a new secure protocol called Trust Ad Hoc On‐demand Distance Vector (AODV) using trust mechanism. Communication packets are only sent to the trusted neighbor nodes. Trust calculation is based on the behaviors and activities information of each node. It is divided in to trust global (TG) and trust local (TL). TG is a trust calculation based on the total of received routing packets and the total of sending routing packets. TL is a comparison between total received packets and total forwarded packets by neighbor node from specific nodes. Nodes conclude the total trust level of its neighbors by accumulating the TL and TG values. The performance of Trust AODV is evaluated under denial of service/distributed denial of service (DOS/DDOS) attack using network simulator NS‐2. It is compared with the Trust Cross Layer Secure (TCLS) protocol. Simulation results show that the Trust AODV has a better performance than TCLS protocol in terms of end‐to‐end delay, packet delivery ratio, and overhead. Next, we improve the performance of Trust AODV using ant algorithm. The proposed protocol is called Trust AODV + Ant. The implementation of ant algorithm in the proposed secure protocol is by adding an ant agent to put the positive pheromone in the node if the node is trusted. Ant agent is represented as a routing packet. The pheromone value is saved in the routing table of the node. We modified the original routing table by adding the pheromone value field. The path communication is selected based on the pheromone concentration and the shortest path. Trust AODV + Ant is compared with simple ant routing algorithm (SARA), AODV, and Trust AODV under DOS/DDOS attacks in terms of performance. Simulation results show that the packet delivery ratio and throughput of the Trust AODV increase after using ant algorithm. However, in terms of end‐to‐end delay, there is no significant improvement. Copyright © 2014 John Wiley & Sons, Ltd.     

TinyOS在CC2530下的移植及AODV路由协议的实现

首先介绍了以TI的无线传感器网络芯片CC2530为核心部件的节点硬件实现,接着介绍TinyOS操作系统的运行机制及其在CC2530平台下的移植过程;并在此基础上以nesC语言实现了AODV路由协议,最后对系统进行组网测试,测试结果表明平台各功能正常运行并且实现AODV协议的基本功能。     

Routing in Large-Scale Wireless Mesh Networks Using Temperature Fields

Many wireless mesh networks are based on unicast routing protocols even though those protocols do not provide a particularly good fit for such scenarios. In this article, we report about an alternative routing paradigm, tailor-made for large multihop wireless mesh networks: field-based anycast routing. In particular, we present HEAT, a routing protocol based on this paradigm. In contrast to previous protocols, HEAT requires communication only between neighboring nodes. The underlying routing concept is a field similar to a temperature field in thermal physics. In extensive simulation experiments, we found that HEAT has excellent scalability properties due to a fully distributed implementation, and it provides much more robust routes than the unicast protocols, AODV and OLSR. As a consequence, in large-scale mobile scenarios, the packet delivery ratio with HEAT is more than two times higher, compared to AODV or OLSR. These promising results indicate that HEAT is suitable for large-scale wireless mesh networks that cover entire cities.     

AODV routing overhead analysis based on link failure probability in MANET

This article puts forward an Ad-hoc on-demand distance vector routing(AODV)routing overhead analysis method in mobile Ad-hoc network(MANET).Although multiple routing protocols have been proposed to improve the performance,scarcely any paper analyzed the routing overhead caused by routing setup and maintenance processes in mathematical way.Routing overhead consumes part of network resources and limits the supported traffic in the network.For on-demand routing protocols like AODV,the routing overhead depends on the link failure probability to a great extent.This article analyzes the collision probability caused by hidden-node problem and the impact on link failure probability.In chain and rectangle scenarios,it presents a mathematical analysis of the theoretical routing overhead of AODV protocol based on link failure probability.Simulations on OPNET 14.5platform match well with the theoretical derivation which confirms the effectiveness of the analysis method.