基于战术互联子网的路由协议性能仿真比较

本文对基于移动Ad Hoc网络的营连以下战术互联子网的网络环境以及应用业务类型特点进行了分析,通过OPNET仿真软件对AODV、DSR和OLSR路由协议在CBR、FrP和Voice三种不同业务类型下进行了仿真,分析了路由协议的平均端到端延时、平均吞吐量和路由控制开销.仿真结果表明,在营连以下战术互联子网在进行战场态势感知任务时,AODV和OLSR协议性能较好;而进行语音话务任务时,OLSR比其AODV和DSR协议性能好.     

短波Ad Hoc路由协议仿真与性能分析

为找到一种适合短波Ad hoc网络使用的路由协议,通过OPNET仿真软件对短波信道进行建模,在该模型的基础上对无线Ad Hoc常用的3种路由协议:优化链路状态路由(Optimized Link State Routing,OLSR)、反应式路由中的动态源路由(Dynamic Source Routing,DSR)和按需距离矢量(Ad hoc On Demand Distance Vector,AODV)进行仿真分析。仿真结果表明,OLSR路由协议网络时延最小、吞吐量最高和数据丢失率最低,其整体性能优于AODV及DSR路由协议,更适合于短波信道,但是OLSR路由协议也存在着开销高的不足,下一步可以针对降低路由开销进行研究。     

基于OPNET的海上无线Mesh网络路由协议的研究与仿真

针对船舶移动和海洋特殊环境本文采用了无线Mesh自组网来实现海上通信.本文首先介绍了Mesh网络的关键技术和OPNET网络仿真平台,然后给出了海上无线Mesh网络架构,最后通过OPNET平台对OLSR协议、DSR协议和AODV协议的时延、投递率和吞吐量进行了仿真分析,得出AODV协议的性能优于其他两种协议,更适合应用于海上通信.     

Ad Hoc网络DSR路由协议仿真性能分析

移动Ad Hoc网络是随着无线通信技术的快速发展而出现的一种新型网络。目前,它的应用越来越广泛。在介绍移动Ad Hoc网络的相关技术后,对动态源路由协议(DSR)进行了研究,通过计算机仿真,在不同的网络负荷、节点移动性条件下,对移动Ad Hoc网络的性能进行了分析,仿真结果表明DSR路由协议对于移动环境下的动态路由适应性较好。     

高动态Ad Hoc路由协议性能分析

Ad Hoc网络是一种没有固定设施的无线移动自组织网络,动态变化的拓扑结构对路由协议的性能有着重要影响。研究了动态源路由(DSR)协议、Ad Hoc按需距离矢量(AODV)路由协议和最优链路状态路由(OLSR)协议3种传统路由协议,利用OPNET软件作为仿真工具,设计了2种不同网络规模条件下空中飞行平台网络拓扑结构背景的高动态仿真方案,通过比较网络时延、归一化网络吞吐量、路由负载和数据传送成功率,分析了它们的性能。仿真结果表明,OLSR协议的综合性能优于其它协议,更适合于节点高速移动且网络拓扑结构频繁变化的Ad hoc网络,并为下一步研究打下基础。     

面向无人机网络快速路由恢复的改进OLSR协议

针对无人机网络中由节点和链路故障引起的频繁路由失效问题,提出了路由恢复时间指标以衡量网络对故障反应的快慢,并给出了相应的测量方法。在OLSR的基础上,提出了一种改进路由协议(Fast Recovery OLSR,FR-OLSR),通过检测HELLO消息中的邻居条目以及时发现节点或链路的突然断开,加快网络的路由恢复。在商用仿真平台EXata进行了实现,仿真结果表明,相较于OLSR,FR-OLSR在增加不超过15%控制开销的情况下,可以将路由恢复时间缩短50%。     

Ad hoc网络按需路由协议DSR性能研究

该文对无线自组网Ad hoc的基于源驱动的按需路由选择协议DSR进行了系统研究,并利用通信网络仿真建模软件OPNET对全部采用固定节点的Ad hoc网络利用DSR作为其路由协议,分设场景进行仿真,并对DSR协议随着节点数增多所表现出来的性能进行了较为详尽的比较和分析。     

基于OPNET的AODV与DSR协议的性能分析

Ad Hoc网络是由一组带有无线收发装置的移动节点组成的一个无线移动通信网络,它不依赖于预设的基础设施而临时组建,节点利用自身的无线收发设备交换信息,当相互之间不在通信范围内时,可以借助其他中间节点中继来实现通信。文中分析了Ad Hoc网络中AODV和DSR路由协议的优缺点,然后利用OPNET网络仿真软件搭建仿真模型,分别在10个和30个通信节点的小规模网络环境下,对AODV和DSR协议的性能进行了初步分析,为以后的研究提供依据。     

Ad Hoc网络中拓扑结构对路由协议性能的影响

介绍了Ad Hoc网络中常见的三种路由协议DSDV、DSR和AODV,针对网络拓扑结构的变化,设计了两种仿真方案,利用NS2仿真工具对三个协议进行了仿真。通过分析报文投递率和平均端到端时延比较了三个协议的性能。仿真结果表明,AODV具有优秀的综合性能,更适合于节点移动速度快且网络拓扑结构变化频繁的网络。     

改进路由维护机制的动态源路由协议

目的是对Ad Hoc网络中按需路由协议DSR进行改进以提高网络的数据通信的实时性.通过对DSR协议中的路由维护和路由表存储机制进行改进来完成降低网络时延的目的,并在OPNET上进行仿真实验.分别比较了普通DSR协议,带多条备用路由的DSR协议和本文提出改进型路由维护的DSR协议进行仿真,比较三种协议下网络平均传输时廷.仿真实验证明,改进的路由协议对降低网络平均时延是行之有效的.     

Performance Evaluation of Video Streaming Over Ad Hoc Networks Using Flat and Hierarchical Routing Protocols

A performance evaluation of real time services (such as video streaming) over mobile ad-hoc networks using both hierarchical and flat routing protocols is shown in this paper. A variety of workload and scenarios, as characterized by mobility, load and size of the ad hoc network have been simulated using NS-2. We use OLSR (Optimized Link State Protocol) as the flat routing protocol and our own implementation of HOLSR (Hierarchical OLSR)—which uses HNA (Host and Network Association) messages—as the hierarchical one, modifying other previous HOLSR version and maintaining the maximum compatibility with the flat OLSR. We carry out a complete comparison between these protocols focused on video evaluation. The simulation lets us compare the quality of service (QoS) of the video streaming paying attention to objective parameters (PSNR, packet delivery ratio, packet delay and interruptions). Some drawbacks of the hierarchical environment are also analyzed, as the link load between cluster heads and the lack of QoS-state-aware in HOLSR design. Quantitative results indicate that the protocol overhead is reduced (more than 40% in larger networks) and the video quality is improved (from 1 to 6 dB in certain cases) using hierarchical protocols.     

Analyzing Control Traffic Overhead versus Mobility and Data Traffic Activity in Mobile Ad-Hoc Network Protocols

This paper proposes a general, parameterized model for analyzing protocol control overhead in mobile ad-hoc networks. A probabilistic model for the network topology and the data traffic is proposed in order to estimate overhead due to control packets of routing protocols. Our analytical model is validated by comparisons with simulations, both taken from literature and made specifically for this paper. For example, our model predicts linearity of control overhead with regard to mobility as observed in existing simulations results. We identify the model parameters for protocols like AODV, DSR and OLSR. Our model then allows accurate predictions of which protocol will yield the lowest overhead depending on the node mobility and traffic activity pattern.     

Comparison of two routing metrics in OLSR on a grid based mesh network

Predicting the performance of ad hoc networking protocols for mesh networks has typically been performed by making use of software based simulation tools. Experimental study and validation of such predictions is a vital to obtaining more realistic results, but may not be possible under the constrained environment of network simulators. This paper presents an experimental comparison of OLSR using the standard hysteresis routing metric and the ETX metric in a 7 by 7 grid of closely spaced Wi-Fi nodes to obtain more realistic results. The wireless grid is first modelled to extract its ability to emulate a real world multi-hop ad hoc network. This is followed by a detailed analysis of OLSR in terms of hop count, routing traffic overhead, throughput, delay, packet loss and route flapping in the wireless grid using the hysteresis and ETX routing metric. It was discovered that the ETX metric which has been extensively used in mesh networks around the world is fundamentally flawed when estimating optimal routes in real mesh networks and that the less sophisticated hysteresis metric shows better performance in large dense mesh networks.     

基于OPNET仿真平台的MANET路由协议性能分析

MANET的特殊性决定了其路由协议的重要性。为了提高MANET路由协议性能,通过比较现有的两种典型MANET路由协议AODV协议和DSR协议,采用图形化界面的OPNET作为仿真工具,通过仿真结果的比较、分析,获得了与理论分析基本相一致的结果,即AODV协议的性能总体上优于DSR协议,并且AODV协议更适合于规模较大的MANET网络。仿真结果为后续提出优化路由协议和对现有协议改进工作提供了有效的仿真依据。     

基于NS2的AODV/DSR Ad Hoc路由协议的性能分析

分析了DSR和AODV两种Ad Hoc典型路由协议的原理和性能,介绍了仿真软件NS2.最后在NS2平台上进行了仿真.仿真结果表明,在动态拓扑变化、网络负载比较大的情况下,AODV性能明显优于DSR路由协议.     

Design and Performance of PRAN: A System for Physical Implementation of Ad Hoc Network Routing Protocols

Simulation and physical implementation are both valuable tools in evaluating ad hoc network routing protocols, but neither alone is sufficient. In this paper, we present the design and performance of PRAN, a new system for the physical implementation of ad hoc network routing protocols that unifies these two types of evaluation methodologies. PRAN (physical realization of ad hoc networks) allows existing simulation models of ad hoc network routing protocols to be used - without modification - to create a physical implementation of the same protocol. We have evaluated the simplicity and portability of our approach across multiple protocols and multiple operating systems through example implementations in PRAN of the DSR and AODV routing protocols in FreeBSD and Linux using the standard existing, unmodified ns-2 simulation model of each. We illustrate the ability of the resulting protocol implementations to handle real, demanding applications by describing a demonstration with this DSR implementation transmitting real-time video streams over a multihop mobile ad hoc network; the demonstration features mobile robots being remotely operated based on the real-time video stream transmitted from the robot over the network. We also present a detailed performance evaluation of PRAN to show the feasibility of our architecture     

Performance analysis of an ad hoc network for emergency and collaborative environments

Ad hoc networks can be used for quickly set up small spontaneous networks, such as in emergency situations or during sessions of cooperative works as in conferences, teaching rooms or meetings. Real-life tests of such networks are invaluable in order to assess models used in simulation. However, the number of factors affecting the performance of an ad hoc network is high, theoretically infinite. There are, for example, system factors, such as routing protocols, MAC and physical layer protocols and their cross-layer interaction, as well as environment factors, such as the presence of walls, foliage and surrounding moving objects. In order to optimize protocols, it is important both to design repeatable experiments of the network and to identify the parameters which really affect the system behavior. We accomplish the former demand by building a simple network by means of off-the-shelf hardware and software. For the latter point, we propose to use methods of statistical testing theory to identify these parameters in a compact manner. In particular, we use OLSR as a routing protocol. Results from real experiments in outdoor and indoor scenarios confirm the horizon effect of ad hoc multi-hop networks and show that there is a treatment effect caused by the window size of OLSR.