复杂网络环境下的DSR路由协议性能仿真

DSR是用于多跳无线Ad hoc网络的一个简单高效的路由协议,DSR协议由路由发现和路由维持两部分组成,允许节点在Ad hoc网络中发现、维持到任意节点的源路由.文章详细介绍了DSR协议的特点并利用Opnet Modeler 10.5构建了小规模(50节点)和大规模(100节点)复杂的(所有节点同时移动、所有节点既是源节点又是目的节点)移动自组网模型,通过改变节点移动速度及发送分组大小,对DSR路由算法的平均路由发现时间、平均路由长度、吞吐量、数据分组平均端到端的时延、及分组交付率在两种场景下进行了仿真分析和性能比较.     

基于Ad hoc的按需路由协议DSR的优化研究与实现

无线Ad hoc网络是一种不需要基础设施的自组织和自管理网络,网络中所有的节点同时具有终端和路由器的功能。因此网络可以通过节点路由发现机制转发分组,并进行路由维护。文中对DSR(动态源路由协议)的路由发现过程进行了优化,并采用OPNET仿真软件对基于DSR协议的Ad hoc网络的路由开销和时延等关键参数进行了仿真统计,分析了改进后的路由协议对网络质量的影响。     

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.     

移动Ad hoc网络中路由协议的研究

移动Ad hoc网络由无线移动节点在没有任何现存的网络基础设施的情况下组成的自治系统,成为一个具有任意通信拓扑图模型的通信网络.由于网络节点的多跳性、有限的传输带宽、高速移动性、能量受限等特点,使路由协议成为Ad hoc网络设计的关键.主要介绍了Ad hoc网络的路由协议设计策略及分类原则,并对现有的具有代表性的路由协议性能进行了比较分析,为进一步研究提出新的课题.     

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。     

基于能量改进的DSR路由协议性能分析

本文简要介绍了Ad hoc网络中路由协议的特殊性，指出节点能量是Ad hoc网络中影响系统路由生存时间的关键性因素。在无线按需路由协议DSR的基础上，提出一种基于节点能量高低增加延时函数来选择路径的协议EDSR。仿真结果显示EDSR相对于DSR提高了系统生存时间。     

移动Ad hoc网络路由协议综述

摘要文章简单介绍移动Ad hoc网络,详细综述了移动Ad hoc网络中的各种路由协议．包括先验式路由协议、反应式路由协议和混合式路由协议,对它们进行了分类、对比和分析。提出了一个Ad hoc网络新型的路由协议的框架。最后,指出了移动Ad hoc路由协议的研究热点和展望。     

Ad hoc网络两种按需路由协议性能分析

Ad hoc网络是一种无需依赖于事先布设的基础设施,而仅依靠网络内部节点之间的协作,就能够完成节点间通信的网络。比较了Ad hoc网络两种主流的按需路由协议：动态源路由协议,自组网按需距离矢量路由协议。使用基于ns-2的仿真模型进行仿真,并通过分组交付率、平均端到端时延、标准化路由负荷、对两种按需路由协议进行评估。实验结果表明即使DSR和AODV协议都是按需路由协议,但它们采取的路由机制的不同,导致它们的性能表现的巨大差异。     

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.     

Ad hoc网络中基于能量的AODV双径路由算法研究

在Ad hoc网络中AODV路由的健壮性、路由开销、网络的生存时间以及分组报文传送率等都是评价该算法优良的指标。为了提高该路由算法的各项指标本文提出了改进的路由算法协议,在Ad hoc网络中避免使用的低于能量阈值的节点作为路由节点以提高整体网络的生存时间,提供主次路径使报文的到达率、网络的健壮性得以提高,同时也减少了链路的修复,减少了路由开销。     

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.     

基于NS2的无线自组织网络路由协议仿真

在无线自组织网络中,由于节点移动,网络拓扑结构变化频繁,所以路由协议的选择一直都是关键问题。该文采用NS2软件对两种主要的协议：动态源路由协议（DSR）和自组网按需距离矢量路由协议（AODV）进行了仿真。并且通过端到端延时、路由开销和分组投递率三种参数在不同条件下的数据对两种协议进行了评估。实验结果表明没有一种协议能够完全适用于自组网,对于特殊环境选择不同协议以满足需要。     

Agent-based trusted on-demand routing protocol for mobile ad-hoc networks

The routing performance in mobile ad hoc networks (MANETs) relies on the co-operation of the individual nodes that constitute the network. The existence of misbehaving nodes may paralyze the routing operation in MANETs. To overcome this behavior, the trustworthiness of the network nodes should be considered in the route selection process combined with the hop count. The trustworthiness is achieved by measuring the trust value for each node in the network. In this paper, a new protocol based on self monitoring (agent-based) and following the dynamic source routing (DSR) algorithm is presented. This protocol is called agent-based trusted dynamic source routing protocol for MANETs. The objective of this protocol is to manage trust information locally with minimal overhead in terms of extra messages and time delay. This objective is achieved through installing in each participated node in the network a multi-agent system (MAS). MAS consists of two types of agents: monitoring agent and routing agent. A new mathematical and more realistic objective model for measuring the trust value is introduced. This model is weighted by both number and size of routed packets to reflect the “selective forwarding” behavior of a node. The performance evaluation via simulation shows that our protocol is better than standard and trusted DSR. The simulation is done over a variety of environmental conditions such as number of malicious nodes, host density and movement rates.     

Trading latency for energy in densely deployed wireless ad hoc networks using message ferrying

Wireless mobile ad hoc networks (MANETs) have the potential for use in important application environments, such as remote environmental monitoring, where energy resources are limited. Efficient power management is necessary to allow these networks to operate over a long period of time. One of the key factors affecting the design of power management mechanisms is the routing protocol in use within the network. In this paper, we investigate the Message ferrying (MF) routing paradigm as a means to save energy while trading off data delivery delay. In MF, special nodes called ferries move around the deployment area to deliver messages for nodes. While this routing paradigm has been developed mainly to deliver messages in partitioned networks, here we explore its use in a connected MANET. The reliance on the movement of ferries to deliver messages increases the delivery delay if a network is not partitioned. However, delegating message delivery to ferries provides the opportunity for nodes to save energy by aggressively disabling their radios when ferries are far away. To exploit this feature, we present a power management framework, in which nodes switch their power management modes based on knowledge of ferry location. We evaluate the performance of our scheme using ns-2 simulations and compare it with a multihop routing protocol, dynamic source routing (DSR). Our simulation results show that MF achieves energy savings as high as 95% compared to DSR without power management and still delivers more than 98% of messages. In contrast, a power-managed DSR delivers many fewer messages than MF to achieve similar energy savings. In the scenario of heavy traffic load, the power-managed DSR delivers less than 20% of messages. MF also shows robust performance for highly mobile nodes, while the performance of DSR suffers significantly. Thus, delay tolerant applications can use MF rather than a multihop routing protocol to save energy efficiently when both routing approaches are available.     

A Performance Evaluation of a Dynamic Source Routing Discovery Optimization Protocol Using GPS System

Ad hoc networks are useful for providing communication support where no fixed infrastructure exists or the deployment of a fixed infrastructure is not economically profitable, and movement of communicating parties is allowed. Therefore, such networks are designed to operate in widely varying environments, from military networks to low-power sensor networks and other embedded systems. Frequent topology changes caused by node mobility make routing in ad hoc wireless networks a challenging problem. In this paper, we propose an optimization technique, which we refer to as GDSR, a reactive protocol that makes use of DSR scheme and the Global Positioning System (GPS). As opposed to the DSR protocol our GDSR scheme consists of propagating the route request messages only to the nodes that are further away from the query source. We discuss the algorithm, its implementation and present an extensive simulation and experimental results to study its performance. We also present a comparative study of GDSR protocol with the existing DSR protocol. Our results clearly indicate that the GDSR protocol outperforms the DSR protocol by significantly decreasing the number of route query packets thereby increasing the efficiency of the network load. Furthermore, we show that a careful GPS screening angle is an important factor in the success of GDSR ad hoc routing protocol.     

Novel multi-path routing scheme for UWB Ad hoc network

1 Introduction Ad hoc networks and ultra-wideband communications technology are a key factor in the evolution of wireless communications. In ad hoc networks, wireless hosts can communications with each other in the absence of a fixed infrastructure. These networks typically consist of equal nodes that communication over wireless links without central control .The followings can be used to describe the ad hoc network[1]: ? Dynamic network topology ? Limited resource ? Multi-hop communication …     

基于CBR与TCP移动白组网路由协议分析

移动自组网是由无线移动主机组成的没有基础设施或集中管理中心的临时性网络。在其组建应用过程中,路由协议起着重要的作用。文中基于仿真软件NS2对移动自组网三种典型路由协议DSDV、DSR、TORA在TCP与CBR业务下的性能进行了比较分析。仿真结果表明,在发送速率144kb／s时,DSR与DSDV性能优于TORA,且TCP业务性能优于CBR业务。     

Safari: A self-organizing, hierarchical architecture for scalable ad hoc networking

As wireless devices become more pervasive, mobile ad hoc networks are gaining importance, motivating the development of highly scalable ad hoc networking techniques. In this paper, we give an overview of the Safari architecture for highly scalable ad hoc network routing, and we present the design and evaluation of a specific realization of the Safari architecture, which we call Masai. We focus in this work on the scalability of learning and maintaining the routing state necessary for a large ad hoc network. The Safari architecture provides scalable ad hoc network routing, the seamless integration of infrastructure networks when and where they are available, and the support of self-organizing, decentralized network applications. Safari’s architecture is based on (1) a self-organizing network hierarchy that recursively groups participating nodes into an adaptive, locality-based hierarchy of cells; (2) a routing protocol that uses a hybrid of proactive and reactive routing information in the cells and scales to much larger numbers of nodes than previous ad hoc network routing protocols; and (3) a distributed hash table grounded in the network hierarchy, which supports decentralized network services on top of Safari. We evaluate the Masai realization of the Safari architecture through analysis and simulations, under varying network sizes, fraction of mobile nodes, and offered traffic loads. Compared to both the DSR and the L+ routing protocols, our results show that the Masai realization of the Safari architecture is significantly more scalable, with much higher packet delivery ratio and lower overhead.     

无线Ad hoc网络机会路由的实现与仿真

在无线自组织网络中,路由协议对网络的性能起着关键性作用。然而由于无线信道的不稳定性经常造成通信中断而需重建路由,使自组织网传统路由协议的效率大大降低。提出了一种应用于无线自组织网络的机会路由协议（WAOR）,利用无线信道的广播特性和多径传输来增强链路的可靠性。采用网络仿真器NS2的仿真结果表明,WAOR的性能优于传统的动态源路由协议（DSR）和自组织网按需平面距离矢量路由协议（AODV）。     

A strategy to reduce the control packet load of MANETs with bidirectional links using DSR

Dynamic source routing (DSR) is a robust protocol commonly applied to multi‐hop wireless mobile ad hoc networks (MANETs). In this paper, an algorithm is proposed for modifying the basic DSR protocol to enhance its performance by reducing the number of redundant route reply packets (RREPs). In the modified DSR (MDSR), for a source destination pair, the destination responds to the first received route request packet (RREQ) with an RREP, and the subsequently received RREQs, bearing the same request ID, are responded to only if the hop count is less than that of all the previously received RREQs. The performance of MDSR has been compared with that of the basic DSR for different network densities and for different mobility of nodes. Simulation results show that MDSR gives fewer control packets, less latency and a higher packet delivery ratio than DSR. Copyright © 2007 John Wiley & Sons, Ltd.