基于生命期预测的移动Ad hoc网络多径路由策略

在移动自组网中,由于网络节点的移动性和拓扑结构的多态性,多路径路由在稳定性,均衡负载方面优于单路径路由,非常适合Ad hoc网络。考虑到移动自组网中节点能量的局限性,在DSR协议的基础上提出了一种新型的多径路由算法。该算法结合节点路径的能量消耗率,预测出链路的生命期,以求找到多条有效路径并进行传输。仿真结果表明,该协议比DSR具有更好的吞吐量和端到端延迟。     

基于遗传算法的移动自组网路由优化

对移动自组网的拓扑结构进行分析,建立其路由网络模型．将遗传算法的基本原理和移动自组 网的路由模型结合起来,提出了一种求解无线网络最优路径的算法．该方法采用可变长度染色体编码,利用 遗传算法优化路由,可以在满足系统开销最小的约束条件下寻找到最优路径．     

一种累计多路径的移动自组网络路由策略

描述了一种基于多路径移动自组网络按需路由策略.在移动自组网络,由于网络节点的移动性及拓扑结构的易变性,路由成为最受关注的问题.在以前的移动自组网络路由算法中,主要采用的是传统的单路径方式.最近,多路径方式也逐渐出现,因为相对单路径路由而言,多路径为移动自组网络提供的QoS支持更可行、更高效.鉴于现有的移动自组网络多路径策略未能为源节点提供充分的信息,提出了一种新型的移动自组网络多路径路由算法.该算法可以将路由信息保存在源节点中,并依此在源节点中采用替换路径或多路径并发的方式进行数据传输.     

一种基于复杂网络理论的移动自组网路由算法研究*

针对移动自组网中节点之间数据包发送成功率不高、路由开销大和包平均延时长等问题,提出了一种基于复杂网络理论的移动自组网路由算法。在该算法中,路由发现基于路由消息在邻域范围的相互借阅,若持续时间在网络平均路由发现时间范围内,则采取动态随机路由,考核跳级数是否满足复杂网络理论的条件来选择以最少跳级数或者最短路径为指标的最优路径建立路由,否则采取位置路由,采取方向最有益的最优路径建立路由。实验分析表明,即使节点稀疏时该路由算法仍具有很好的包发送成功率和包平均延时,其综合性能优于OLSR协议和AODV协议。     

满足QoS约束的自适应Ad Hoc网络路由算法

自组网是由一组带有无线收发装置移动节点组成的一个能够支持多跳的临时性计算机通信网络，其拓扑的动态变化是该类网络的一个重要特征，文章提出了一种满足QoS约束的自适应路由算法，将业务的多个QoS参数进行综合评判，对比各条路径综合路由状态，选择出最适合业务请求的路径。仿真显示该算法在支持QoS的同时，对移动Ad Hoc网络因拓扑动态变化而引起的信息不精确性有很好的适应度。     

自组网中基于熵的定向洪泛QoS路由算法研究

为了减少移动自组网中路由频繁失效和重构,提高网络性能和资源利用率,提出了基于熵的定向洪泛QoS路由算法。该算法利用定向洪泛的机制控制路由请求转发范围,降低网络的控制开销;并采用一种度量方法——熵来选择稳定的路由,减少重路由,提高数据成功传输率。利用OPNET对算法进行仿真,结果表明该算法能以较小控制开销获得较好的数据传输,降低了路由重构的概率,适合移动自组网的高度动态的特点。     

无人机自组网路由协议研究综述

随着无人机软硬件技术的发展,多无人机集群自组织形成的无人机自组网（Flying Ad-Hoc networks, FANETs）受到了越来越多的来自学术界和工业界的关注,其灵活的部署和快速的反应能力使其能高效地完成多种多样的任务。而无人机自组网路由协议是提高服务质量（Quality of service, QoS）最重要的方法之一,但无人机自组网的移动性和动态性给路由协议的设计带来了严峻的挑战。传统的移动路由协议不能很好地满足无人机自组网的路由需求,因此研究者们从基于拓扑、地理和分层的角度提出了各式各样的无人机自组网路由协议,旨在克服移动性和提高网络的服务质量,并指出未来无人机自组网的路由协议可以考虑机会路由、软件定义网络（Software defined network,SDN）决策和预测驱动决策等综合提高QoS。本文主要针对无人机自组网网络特征,从不同的路由方法出发,SDN对路由协议进行总结和归纳,并对未来的研究方向进行了展望。     

基于节点度的移动自组网络Grover路由算法研究

移动自组网络是当前无线网络研究的热点问题,网络路由算法研究是其中的一个关键问题.在深入分析现有移动自组网络路由协议基础上,本文结合动态源路由协议的特点,提出了一种基于节点度值计算的Grover路由算法.该方法系统地研究移动自组网络的主要特征:节点度值、节点能量等,利用Grover搜索算法构造操作矩阵和概率扩散矩阵计算得...     

可量化的移动Ad Hoc 网络时空动态特性评估方法

移动模型是Ad Hoc网络区别于其他形式网络的重要标志,对其产生的动态网络特性(简称动态特性)进行评估,是研究Ad Hoc网络的协议仿真和网络相关技术(如拓扑控制和网络性能测量等)的基础性问题.在已有研究的基础上,改进了网络的模型化描述,克服了以往模型无法很好地描述相关联的时空动态特性的缺陷,并在此基础上,提出了移动模型通用的可量化时空动态特性评估方法.通过构建节点空间位置分布,建立网络拓扑时空动态特性的分析模型,深入研究了几种移动模型的动态性.提出一种圆周曲线移动模型,弥补了以往移动模型难以描述现实的曲线移动场景.仿真实验结果表明,该方法能够有效地对现有移动模型的动态性进行评估.实验结果表明,圆周曲线移动模型与以往移动模型相比,具有良好的时空动态特性.     

基于复杂网络理论的移动自组网路由算法研究

移动自组网中节点通信时路由开销较大,从而引起整个自组网的能耗过高;为了解决这一问题,针对移动自组网的现实组网特征进行了研究,提出了基于复杂网络理论的移动自组网路由算法;在该路由算法中,路由发现基于源节点到目的节点的梯度方向,源节点选取下一级跳数据转发对象时,在其邻域范围内以选取路径是否符合最速下降法作为判断依据;当源节点和目的节点之间存在的节点个数超过复杂网络理论中的达到条件时,源节点在路由方向上选取其邻域内最接近的节点进行转发后,按照最速下降法继续寻找最优路径;实验表明,该路由算法具有较少的跳级数,可以减轻整个自组网的数据存储压力,路由开销在节点疏密度不同时,介于OLSR协议和AODV协议之间.     

移动自组网基于邻居变化率稳定路径选择方法

节点移动是导致移动自组织网络性能下降、限制网络规模扩展的关键因素之一.寻找稳定路径是减小节点移动影响的有效手段.现有的稳定路径寻找方法存在以下局限:需要节点具有地理位置定位的硬件功能支持,或需要信号强度上传的交叉层功能支持.为此,提出了不需要特殊硬件支持、可独立于底层协议工作、基于邻居变化率的稳定路径选择方法.以AODV(Ad hoc on-demand distance vector)按需路由协议为基础,扩展为NCR-AODV(Neighbor change ratio Ad hoc on-demand     

A cost matrix agent for shortest path routing in ad hoc networks

Wireless ad hoc networks do not rely on an existing infrastructure. They are organized as a network with nodes that act as hosts and routers to treat packets. With their frequent changes in topology, ad hoc networks do not rely on the same routing methods as for pre-established wired networks; they require routing methods for mobile wireless networks. To select a path from a source to a destination in dynamic ad hoc networks, an efficient and reliable routing method is very important. In this paper, we introduce a cost-matrix-based routing algorithm. An agent node creates topology information in the form of the adjacency-cost matrix which shows link costs of the network.Based on the adjacency-cost matrix, the minimum-cost matrix and the next-node matrices can be calculated. Based on the minimum-cost matrix and the next-node matrices, the minimum cost between source and destination nodes and between intermediate nodes on the minimum-cost paths can be calculated.The matrices are periodically distributed by the agent to the other nodes. Based on the minimum-cost matrix and the next-node matrices, each node decides the minimum-cost path to its destination. Because none of the nodes except the agent needs to gather network topology information, the control overhead of the proposed method is small compared with those of the general table-driven routing protocols.     

Minimum disruption service composition and recovery in mobile ad hoc networks

The dynamic nature of mobile ad hoc networks poses fundamental challenges to the design of service composition schemes that can satisfy the end-to-end quality of service requirements and minimize the effect of service disruptions caused by dynamic link and node failures. Although existing research on mobile ad hoc networks has focused on improving reliability, little existing work has considered service deliveries spanning multiple components. Moreover, service composition strategies proposed for wireline networks (such as the Internet) are poorly suited for highly dynamic wireless ad hoc networks.This paper proposes a new service composition and recovery framework designed to achieve minimum service disruptions for mobile ad hoc networks. The framework consists of two tiers: service routing, which selects the service components that support the service path, and network routing, which finds the optimal network path that connects these service components. Our framework is based on the disruption index, which is a novel concept that characterizes different service disruption aspects, such as frequency and duration, that are not captured adequately by conventional metrics, such as reliability and availability.Using the definition of disruption index, we formulate the problem of minimum-disruption service composition and recovery (MDSCR) as a dynamic programming problem and analyze the properties of its optimal solution for ad hoc networks with known mobility plan. Based on the derived analytical insights, we present our MDSCR heuristic algorithm for ad hoc networks with uncertain node mobility. This heuristic algorithm approximates the optimal solution with one-step lookahead prediction, where service link lifetime is predicted based on node location and velocity using linear regression. We use simulations to evaluate the results of our algorithm in various network environments. The results validate that our algorithm can achieve better performance than conventional methods.     

移动Ad hoc网络安全分簇综述

移动Ad hoc网络是由移动节点组成的无线移动通信网络,它具有动态拓扑、无线通信的特点,但又易受到各种安全威胁。规模较大的移动Ad hoc网络可以用分簇的方法来减少路由和控制开销,并提高网络的可扩充性。综合分析了以安全为部分或全部目的的移动Ad hoc网络分簇方法研究的最新进展。首先分析了移动Ad hoc网络的特点、体系结构和面临的安全威胁,然后将较大规模移动Ad hoc网络的安全分簇方法分为3个重要方面:认证模型、信任度量和不良节点发现。对每个方面的一些典型方案进行了分类论述和综合比较。最后指出了下一步研究中应当着重考虑的问题。     

Risk-based attack strategies for mobile ad hoc networks under probabilistic attack modeling framework

In this paper, we introduce and design a modeling framework that allows for the study and analysis of attack propagation in mobile ad hoc networks. The choice of a statistical approach for the problem is motivated by the dynamic characteristics of the ad hoc topology and the stochastic nature of threat propagation. Based on this probabilistic modeling framework, we study the impact of topology and mobility in the propagation of software threats over ad hoc networks. We design topology control algorithms that indicate how to properly adjust an attacker’s transmission radius, according to the measured topological characteristics and availability of its resources, in the process of infecting a network more effectively. Then based on these topology control algorithms we develop different attack strategies that may range from independent attacks to cooperative scenarios in order to increase the negative impact of an attack on the network. Our performance evaluation results demonstrate that the proposed topology control algorithms and respective attack strategies effectively balance the tradeoffs between the potential network damage and the attackers’ lifetime, and as a result significantly outperform any other flat and threshold-based approaches.     

高动态飞行器自组织网络组网研究

节点高速移动和网络拓扑变化迅速严重影响着高动态飞行器自组织网络性能。提出了一种适于高动态场景的移动自组织网络协议栈设计。该设计着重QoS需求,围绕网络拓扑高动态变化特征,合理配置不同层次的网络协议,适合高动态应用场景。以平面网络为例,分析评估了FANET网络在高动态环境下的性能。实验结果表明,该组网方式可行并能满足高动态飞行器自组织网络的功能和性能需求。还提出了节点在个体移动方式下保持网络高性能的最佳节点数目和网络各层次协议适应高动态拓扑变化的应对策略。     

Backup path set selection in ad hoc wireless network using link expiration time

Topological changes in mobile ad hoc networks frequently render routing paths unusable. Such recurrent path failures have detrimental effects on quality of service. A suitable technique for eliminating this problem is to use multiple backup paths between the source and the destination in the network. Most of the proposed on-demand routing protocols however, build and rely on single route for each data session. Whenever there is a link disconnection on the active route, the routing protocol must perform a path recovery process. This paper proposes an effective and efficient protocol for backup and disjoint path set in an ad hoc wireless network. This protocol converges into a highly reliable path set very fast with no message exchange overhead. The paths selection according to this algorithm is beneficial for mobile ad hoc networks, since it produces a set of backup paths with much higher reliability. Simulations are conducted to evaluate the performance of our algorithm in terms of route numbers in the path set and its reliability. In order to acquire link reliability estimates, we use link expiration time (LET) between each two nodes.In another experiment, we save the LET of entire links in the ad hoc network during a specific time period, then use them as a data base for predicting the probability of proper operation of links.Links reliability obtains from LET. Prediction is done by using a multi-layer perceptron (MLP) network which is trained with error back-propagation error algorithm. Experimental results show that the MLP net can be a good choice to predict the reliability of the links between the mobile nodes with more accuracy.     

高能量节点驱动的按需距离矢量路由协议

无线自组织网络中的按需距离矢量路由协议(AODV)没有考虑到能量消耗的均衡性和网络生命期的问题。针对AODV的这一缺点,提出了一种高能量节点驱动的AODV协议(HN-AODV)。此协议将高能量节点驱动的策略应用于按需路由发现过程,尽量选择能量较高的节点来承担转发任务,以此来平衡网络能耗。仿真结果显示,HN-AODV在基本不降低数据传输性能的前提下,显著提高了网络生命周期。这种高能量节点驱动的方案同样可以运用在其它类似的反应式路由协议中。     

Dynamic address autoconfiguration in hybrid ad hoc networks

The use of ad hoc networking technologies is emerging as a viable and cost-effective solution to extend the range of traditional wireless local area networks (WLANs). In these networks, mobile client traffic reaches the access points through multi-hop wireless paths that are established by using an ad hoc routing protocol. However, several technical challenges have to be faced in order to construct such an extended WLAN. For instance, traditional autoconfiguration protocols commonly used in infrastructure-based WLANs, such as DHCP or Zeroconf, are not directly applicable in multi-hop wireless networks. To address this problem, in this paper we propose extensions to DHCP to enable the dynamic allocation of globally routable IPv4 addresses to mobile stations in hybrid ad hoc networks, which transparently integrate conventional wired technologies with wireless ad hoc networking technologies. Some of the attractive features of our solution are its ability to cope with node mobility, the introduction of negligible protocol overheads, and the use of legacy DHCP servers. We have implemented a prototype of our scheme, and tested its functionalities considering various topology layouts, network loads and mobility conditions. The experimental results show that our solution ensures short address configuration delays and low protocol overheads.