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。     

基于链路可用性预测的AODV路由协议研究

传统的AODV路由协议无法适应Ad hoc网络拓扑的高度动态变化.对AODV路由算法进行链路可用性预测扩展,节点通过接收分组的能量值和链路连续可用时间选择最可靠的路径进行路由,并在链路真正失效之前启动预先修复过程.仿真结果表明,改进后的AODV协议提高了分组的投递率,降低了分组端到端平均传输延时,路由协议的可靠性得到改进.     

移动Ad hoc网络基于链路质量和拓扑质量的路由协议

移动Ad hoc网络中节点的移动性使得频繁的路由失效与路由发现,路由发现中的控制开销是影响路由性能的一个重要的因素。传统的按需路由协议多采用洪泛的方式进行路由发现,并选取最小跳数路由。每个中间节点盲目的转发收到的路由请求包,不仅没有考虑链路质量,而且会引起广播风暴问题。本文提出一种基于链路质量和拓扑质量的路由协议,该协议根据相邻节点之间剩余链路生存期作为链路质量指标,同时根据中间节点与"源-目的"节点连线的距离关系作为拓扑质量指标。结合两个指标设置转发概率,不仅能避免频繁的路径断开,而且限制了路由请求包的传播范围。模拟结果显示,本文提出的方法在显著地降低路由控制开销的同时,还能够提高分组投递率并降低端到端延迟,从而提高了路由性能。     

MANETs中基于节点移动度的虚连接的路由

由于移动自组织网络MANETs中节点的快速移动,使得维持源节点与目的节点间的通信路径成为一项挑战性工作。节点的高速移动导致通信链路频繁断裂。为此,提出基于节点移动度的虚连接的路由(MDVRP)。虚路由为一条动态的逻辑路由,其由一系列的特定地理区域构成。每个区域内的节点依据自己的移动度设置转发数据包的定时器,移动度越小,具有优先转发数据包权。MDVRP通过虚路由策略,在源节点与目的节点间建立了多条传输路通,每个节点能独立选取下一跳转发节点,并利用节点移动度,择优选取转发数据包下一跳节点,从而提高链路的稳定性。仿真结果表明,提出的路由协议在端到端传输时延、路由开销以及数据包传输率性能均得到提高。     

一种基于AODV的链路质量与能效优先的跨层路由协议

无线ad-hoc网络部署在非人为控制的外部环境中,采用电池供电.在这种应用环境中,如何通过合理的路由协议设计降低能量开销、提高网络的生存时间是近年来研究的热点.文章提出一种结合链路质量与能效的跨层路由协议.在路由建立阶段综合考虑链路质量、发送数据包的能耗和节点剩余能量来建立路由.通过在路由维护阶段对链路质量和节点剩余能量进行检测,预测路由中断的发生,并进行本地修复.通过在IEEE 802.15.4 Matlab模拟器下进行仿真,验证了该协议能够有效地提高网络的生存时间、数据投递率及AODV协议的性能和稳定性.     

基于时间序列分析的链路质量预测和稳定路由算法研究

针对现有链路质量预测算法不适用于实际通信场景的问题,该文提出一个不依赖于任何特定信号传输模型和节点移动模型、低复杂度的实时链路质量预测算法,并将其应用于稳定路由协议设计。通信节点存储并更新其邻节点的接收信号强度集合以构成时间序列,将时间序列分析中的局部线性核平滑方法和滑动窗口局部多项式预测方法引入链路质量判断及预测。在此基础上,结合跨层协作思想,提出了节点移动自适应的提前路由修复机制。仿真结果表明,该预测算法具有较高的预测准确度,并能显著增强路由稳定性,提高网络性能。     

基于能量与链路稳定性感知的按需路由协议

对于复杂的室外环境,无线传感器网络如何建立可靠的路由,并尽可能延长全网寿命是一个关键问题.在分析总结现有无线Ad Hoe网络路由协议的优缺点的基础上,提出了一种基于能量与链路稳定性感知的多度量的按需路由协议ELSA-AODV.ELSA-AODV协议是AODV协议的增强与扩展,在保证路由可靠性与稳定性的同时,平衡全网的通信负荷与能量,大大延长了全网的工作寿命.通过仿真实验,验证了ELSA-AODV的有效性.     

移动Ad hoc网络基于链路可用时间的动态源路由协议

为了提高链路的稳定性,增加路径可用时间,提出一种应用于移动Ad hoc网络的基于链路可用时间的动态源路由协议(LARP).该协议以路径可用时间作为路径评价的参数,优先选择具有最大路径可用时间的路径进行数据包传递.路径可用时间反映了当前节点移动对路径稳定性的影响,其数值取决于路径中的最小链路可用时间.仿真结果表明该协议相...     

基于IPv6无线传感网络的最佳转发路由协议

提出一种基于IPv6无线传感网络的最佳路由转发协议,在性能上其吞吐量比RIP(路由信息协议)和贪婪算法路由协议要分别提高11%和43%。该转发是基于对从该节点到邻居节点的链路估值、代价估值和接收信号强度估值计算得出的转发值进行的。如果该链路数据传输不成功,该协议将会选择其他具有次最佳转发权值的节点进行转发。     

基于链路质量的WSN代价均衡路由选择算法

该文针对无线传感器网络中不可靠链路通信耗能过大的问题,基于链路质量进行路由代价函数构建,并为各条路径分配适当的选择概率,采用最小跳数转发策略设计了代价均衡的路由选择算法CBLQ;为了进一步降低和均衡路由代价,分析同跳节点的备选转发条件,又扩展形成了新的路由选择算法CBLQ-E。仿真实验结果证明,两种算法均使网络的能量利用率得到有效提高,同时还降低了网络的数据传输时延。     

Moralism: mobility prediction with link stability based multicast routing protocol in MANETs

In recent research, link stability is getting tremendous attention in mobile adhoc networks (MANETs), because of several impediments that occur in a reliable and robust network. Link stability metric is used to improve network performance in terms of end-to-end delay, data success delivery ratio (DSDR) and available route time (ART). Energy consumption, bandwidth and communication delay of major concern in ad hoc networks. A high mobility of MANET nodes reduces the reliability of network communication. In a dynamic networks, high mobility of the nodes makes it very difficult to predict the dynamic routing topology and hence cause route/link failures. Multicast in MANETs is an emerging trend that effectively improves the performance while lowering the energy consumption and bandwidth usage. Multicast routing protocol transmits a packet to multicast a group at a given time instant to achieve a better utilization of resources. In this paper, node mobility is considered to map better their movement in the network. So, the links with long active duration time can be identified as a stable link for route construction. Variation in signal strength is used to identify whether the direction of the node is towards or away from estimating node. We consider signal strength as QoS metric to calculate link stability for route construction. Efforts are made to identify the link with highly probable longer lifetime as the best suitable link between two consecutive nodes. We predict the movement time of nodes that define the route path to the node destination. Exata/cyber simulator is used for network simulation. The simulation results of the proposed routing protocol are compared with on-demand multicast routing protocol and E-ODMRP, which works on minimum hop count path. Analysis of our simulation results has shown improvement of various routing performance metrics such as DSDR, ART, routing overhead and packet drop ratio.     

移动Adhoc网络中按需路由协议的安全性改进方案

在移动Adhoc网络中,安全性是保证其可用性的一个重要方面.文章提出了一种针对按需路由协议的安全性改进方案,这种方案采用了对邻居节点的身份即时认证、对远端节点按需认证、匿名寻找路由,逐跳加密传输的机制,能够有效地阻止恶意节点对网络的窃听、篡改等攻击,确保网络路由信息的安全.     

低开销的MANET网络按需路由协议

针对简单泛洪效率低的问题,提出了一个限制洪泛的高效的路由广播算法,通过Euclidean距离来限制路由发现过程中请求分组被转发的次数;研究了减少路由维护开销,并降低路由发现的频率的方法,提出了一个基于节点高度的路由修复与优化算法,该算法使用节点监听来对链路断裂的路由进行修复与优化.基于限制泛洪的高效的路由广播算法和路由修复优化算法,提出了一种新的低开销的MANET网络按需路由协议LOOR(low overhead on-demand routing).仿真结果表明,新协议增强了路由的顽健性,减少了路由跳数,降低了路由发现的频率,提高了数据分组递送率,并显著地降低了路由控制开销.     

A Novel Robust Routing Scheme Against Rushing Attacks in Wireless Ad Hoc Networks

Standard on-demand routing protocols in wireless ad hoc networks were not originally designed to deal with security threats. Because of that, malicious users have been finding ways to attack networks. Rushing attacks represent one of such possibilities. In these attacks, malicious nodes forward the Route Request (RREQ) packets, asking for a route, to the destination node quicker than the legitimate nodes do. This is possible because the legitimate nodes only forward the first received RREQ packet for a given route discovery. Besides, the attackers can tamper with either the Medium Access Control or routing protocols to get faster processing. As a result, the path through the malicious nodes is chosen, which renders throughput degradation. We propose here a novel, robust routing scheme to defend ad hoc networks against rushing attacks. Our scheme utilizes the “neighbor map mechanism” to establish robust paths as far as rushing attacks are concerned. The proposed scheme also improves path recovery delay by using, whenever it is possible, route maintenance rather than route discovery. Yet, it is energy efficient. The simulation results show that our proposal is indeed viable.     

SDR: A Stable Direction-Based Routing for Vehicular Ad Hoc Networks

A stable and reliable routing mechanism for vehicular ad hoc networks (VANETs) is an important step toward the provision of long data transmission applications, such as file sharing and music download. Traditional mobile ad hoc network (MANET) routing protocols are not suitable for VANET because the mobility model and environment of VANET are different from those of traditional MANET. To solve this problem, we proposed a new stable routing algorithm, called stable directional forward routing. The novelty of the proposed routing protocol is its combining direction broadcast and path duration prediction into ad hoc on-demand distance vector routing protocols, which including: (1) Nodes in VANET are grouped based on the position, only nodes in a given direction range participating in the route discovery process to reduce the frequency of flood requests, (2) Route selection is based on the link duration while not the hops or other metrics to increase the path duration, (3) Route discovery is executed before the path expiration in order to decrease the end to end delay. The performance of the new scheme is evaluated through extensive simulations with Qualnet. Simulation results indicate the benefits of the proposed routing strategy in terms of decreasing routing control packet, reducing the number of link-breakage events, improving the packet delivery ratio and decreasing the end-to-end delay.     

Weighted dominating set based routing for ad hoc communications in emergency and rescue scenarios

Disasters create emergency situations and the services provided must be coordinated quickly via a communication network. Mobile adhoc networks (MANETs) are suited for ubiquitous communication during emergency rescue operations, since they do not rely on infrastructure. The route discovery process of on-demand routing protocols consumes too much bandwidth due to high routing overhead. Frequent route changes also results in frequent route computation process. Energy efficiency, quick response time, and scalability are equally important for routing in emergency MANETs. In this paper, we propose an energy efficient reactive protocol named Weighted-CDSR for routing in such situations. This protocol selects a subset of network nodes named Maximum Weighted Minimum Connected Dominating Set (MWMCDS) based on weight, which consists of link stability, mobility and energy. The MWMCDS provides the overall network control and data forwarding support. In this protocol, for every two nodes u and v in the network there exists a path between u and v such that all intermediate nodes belong to MWMCDS. Incorporating route stability into routing reduces the frequency of route failures and sustains network operations over an extended period of time. With fewer nodes providing overall network control and data forwarding support, the proposed protocol creates less interference and consumes less energy. The simulation results show that the proposed protocol is superior to other protocols in terms of packet delivery ratio, control message overhead, transmission delay and energy consumption.     

AODV_RR: A Maximum Transmission Range Based Ad Hoc on-Demand Distance Vector Routing in MANET

Nodes in a mobile ad hoc network are battery constrained devices and energy efficiency becomes an important consideration. In a multi-hop mobile ad hoc network the most common method to achieve energy efficiency is the transmission power control scheme in which a node transmits the data packets to its nearest neighbor which is at minimum required power level. However this scheme minimizes only the transmission power within the node’s neighborhood and energy efficiency at the link level is possible. With this scheme it is not possible to minimize the overall energy consumption of the network and the communication overhead of the network is not minimized. An analysis has been performed and our results have proved that instead of using low transmission power, the routing strategy needs to be controlled and only certain nodes are to be allowed to receive and process this routing request based on the received signal strength, then the overall energy consumption of the network can be minimized and the communication overhead is also minimized. The modified routing strategy is applied to the basic ad hoc on-demand distance vector (AODV) routing protocol and a maximum transmission range based ad hoc on-demand distance vector routing protocol named AODV range routing (AODV_RR) is proposed and studied under different network sizes. Measurable difference in performance is realized and the proposed AODV_RR perform better than normal AODV with respect to all the selected metrics.     

一种改进的多跳分组无线网路由协议

对于多跳分组无线网来说,路由协议非常重要.而传统的主动式路由、按需路由和混合路由由于自身的缺陷,都不能保证多跳分组无线网传输的可靠性.为了适应网络拓扑不断变化的客观环境,提高数据通信的可靠性,提出了一种相邻矩阵路由协议,它克服了传统路由协议的缺点,大大提高了多跳分组无线网的链路性能.     

面向链路稳定性的MANET路径建立机制

为了适应拓扑动态变化的Ad hoc网络,该文提出了一种面向链路稳定性的路由机制,节点根据少量接收信号强度样本值建立牛顿插值多项式描述连续时间域上的信号强度,进而在不预测节点运动方向和速度等相关参数的情况下估计链路生存时间,按照链路生存时间和跳数两个约束条件,源节点逐跳建立稳定的端到端路径。仿真结果表明,所建立的牛顿插值多项式能够准确地逼近节点随机移动过程中的实际接收信号强度,并且该路由机制能够有效地减少路由重建次数,降低数据包丢弃概率。     

一种基于信号强度的OLSR路由协议改进算法

借助接收分组时测得的信号强度,提出OLSR-PSSA(Pre-rerouting and Signal Strength A-ware OLSR)改进协议。为了建立和维护生存时间更长、链路更加健壮的路由,并加入预切换路由机制,来适应节点的移动和网络拓扑结构的频繁变化。OPNET仿真结果显示,与传统OLSR协议相比,OLSR-PSSA改进协议提升了传输成功率,增加了网络吞吐量。