无线网络中的一种基于小世界模型的路由协议

最近,利用节点的移动性提升网络系统性能的方法引起了不少关注。这些方法已经被运用于包括移动Adhoc网络（MANET）、无线传感网络（WSN）和容忍延时网络（DTN）在内的一些新兴网络中,他们都认为节点是随机或者可控移动的。为了达到优化或平衡包括延时、平均中继节点数目和移动距离在内的一些度量参数的目的,本文提出了一种基于于小世界模型的路由协议（SWR）。通过分析,该协议只有多对数数量级的中继节点,大大减少了报文传输过程中中继节点的数量。文中定义了短链接与长链接的概念,其中每一节点与其最邻近的节点之间存在“短”链接,而与其他遵循桌一概率分布的节点间存在着“长”链接。短链接通常是无线链接,而长链接通常是利用移动节点来实现的。本文在网络规模、使用数据搭乘者、多重长链接和等待移动节点时间方面进行了分析。通过仿真结果,我们对各方面性能进行了评估。     

基于分簇的移动协助无线传感器网络路由协议

提出了一种基于分簇的移动协助（ CMA）无线传感器网络路由协议。在圆形网络中,Sink以恒定速率做圆周运动,网络初始阶段根据应用时延要求和能量消耗确定移动 Sink的运动半径,按照确定的Sink运动轨迹,将网络进行分簇。然后在Sink通信范围内确定一批普通节点作为汇聚点（ RP）,最后Sink对汇聚节点的缓存数据以及其单跳范围内的簇头进行采集。仿真实验结果表明：与现有的几种路由协议相比,CMA在满足时延要求条件下有效地延长了网络生命周期。     

Logarithmic Store-Carry-Forward Routing in Mobile Ad Hoc Networks

Two schools of thought exist in terms of handling mobility in mobile ad hoc networks (MANETs). One is the traditional connection-based model, which views node mobility as undesirable and tries to either remove (through recovery schemes) or mask (through tolerant schemes) the effect of mobility. The other is the mobility-assisted model, which considers mobility as a desirable feature, where routing is based on the store-carry-forward paradigm with random or controlled movement of mobile nodes (called ferries). It is well known that mobility increases the capacity of MANETs by reducing the number of relays in routing. Surprisingly, only two models, diameter hop count in the connection-based model and constant hop count in the mobility-assisted model, which correspond to two extremes of the spectrum, have been systematically studied. In this paper, we propose a new routing model that deals with message routing, as well as trajectory planning, of the ferries that carry the message. A logarithmic number of relays are enforced to achieve a good balance among several contradictory goals, including increasing network capacity, increasing ferry sharing, and reducing moving distance. The model considers the dynamic control of ferries in terms of the number of ferries, trajectory planning of ferries, and node communication and synchronization. The effectiveness of the proposed model is evaluated analytically, as well as through simulation     

Efficient energy conservation in MANET using Energy Conserving Advanced Optimised Link State Routing model

Mobile Ad-hoc Network (MANET) is formed dynamically by the independent organisation of the mobile nodes connected through wireless links without using any centralised administration. Energy consumption is the most significant issue in the MANETs, since most of the mobile hosts operate on limited battery resources. Reduction in the energy consumption results in the increase in the lifetime and throughput of the network. The performance of existing techniques was less in terms of energy conservation issues. To overcome these limitations, this paper proposes an energy conservation mechanism integrated with a proactive MANET routing scheme. The routing schema is based on the energy level and the mobility of the nodes. Calculation of energy cost is performed based on the prediction of the energy consumption level of the node, using Energy Conserving Advanced Optimised Link State Routing (ECAO) model. The performance of the proposed ECAO model is compared with the existing Optimised Link State Routing and Advanced Optimised Link State Routing models. From the comparison result, it is clearly observed that the proposed model achieves better performance in terms of number of TC messages, Packet Delivery Ratio, average time, end-to-end delay, and link delay and energy consumption.     

Research on multicast routing protocols for mobile ad-hoc networks

A mobile ad-hoc network (MANET) is composed of mobile nodes without any infrastructure. Mobile nodes self-organize to form a network over radio links. The goal of MANETs is to extend mobility into the realm of autonomous, mobile and wireless domains, where a set of nodes form the network routing infrastructure in an ad-hoc fashion. The majority of applications of MANETs are in areas where rapid deployment and dynamic reconfiguration are necessary and wired network is not available. These include military battlefields, emergency search, rescue sites, classrooms and conventions, where participants share information dynamically using their mobile devices. These applications lend themselves well to multicast operations. In addition, within a wireless medium, it is crucial to reduce the transmission overhead and power consumption. Multicasting can improve the efficiency of the wireless link when sending multiple copies of messages by exploiting the inherent broadcast property of wireless transmission. Hence, reliable multicast routing plays a significant role in MANETs. However, to offer effective and reliable multicast routing is difficult and challenging. In recent years, various multicast routing protocols have been proposed for MANETs. These protocols have distinguishing features and employ different recovery mechanisms. To provide a comprehensive understanding of these multicast routing protocols and better organize existing ideas and work to facilitate multicast routing design for MANETs, we present the taxonomy of the multicast routing protocols, their properties and design features. This paper aims to aid those MANETs researchers and application developers in selecting appropriate multicast routing protocols for their work.     

Improving routing protocol performance in delay tolerant networks using extended information

Delay tolerant networks (DTNs) are wireless mobile networks that do not guarantee the existence of a path between a source and a destination at any time. When two nodes move within each other’s transmission range during a period of time, they can contact each other. The contact of nodes can be periodical, predictable and nonpredictable. In this paper, we assume the contact of nodes is nonpredictable so that it can reflect the most flexible way of nodes movement. Due to the uncertainty and time-varying nature of DTNs, routing poses special challenges. Some existing schemes use utility functions to steer the routing in the right direction. We find that these schemes do not capture enough information of the network. Thus, we develop an extended information model that can capture more mobility information and use regression functions for data processing. Experimental results from both our own simulator and real wireless trace data show that our routing algorithms based on the extended information model can increase the delivery ratio and reduce the delivery latency of routing compared with existing ones.     

基于MANET的无线自组织网按需路由协议DSR的优化研究与实现

无线自组织网络由不需要任何基础设施的一组具有动态组网能力的节点组成,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。这种网络适应了军事和商用中对网络和设备移动性的要求,而引起了人们的关注,并在20世纪90年代以后获得了广泛的研究和发展。文章对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。     

移动自组网路由局部修复算法的研究

移动自组织网(mobile ad hoc networks,MANET)的多跳的无线连接、动态拓扑和有限的带宽等特征,给其路由协议带来了很多挑战.当多跳路径失效时,路由协议需要对其进行修复.已有的修复机制需要很多的开销和很长的端到端时延.在此修复机制的基础上,提出了一种新的路由局部修复算法,将修复尽量限制在断链的局部范围内,以减少对链路断裂的反应时间和降低路由维护的开销,而且不用考虑失效链路在整个路由上的相对位置,都可以对其进行修复,提高了处理失效链路的能力,有利于提高MANET的可扩展性.仿真表明,这种新的路由局部修复算法明显地提高了网络多方面的性能.     

路由深度对Sink轨迹固定传感器网络的影响

无线传感器网络中,使用移动Sink进行数据采集能够减少网络节点死亡速度,延长网络时间,是最有效均衡网络负载的方法之一。在实际应用中,移动Sink通常采用固定路径策略,同时路由深度的改变直接影响网络拓扑和路由选择结果。比较了在不同路由深度下,采用4种典型固定策略的移动Sink网络的网络能耗、网络寿命和包延时。仿真结果表明:在较小的路由深度下,外边界策略能更好地降低节点能耗,延长网络寿命;内边界策略能取得更好的覆盖和较低的时延。     

An anonymous distributed routing protocol in mobile ad-hoc networks

This paper proposes an efficient anonymous routing protocol for mobile ad hoc networks (MANETs). This protocol considers symmetric and asymmetric links during the wireless communication of MANETs. A MANET is one type of self-organized wireless network that can be formed by several wireless devices such as laptops, tablet PCs, and smartphones. Different wireless transmission ranges of different mobile devices lead to a special communication condition called an asymmetric link. Most research on this topic focuses on providing security and anonymity for the symmetric link without considering the asymmetric link. This paper proposes a novel distributed routing protocol beyond the symmetric and asymmetric links. This protocol guarantees the security, anonymity, and high reliability of an established route by avoiding unreliable intermediate nodes. The routes generated by the proposed protocol are shorter than previous research. The proposed protocol enhances MANET performance in assuring security and anonymity.     

节点密度感知的容迟网络路由协议*

为适应容迟网络的动态变化,提高路由性能,结合空间节点分布和节点度中心性,提出一种节点密度感知的容迟网络路由协议DAR。该协议引入移动模型的节点分布,通过感知节点当前所处位置的节点密度,动态选择在网络中传播的消息副本数量,并根据节点的度中心性选择中继和分配消息副本数量。仿真结果表明,DAR能够提高传输率、降低传输延迟,在一定程度上降低了资源消耗。     

QMRPRNS: Design of QoS multicast routing protocol using reliable node selection scheme for MANETs

A mobile Ad-Hoc networks (MANETs) is a continuously self-configuring, infrastructure-less network of wireless mobile devices. In which multicast is one of the efficient way of communication. Currently, several research have been conducted to design multicast routing protocols for wireless mobile ad-hoc networks (MANETs). Multicasting is a technique that allow to send the same message to a group of destinations simultaneously. However, it faces several challenges against its implementation in ad-hoc network due to its dynamic nature, lack of bandwidth, short battery lifetime of the mobile devices. The multicast routing protocol MAODV have several constraints as mentioned above. Hence to address these constraints a reliable neighbour nodes selection scheme has been integrated over MAODV. This paper attempt a Quality of Service (QoS) based multicast routing protocol using reliable neighbour nodes selection scheme (QMRPRNS) for same. The simulation has been conducted to compare the performance of the proposed scheme against some existing multicast routing protocols which shows significant improvement over EMAODV and MAODV.     

容迟网络路由算法

容迟网络泛指那些由于节点移动、能量管理、调度等原因而出现频繁中断、甚至长时间处于中断状态的一类网络.它涵盖了由于节点调度而处于间歇式连通的无线传感网络、移动Ad hoc网络、周期性连通的卫星网络、乡村网络、野生动物追踪网络以及个人设备交换网络等等.具有十分广阔的应用前景,引起了广泛的关注.与传统网络相比,容迟网络没有稳定的端到端传输路径,因而其路由问题更为复杂.已有的研究工作也主要集中于这一问题.并提出了许多的容迟网络路由算法.对这些算法的最新进展进行了综述.首先,介绍了容迟网络路由算法的性能评价标准.其次.给出了容迟网络路由算法的分类方法.按照路由策略来分.客迟网络路由算法可以分为基于复制策略的算法和基于转发策略的算法.按照网络模型来分,容迟网络路由算法又可以分为面向主动移动模型的算法和面向被动移动模型的算法.然后,针对每一分类.重点综述了其中具有代表性的一些容迟网络路由算法,并总结了各算法的优缺点.最后,讨论了未来的研究方向.     

MANET路由协议及其性能研究

MANET(Mobile Ad Hoe Network)是由一组无线移动主机组成的一个没有任何建立好的基础设施或集中管理设备的临时网络。网络拓扑易变、带宽、能源有限是Ad Hoc移动网络的主要特点。重点介绍了Ad hoc网络的组网关键技术——路由协议，并对现在的具有代表性的协议性能进行了比较，研究了在不同环境下的各自路由协议仿真实验所体现出来的性能差别，对Ad hoc的组网具有指导意义。     

Genetic algorithms with immigrants schemes for dynamic multicast problems in mobile ad hoc networks

In this paper, the problem of dynamic quality-of-service (QoS) multicast routing in mobile ad hoc networks is investigated. Lots of interesting works have been done on multicast since it is proved to be a NP-hard problem. However, most of them consider the static network scenarios only and the multicast tree cannot adapt to the topological changes. With the advancement in communication technologies, more and more wireless mobile networks appear, e.g., mobile ad hoc networks (MANETs). In a MANET, the network topology keeps changing due to its inherent characteristics such as the node mobility and energy conservation. Therefore, an effective multicast algorithm should track the topological changes and adapt the best multicast tree to the changes accordingly. In this paper, we propose to use genetic algorithms with immigrants schemes to solve the dynamic QoS multicast problem in MANETs. MANETs are considered as target systems because they represent a new generation of wireless networks. In the construction of the dynamic network environments, two models are proposed and investigated. One is named as the general dynamics model in which the topologies are changed due to that the nodes are scheduled to sleep or wake up. The other is named as the worst dynamics model, in which the topologies are altered because some links on the current best multicast tree are removed. Extensive experiments are conducted based on both of the dynamic network models. The experimental results show that these immigrants based genetic algorithms can quickly adapt to the environmental changes (i.e., the network topology changes) and produce high quality solutions following each change.     

An improved ant colony optimization-based approach with mobile sink for wireless sensor networks

Traditional wireless sensor networks (WSNs) with one static sink node suffer from the well-known hot spot problem, that of sensor nodes near the static sink bear more traffic load than outlying nodes. Thus, the overall network lifetime is reduced due to the fact some nodes deplete their energy reserves much faster compared to the rest. Recently, adopting sink mobility has been considered as a good strategy to overcome the hot spot problem. Mobile sink(s) physically move within the network and communicate with selected nodes, such as cluster heads (CHs), to perform direct data collection through short-range communications that requires no routing. Finding an optimal mobility trajectory for the mobile sink is critical in order to achieve energy efficiency. Taking hints from nature, the ant colony optimization (ACO) algorithm has been seen as a good solution to finding an optimal traversal path. Whereas the traditional ACO algorithm will guide ants to take a small step to the next node using current information, over time they will deviate from the target. Likewise, a mobile sink may communicate with selected node for a relatively long time making the traditional ACO algorithm delays not suitable for high real-time WSNs applications. In this paper, we propose an improved ACO algorithm approach for WSNs that use mobile sinks by considering CH distances. In this research, the network is divided into several clusters and each cluster has one CH. While the distance between CHs is considered under the traditional ACO algorithm, the mobile sink node finds an optimal mobility trajectory to communicate with CHs under our improved ACO algorithm. Simulation results show that the proposed algorithm can significantly improve wireless sensor network performance compared to other routing algorithms.     

基于遗传算法的防止无线移动网络路由攻击策略

在无线移动网络中,恶意节点可以通过发送虚假信息和假路由信息、广播假链接等中断路由操作对网络进行攻击。本文在分析了几种常见路由攻击的基础上,提出了一种基于遗传算法的路由优化策略。实验数据表明,这种优化策略可以较好地预防路由攻击,提高网络的整体性能。     

一种新的基于DSR的移动自组网节能路由策略

移动自组网是由一组带有无线收发装置的移动节点组成的一个支持多跳的临时性的网络自治系统。由于移动自组网的大多数节点是由有限寿命的电池来提供的，因此能量保护策略成为制定路由协议的一个重要依据。该文提出了一种新的基于动态源路由协议的节能路由策略。仿真表明该策略有效地延长了网络的生存时间。并很好地均衡了节约能耗和保护网络传统性能的需求。     

MANET中基于位置的无信标路由算法与DSR的性能比较

由于节点的移动性、无线链路的带宽有限、可获得的能量有限等原因,对移动Ad hoc网络进行路由提出了具有挑战性的要求。基于位置的路由协议由于不必维护明确的路由,在这种高度动态的网络中具有很好的扩展性。该文通过仿真将一种基于位置的贪婪转发路由:基于改进进程无信标路由(IPPBBLR),与一种基于拓扑的路由:动态源路由(DSR)进行了性能比较。仿真结果表明基于位置的路由比基于拓扑的路由在移动的情况下可以达到更高的发送成功率和更小的端到端延迟,且端到端延迟几乎不受移动速率的影响。     

TCP Issues in Mobile Ad Hoc Networks: Challenges and Solutions

Mobile ad hoc networks （MANETs） are a kind of very complex distributed communication systems with wireless mobile nodes that can be freely and dynamically self-organized into arbitrary and temporary network topologies. MANETs inherit several limitations of wireless networks, meanwhile make new challenges arising from the specificity of MANETs, such as route failures, hidden terminals and exposed terminals. When TCP is applied in a MANET environment, a number of tough problems have to be dealt with. In this paper, a comprehensive survey on this dynamic field is given. Specifically, for the first time all factors impairing TCP performance are identified based on network protocol hierarchy, i.e., lossy wireless channel at the physical layer; excessive contention and unfair access at the MAC layer; frail routing protocol at the network layer, the MAC layer and the network layer related mobile node; unfit congestion window size at the transport layer and the transport layer related asymmetric path. How these factors degrade TCP performance is clearly explained. Then, based on how to alleviate the impact of each of these factors listed above, the existing solutions are collected as comprehensively as possible and classified into a number of categories, and their advantages and limitations are discussed. Based on the limitations of these solutions, a set of open problems for designing more robust solutions is suggested.