无线移动传感器网络节点自定位控制仿真研究

研究移动节点确认自身位置信息的节点自定位问题,传感器节点的移动部署和数据通信容易受外界环境的干扰,造成网络节点自定位精度低。为解决上述问题,提出了一种改进的灰色系统预测移动节点定位技术。改进方法采用跨层设计,利用灰色系统预测移动节点及其相邻节点移动状态和距离来实时地根据自身及相邻节点位置重新成簇进而实现移动节点自定位控制。仿真表明,提出的灰色系统预测模型能够有效地提高了移动节点位置计算精度,在算法时空复杂度和能效上可以实现合理的自定位控制。     

一种MANET环境中基于稳定路径的分簇算法

本文提出一种新的分布式分簇算法来组织MANET中的移动节点。算法基于节点问路径的稳定性，保证簇内任意两点间的路径可用概率大于某个确定的界。由于算法基于路径的可用概率，因此形成的簇能适应网络拓扑变化。算法的目的是为了支持MANET环境中的数据复制，通过分簇来预测网络分割，以提高数据访问的可用性。本文对算法的复杂性
作了理论性分析，对簇的性质进行了理论证明和实验分析。     

一个应用于移动Ad Hoc网络管理的簇生成算法

移动Ad hoc网络(mobile Ad hoc network,简称MANET)作为一种新型移动无线通信网,与其他通信网络相比独有的特性增加了网络管理的难度.目前对MANET网络管理的研究处于起步阶段,一些标准尚未制定,而且像存在单向链路和节点的相对移动性这类问题也在研究中被忽视.为此,提出了一个利用令牌机制与最小节点标识相结合,适用于层次性管理结构的基于图的MANET簇生成算法,以及对MIB(management information base)的建议性改进.算法充分考虑了网络存在的单向链路和节点的相对移动性,提高了网络管理的灵活性和可扩展性,为MANET的网络管理提出了一种新方法.     

移动自组网中的服务质量模型研究

服务质量（QoS）是移动自组网络（MANET）研究的热点问题之一。由于MANET网络节点的移动性和节点自身的特点,导致MANET网络实现QoS存在许多困难。从系统实现和软件工程的角度,综述了基于MANET网络实现QoS的各种模型,重点介绍了各QoS模型的工作过程、特点和不足之处,并比较了不同模型的性能。最后说明了该领域进一步研究的方向。     

MANET环境中多角色的分簇信任评估模型研究

MANET是一种自组网络工作组,其将节点划分为固定节点和移动节点.在MANET环境下网络拓扑结构不断发生变化,网络节点之间相互协作完成互联与通信.正是由于移动MANET环境下路由的复杂性,网络中角色的信任评估机制对于网络的安全性具有非常重要的作用.对多角色节点的信任值进行研究,构建多角色的分簇信任评估模型,将节点角色划分为簇头、簇成员、网管、代理4种类型,从节点的相关度、信任值和移动性等多方面因素进行分析,计算簇头节点的信任值,并通过代理节点进行监督计算,构建基于簇透、代理和网关节点的简化网络,以节点分配关系计算节点的可信度,以NS2仿真检验模型的有效性,得出结果表明,研究的多角色的分簇信任评估模型能够较快、较为准确地检测出恶意节点,保证了移动网络应用的安全性.     

MANET下环境感知的服务可用性量化评估模型

移动Ad hoc网络(MANET)环境下,移动节点通过向其他节点提供服务是进行资源共享与能力协同的有效方式.但是由于 MANET环境的复杂性、链路的动态性和节点的异构性等特点,使得服务可用性时刻都在发生变化,且难以量化.通过对 MANET环境下服务运行环境和对影响服务可用性的节点、网络环境可用性的分析,提出了一个具有环境感知能力的服务可用性量化评估模型EQAM-SA,该模型由服务请求触发,实时获取服务运行参数、量化评估指标,并采用层次分析法和多属性综合评估法对服务的可用性进行量化评估.最后通过仿真实验验证了EQAM-SA的可行性和有效性.     

MANET中基于DHT的资源共享技术

P2P因良好的可扩展性、低廉的部署开销及能够聚集闲置资源等优点而被广泛应用于文件共享领域。移动自组网(MANET)是一种具有高度动态拓扑结构、节点任意移动的自组织网络,与P2P有很多共同点,近来开始出现了将两者融合的研究。该文提出一种在MANET环境下基于结构化P2P的资源共享模型,将MANET中的节点按其物理位置组成多个域,每个域中有若干节点,域和域中的节点用CAN管理。模拟结果显示该模型可以明显减少路由所需的跳数。     

MANET中移动预测方法研究

MANET具有网络资源有限、网络中的节点可以任意移动、网络拓扑结构变化迅速等特点,导致了重路由操作的频繁发生,极大地消耗了网络资源,降低了网络性能。网络节点运动的预测在很大程度上有利于解决这个问题。本文首先讨论了MANET的移动特性和链路预测的可行性,然后对各种链路预测的基本原理和方法进行了分析与比较,最后探讨了该问题进一步的研究工作。     

节点移动性对MANETs网络拓扑特征的影响

在影响MANETs网络性能的众多因素之中,动态变化的网络拓扑结构是不可忽视的一个重要方面,而节点的移动特性是导致MANET网络拓扑变化的主要原因之一,因此研究节点的移动性对网络拓扑结构特性的影响具有重要的意义。采用复杂网络理论研究节点移动性对MANET网络拓扑结构统计特性的影响。介绍复杂网络的基本统计特性参数,通过仿真实验,详细分析了几种经典节点移动模型下,节点移动速度、信号辐射半径、节点密度等参数对MANET网络的平均度、聚类系数和调和平均最短路径长度的影响。结果表明节点的移动方式对MANET网络拓扑结构统计特性产生不同的影响。     

基于门控循环单元的移动社会网络链路预测方法

链路预测是指通过已知的网络拓扑和节点信息来预测未来时刻节点之间的潜在关系，链路预测能够帮助在各种存在链路的应用领域更加合理地分配资源、降低资源开销.移动社会网络属于动态网络的一种，其网络结构总是随着节点和链路的出现、消失以及时间推移而不断演变.针对移动社会网络的特点，当前已有的研究使用愈加复杂的模型来分析链路之间的联系，然而复杂的模型不但空间复杂度大而且容易造成过拟合问题.为了解决以上问题，提出一种基于门控循环单元的移动社会网络链路预测方法.首先对输入数据集进行排序筛选，将目标网络划分为快照图，并按一定的规则转化为邻接矩阵形成样本集，然后基于自动编码器和门控循环单元构建预测模型，提取出移动社会网络的时间变化特征.在KONECT数据集上，与其他模型的对比实验结果表明，该方法能够保持预测性能几乎不变的情况下，使模型训练效率提升49.81%.     

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.     

A novel mobility model based on semi-random circular movement in mobile ad hoc networks

When simulating a mobile ad hoc network (MANET), it is important to use a realistic mobility model to reflect the actual performance of a mobile system. The spatial distribution of node locations in a mobile model plays a key role when investigating the characteristics of a MANET. However, most existing mobility models with random and simple straight line movement lead to unrealistic scenarios and non-uniform distributions, and can not describe the actual movement of Unmanned Aerial Vehicles (UAVs) connected via a MANET. To address this issue, a novel mobility model based on semi-random circular movement (SRCM) is presented. The approximate node distribution function in SRCM is derived within a 2D disk region. The relationship between application performance and node distribution is investigated for a UAV MANET, with focus on scan coverage and network connectivity. A simulation using the NS2 tool is conducted. It is shown that the presented model with a uniform distribution performs better than the popular Random Waypoint mobility model. The SRCM model with the NS2 simulator provides a realistic way for simulation and performance evaluation of UAV MANETs.     

基于轨道预测的自适应Ad Hoc分簇算法

本文在深入研究移动预测技术的基础上,分析已有分簇算法存在的诸多不足,提出了一种基于轨道预测的自适应分簇算法,根据节点的运动状态预测其将来的轨道,估算相邻节点间连接稳定性,并构造出与连接稳定度相关的网络拓扑图,最后用图着色技术对MANET中的节点进行分簇。该算法保持了分簇结构的稳定性,有效防止了通信的中断,弥补了已有分簇算法的不足。     

Ad hoc node connectivity improvement analysis – Why not through mesh clients?

A mobile ad-hoc network (MANET) is a complex distributed system with unpredictable node movements, which results in frequent node disconnectivity. In a MANET, each node works independently, using the resources based on individual need. The main problem with this arises during the movement of the nodes and random utilization of network resources. This work attempts to solve the mobility maintenance issues using three mesh structures; (i) mesh tree (M_T), (ii) mesh backbone (M_B) and (iii) mesh cluster (M_C). The mobility maintenance architectures are formed based on a localized connectivity analysis and the node degree as a key parameter for network construction. The performance of the proposed work is analysed through mathematical models and simulation results.     

移动自组网的访问控制技术研究

网络资源的共享与保护是移动自组网需要解决的关键问题之一。运用Voronoi图模型和quorum系统的思想,提出了一种移动自组网的动态路径quorum系统,设计了动态路径quorum的生成算法。基于移动自组网的动态路径quorum系统,提出了基于quorum系统的移动自组网的分布式访问控制机制,详细描述了节点的身份认证、网络资源的访问控制和权限管理协议。与传统的基于单个节点自身的访问控制机制相比,该访问控制机制具有较强的抗攻击能力和较高的可靠性,能够有效地提高移动自组网的资源共享与保护水平。     

SAAMAN: Scalable Address Autoconfiguration in Mobile Ad Hoc Networks

Address autoconfiguration is one of the fundamental issues in mobile ad hoc networks (MANET). A node must need some form of identity before participating in any sort of communication. So each host in a MANET needs to be uniquely addressed so that the packets can be relayed hop-by-hop and delivered ultimately to the desired destination. Moreover, nodes in the MANET are free to move and organize themselves in an arbitrary fashion. Therefore any fixed infrastructure based solution for assigning identity (i.e. IP address) is not directly applicable to MANET. Under this infrastructureless and sporadic nature of the mobile nodes, several protocols of address autoconfiguration in the mobile ad hoc networks (MANET) have been proposed. Although some of these protocols perform decently in sparse and small networks, but exhibit poor performance (e.g., single point of failure, storage limitation, large protocol overhead and so on) when the network is either dense or very large. In this paper, we propose an efficient and scalable address autoconfiguration protocol that automatically configures a network by assigning unique IP addresses to all nodes with a very low overhead and minimal cost. Evenly distributed Duplicate-IP address Detection Servers are used to ensure the uniqueness of an IP address during IP address assignment session. In contrast to some other solutions, the proposed protocol does not exhibit any problems pertaining to leader election or centralized server-based solutions. Furthermore, grid based hierarchy is used for efficient geographic forwarding as well as for selecting Duplicate-IP address Detection Servers. Through simulation results we demonstrate scalability, robustness, low latency, fault tolerance and some other important aspects of our protocol.     

基于移动节点的三维水下传感器网络定位

为有效解决传感器节点在水中的移动性问题,而节点移动主要是因为水流和随机干扰,提出了一种基于移动节点的定位算法—MNLS（移动节点定位算法）．移动节点定位算法是在分析现有相关定位算法的基础之上,提出了首先预测节点的运动轨迹,然后进行节点的测距与定位的算法思路．利用MATLAB对算法进行了仿真,实验结果表明MNLS与chan算法相比较,单个节点的定位精度以及不同速度下节点的定位精度都得到了提高,因此,该算法对水下传感器网络定位有着实际的应用价值．     

A Novel Gradient Boosted Energy Optimization Model (GBEOM) for MANET

Mobile Ad Hoc Network (MANET) is an infrastructure-less network that is comprised of a set of nodes that move randomly. In MANET, the overall performance is improved through multipath multicast routing to achieve the quality of service (quality of service). In this, different nodes are involved in the information data collection and transmission to the destination nodes in the network. The different nodes are combined and presented to achieve energy-efficient data transmission and classification of the nodes. The route identification and routing are established based on the data broadcast by the network nodes. In transmitting the data packet, evaluating the data delivery ratio is necessary to achieve optimal data transmission in the network. Furthermore, energy consumption and overhead are considered essential factors for the effective data transmission rate and better data delivery rate. In this paper, a Gradient-Based Energy Optimization model (GBEOM) for the route in MANET is proposed to achieve an improved data delivery rate. Initially, the Weighted Multi-objective Cluster-based Spider Monkey Load Balancing (WMC-SMLB) technique is utilized for obtaining energy efficiency and load balancing routing. The WMC algorithm is applied to perform an efficient node clustering process from the considered mobile nodes in MANET. Load balancing efficiency is improved with a higher data delivery ratio and minimum routing overhead based on the residual energy and bandwidth estimation. Next, the Gradient Boosted Multinomial ID3 Classification algorithm is applied to improve the performance of multipath multicast routing in MANET with minimal energy consumption and higher load balancing efficiency. The proposed GBEOM exhibits ∼4% improved performance in MANET routing.     

移动Ad Hoc网络通信量相关干扰感知路由协议

干扰严重影响移动Ad hoc网络的网络吞吐量、能量消耗、网络寿命等性能.在已有基于邻居数目和分布位置的干扰模型基础上,进一步考虑各邻居上的通信量情况,提出通信量干扰模型.并在该干扰模型的基础上,提出一个通信量相关干扰感知路由TIR(traffic load-based interference-aware routing)协议.TIR通过在源节点和目的节点之间选择干扰最小的路径来降低数据包在转发过程中可能受到的干扰.模拟实验结果表明,所提出的通信量干扰模型符合移动Ad hoc网络的特性,通信量相关干扰感知路由协议对网络寿命、通信延迟及吞吐量等网络性能有明显改善.