一种航空自组网GRID路由协议栅格长度划分方法

分析了航空自组网GRID路由协议的特点,在对GRID路由协议中栅格长度、节点有效辐射 半径以及节点通信功率联合研究的基础上,通过理论分析和数学推导,得出栅格长度、节点 有效辐射半径在一定通信功率条件下的定量关系,为GRID路由协议中栅格长度的划分提供了 一 种新的思路和科学的划分方法,对GRID路由协议在今后航空自组网中的研究设计具备一定的 实用价值。     

Ad hoc网络运动模型及其连通强度相关性的研究

介绍了现有的几种ad hoc运动模型，提出了一种ad hoc连通强度的评价公式，并对三种常用的运动模型进行了仿真。利用Boltzmann函数对仿真数据进行曲线拟和分析，得到三种运动模型各自的节点数、传播范围和连通强度的曲线函数，为实际的ad hoc组网提供了明确的评判依据。     

移动Ad hoc网络中AODV路由协议的研究与改进

针对移动Ad hoc网络AODV路由协议存在的一些缺点,提出了一个改进的路由协议。在改进方案中增加了备份路由和电池电量门阀值,可以有效避免路由的重新发现。性能分析与仿真结果表明,改进后的AODV路由协议更能适应网络拓扑结构的变化,并能在链路中断后迅速找到可用的路由。     

Markov model of link connectivity in mobile ad hoc networks

This paper proposes a Markov model of link connectivity for mobile ad hoc networks. Under a random behavior, the model provides a unified approach to describe many different mobility models including entity mobility models and group mobility models. Using the model, we can predict the time dependence of link connectivity, and estimate a settling time for which node movements are considered in a transient state. We verify the model with the simulation results of four different mobility models using a global connectivity and a link duration distribution. This research was supported in part by the National Science Foundation under grant CCF-0514975. Seok K. Hwang received the B.S. degree in Control and Instrumentation Engineering from Korea University, Korea in 1998. He received the M.S. degreeand the Ph.D.degree in Electrical Engineering at POSTECH, Korea in 2000 and 2006, respectively.His research interests include intelligence controls and computational intelligence for multi-objective optimization problems. He is working on multimedia communication as a senior researcher at Korea Telecom since 2006. Dongsoo Stephen Kim received the B.S. degree from Korean University in 1987, the M.S. degree in computer science from the University of Texas in 1994, and the Ph.D. degree in computer science and engineering from the University of Minnesota in 1998. During 1986–2002, he was a Research Associate at Electronic and Telecommunication Research Institute, Taejon, Korea. In 1998–2000, he was a project manager at Megaxess Inc., Germantown, Maryland. He joined the Department of Electrical and Computer Engineering at Purdue School of Engineering and Technology, IUPUI in 2000. His current research interests include mobile wireless networks, mobility modeling, traffic modeling, and performance evaluation of communication networks.     

An Optimization Forwarding Range Routing Protocol for VANET in City Environments

In city environment, the vehicle communi- cation is affected by the around obstacles due to the espe- cial condition of wireless channels. However, most of prior works adopt the fixed radio range value of vehicles to trans- mit packets. In this paper, we design an optimization for- warding range routing protocol for VANET in urban area. It has an optimized and adjustable forwarding range, which changes with different environments based on the path loss and the city model. And the proposed geo-routing protocol has a novel idea in computing the connectivity of roads and the adjustable strategy in a sparse network. Simulation re- suits indicate that the OFRR enjoys desirable performance in the urban area.     

Ad Hoc网络移动模型节点空间分布研究

节点空间分布是Ad Hoc网络移动模型研究的重点,也是对移动模型评价的重要指标.对RW,RD,RWP,GM,SMS移动模型分别在不同条件下处于矩形及圆仿真区域中节点空间分布进行了仿真,并对其进行比较研究,得出了不同速度、速度服从不同分布,暂停时间服从不同分布和不同仿真区域对移动模型节点空间分布的影响,为移动模型的选择、仿真区域的选择及模型中各类参数的设置提供了重要的依据.     

无线Ad hoc网络中虚拟骨干网的模型和设计

利用网络图论中支配集的概念，给出无线Ad hoc网络中虚拟骨干网的数学模型。介绍了目前几种常用的虚拟骨干网设计方案，并从算法的复杂度和所需的邻居信息等方面对其进行比较。     

针对基于忙音的广播方法的仿真研究

在高动态拓扑自组织网络中,基于常规握手机制的广播方法难以有效进行信息分发,为此,提出了一种基于忙音的广播方法。针对此方法,利用网络仿真平台OPNET,建立并实现了该广播方法的模型,通过仿真实验,分析了其性能。仿真结果表明,该基于忙音的广播方法适用于高动态拓扑网络。     

ad hoc网络组播对于DoS攻击畦抵抗策略分析

与固定有线网络相比,无线ad hoc网络动态的拓扑结构、脆弱的无线信道、网络有限的通信带宽以及节点兼备主机和路由功能等特点,使得网络容易遭受拒绝服务（DOS）攻击。文章针对ad hoc网络的组播应用在抵御DoS攻击方面的不足,提出外部和内部两种组播DoS泛洪攻击模型,同时针对ad hoc网络组播组内的攻击提出相应的两种抵抗策略和具体实现步骤。     

移动自组织网络QoS研究

由于自组网独特的特性,在该网络中支持QoS非常困难,需要进行系统研究。本文首先分析了自组网中QoS支持面临的挑战,接着从系统角度出发,结合自组网的特点,在QoS模型和QoS支持体系以及体系中具体的QoS技术等方面对自组网QoS支持做了详尽的分析与探讨,同时指出：定义自组网QoS模型需要综合考虑应用需求和网络特性;实现QoS模型可以采用分层QoS支持体系或跨层QoS支持体系,而后者将是今后研究的重点;结合路由层、MAC层和物理层的跨层QoS支持体系具有研究价值。     

无线ad hoc网络中多路径负载平衡性能分析

提出了一种新颖的分析模型来计算无线ad hoc网络中多路径情况下的负载。该模型考虑到多路径的数目、路由的选取方法以及网络中节点的密度等条件，能够对不同网络条件下的负载进行较好的分析与理论计算。仿真结果与理论计算有良好的一致性，结果表明在无线ad hoc网络中简单地使用多路径路由并不能有效地平衡网络负载。这一结论与目前普遍认定的结论（在无线ad hoc网络中使用多路径路由和在有线网络中使用多路径路由一样，可以很好地平衡网络负载、增加网络的吞吐量）是不一致的。     

移动自组网QoS路由协议研究

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多跳的临时性的自治系统。随着无线通信中多媒体业务的增加,在移动自组网中提供QoS(Quality of Sevice服务质量)保障具有越来越重要的意义,而QoS路由技术则是其中的核心技术和热点问题。文章指出移动自组网QoS路由的困难,对移动自组网典型QoS路由协议进行了详细的分析与比较,并对几种较新的移动自组网QoS路由协议进行了介绍,末了对移动自组网QoS路由协议的发展进行了展望。     

LTE-Advanced SON自优化和自愈用例研究

为了最大限度降低网络运行费用,提供自组织网络(SON)是LTE-Advanced的主要目标之一。文章介绍了自组织网络的产生背景,给出了移动负载均衡(MLB)解决方案,分析了移动鲁棒性优化(MRO)的工作原理,描述了随机接入信道优化过程,提出了节能思路,最后研究了自组织网络功能管理参考模型。     

移动自组网在灾后营救中的应用研究

介绍移动自组网的特点、发展与现状,并与现有通信手段进行分析对比,指明移动自组网在各类灾后营救中的相比传统通信手段所更能发挥的积极作用,展望移动自组网在各个领域中的应用前景。     

PCSSHO: An implementation of Percentage of Circle Search and Spotted Hyena Optimizer for multi-constraint load balancing and routing framework in FANET

Flying ad hoc network (FANET) is a technology that has seen tremendous growth in the past years due to its application in various military and civil developments. Conventional topology-aided routing schemes are not suitable for large-scale FANETs. This is because of the higher mobility rate in UAVs with the architecture differences. Hence, several path entries in routing become invalid and the neighboring nodes can be occupied before the interruption. Hence, it is very important to solve the afore-explained issues in FANET. Initially, the task is assigned to the UAVs. These tasks are performed by satisfying the demands such as timing, congestion, and energy to attain the effective load-balancing performance. Then, the optimal clustering and cluster head (CH) selection are performed using the developed Percentage of Circle Search and Spotted Hyena Optimizer (PCSSHO) in the communication path. Here, the feature selection is done based on constraints like position, speed, moving direction, height variation, link quality, and inter- and intra-cluster distance. Then, the developed PCSSHO model performs routing by considering different constraints such as “end-to-end delay, delivery ratio, power consumption, and link quality.” Thus, the recommenced load balancing model in FANET secures an enhanced performance rate than the conventional load balancing frameworks.     

无源雷达多站定位LFM弱信号检测

无源雷达多站TDOA定位时,要求多站同时截获目标雷达的辐射信号,并且为满足定位精度而要求一定的基线长度,然而现代机载雷达采用超低副瓣、降低平均功率等许多低截获措施,使得双接收站配置一般不会被机载雷达主瓣同时覆盖,致使一个接收站处在发射天线的主波束内时,另一接收站处在副瓣或零点位置,因此双接收站之间接收的信号强度相差悬殊,至少差20dB的主副瓣比。为此,利用相关接收理论分析了在雷达主瓣方向的侦察接收机截获的强信号,确定脉冲重复周期、脉内调制等基本信息。并利用该信息及信号协同在雷达副瓣方向的侦收机的微弱信号进行相关接收,推导出独立于截获信号结构的混合积模型,从而使双通道侦收机的信号处理可以直接借鉴传统雷达的相参与非相参等信号积累方法。通过雷达实测信号构建双路信号的仿真验证表明该方法的理论可行性和工程可用性。     

An analytical study of the communication cost of data-centric storage in mobile ad hoc networks

Data-centric storage is a fundamental data management paradigm in wireless multihop networks. Originally introduced for wireless sensor networks, existing approaches are in principle also applicable in mobile ad hoc networks. However, the mobility of such networks strongly impacts storage performance in general and communication cost in particular. While this is recognized in the research community, a detailed account of the performance in terms of communication cost is lacking.In this article, we provide a detailed study of the communication cost of previously proposed data-centric storage mechanisms that are viable in mobile ad hoc networks. We first introduce a comprehensive analytical model that suitably characterizes the communication cost of data-centric storage mechanisms from the literature. We then use our model to evaluate the considered mechanisms in comparative terms as a function of relevant system parameters, including the amount of considered data, the frequency of data updates and queries, and node speed. Our results give a detailed account of data-centric storage performance and are able to identify the most suitable ranges of operation for each of the considered mechanisms.     

P2P网络中一种新的多层多维信誉模型

现有的信任模型大多通过单一信任值来判定节点的好坏,这种方法无法抵抗网络中的某些恶意行为,特别是对于P2P网络中独有的搭便车行为、＂公共物品的悲哀＂等问题,缺乏有效的抑制。针对这些问题,文中针对P2P网络提出了一种新的多层多维信誉模型,通过节点的信任值、贡献值、资源值等不同维度综合评价节点的信誉,并且按照信誉将节点划分为不同层次。分析可知该模型可以有效抵御多种恶意行为及多种自私行为,并能解决传统信任模型产生的一些性能问题。     

Distributed formation of core-based forwarding multicast trees in mobile ad hoc networks

A core-based forwarding multicast tree is a shortest path tree rooted at core node that distributes multicast packets to all group members via the tree after the packets are sent to the core. Traditionally, the bandwidth cost consumed by transmitting a packet from the core via the tree is evaluated by the total weights of all the edges. And, the bandwidth cost is minimized by constructing the multicast tree that has minimum total weights of edges to span all group members. However, when the local broadcast operation is used to multicast a packet, we found that the bandwidth cost is supposed to be evaluated by the total weights of all senders that include the core and all non-leaves. Since the multicast tree with the number of nodes greater than or equal to three has minimum bandwidth cost only when the core is not a leaf, it leads us to find the multicast tree with the minimum number of non-leaves when each sender node has a unit weight. However, no polynomial time approximation scheme can be found for the minimum non-leaf multicast tree problem unless P = NP since the problem is not only NP-hard but also MAX-SNP hard. Thus, a heuristic is proposed to dynamically reduce the number of non-leaves in the multicast tree. Experimental results show that the multicast tree after the execution of our method has smaller number of non-leaves than others in the geometrically distributed network model.