无人机自组网技术研究

在无人机系统中,编组和协同作战能力对提高无人机作站效能和生存能力具有重要意义。无线自组网是一种特殊结构的无线通信网络,其通信依靠节点之间的相互协作,以无线多跳方式完成,因此网络不依赖于任何固定设施,具有自组织和自管理的特性,这种特殊的组网方式使得无线自组网非常适用于无人机系统。介绍了无线自组网的原理,分析了无线自组网应用于无人机系统主要面临的关键技术:路由技术和安全问题。介绍了无线自组网的发展情况和在无人机领域的研究情况。     

基于Q-learning算法的无人机自组网AODV稳定路由改进方法

针对小型无人机集群组网中节点高速移动、网络拓扑变化剧烈导致的网络性能下降问题,在无线自组网按需平面距离向量（AODV）协议基础上,提出一种具有链路稳定度意识的无人机自组网路由协议（LN-AODV）。首先,通过加权计算链路维持时间和邻居节点变化度,从而选择稳定路径,解决拓扑结构动态变化条件下数据传输延迟和数据成功投递率下降的难题;然后,结合Q-learning算法自适应调整Hello消息的发送周期,使协议能够通过感知拓扑变化程度调整路由控制开销和拓扑感知灵敏度。仿真结果表明,相比于AODV,所提方法在端到端延迟、分组投递率、路由开销和数据吞吐量4个网络性能指标上分别提升7.56%,2.58%,17.39%,2.62%,可适应于节点高速运动的无人机自组网,对于无线自组网理论研究及拓展应用具有重要的借鉴意义。     

无人机自组网研究进展综述

随着世界各国对无人机(UAV)运用的不断重视、多无人机协同应用的兴起和无线自组网应用研究的迅猛发展,无人机自组网已成为新的研究热点.首先对无人机自组网的基本概念、主要特点和应用优势进行了总结,进而重点对MAC协议、路由协议、传输协议、跨层设计、机会网络5个方面关键技术的研究进展进行了系统综述,简要介绍了国内外主要研究机构的实验平台开发情况,最后指出了无人机自组网存在的挑战和亟待研究解决的重点问题.     

浅谈无人机集群组网通信技术

无人机集群通信技术是无人机集群组网的关键技术之一。本文首先介绍无人机技术发展是从军事需求逐步应用到各行各业。随着对无人机作业自主性、智能化、多任务等方面要求的提高,无人机从单机作业发展到机群组网,组网通信也遇到了数据传输量剧增、静态的频谱分配效率不高、机群系统性能下降等问题。根据无人机集群作业需求,提出星型组网、网状自组网和分层混合组网等通信组网模式,并根据无人机集群组网的特点提出认知无人机通信技术、大规模高动态无人机组网路由技术、物理层安全传输技术、能量有效通信技术等关键技术,对无人机集群通信的频谱资源分配、供能受限、物理层通信安全等关键问题给出了可行的解决方法,并对无人机集群通信未来发展趋势做了介绍。     

飞行自组网路由协议的仿真与分析

飞行自组网是移动自组网的一个新的研究方向,它将移动自组网的思想拓展到空天领域。但由于节点的高动态性和拓扑结构快速变化等特点,飞行自组网对路由协议提出更多挑战,传统移动自组网路由协议的适用性有待验证。文章利用OMNe T++仿真工具,针对飞行器组网的特定场景,对多种路由协议进行仿真,分析对比了各协议性能,探讨了无人机自组网路由协议的优选问题。实验结果表明OLSR_ETX协议综合性能优于其他几类协议,更适用于飞行自组网场景,但它在节点需要动态入网时表现不佳,还需要进一步的优化。     

嵌入式系统实现无线自组网与PSTN网互联

无线自组网作为一种新型的多跳无线网络,由于其组网方便、灵活、无需预先设立基站等基础设施,已得到了广泛关注。但为了使得孤立的无线自组网能够充分利用因特网上的资源,无线自组网必须实现与其他异种网络的互联,包括蜂窝网络、用电信网、Wlan等等。     

中继式无人机自组网安全协议研究

为了提高无人机集群战术通信链路传输的连贯和安全,针对当今无人机自组链路网络的不足,提出了一种中继式无人机自组网安全协议.该协议将无人机集群划分为普通节点和中继节点,中继节点担任空间网络环境信息采集和分析的作用,并作为无人机集群协同化中心通过获得的信息为整个集群规划路径,此时新加入的无人机节点不会影响整个战术通信链路,保...     

应急通信保障中无线自组网技术的应用研究

无线自组网具有无中心、自配置和快速组网等显著特点,非常适合用于应急通信保障。首先,介绍了当前国内应急通信的现状和存在的问题。然后,概述了以Ad Hoc网络、无线传感网和无线mesh网络为代表的无线自组网的显著特点和技术优势,并举例说明了无线自组网在应急通信保障中的几种具体应用。最后,展望了应急通信网络今后的发展方向。     

网络中心战下的雷达自组网技术

现有雷达组网从数据的角度实现雷达的组网,并没有实现雷达网络的组网。文中提出的雷达自组网机制实现了雷达网络的真正组网。在这种机制中,雷达可以自发地与其他相邻雷达进行通信,协同完成数据融合等功能,并能自主地寻找转发路径,将有效数据返回到指挥中心。通过对两种组网机制的定量分析,雷达自组网在数据冗余和通信距离方面具有一定的优势。     

基于无线Mesh的地震观测仪器组网与实现基于脑电信号组合熵特征的驾驶疲劳检测分析

地震观测台站监测系统通常存在布线复杂、布设成本高、建设困难等问题,本方案设计了一种基于Raspberry Pi 4B和无线Mesh的地震台站行业网络传输系统。该系统包括无线Mesh自组网系统及地震观测仪器组成。本设计采用前兆倾斜仪为例,采用开源的Raspberry Pi 4B作为无线Mesh自组网硬件平台,采用Openwrt开源软件实现无线Mesh自组网应用。本文给出了无线Mesh地震观测台站组网方案的硬件设计和软件流程。经在地震观测台站实验表明,无线Mesh组网系统具备易于布设、组网灵活、稳定性高等优点,可广泛应用于复杂观测环境下的地震观测系统组网。     

定向Ad hoc网络MAC组网技术研究

定向天线利用数字信号处理技术产生空间定向波束,将发射信号能量集中在某一个或者某些特定的方向上进行辐射,其应用于传统的Ad hoc网络中能够有效减少相邻节点间的互干扰,并能通过增加同时传输的节点对数达到显著提升网络空间复用率和容量的目的。首先简单介绍了定向天线和定向通信特点,然后对定向Ad hoc网络MAC层组网关键技术进行了综述,并对定向邻居发现协议、空分TDMA动态时隙分配机制、定向波束对准与跟踪技术等进行介绍和梳理,最后总结现有研究不足并指出未来重点研究方向。     

自组织网中的Anycasting研究

移动无线自组织网络正成为研究的热点,最近在网络通信中提出了一种为任播(anycasting)的通信模式,这里介绍了自组织网中任播的概念以及应用,说明了如何在网络层通过路由实现任播功能。     

Ariadne: A Secure On-Demand Routing Protocol for Ad Hoc Networks

An ad hoc network is a group of wireless mobile computers (or nodes), in which individual nodes cooperate by forwarding packets for each other to allow nodes to communicate beyond direct wireless transmission range. Prior research in ad hoc networking has generally studied the routing problem in a non-adversarial setting, assuming a trusted environment. In this paper, we present attacks against routing in ad hoc networks, and we present the design and performance evaluation of a new secure on-demand ad hoc network routing protocol, called Ariadne. Ariadne prevents attackers or compromised nodes from tampering with uncompromised routes consisting of uncompromised nodes, and also prevents many types of Denial-of-Service attacks. In addition, Ariadne is efficient, using only highly efficient symmetric cryptographic primitives.     

Mesh networks: commodity multihop ad hoc networks

In spite of the massive efforts in researching and developing mobile ad hoc networks in the last decade, this type of network has not yet witnessed mass market deployment. The low commercial penetration of products based on ad hoc networking technology could be explained by noting that the ongoing research is mainly focused on implementing military or specialized civilian applications. On the other hand, users are interested in general-purpose applications where high bandwidth and open access to the Internet are consolidated and cheap commodities. To turn mobile ad hoc networks into a commodity, we should move to more pragmatic "opportunistic ad hoc networking" in which multihop ad hoc networks are not isolated self-configured networks, but rather emerge as a flexible and low-cost extension of wired infrastructure networks coexisting with them. Indeed, a new class of networks is emerging from this view: mesh networks. This article provides an overview of mesh networking technology. In particular, starting from commercial case studies we describe the core building blocks and distinct features on which wireless mesh networks should be based. We provide a survey of the current state of the art in off-the-shelf and proprietary solutions to build wireless mesh networks. Finally, we address the challenges of designing a high-performance, scalable, and cost-effective wireless mesh network.     

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。     

Power-aware routing protocols in ad hoc wireless networks

An ad hoc wireless network has no fixed networking infrastructure. It consists of multiple, possibly mobile, nodes that maintain network connectivity through wireless communications. Such a network has practical applications in areas where it may not be economically practical or physically possible to provide a conventional networking infrastructure. The nodes in an ad hoc wireless network are typically powered by batteries with a limited energy supply. One of the most important and challenging issues in ad hoc wireless networks is how to conserve energy, maximizing the lifetime of its nodes and thus of the network itself. Since routing is an essential function in these networks, developing power-aware routing protocols for ad hoc wireless networks has been an intensive research area in recent years. As a result, many power-aware routing protocols have been proposed from a variety of perspectives. This article surveys the current state of power-aware routing protocols in ad hoc wireless networks.     

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。     

A detailed study of a CDMA based approach to enhance ad hoc network performance

Random access schemes operate typically on a contention based common channel, which brings problems with increasing traffic load. These problems are emphasized in a multi-hop wireless ad hoc network environment. Efficient collision avoidance methods are needed, but they also tend to decrease the spatial capacity of the network. With CDMA (Code Division Multiple Access), it is possible to make multiple simultaneous co-located successful transmissions and thus increase network capacity within the limits of multiple access interference (MAI). Bi-code channel access (BCCA) is a method to apply CDMA in ad hoc networking, providing also a common access channel for network connectivity maintenance and self-configuration. With BCCA, collisions are rare, and thus, more straightforward medium access control (MAC) methods can be used. A MAC solution designed especially for BCCA (BC-MAC) and ad hoc networking increases the efficiency of the channel usage. As BCCA is based on receiver code CDMA, the spreading code of the next hop node is needed. A novel network layer spreading code distribution (NSCD) method is proposed for this purpose. The spreading codes are distributed within routing protocol control packets at the route establishment phase.A detailed study on the performance behavior of different methods is provided. Also, interesting aspects considering the ad hoc network operation are discussed. Instead of the widely used unrealistic cut propagation model, a propagation model with realistic MAI calculation is used in this study. It is shown that the use of NSCD increases the network control load only slightly, and that the performance is practically the same as it is with the assumption of known spreading codes. BCCA with its dedicated MAC and NSCD clearly outperforms commonly used methods (like IEEE 802.11) and yet is easy to implement, robust for design parameters under different conditions while maintaining the original idea of ad hoc networking.     

Securing ad hoc networks

Ad hoc networks are a new wireless networking paradigm for mobile hosts. Unlike traditional mobile wireless networks, ad hoc networks do not rely on any fixed infrastructure. Instead, hosts rely on each other to keep the network connected. Military tactical and other security-sensitive operations are still the main applications of ad hoc networks, although there is a trend to adopt ad hoc networks for commercial uses due to their unique properties. One main challenge in the design of these networks is their vulnerability to security attacks. In this article, we study the threats on ad hoc network faces and the security goals to be achieved. We identify the new challenges and opportunities posed by this new networking environment and explore new approaches to secure its communication. In particular, we take advantage of the inherent redundancy in ad hoc networks-multiple routes between nodes-to defend routing against denial-of-service attacks. We also use replication and new cryptographic schemes, such as threshold cryptography, to build a highly secure and highly available key management service, which terms the core of our security framework