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为了解决由于自然灾害所造成的通信故障问题,文章建立一种应急通信系统,对于受灾地区的救援工作可以起到重要作用。本文以移动自组网络为主,建立一种无人机通信系统,利用无人机监测特殊地区的真实情况,完成视频的传输功能。利用无人机在空间、地理位置上的优势,感应并监测特殊地区的损坏数据,利用层次化的自组网,实现信息的回传、共享和下载等功能。结果表明,该系统可以实现无人机之间传输数据的低时延功能,很好地满足了应急通信的应用场景。 相似文献
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移动自组网(MANET)是新型的无线移动网络,它不依赖固定网络设施,是能快速展开、自治、多跳的网络结构。它由一组带有无线收发装置的节点组成,整个网络通过移动节点间的相互协作保持网络互联。网络中的每个节点都能快速移动,同时具备主机和路由器功能。移动自组网的前身是分组无线 相似文献
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传统网络编码可以减少数据包的转发次数,但会造成数据包较大的延时,且容易造成网络的拥塞.本文提出一种基于部分网络编码的实时多播协议——PNCRM.该协议将部分网络编码与mesh的建立结合在一起,有效地减小了端到端的延时,并且改善了网络吞吐量性能.仿真结果表明,与PUMA或基于传统网络编码的实时多播协议相比,PNCRM更好地适应接收节点较多、动态性较大的环境,且在数据包投递率及端到端的延时方面有着显著的优势. 相似文献
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提出了新一代的高速网络模拟器的设计方案,从而为移动自组网网络协议和高速无线分组网协议软件的调试提供了更为便利的室内网络环境,避免了通过实际物理效益而进行大量野外试验. 相似文献
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移动自组网中各移动节点的能量消耗比较大,而大多数节点都是由有限寿命的电 池来提供的,因此在制定路由协议时必须考虑其能量保护。拓扑控制算法通过控制结点的传 输范围使生成的网络拓扑满足一定的性质,以延长网络生命周期,降低网络干扰。详细分析了 cone-based拓扑控制算法(CBTC),及其进行改进以适应自组网移动性的特点。 相似文献
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一种基于网络编码的移动自组网实时多播协议 总被引:1,自引:1,他引:0
针对移动自组网中的实时多播场景,提出一种基于网络编码的协议—NCRM.该协议可通过减少网络中数据包的转发次数降低节点能耗,并可改善网络吞吐量性能.为适应实时性要求,在NCRM中引入了严格的时延限制机制.仿真结果显示,与PUMA、MAODV等传统协议相比较,NCRM能更好地适应存在多接收节点、高移动性的环境,且在传输可靠性与节省能耗方面具有显著优势. 相似文献
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为满足基于TDD同步调度机制的移动自组网设计方案中网络层路由算法与MAC层调度协议处理需求,构建了基于S3C6410 ARM处理器与TMS320C6416 DSP处理器的多核构架的移动自组网节点路由与调度处理单元,并给出了基于HPI接口的多处理器层间数据交互硬件设计方案与软件设计架构。实现结果证明HPI接口可靠、稳定,满足自组网节点层间高速数据传输要求。 相似文献
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移动自主网的独特性使其广泛应用在不便铺设网络或者需要快速组网的场合,移动自主网最早应用在军事领域,现在也普遍应用在民事活动中,比如在消防部队抢险救援中发挥着越来越重要的作用。文中介绍了移动自主网的定义及特征,并且通过对现有消防救援通信技术的比较研究,证明了其在消防部队抢险救援通信保障中的优势作用。 相似文献
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基于博弈理论的移动自组网激励机制研究 总被引:1,自引:0,他引:1
摘 要:针对移动自组网中节点在报文转发过程中的表现出的自私行为,利用博弈理论,从静态和动态2个方面对其进行了完整的建模与分析。首先,提出了一种严厉针锋相对策略,并建立了一个无限重复报文转发博弈模型,求得了激励一致性条件。然后,利用演化博弈理论对节点由自私向协作转变的动态过程进行了分析,并证明了严厉针锋相对策略的演化稳定性。仿真结果表明,即使在自私节点比率为1的条件下,只要合理选择惩罚参数,均可有效激励自私节点的协作转发行为,整体网络性能最多可提升80%。 相似文献
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Yunfeng Peng Riheng Jia Xing Gao Xiaoying Gan 《Wireless Communications and Mobile Computing》2016,16(15):2287-2297
With the prevalence of mobile devices, it is of much interest to study the properties of mobile ad hoc networks. In this paper, we extend the concept of diameter from static ad hoc network to mobile ad hoc network, which is the expected number of rounds for one node to transmit a message to all other nodes in the network, reflecting the worst end‐to‐end delay between any two node. Specifically, we investigate the diameter of identically and independently mobility model in cell‐partitioned network and random walk mobility model in two‐dimensional torus network, achieving the boundary , when (k=Ω(n)), and O(k log2k), respectively, where n is the number of nodes and k is the number of cells of network and especially under random walk mobility model . A comparison is made among the diameter of mobile ad hoc networks under identically and independently mobility model, random walk mobility model and static ad hoc network, showing that mobility dramatically decreases the diameter of the network and speed is an essential and decisive factor of diameter. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Mao-Lun ChiangAuthor Vitae 《Ad hoc Networks》2012,10(3):388-400
Reliability is an important research topic in the study of distributed systems. Under many circumstances, a healthy processor in a distributed system needs to reach a common agreement before performing some special tasks even if the faults exist. In order to achieve fault-tolerance in distributed systems, one must deal with the Byzantine Agreement (BA) problem. Most BA problem require all the healthy processors to obtain an agreement at the same round, this kind of agreement is called an Immediate Byzantine Agreement (IBA). Another kind of agreement, Eventual Byzantine Agreement (EBA), allows its participants to reach a common agreement at different rounds when the fact < fp (fact is the number of actual arbitrary faulty processors; fp is the number of tolerate arbitrary faulty processors). However, the traditional EBA problem is solved in well-defined networks, but the Mobile Ad hoc NETworks (MANETs) are increasing in popularity. Therefore, EBA problem is revisited under dual failure mode (processors and transmission media) in the MANET. The proposed protocol, Early Dual Agreement Protocol (EDAP), can achieve agreement while tolerating the maximum number of faulty processors and transmission media in a MANET by using the minimum number of message exchanges. Furthermore, our protocol can manage and organize the network efficiently even if the processors move around the network. 相似文献
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In this paper, we present a Petri net model for performance evaluation of IEEE 802.11 distributed coordination function as a popular media access control layer protocol in mobile ad hoc network. The goal of this evaluation is to examine this protocol under the existing of misbehavior nodes that selfishly try to grasp common channel in a neighbor area. The presented model consists of 2 separate models based on stochastic reward net (SRN), as a variation of stochastic Petri net. The first model, which is called one node operation model , is supposed for presenting all distributed coordination function operations in a single node such as collision avoidance, request to send/clear to send (RTS/CTS) handshake, and backoff mechanism. The next SRN model, all node operation model , is used for modeling nodes competition for occupying channel in a neighbor area. The models could be adjusted to a dynamic network with any number of nodes, dimension scale, and nodes' speed. For evaluation purpose, 4 distinct attack types implemented by modifying associated transitions in SRN models. The proposed SRN model has been quantified by deriving 2 performances metrics as Throughput and Delay . Both metrics are also compared to the value obtained from NS‐2 in terms of different number of nodes and 3 packet generation rates. Three additional metrics measuring the channel usage are also quantified in terms of different attack strategies using only presented SRN model. 相似文献
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Ratish Agarwal Roopam Gupta Mahesh Motwani 《International Journal of Electronics》2016,103(3):355-371
Mobile ad hoc networks are self-organised, infrastructure-less networks in which each mobile host works as a router to provide connectivity within the network. Nodes out of reach to each other can communicate with the help of intermediate routers (nodes). Routing protocols are the rules which determine the way in which these routing activities are to be performed. In cluster-based architecture, some selected nodes (clusterheads) are identified to bear the extra burden of network activities like routing. Selection of clusterheads is a critical issue which significantly affects the performance of the network. This paper proposes an enhanced performance and trusted weight-based clustering approach in which a number of performance factors such as trust, load balancing, energy consumption, mobility and battery power are considered for the selection of clusterheads. Moreover, the performance of the proposed scheme is compared with other existing approaches to demonstrate the effectiveness of the work. 相似文献
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This paper presents an efficient route recovery approach for a collaborative mobile ad hoc network (MANET). In the collaborative MANET, the movement of a node can be controlled by other nodes. Based on the property of the controllable movement, each active node (each node on a route) can be protected by its neighboring nodes. When the movement of an active node causes a link breakage on a route, its neighboring nodes compete with each other to move to the original location of the moving active node. Using the movements of neighboring nodes, the proposed approach can achieve route recovery without pre‐establishing or dynamically finding backup routes. The proposed approach also has much less recovery overhead than previous approaches because of the local recovery. Finally, we perform extensive simulations to compare the proposed approach with previous approaches. The simulation results show that the proposed approach has better recovery performance under dense and sparse MANET architectures. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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针对移动ad hoc网络拓扑结构变化大、路由复杂度高、数据传输性能低等问题,提出了一种新的移动通信系统自适应路由算法。为了使得网络拓扑结构更接近移动网络间歇性连接的特点,该算法在网络结构上采用了一种改进的Levy Walk移动模型。采用一种粒子滤波步行长度预测的方法,通过蒙特卡罗抽样得到递归贝叶斯滤波器,并在粒子滤波后进行步行长度预测,确定消息的副本数量,从而减少由于节点转发过多消息副本带来的能量消耗量,提高消息的传递效率。实验仿真结果表明:与基于改进蚁群优化和利润优化模型的路由算法相比,该算法的消息传递成功率分别提高了0.08和0.04,节点平均能量效率提高了17.9%和13.4%,在提升数据传输成功率和节能上具有较好效果。 相似文献
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The paper proposes a dynamic and hierarchical IPv6 address configuration scheme for a mobile ad hoc network (MANET). The scheme proposes the hierarchical architecture and combines the distributed and centralized address configuration approaches. In the architecture, a central node assigns IPv6 addresses for cluster heads that are distributed around a MANET, and distributed cluster heads assign IPv6 addresses for cluster members. The generation algorithm of a cluster is proposed, and it uses the number of potential cluster members as a measurement unit and minimizes the number of cluster heads. Therefore, the address configuration cost for cluster heads is reduced. A central node/cluster head uses the unicast communication mode to achieve the real‐time address recovery in order to ensure that it has enough address resources for assignment. The paper also proposes the low‐cost MANET merging/partitioning algorithm that guarantees that no address collision happens during the MANET merging/partitioning process. This paper analyzes the performance parameters of the proposed scheme, including the address configuration cost, the address configuration delay, and the number of MANET merging. The analytical results show that the proposed scheme effectively reduces the address configuration cost, shortens the address configuration delay, and decreases the number of MANET merging. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Y. Zhen M. Q. Wu D. P. Wu B. Sun X. Y. Li C. X. Xu 《International Journal of Communication Systems》2009,22(11):1377-1401
The opportunistic routing mechanism can use several lossy broadcast links to support reliable transmission. In this paper, a simple opportunistic routing mechanism for real‐time multimedia services is proposed. This mechanism is based on the dynamic source routing protocol with some modifications, multiple route request, and route reply messages are used to construct the forwarder list, and the nodes within the forwarder list forward the packets which they overhear. The forwarder list is placed on the packet header in the form of a Bloom filter, which will restrict the size of the forwarder list to a constant value. There are no strict scheduling mechanisms for the forwarding order of the forwarder nodes, thus our opportunistic routing mechanism can be scalable for multiple simultaneous flows. Simulations show that our mechanism can effectively decrease the transmission times and the amount of the control messages for each packet and reduce the end‐to‐end delay for real‐time voice service, the quality of service for these services can be supported well over the unstable wireless channel. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献