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1.
移动自组网IP地址分配技术综述   总被引:1,自引:0,他引:1  
对近年来提出的多种移动自组网(MANET)地址分配技术进行了较详细地分类评价和性能比较,包括基于状态维护的算法,基于冲突检测的算法和基于网络分层的算法等,并在最后指出了未来的技术发展方向。  相似文献   

2.
随着无线通信的日益发展,无线自组织网络正逐渐从军用扩大到民用等诸多领域。但是无线自组织网络一般由电池供电,由于提高电池容量的技术进步缓慢,功率控制是一个重要的研究课题。无线自组织网络中的功率控制机制研究主要集中在3个方面,即网络层功率控制、链路层功率控制以及混合功率控制。重点是从分层的角度对功率控制进行阐述,主要介绍了网络层及链路层的功率控制,并介绍了一些节能协议。跨层设计综合考虑了各层性能能更好地为功率控制与节能服务。  相似文献   

3.
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   

4.
分析了移动自组网的异构性、路由协议和能量保护问题,应用移动代理和主动网络技术,给出了一个开放的、扩展性强的基于移动代理的主动自组网构架,该构架通过分群策略,使多个路由协议能在异构环境下并行工作,而且也满足移动节点能量保护的需求。  相似文献   

5.
李司 《中国数据通信》2014,(17):101-103
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   

6.
以优化的链路状态路由(Optimized Link State Routing,OLSR)协议为原型,为无线移动自组织网络(Mobile Ad Hoc Networks,MANETs)设计了基于跨层的速率自适应的加权路由协议。该协议充分考察无线信道的时变性质,在路由计算过程中通过跨层信息共享节点的邻居关系及获取节点的当前发送速率,削减了协议的开销。将无线链路的速率与跳数相结合,设计了一种新的路由度量规则。仿真结果表明,提出的加权路由协议能够显著降低网络层的路由开销,提升网络吞吐量,降低端到端时延。  相似文献   

7.
李晓鸿  张大方  陈文斌  王东 《电子学报》2010,38(6):1399-1404
 针对自适应波束定向天线自组网,运用样方统计法推导自组网高概率连通的关键传输半径和邻居数K,提出一种基于邻居数的分布式拓扑控算法DK-Neigh,构建结点出度等于(或略小于)K的有向连通拓扑图.仿真结果表明:DK-Neigh可以保证网络连通率大于96%;当天线波束宽度小于60时,DK-Neigh的结点节能比全向天线K-Neigh算法提高15%.DK-Neigh在保证网络高概率连通的同时减少结点能耗,提高网络能量效率.  相似文献   

8.
王建新  拉米 《电信快报》2004,(5):18-19,26,26
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   

9.
MAC层是移动自组网的一个重要研究领域,特别是暴露终端和隐终端问题的解决尤为重要。介绍了当前移动自组网中MAC层研究的新成果,进行了分析比较,给出了进一步的研究方向。  相似文献   

10.
如何在大规模的移动自组网络中快速地找到所需的资源是一个迫切需要解决的问题.提出了一种称为EAQOS(Energy Aware QoS)的资源发现协议,本协议将资源查询请求过程同路由协议紧密结合,通过合并资源请求、QoS探测以及路径请求信息能够快速定位网络中的最优QoS的资源供应者并进行访问,同时有效降低了网络中的通信量以及能量消耗.最后通过NS2进行模拟实验,与两种不同的Qos资源发现协议相比,结果表明所提出协议的性能,包括查询延迟、通信代价以及能量消耗都有显著的提高.  相似文献   

11.
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。  相似文献   

12.
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   

13.
Recently more and more research interest focuses on the energy efficient routing in mobile ad hoc networks and many related routing algorithms are reported. In this paper, a new optimized priority based energy efficient routing algorithm is presented and priority is added to the existing routing algorithm according to the residual energy proportion of the nodes. Lower residual energy means lower priority and the nodes with lower priority are less likely to forward packets to other nodes. The algorithm needs no global information of the networks and only a little modification is needed to the existing algorithm, so it is practical to be implemented. The algorithm can improve the performance of routing discovery, routing maintenance and cache management at the same time. Some optimization strategy is taken to reduce the network overhead and the lifetime of the network is much longer and the network with our algorithm can transfer much more effective data. Simulation with NS-2 is done and satisfying results are obtained with this algorithm. The results show that the algorithm is efficient.  相似文献   

14.
OLSR performance measurement in a military mobile ad hoc network   总被引:2,自引:0,他引:2  
Wireless ad hoc networks are autonomous, self-configurating and adaptive. Thus, such networks are excellent candidates for military tactical networks, where their ability to be operational rapidly and without any centralized entity is essential. As radio coverage is usually limited, multihop routing is often needed; this is achieved by an ad hoc routing protocol supporting nodes mobility. In this paper, we present performance measurements of the Optimized Link State Routing (OLSR) routing protocol, having the status of IETF RFC. The measurements are performed at CELAR site on a platform representative of military scenarios in urban areas. This platform consists of ten routers, eight PDAs and laptops using a IEEE 802.11b radio interface and implementing OLSR v7. Some nodes are mobile within vehicles. The emphasis of the measurements is on the performance of the network (route repair, network convergence speed, user traffic performance) in presence of this mobility.  相似文献   

15.
Internet-based mobile ad hoc network (Imanet) is an emerging technique that combines a wired network (e.g. Internet) and a mobile ad hoc network (Manet) for developing a ubiquitous communication infrastructure. To fulfill users’ demand to access various kinds of information, however, an Imanet has several limitations such as limited accessibility to the wired Internet, insufficient wireless bandwidth, and longer message latency. In this paper, we address the issues involved in information search and access in Imanets. An aggregate caching mechanism and a broadcast-based Simple Search (SS) algorithm are proposed for improving the information accessibility and reducing average communication latency in Imanets. As a part of the aggregate cache, a cache admission control policy and a cache replacement policy, called Time and Distance Sensitive (TDS) replacement, are developed to reduce the cache miss ratio and improve the information accessibility. We evaluate the impact of caching, cache management, and the number of access points that are connected to the Internet, through extensive simulation. The simulation results indicate that the proposed aggregate caching mechanism can significantly improve an Imanet performance in terms of throughput and average number of hops to access data items.  相似文献   

16.
移动自组网中任意时刻链路可用性计算方法   总被引:1,自引:0,他引:1  
链路可用性和基于其扩展的路径可用性是选择更稳路由的重要度量尺度.基于修正的随机行走运动模型,利用节点估测的第一次保持运动状态不变的时间T,本文提出了一种任意时刻t的链路可用性计算方法LA(t).同时本文给出了计算在给定运动模型的基础上传输链路保持连接时间LET的平均值方法,并且给出了链路可用性LA(t)的一般表达式.不同条件的模拟实验结果表明:计算方法LA(t)表现出了十分接近模拟实验值的效果,比目前提出的几种预测方法更准确更实用.  相似文献   

17.
Ad hoc网络中基于数据流的QoS路由协议   总被引:6,自引:1,他引:6  
刘占军  赵为粮  李云  隆克平 《通信学报》2004,25(12):125-130
已有ad hoc网络中的QoS路由都是基于目的地址的选路并预留资源,当源节点针对同一个目的节点先后建立两个或者多个实时业务流的时候,将导致几个数据流争用资源,使得几个流的QoS都无法得到保证。针对这个问题,文章提出了基于流的QoS路由机制,并且进行了仿真分析,仿真结果表明这种机制能够解决这个问题,使QoS得到保证。  相似文献   

18.
Ad hoc网中基于位置信息的QoS路由算法   总被引:8,自引:1,他引:8  
在分析ad hoc网络的单播QOS路由问题的基础上,本文提出了一种新的分布式QoS路由算法-LMLAR(local multicasting location-aided routing)算法。LMLAR算法最关键的思想是利用了“本地多播”机制和位置信息选择路由。仿真结果表明:LMLAR算法能够以较小的路由消息开销取得较高的路由成功率,具有比TBP算法更好的性能,适合于adhoc网的高度动态的环境。  相似文献   

19.
Using directional antennas in wireless mobile ad hoc networks can greatly improve the transmission range as well as the spatial reuse. However, it will also cause some problems such as deafness problem and hidden terminal problem, which greatly impair the network performance. This paper first proposes a MAC protocol called Selectively Directional MAC (SDMAC) that can effectively address these problems and significantly improve the network throughput. Then two improvements on SDMAC are proposed. The first one is to improve the network throughput by scheduling the packets in the queue (a scheme called Q-SDMAC), thus the head-of-line (HOL) blocking problem can be addressed. The second one is to relax the assumption that each node knows the relative directions of its neighboring nodes and use caches to buffer those relative directions (a scheme named Q-SDMAC using cache). Extensive simulations show that: (1) SDMAC can achieve much better performance than the existing MAC protocols using directional antennas; (2) The network throughput can be significantly improved by scheduling the packets in the queue; (3) Using caches can still achieve high network throughput when nodes are moving; and (4) Network throughput decreases when directional antennas have side lobe gain.
Yuguang Fang (Corresponding author)Email:
  相似文献   

20.
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。  相似文献   

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