共查询到17条相似文献,搜索用时 55 毫秒
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为了在无线ad hoc网络上构建各种应用系统,有必要提供一种高效的数据共享机制,使得网络中各节点之间能够方便地进行协同和交互。该文将分布式哈希表(DHT)的基本思想与无线ad hoc网络中的基于地理位置的路由技术结合起来,提出了一种新型的面向无线ad hoc网络的数据共享方案——基于位置的DHT(LDHT)。与传统的DHT方案相比,LDHT不是通过逻辑上的覆盖网络来实现,而是直接基于网络的物理拓扑结构来构建,有效地消除了传统DHT方案的拓扑结构不匹配问题,提高了在无线ad hoc网络中进行数据共享的效率。 相似文献
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无线Ad Hoc网络支持QoS的研究进展与展望 总被引:29,自引:0,他引:29
无线ad hoc网络的应用环境以及与Internet的互连要求它必须提供一定的服务质量(QoS)保证,然而,无线信道固有的特点及节点移动造成网络拓扑的频繁变化,使得在无线ad hoc网络中支持QoS面临许多新的挑战.从无线ad hoc网络的QoS体系结构、QoS路由、QoS信令、支持业务区分和资源预留的介质访问控制协议这4个方面出发,对近年来国内外在该方向取得的研究成果作了全面的概括总结和比较分析,系统阐述了在无线ad hoc网络中支持QoS的问题,指出了亟待解决的问题和今后的研究方向. 相似文献
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针对无线ad hoc网络的数据安全性问题,提出了一种增强安全性的多路径路由算法.该算法通过目标节点发送检测数据包的机制,动态维护多路径路由信息的有效性.源节点则根据收到检测包的信息自适应地更新当前的最优传输路径,充分利用路由寻找及维护过程中的信息建立多条可用路径,提供最优的路由方案,并增强了无线ad hoc网络数据传输的安全性.仿真结果表明此算法的数据传输安全性达到了合理的水平. 相似文献
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夏铭 《网络安全技术与应用》2008,(6):46-47
无线ad hoc网络是一种新型的无线移动网络。介绍了ad hoc网络的体系结构和主要特点,归纳了ad hoc网络的安全目标,提出了解决其安全问题的安全策略。最后,展望了无线ad hoc网络的研究方向。 相似文献
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ad hoc网络是一组具有路由和转发功能的移动节点组成的一个多跳的临时性自治系统,是一种无中心的无线网络,现有的安全策略都是从某一方面提出改进方法;基于系统论思想方法,提出了一种基于移动Agent 的ad hoc可信网络架构,并进行了初步分析. 相似文献
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无线Ad Hoc网络QoS路由协议研究的进展与展望 总被引:6,自引:0,他引:6
无线ad hoc网络是一种无固定通信设备支持、节点可自由移动的多跳全分布式无线网络。无线ad hoc网络的应用环境以及与Internet的互连要求它必须提供一定的服务质量(QoS)保证,而QoS路由协议是无线ad hoc网络支持QoS的一个关键理论和技术,也是目前的一个研究热点。本文回顾了近年来国内外在无线ad hoc网络QoS路由协议研究方面取得的研究成果,对已有的无线ad hoc网络的QoS路由协议进行了分类.并对它们作了较全面的概括。总结和深入的比较分析,系统阐述了在无线ad hoc网络中实现QoS路由协议时需要考虑的因素,指出了亟待解决的问题和今后的研究方向。 相似文献
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无线Ad hoc网络路由协议的分析比较 总被引:9,自引:0,他引:9
无线adhoc的路由算法是adhoc领域的研究难点。论文分析了四种路由协议DSDV、CGSR、AODV、DSR的机制,并进行了网络模拟试验,在网络时延、吞吐量、路由开销、平均跳数等方面进行了对比。试验结果表明按需路由在无线adhoc网络环境下具有更好的性能。 相似文献
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OVSF-CDMA Code Assignment in Wireless Ad Hoc Networks 总被引:1,自引:0,他引:1
Orthogonal Variable Spreading Factor (OVSF) CDMA code consists of an infinite number of codewords with variable rates, in
contrast to the conventional orthogonal fixed-spreading-factor CDMA code. Thus, it provides a means of supporting of variable
rate data service at low hardware cost. However, assigning OVSF-CDMA codes to wireless ad hoc nodes posts a new challenge
since not every pair of OVSF-CDMA codewords are orthogonal to each other. In an OVSF-CDMA wireless ad hoc network, a code
assignment has to be conflict-free, i.e., two nodes can be assigned the same codeword or two non-orthogonal codewords if and only if their transmission will
not interfere with each other. The throughput (resp., bottleneck) of a code assignment is the sum (resp., minimum) of the
rates of the assigned codewords. The max-throughput (resp., max-bottleneck) conflict-free code assignment problem seeks a
conflict-free code assignment which achieves the maximum throughput (resp., bottleneck). In this paper, we present several
efficient methods for conflict-free code assignment in OVSF-CDMA wireless ad hoc networks. Each method is proved to be either
a constant-approximation for max-throughput conflict-free code assignment problem, or a constant-approximation for max-bottleneck
conflict-free code assignment problem, or constant-approximations for both problems simultaneously.
The work of Peng-Jun Wan and Xiang-Yang Li is partially supported by NSF CCR-0311174.
The preliminary version of the paper first appeared in ACM DIAL M-POMC 2004, workshop of ACM MobiCom 2004. 相似文献
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An efcient hop count route fnding approach for mobile ad hoc network is presented in this paper.It is an adaptive routing protocol that has a tradeof between transmission power and hop count for wireless ad hoc networks.During the route fnding process,the node can dynamically assign transmission power to nodes along the route.The node who has received route request message compares its power with the threshold power value,and then selects a reasonable route according to discriminating algorithms.This algorithm is an efective solution scheme to wireless ad hoc networks through reasonably selected path to reduce network consumption.Simulation results indicate that the proposed protocol can deliver better performances with respect to energy consumption and end-to-end delay. 相似文献
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Romit Roy Choudhury Krishna Paul Somprakash Bandyopadhyay 《Autonomous Agents and Multi-Agent Systems》2004,8(1):47-68
Supporting mobility in a multi hop wireless environment like the MANET still remains a point of research, especially in the context of time-constrained applications. The incapacity of ad hoc networks to offer services of the likes of static or infratructured networks may be attributed to two major reasons. One, unpredictable mobility of hosts cause location-transparent-packet-delivery to be implemented only at the expense of large control overhead. Two, the lack of central control causes connection management and scalability to be major problems in the multi hop environment. In this paper we propose an efficient agent based routing mechanism that not only incurs minimal overhead, but also lays the foundation for additional functionalities as network management and real time applications. In other words, we show that the agent framework makes the MANET robust and survivable under stringent system constraints. 相似文献
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提出了基于网络分簇和多路径的自组织网络匿名通信协议(CMAR),该协议中节点首先在不暴露身份信息的情况下,利用双线性配对技术生成和邻居节点共享的密钥,并以此为基础,秘密地建立用于成员节点和簇头节点之间通信的簇内路由表项,在簇内路由表项的辅助下,完成源节点和目标节点之间多路径的匿名建立,以及数据报文的匿名转发。通过性能分析可以发现,CMAR协议的密码学运算负荷较低,且网络通信性能良好。 相似文献
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无线自组网络中基于簇结构的安全方案 总被引:2,自引:0,他引:2
无线自组网络是一种不需要基础通信设施的自组织网络,正得到越来越多的应用.当前自组网络的安全性研究正成为一个热点.对基于簇结构的自组网络进行了安全分析,并且针对存在的安全问题提出了新的安全解决方案.主要贡献在于:①提出了一个保护簇首的安全机制;②针对节点簇间漫游的安全隐患,提出一个基于请求的节点信息共享机制,并给出了相应的算法.对该方案进行了仿真实验,结果显示,该方案具有充分的可行性.与已有方案相比,该方案具有较完善的安全机制,网络性能也较好. 相似文献
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YI Ping HOU Yafei ZHONG Yiping ZHANG Shiyong 《通讯和计算机》2005,2(1):34-40,74
Mobile ad hoc network of lets convenient infrastructure less communication over the shared wireless channel. However, the nature of ad hoc networks makes them vulnerable to security attacks. Existing security technologies such as intrusion prevention and intrusion detection are passive in response to intrusions in that their countermeasures are only to protect the networks and there is no automated, network-wide counteraction against detected intrusions. While they all play an important role in counteracting intrusion, they do not, however, effectively address the root cause of the problem - intruders. In this paper, wc propose the architecture of automated intrusion response. When an intruder is found in our architecture, the block agents will get to the neighbor nodes of the intruder and formed a firewall to isolate the intruder. In the end, we illustrate our architecture by an example. 相似文献