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Geographic information system(GIS)is increasingly managing very large sets of data,hence a centralized data index may not always provide the most scalable solution.Recently,the peer to peer(P2P)networks have become very popular for sharing information in a totally decentralized manner.In this paper,a new hybrid P2P spatial indexing network(HPSIN)is proposed,which combines distributed quad-tree with distributed Hash table(DHT)based Chord network to maintain both query efficiency and system load balance.In addition,a simple theoretical model based on opened queueing network for HPSIN is established.Assuming each peer as M/M/1 queueing processor in the model,fundamental characteristics of the system is captured,and expression of average query delay is obtained in close form.The theoretical analysis and numerical computing results show that there exists an optimum point of tradeoff between efficiency and load balance.By setting a proper value of start index level ls for different network scale and query rate,HPSIN will achieve the minimum overall query delay,therefore,can adapt to different P2P application environments.  相似文献   

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褚蓓  黄佩伟 《信息技术》2006,30(9):67-70
陆地蜂窝系统的发展将引入自组织网络功能,P2P就是支持该项功能的关键一步,无线定位技术是第三代移动通信系统中一个非常有前景的技术。首先,简要介绍了引入P2P功能的,TD-SCDMA系统,并重点对引入P2P的,TD-SCDMA系统中的无线定位技术进行了分析。然后提出了针对其中P2P用户的几种定位方法,最后分析了定位技术如何用于进一步提高系统的性能。  相似文献   

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随着信息技术和网络技术的飞速发展以及人们的应用需求,产生了网络视频会议系统.针对P2P网络技术协同网络会议系统的需求,分析流媒体传输与控制技术、Java Media Framework (JMF)媒体框架技术、RTP/RTCP流媒体传输与控制协议、P2P结构分析和P2P工作原理,建立P2P结构的系统框架和基于时间戳的RTCP流媒体同步机制,设计了基于JMF类及P2P结构的网络视频会议系统.  相似文献   

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Wireless sensor networks improve the quality of human daily life like ubiquitous city and healthcare services as well as the fundamental monitoring such as environment pollution, tunnel monitoring, earthquake diagnostic, and so on. To increase usability and feasibility of collected sensor data, a wireless sensor network should be required to apply a variety of mobile devices to give the information at anytime and anywhere to users. Thus, we present multi-sensor centric smart sensor network architecture using general mobile devices in order to provide more efficient and valuable sensor network application and services. The proposed system architecture is based on IEEE 802.15.4-2006 standard with smart mobile devices. We also show some scenarios with on-demand request and real time event driven data to show the feasibility of the proposed architecture using five kinds of sensors such as magnetic, photodiode, microphone, motion and vibration. Based on the experiment results, we show that the proposed system has the potential as smart mobile device-based wireless sensor network architecture.  相似文献   

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目前电子围栏和伪基站是公安系统信息采集的主要设备,常分布在人流密集区域,容易影响通信网络质量,给运营商的品牌、经济效益造成负面影响。搭建不影响通信网络的信息采集系统变得日益紧迫。本文从离散轨迹建模回溯的方向进行研究,利用信令切换数据和基站的切换信息,结合扫频、软硬采信令等大数据模型,构建出道路移动用户运动轨迹定位回溯系统,可用于公安系统信息采集,控制并减少电子围栏和伪基站的数量,保证通信网络质量。  相似文献   

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电力输电线巡检是电力安全生产的一个重要环节.目前的电力线巡检系统存在定位精度较低,自动化程度较低、耗费人力物力等问题.提出一种新的基于无线传感网络技术的电力线巡检系统.该系统将电力线巡检系统划分为三部分:杆塔线路信息采集系统,手持设备,和中心站管理信息系统.信息采集系统从各传感器节点收集信息,并使用无线网络将信息发送到手持设备,手持设备发送的信息中心站管理信息系统.最后讨论了该系统在电力线巡检的应用前景.  相似文献   

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In wireless sensor network (WSN), it is a complex task to track the target when it is moving randomly in an unknown environment. It also becomes difficult to cover a complete searching area because of the limited searching range and energy of sensor nodes as they are few in number. The author proposes a distributed energy efficient tracking in a hybrid WSN (DEETH) to track a randomly moving target in an unknown searching. Hybrid WSN that is proposed has both static sensor nodes (SSNs) and mobile sensor nodes (MSNs), which are deployed in the searching area. The MSNs move collectively using particle swarm techniques to search a target. The SSNs are deployed for tracking the presence of a target and giving this information to the base station. As per the information given by SSN, MSNs travel to the target and track it. Simulation results prove that proposed technique successfully tracks the target using less number of nodes and also less amount of energy.  相似文献   

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结构化P2P资源搜索算法及其在未来光网络中的应用   总被引:1,自引:1,他引:0  
推进绿色节能光网络是未来光网络面临的重要挑战之一。基于DHT的结构化P2P资源搜索算法因为可扩展性、鲁棒性、负载均衡、查询效率高等特点更适用于具有云计算、物联网、移动互联网等特点的未来光网络中的资源搜索。研究结构化P2P资源搜索算法的特点,从降低能耗角度分析算法对未来光网络产生的影响,提出在名址分离架构的未来网中快速资源搜索设计方法,最后探讨P2P资源搜索算法在未来光网络中面临的挑战。  相似文献   

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对低移动性、频繁搜索文件的无线Ad-Hoc网络,提出一种新型P2P文件共享系统,介绍一种将文件查找和路由功能统一起来形成跨层的方案。所有共享文件采用全分布哈希表,在无线网络拓扑结构建立的同时存储和保留位置信息以及路由信息.通过节点间的树形逻辑结构解决共享文件的定位查询和下载问题。  相似文献   

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混合式P2P软件是目前互联网上广泛应用的P2P文件共享软件,但混合式P2P协议并没有特别考虑移动设备(Mobile Device)线接入的问题。文章将在混合式P2P模型的基础上,针对MD计算能力、存储能力的限制和无线连接的特点.提出一种支持MD无线接入的新型混合式P2P网络模型。它通过扩展移动支持节点的功能,使用移动代理代表MD接入P2P网络共享资源。并利用客户机缓存技术进行优化,有效的减少了MD自身的开销以及无线通信的开销.同时对MD的移动性和无线连接的断接性提供了很好的支持。  相似文献   

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Peer-to-peer (P2P) computing technology has been widely used on the Internet to exchange data. However, it occupies much network bandwidth, and thus greatly influences traditional business on the Interact. Besides, problems about free-riders and 'tragedy of the commons' in the P2P environment estrange from it P2P users who constantly contribute to the network with quality resources. This article proposes a new P2P network traffic control mechanism based on global evaluation values. It aims to help individual users to avoid peak traffic time as much as possible, ease network congestion and protect traditional business on the Interact, as well as differentiating priority grades of peers according to their contributions and stimulating them to share their valuable resources actively. This article first analyzes the current state of network traffic, and then elaborates on P2P network traffic control policies and proposes the peer's priority level differentiation mechanism based on global evaluation values. Finally,after the testing results and analysis of the proposed P2P network traffic control mechanism are discussed, conclusions are drawn.  相似文献   

13.
Mobile robots need sufficient sensors and information on the environment in order to navigate. In this paper, we propose a system of mobile robots, which is controlled in a distributed intelligent sensor network. In such a networked space, the environment is divided by distributed sensors. Each area is monitored by a distributed sensor device, which connects with other distributed sensor devices and robots throughout the network. As a result, the mobile robots are able to accomplish tasks simply by following orders from the sensor devices in the networked environment, although the mobile robots are not self-contained with information on the environment and sensors for self-positioning and control. We test several situations to verify the proposed system.  相似文献   

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Sensors carried by moving objects in the cities can be used in various applications such as environmental monitoring, traffic control and recreational purposes. A mobile sensor network can be formed by sensors carried by people or buses. In this paper, we will present a mobile sensor network programming system (MSNPS) that can program or reprogram such mobile sensor networks. The programming process is usually initiated by a user from the Internet. MSNPS uses a gateway protocol to bridge the Internet and sensor network, so that control and data messages can be exchanged between these two networks. MSNPS sends the program data to the targeted sensor platforms using a tree structure formed by control messages. We developed a prototype implementation, and analyzed MSNPS system performance. We also simulated the system in a mobile sensor network.  相似文献   

15.
基于P2P的无线传感器网络应用架构研究   总被引:3,自引:0,他引:3  
通过基础网络互联多个传感器网络,为用户提供大规模、大范围、多样化的信息服务成为未来无线传感器网络的应用模式之一。据此,提出了一种基于P2P(Peer-to—Peer)技术的无线传感器网络应用架构。采用P2P技术,解决了大数据量的通信瓶颈,传感器网络亦可自由加入、变更或退出,方便部署,网络可扩展性好.同时屏蔽底层网络差异及多种接入方式.为用户提供多个访问入口。  相似文献   

16.
僵尸网络日益猖獗。其危害从终端用户到国家,甚至军方与政府也不断遭受着僵尸网络的攻击。越来越多与僵尸网络密切相关的词汇进入人们的视线:恶意软件、身份财务信息盗取、恶意广告弹窗、垃圾邮件、网络钓鱼。WLAN作为公共使用的网络环境,能够从源头入手处理僵尸网络获得良好效果,因此本文从网络结构开始,对时下最难防护与处理的P2P网络进行分析,并提供在WLAN环境下实际可行的处理机制。  相似文献   

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一种全新的P2P网络解决方案-JXTA技术   总被引:3,自引:0,他引:3  
对等网络P2P(Peer to Peer)是因特网实现下一次飞跃的的关键。在P2P网络模式的研究领域里,JXTA (juxtapose,并行)作为一种全新的P2P网络解决方案已经日益受到业界的关注。首先介绍了P2P网络以及它与传统网络模式的区别,然后详细介绍了JXTA技术,并在此基础上提出了对等体发现的几点思路。  相似文献   

18.
To relieve the negative effect brought by the intricate wireless network environment and unstable user behavior in layered mobile peer-to peer(P2P) streaming service,an evolved layered P2P (E-LP2P) dat...  相似文献   

19.
A cross-layer optimized query routing mismatch alleviation(QRMA)architecture is proposed to mitigate the problem of query routing mismatch(QRM)phenomenon between the structured peer to peer(P2P)overlay and the routing layer in mobile Ad-hoc networks(MANETs),which is an important issue that results in the inefficiency of lookup process in the system.Explicated with the representative Chord protocol,the proposal exploits the information of topologic neighbors in the routing layer of MANETs to find if there is any optimized alternative next hop in P2P overlay during conventional lookup progress.Once an alternative next hop is detected,it will take the shortcut to accelerate the query procedure and therefore alleviate the QRM problem in scalable MANETs without any assistance of affiliation equipments such as GPS device.The probability of finding out such an alternative node is formulated and the factors that could increase the chance are discussed.The simulation results show that the proposed architecture can effectively alleviate the QRM problem and significantly improve the system performance compared with the conventional mechanism.  相似文献   

20.
P2P系统具有开放性和匿名性,这就使得恶意节点能够轻易地在网络中传播虚假的甚至有害的文件,从而损害了整个P2P系统的鲁棒性.针对该问题,文中提出了一种基于信任传递关系建立可信对等网络的算法,能够动态调整信任路径,隔离恶意节点和恶意节点集.实验表明即使在大量恶意节点相互合作的情况下,算法仍能有效地降低网络中虚假文件的下载数量.  相似文献   

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