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1.
根据small-world的研究发现,在实际的P2P拓扑结构中存在若干度数很高的节点。传统的Chord算法假定关键字的查询请求是随机分布的,没有考虑到节点之间的"短链"效应。提出一种基于Chord在一定程度上逐步找到系统节点的"短链"的方法。该方法根据关键字检索命中率动态调整路由表中记录的排序。仿真实验表明,该算法加快了关键字的查询时间,提高了路由表的查询效率。主要创新点在于针对实际P2P网络中查询请求的分布特性提出一种改进的Chord路由算法,该算法能有效改善系统的查询性能。  相似文献   

2.
对等网络Chord搜索路由算法的改进   总被引:1,自引:0,他引:1  
在对等网络中,如何高效地搜索广泛分布的网络资源一直是研究的重点.基于分布式哈希表(DHT)的资源搜索算法是目前比较流行的算法之一.介绍了其中具有代表性的Chord算法,分析其存在的缺陷,提出了一种聚类超级节点搜索路由的改进算法,继承了Chord算法简单、高效、可靠、负载平衡及开销少的优点,明显提高了搜索查询的效率.  相似文献   

3.
在当前的分布式的网络环境下,如何提高数据资源的查询搜索效率是对等网络技术研究的关键内容和热点问题.在Chord网络规模比较小时,路由查找效率可以接受,但随着网络规模增大,查找效率变得不够理想.针对如何解决Chord网络中资源查找效率低的问题,本研究提出了一个新的E-Chord(基于Chord的扩展)模型.该模型主要是针对Chord中的路由表查找算法和路由表的结构进行扩展改进.经过一系列的理论分析验证,改进后的EChord模型和原Chord模型相比,资源查询效率得到明显的提高.  相似文献   

4.
为提高移动自组织网络(mobile ad hoc network,MANET)路由查询效率,通过对P2P(peer-to-peer)网络与MANET的交叉研究,在DSR协议基础上引入Chord算法,提出双向路由模型BPDSR.BPDSR双向路由发现算法和路由资源共享算法,降低了查询复杂度,减少了路由失效和绕路问题.通过BPDSR算法性能分析和NS--2仿真实验表明,BPDSR路由模型的路由效率明显提高.  相似文献   

5.
移动代理通过遍历网络收集信息,由于网络的开放性,代理及其内部数据的安全受到巨大威胁。提出了一种基于安全移动代理的路由算法的设计思想,使用概率值来构造路由表,通过移动代理在网络节点间地迁移,来发现网络状态,更新节点路由表。同时在网络节点处建立信任表,定期生成TestDataAgent(测试代理)在虚拟空间中运行,并对其属性和关键数据进行检测以保证网络节点的可靠性,实现代理在网络中的安全。还用Grasshopper移动代理开发平台构造了一个简单网络模型,对此算法进行了验证。  相似文献   

6.
Chord算法是一种典型的结构化P2P搜索算法,该算法简洁而且拓扑结构清晰,但该算法还存在着路由表信息冗余,查找效率不高的问题。在分析经典Chord算法的基础上,通过扩展Chord路由表,提出一种新的查找算法,该算法能够消除路由表的一些冗余信息,减少查找次数。通过理论分析,该算法提高了Chord的查找效率。  相似文献   

7.
移动路由属于一种QoS路由,具有网络拓扑时刻变化,无线网络环境复杂多变,网络高速移动等特点。目前,对移动路由选路算法的研究尚不充分。准确快速地找到最优路径,保证QoS是本文研究的主要目标。本文给出了一种移动路由模型,为满足移动路由的网络环境,设计了使QoS参数时刻变化的函数实现。然后将粒子群算法应用到该模型中实现路径的寻优。仿真结果表明,将粒子群算法用于该移动路由模型中能够得到很好的收敛速度和寻优结果。  相似文献   

8.
分析移动自组网路由协议特点,提出路由协议设计时所需具备的相关要求。根据当前路由协议发展及研究现状,从路由策略角度分四大类对移动自组网路由协议进行详细阐述。结合传统单路径路由协议在工作过程中表现出的诸多不足,阐述多路径路由协议工作原理、分类及优势,提出未来移动自组网路由协议将向多路径路由协议发展。详细分析并对比当前常见几个多路径路由协议,指出还需对多路径路由协议进行有效研究并与实际应用相结合,进而拓展并提升移动自组网在社会工作生活中的实际应用。  相似文献   

9.
移动Ad Hoc无需基础设施,可支持高动态的移动数据通信,具有广泛应用的前景。然而,其高动态特性导致互联网现有路由协议不再适用。近年来学者针对Ad HOC网络提出了大量的路由选择算法。给出了各种路由技术分类方法,简述了Ad Hoe网络的基本路由协议和路由选择算法,进而从预测模型、能量模型、位置信息、服务质量控制和安全支持等5个角度,深入分析了当前Ad Hoc。  相似文献   

10.
针对一类基于移动代理的无线传感器网络内移动代理的迁移路由问题,提出了一种基于网格和遗传算法的移动代理迁移路由算法.该方法通过改进的自适应遗传算法获取迁移的基路径信息,再结合网络网格化和路由修复策略来实现路由节点失效时的路由修复,从而有效降低能耗和实现成功迁移.  相似文献   

11.
因为移动P2P网络具有动态性而且移动节点能量受限,提升移动P2P数据传输效率至关重要.利用蚁群优化算法,将蚂蚁的信息素与节点的能量和通信带宽结合起来,在蚁群选择路径时,减少其寻优路径上的信息素浓度,根据概率路由表中信息素的浓度对路由选择策略进行调整,避免网络拥塞和个别节点能量消耗过快,提出了一种移动P2P网络的多路径路由选择算法.实验结果表明,与EDSR路由协议相比,提出的算法能够降低节点的分组丢失率和端到端的平均时延,提高了网络的生存周期.  相似文献   

12.
由于EDSR路由协议在路由选择是采取向邻居节点全部转发路由信息的策略,在路由请求时,容易引起转发次数过多而导致网络瘫痪。本文提出借助LAR协议利用目的节点的位置信息设置路由的期望域,从而构建路由选择区域,提高发起路由请求时预知目的节点位置的几率,提出增强性LAR路由协议。当位置辅助路由协议发现路由失败时避免采用全网洪泛机制,采用基于距离的位置路由改进算法,设置距离更新门限来达到节点位置信息实时性与更新负载的平衡,通过路由选择权重值Qpath使路由选择达到最优。  相似文献   

13.
张玲  聂少华 《电讯技术》2016,56(3):331-336
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   

14.
An optimal energy efficiency routing strategy based on community was proposed,which minimized the network energy consumption under the given delay constraint.Firstly the expected energy consumption and delay of message delivery in the connected network were obtained through Markov chain.Then the comprehensive cost function for delivering message from source node to destination node was designed,which was combined with energy consumption and delay.Thus,the optimization function to comprehensive cost of relay node delivering message was obtained,and further the reward function of relay node was gotten.Finally the optimal expected reward of optimal relay node was achieved using the optimal stopping theory,so as to realize the optimal energy efficiency routing strategy.In simulations,the average energy consumption,the average delay and the average delivery ratio of routing optimization strategy were compared with those of other routing strategies in related literatures.The results show that the strategy proposed has smaller average energy consumption,shorter average delay and higher average delivery ratio,gaining better energy consumption optimization effect.  相似文献   

15.
16.
The key idea behind cultural algorithm is to explicitly acquire problem-solving knowledge from the evolving population and in return apply that knowledge to guide the search. In this article, cultural algorithm-simulated annealing is proposed to solve the routing problem of mobile agent. The optimal individual is accepted to improve the belief space's evolution of cultural algorithms by simulated annealing. The step size in search is used as situational knowledge to guide the search of optimal solution in the population space. Because of this feature, the search time is reduced. Experimental results show that the algorithm proposed in this article can ensure the quality of optimal solutions, and also has better convergence speed. The operation efficiency of the system is considerably improved.  相似文献   

17.
Wireless ad hoc networks are growing important because of their mobility, versatility, and ability to work with fewer infrastructures. The mobile ad hoc network is an autonomous system consisting of mobile nodes connected with wireless links. Establishing a path between two nodes is a complex task in wireless networks. It is still more complex in the wireless mobile ad hoc network because every node is no longer as an end node and an intermediate node. In this paper, it focuses on design of connectionless routing protocol for the wireless ad hoc networks based on the mobile agent concept. The proposed model tries to discover the best path taking into consideration some concerns like bandwidth, reliability, and congestion of the link. The proposed model has been simulated and tested under various wireless ad hoc network environments with the help of a different number of nodes. The results demonstrate that the proposed model is more feasible for providing reliable paths between the source and destination with the minimum control message packets over the network. It has delivered more number of packets to the destination over the network. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

18.
Chord是一种数值逐步逼近的P2P路由算法,它能够快速地定位资源。在Chord环上由于结点的随机性,资源定位时产生了逻辑路径和物理路径不一致及绕环问题,致使网络延迟增大。混合P2P具有很强的网络局部性,但查询效率低。提出了基于改进的混合P2P的Chord算法(Chord Algorithm Based on Enhanced Hybrid P2P,CBEH),该算法利用增强的混合P2P中超级结点的网络信息,在路由过程中优先选取物理距离近的结点。实验表明CBEH能够有效地减少路由查找时延,提高路由性能。  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.
To solve the problem that the successful rate of resource query is low in opportunity social network,a query message routing algorithm based on time-variant interest community was proposed.Two well-known mobile social datasets were firstly analyzed,and then the temporal and spatial correlations of users were found.The time-variant interest communities based on temporal and spatial correlations of users were constructed.Next,a dynamic query routing on the constructed time-variant interest communities was proposed.Theoretical analysis shows that the proposed routing can run in O (nlog n) time.The comparisons between the proposed routing and state-of-the-art message delivery algorithms show that the proposed routing can keep high query success rate,reduce the average query latency and the hop count of a query and maintain low system overhead.  相似文献   

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