基于蚁群的AdHoc网络分簇路由算法

无线AdHoc网络是一个多跳、临时性的对等移动自治系统,它由一组带有无线收发装置的移动节点组成。而路由协议是AdHoc网络体系结构中不可或缺的重要组成部分,因此路由协议的研究成为当前AdHoc网络研究的重点。针对AdHoc网络节点能量有限的特性,提出了一种基于分簇及蚁群的组合路由算法（CRBAC）。给出了分簇策略下的簇内簇间路由机制,簇内采用按需路由策略,将改进的蚁群算法应用到簇内路由机制中,通过扩散信息素选择能量高的邻节点均衡网络节点能量,而簇间采用尽可能简单的表驱动路由策略。仿真结果表明,该算法是合理的,不仅有效地减少了端到端时延,而且提高了网络的生存时间。     

一种基于分簇结构的AdHoc密钥管理方案

无线AdHoc网络是一种移动、多跳、自组织、无中心的新型网络,因其具有很强的鲁棒性、抗毁性和组网迅速等特点而在军事以及商业领域都有广阔的应用前景。然而,其灵活特性又使其安全性面临着严峻的挑战。密钥管理是AdHoc网络安全的关键技术,文章提出了一种基于分簇结构的AdHoc密钥管理方案,方案使用了基于身份密码算法,有效地降低了移动终端计算、存储能力的需求和系统密钥管理的通信开销,通过引入密钥协商算法,有效地解决了端到端通信保密问题。     

Ad Hoc网络中的一种新型分簇算法

经过查阅大量有关分簇算法的资料,本文提出了一种新型分簇算法SACA,并从理论和初步的实验上证明了SACA适用于大规模AdHoc网络,而且即使是在移动设备高速运动的状态下,SACA依然是易于实现的。因此对这种分簇算法的研究更有意义。     

基于链接率的AdHoc自适应按需加权分簇算法

AdHoc网络通过分簇算法来实现网络分层,以支持高效的资源管理和路由策略。稳定的分簇算法可以减少网络的计算和通信开销。为了提高分簇算法的稳定性,文中提出了一种基于链接率的自适应按需加权分簇算法（AOWLR）。该算法将节点的运动轨迹抽象为直线形和圆弧形两种,并引入邻居节点的平均链接率预测值作为衡量簇稳定性的一个重要标准。NS2仿真结果证明,同AOW相比,AOWLR算法的负载平衡因子较高,连通统治集（CDS）更新频率和节点充当簇头的公平性指数（HFI）较低。     

基于簇和代理的AdHoc网络分布式入侵检测模型

基于簇技术,针对由于AdHoc网络的独特网络特性而致使其安全性特别脆弱的现状,提出一种新的AdHoc网络分布式代理入侵检测模型。此模型有效地解决了以往入侵检测审计数据的不准确、不及时、不可靠等弱点,同时很好地提高了Adhoc网络的安全性和对分布式攻击的协同检测能力。该模型具有较好的扩展性、灵活性和准确性,比较适合带宽和资源有限的AdHoc网络。     

稳定且负载均衡的移动AdHoc网络加权分簇算法

针对移动AdHoc网络中传统加权分簇算法(WCA)的缺陷,提出一种稳定且负载均衡的改进型WCA(SLB-WCA).在节点组合权值计算中,增加了考虑节点的稳定性,并提出一种"相对典型节点度"代替传统WCA中的单纯节点度因素,同时根据各个节点的节点度制定本地簇大小约束,代替传统算法中的全局约束.SLB-WCA能够更加合理的计算节点权值和控制簇大小,均衡网络负载.通过实验与传统WCA相比,SLB-WCA形成的簇数目较少且具有良好的覆盖率,提高了网络的生命周期.     

层状Ad Hoc网络的信息传播路由算法研究

讨论了层状移动AdHoc网络的一个信息传播路由算法和基于半马尔可夫过程的节点移动跟踪模型,通过该路由算法可以有效地解决层状子网络间的通信和信息交换。通过路由算法得到的中继节点的移动跟踪模型和计算机仿真,分析了层状移动AdHoc网络的传播性能和路由开销,并得出:当 0≤ρ≤ 1时,层状AdHoc网络的传播性能显著地受到移动呼叫率ρ的影响,当ρ>1时,层状AdHoc网络的传播性能主要取决于移动网络的节点总数、节点移动速度和加速度的结论。     

动态延时的无线多播路由协议

在分析基于共享树的AdHoc网络多播路由协议MAODV的基础上,结合能量模型,提出了一种AdHoc网络基于动态延时的多播路由协议ECBMR。算法分析和仿真结果显示,在不增加算法复杂性的前提下,ECBMR明显地改善了MAODV协议的延时特性,节点的能量消耗比较均衡,一方面降低了系统的能耗,另一方面有效地延长了网络的存活时间,比较好地解决了AdHoc网络能量和延时相互矛盾的问题。     

移动AdHoc网络中基于动态规划法的OoS路由研究

在移动AdHoc网络中,为不同的多媒体应用需求提供QoS保证已经成为一个热点问题。目前,大多数的研究者都将研究点关注于QoS路由的度量选择上,而忽视了移动AdHoc网络自身的能量局限性的问题,而能量又是影响AdHoc网络一个极其关键的因素。因此,在本文中我们使用一种动态规划算法来解决AdHoc网络的电池约束。首先,我们构建了一个基于动态规划法的QoS路由模型,然后分析了该算法的时间复杂度,最后通过仿真验证了本文提出的改进算法的优越性。     

无线自组织网络中CBRP路由算法改进

移动自组织网络(MobileAdHocNetworks)是一种完全由无线移动主机自主构成的通信网络,常用在需要紧急或临时搭建网络的环境下,具有带宽有限和拓扑结构易变等特点。为了提高AdHoc网络路由算法性能,实现并分析了IETF提出的基于层次化“簇”结构的CBRP路由算法协议(ClusterBasedRoutingProtocol),并提出了针对CBRP算法的网关节点选择优化机制和网络结构维护优化策略。最后通过单台计算机对一组具有不同终端节点的网络小区进行仿真。其结果表明,优化后的算法提高了紧急情形和恶劣环境下CBRP路由算法的性能。     

LLACA: An adaptive localized clustering algorithm for wireless ad hoc networks

Performance of ad hoc networks dramatically declines as network grows. Cluster formation in which the network hosts are hierarchically partitioned into several autonomous non-overlapping groups, based on proximity, is a promising approach to alleviate the scalability problem of ad hoc networks. In this paper, we propose a localized learning automata-based clustering algorithm for wireless ad hoc networks. The proposed clustering method is a fully distributed algorithm in which each host chooses its cluster-head based solely on local information received from neighboring hosts. The proposed algorithm can be independently localized at each host. This results in a significantly reduction in message overhead of algorithm, and allows cluster maintenance can be locally performed only where it is required. To show the performance of proposed algorithm, obtained results are compared with those of several existing clustering methods in terms of the number of clusters, control message overhead, clustering time, and load standard deviation.     

HyMN-injection-based multimedia content distribution in hybrid wireless networks

Infrastructured networks typically employ centralized approaches for group management and information provisioning. In contrast to that, in multi-hop ad hoc networks each node acts as a router as well as sender and receiver. In pure ad hoc networks, no Internet access is available. An additional challenge is to deal with mobility that causes network partitioning and re-organizations. Technically, these problems can be tackled by providing additional uplinks to a backbone network. Those can be used to access resources in the Internet as well as to inter-link multiple ad hoc network partitions, creating a hybrid wireless network. In this paper, we present HyMN, a prototypically implemented hybrid wireless network system optimized for multimedia content providing. Within the ad hoc network, adequate devices are elected to maintain uplinks to a backbone, which can provide for instance multimedia news from certain sports events like Football Championships, Olympic Games and alike. In order to efficiently manage the ad hoc communicating devices, a weighted clustering algorithm is employed. Based on an article presented at the 2nd ACM Workshop on Wireless Multimedia Networking and Performance Modeling, WMuNeP 2006, Torremolinos, Málaga, Spain, October 2006.     

基于分簇结构的无线移动网络多播路由协议

移动自组网（MANET，Mobile Ad hoc Networks）是一种特殊的、应用前景广阔的新型移动无线网络。特有的网络特性使它在诸如灾难救助、战场、传感器网络、分布式计算等领域有着广泛的应用前景。结合在移动自组网络中应用最为广泛的分层结构——簇结构的特点，提出了一种基于簇结构的移动自组网多播波路由协议。协议通过对移动自组网进行簇划分，形成由簇头、簇间节点和簇内节点构成的分簇网络结构，并且在由簇头和簇间节点形成的虚拟骨干网基础上，对其进行回路检测和冗余剪枝算法处理，最终得到一个能满足多播要求的多播树，从而实现在移动自组网中的多播路由。通过对仿真实验结果的分析，该协议具有稳定的数据包发送率和较低的路由建立时间。     

Robust self-stabilizing weight-based clustering algorithm

Ad hoc networks consist of wireless hosts that communicate with each other in the absence of a fixed infrastructure. Such networks cannot rely on centralized and organized network management. The clustering problem consists of partitioning network nodes into non-overlapping groups called clusters. Clusters give a hierarchical organization to the network that facilitates network management and that increases its scalability.In a weight-based clustering algorithm, the clusterheads are selected according to their weight (a node’s parameter). The higher the weight of a node, the more suitable this node is for the role of clusterhead. In ad hoc networks, the amount of bandwidth, memory space or battery power of a node could be used to determine weight values.A self-stabilizing algorithm, regardless of the initial system configuration, converges to legitimate configurations without external intervention. Due to this property, self-stabilizing algorithms tolerate transient faults and they are adaptive to any topology change.In this paper, we present a robust self-stabilizing weight-based clustering algorithm for ad hoc networks. The robustness property guarantees that, starting from an arbitrary configuration, after one asynchronous round, the network is partitioned into clusters. After that, the network stays partitioned during the convergence phase toward a legitimate configuration where the clusters verify the “ad hoc clustering properties”.     

移动自组网中基于电源消耗的数据位置管理策略

在移动自组网中,网络频繁的断接使得数据的可访问性低于传统的固定网络中的数据可访问性。当网络中存在一个数据项的多个副本时,应避免对某一个数据项的所有访问都集中在某一台移动主机上,从而防止主机电源耗尽而脱离整个网络,降低数据的可访问性。本文基于对移动主机的电源能力的考虑,提出了一种新的数据项或副本位置管理的方法,有效的避免因为电源耗尽而导致的网络分裂,从而保证了数据的可访问性。     

一种基于地理定位信息的Ad Hoc分簇算法

Ad hoc网络的分簇机制目的是为了利用网络的分级结构来管理众多的移动设备。为了创建和维持一个当节点高速移动时仍然有效的分级结构,必须满足下面的需求:(1)分级结构中每个移动设备能够根据本地信息自动转换它的角色;(2)分级结构的管理负载要小,每个簇内的节点数目要尽可能地相同。该文提出了一个基于地理定位系统的自适应的多跳分簇机制,试验结果表明新的算法不依赖于节点的移动速度和传播范围,满足上面两个要求。     

无线自组网中基于移动预测与功率调整的适应性分簇算法

传送功率控制是无线自组网中资源管理和控制干扰的中心技术.传统上功率控制只是用作消除信道消隐负作用的一种手段,当前观点一般认为功率控制是一种可以为单个用户提供服务质量的灵活机制.提出一种分簇算法以达到减轻网络拓扑的动态变化的同时节省电能.此提案是基于全球定位系统的(GPS).根据移动主机的历史轨迹预测它下一个最可能处在的位置,预先调整传送功率.为了最大化网络的吞吐量,算法自适应性的控制每个簇在合适的大小.在GlomoSim模拟器上仿真了提出的算法.仿真结果表明,它是无线自组网中有效的拓扑管理机制,对由高速运动主机组成的网络特别有效.     

基于分簇位置管理的最优地理路由

分析传统位置管理方案和地理信息路由协议的局限,提出一种K跳分簇位置管理方案,实现了无线节点完整位置信息的维护。基于从该位置管理方案获取的全网拓扑信息,采用启发式搜索算法实现最优地理路由。仿真结果表明,基于分簇位置管理的最优地理路由在移动Ad hoc网络中具有较好的网络性能和较高的可靠性。     

基于移动保持时间的无线自组网分簇算法

无线自组网不依赖固定的基础设施,其最主要的特点是无中心结构和高度的动态变化。本文提出一种新的节点移动保持时间计算方法,并在此基础上开发了最大稳定性加权分簇算法MSWCA,在稳定性、能耗、负载平衡等因素权衡中,侧重考虑簇结构的稳定性,从而进一步提高网络可靠性,有利于更大规模网络的组建。最后探讨了进一步的需要进行研究和改进的问题。     

Energy-efficient clustering in mobile ad-hoc networks using multi-objective particle swarm optimization

A mobile ad hoc network (MANET) is dynamic in nature and is composed of wirelessly connected nodes that perform hop-by-hop routing without the help of any fixed infrastructure. One of the important requirements of a MANET is the efficiency of energy, which increases the lifetime of the network. Several techniques have been proposed by researchers to achieve this goal and one of them is clustering in MANETs that can help in providing an energy-efficient solution. Clustering involves the selection of cluster-heads (CHs) for each cluster and fewer CHs result in greater energy efficiency as these nodes drain more power than noncluster-heads. In the literature, several techniques are available for clustering by using optimization and evolutionary techniques that provide a single solution at a time. In this paper, we propose a multi-objective solution by using multi-objective particle swarm optimization (MOPSO) algorithm to optimize the number of clusters in an ad hoc network as well as energy dissipation in nodes in order to provide an energy-efficient solution and reduce the network traffic. In the proposed solution, inter-cluster and intra-cluster traffic is managed by the cluster-heads. The proposed algorithm takes into consideration the degree of nodes, transmission power, and battery power consumption of the mobile nodes. The main advantage of this method is that it provides a set of solutions at a time. These solutions are achieved through optimal Pareto front. We compare the results of the proposed approach with two other well-known clustering techniques; WCA and CLPSO-based clustering by using different performance metrics. We perform extensive simulations to show that the proposed approach is an effective approach for clustering in mobile ad hoc networks environment and performs better than the other two approaches.