MANET分簇策略的仿真研究与实现

无线移动自组织网络（MANET）是一种无需基础设施支持的无线网络,而MANET分簇策略的性能研究有着广泛的应用。本文对MANET分簇策略仿真平台进行研究与实现,并对现有的MANET分簇算法进行仿真分析。本文所提出的平台不仅能统计和分析分簇策略的性能,还能对MANET分簇过程的实时状态进行仿真和输出。与现有的通用型网络模拟平台相比,该平台是针对MANET所设计的,具有交互性好、可扩性强、便于分簇策略优化改进等特点。     

MANET网络分簇组网协议比较与分析

基于分簇结构的MANET网络不依赖固定基础设施即可以实现动态组网与数据传输,可以通过跨簇节点实现大规模组网。对分簇组网协议与算法进行了分析与介绍,在此基础上基于最大连接度算法提出了一种解决分簇组网中跨簇处理的双信道跨簇策略。最大连接度算法能够在保障网络的稳定性的同时提高跨簇通信的效率,双信道跨簇处理有利于实现网络的分层管理与控制,组成与逻辑关系一致的实体网络,网络之间在保持通联的同时具备较高的独立性,传输效率更高。     

WSN中引入移动节点的路由协议设计与仿真

对于节点部署不均或者节点死亡而导致的监测盲区,可通过在WSN中引入移动节点来修复。提出一种修复策略,可较为及时、准确地修复监测盲区,同时考虑节点的能量均衡问题。在LEACH-M分簇路由算法的基础上,给出了一种按节点能量分配工作量的能量均衡分簇路由算法LEACH-M-G,并运用MATLAB仿真工具进行了仿真分析。仿真结果表明,所提出的监测盲区修复策略、以及LEACH-M-G路由能有效地修复监测盲区,均衡网络能量、延长网络生命周期。     

一种新型的 Ad Hoc 网络按需加权分簇算法

提出了一种新型的适用于 Ad Hoc 网络的按需加权分簇算法，根据节点的权值来进行簇 的划分，在计算权值时，综合考虑节点度，节点的能量和移动性等多方面因素。为了提高网络体系结构 的稳定性，减少计算和通信开销，采用按需策略来完成簇结构的维护。首先介绍了2种典型的分簇算 法，然后详细说明了新型的按需加权分簇算法并利用仿真实验对3种分簇算法进行了比较。仿真结果 表明，按需加权分簇算法的性能优于另外2种分簇算法。     

面向高动态移动自组织网络的生物启发分簇算法

分簇可以有效地提高大规模移动自组织网络的性能.但高动态的移动自组织网络具有节点移动性强、网络拓扑变化快的特点,应用传统的分簇算法会造成网络性能迅速下降,频繁的簇拓扑更新造成了簇结构的不稳定和控制开销的增加.为了解决传统分簇算法无法适应高动态的大规模移动自组织网络的问题,提出了一种基于生物启发的移动感知分簇算法,该算法对多头绒泡菌的觅食模型进行了改进,使其适用于移动自组织网络领域.由于该算法与节点的移动特性进行了结合,所以该算法可以有效地在高动态移动自组织网络中进行簇的建立与维护.实验结果表明,相较于其他传统分簇算法,本文算法提高了平均链路连接保持时间和平均簇首保持时间,使得簇结构更加稳定,提高了对高动态、大规模移动自组织网络的适应能力.     

移动自组织网络预测分簇算法的路由协议

针对移动自组织网络中传统分簇算法存在稳定性低、网络开销大的问题,在WCA分簇算法的基础上,提出一种带有预测机制的EWCA-MP(Efficient on-demand Weighted Clustering Algorithm using Mobility Prediction)分簇算法,该算法在簇头选择时充分考虑节点间的链路保持时间,在簇维护阶段引入模糊逻辑的概念,对Hello消息包的广播周期进行优化。并将其应用于CBRP中,提出了一种ECBRP-MP(Efficient Cluster Based Routing Protocol using Mobility Prediction)移动预测的分簇路由协议。仿真结果表明,EWCA-MP算法在簇头数目、单位时间内节点转移次数和统治集更新次数明显减少,ECBRP-MP路由协议在路由开销、分组投递率的性能得到优化。     

无线自组网的分簇算法研究

分簇算法是构造分级网络结构的关键技术,它的好坏直接影响着无线自组网的性能。本文介绍了无线自组网中分簇算法提出的背景,并阐述了分簇算法的原则和目标,并对无线自组网现存的多种分簇算法进行了详尽的分类介绍和比较分析,包括有簇头和无簇头、单跳簇和多跳簇、主动分簇和被动分簇算法等。最后,对簇维护策略进行了简要说明。     

基于分布式密钥共享的UWSN安全分簇方案

针对无照料的无线传感网（UWSN, unattended wireless sensor network）收集效率和安全问题,提出一种安全的UWSN分簇方案,实现了一种三角形网格图的网络拓扑分簇算法,并可完成簇头对移动节点的认证。该方案利用三角形的性质提高了网络的连通度,折中数据收集效率与能耗;将分布式密钥共享方案与分簇算法无缝结合,在网络中高效地搜索移动节点公钥信息,从而在本地不存有对应公钥信息的情况下验证签名信息。实验结果表明,该算法在节点密度越大的情况下分簇越趋近于正三角形网格图,且分簇后的网络对于低于20%节点变节有95%以上概率抵御攻击。     

一种基于网络密度分簇的移动信标辅助定位方法

现有移动信标辅助定位算法未充分利用网络节点分布信息,存在移动路径过长及信标利用率较低等问题。该文把网络节点分簇、增量定位与移动信标辅助相结合,提出了一种基于网络密度分簇的移动信标辅助定位算法(MBL(ndc))。该算法选择核心密度较大的节点作簇头,采用基于密度可达性的分簇机制把整个网络划分为多个簇内密度相等的簇,并联合使用基于遗传算法的簇头全局路径规划和基于正六边形的簇内局部路径规划方法,得到信标的优化移动路径。当簇头及附近节点完成定位后,升级为信标,采用增量定位方式参与网络其它节点的定位。仿真结果表明,该算法定位精度与基于HILBERT路径的移动信标辅助定位算法相当,而路径长度不到后者的50％。     

基于分环多跳的无线传感网分簇路由算法

为了提高无线传感网在大区域情形下的能量效率,提出了一种分环多跳分簇路由算法RBMC(ring based multi-hop clustering routing algorithm).RBMC算法采用分环的方式实现簇头间的多跳通信,通过在不同环内构建大小不同的簇解决传感器网络中存在的"热点"问题,在不同的簇头选举策略下,能够同时满足节点能量同构及异构两种情形.仿真结果表明,在大区域环境下,分环多跳分簇路由算法能在很大程度上均衡节点能量消耗,延长网络的生命周期.     

Double Q-learning-based adaptive trajectory selection for energy-efficient data collection in wireless sensor networks

This paper proposes a novel distributed stochastic routing strategy using mobile sink based on double Q-learning algorithm to improve the network performance in wireless sensor network with uncertain communication links. Furthermore, in order to extend network lifetime, a modified leach-based clustering technique is proposed. To balance the energy dissipation between nodes, the selected cluster head nodes are then rotated based on the newly suggested threshold energy value. The simulation results demonstrate that the proposed algorithms outperform the QWRP, QLMS, ESRP and HACDC in terms of network lifetime by 18.33%, 35.1%, 39.7% and 44.7%, respectively. Moreover, the proposed algorithms considerably enhances the learning rate and hence reduces the data collection latency.     

3G时代移动网络运营商的商业生态系统战略

 本文将商业生态系统的概念运用于移动通信产业,以帮助移动网络运营商制定其3G（第三代移动通信）时代的发展战略。文章首先根据商业生态系统的定义,分析了移动网络运营商的生态系统结构,指出运营商作为生态系统中的重要连接点,在战略上应定位为骨干型企业,并总结了骨干型企业战略的要点,最后对中国移动网络运营商的发展提出了建议。     

无线传感器网络分簇算法分析与性能比较

文中在介绍无线传感器网络路由协议的基础上,重点分析了几种有代表性的分簇路由协议算法。然后对各种分簇算法从10个评价参数上进行了一个综合对比,总结了无线传感器网络现有分簇路由协议的优点和存在的问题。最后从网络安全性和协议的实用性等方面,并对无线传感器网络分簇路由协议算法进行了展望。     

Business Ecosystem Strategies of Mobile Network Operators in the 3G Era

This paper applies the perspective of business ecosystem to mobile communications industry,trying to help mobile network operators improve their strategies in the era of the third generation mobile communications(3G).According to the definition of the business ecosystem,the ecosystem structure of mobile network operators is analyzed.As an important hub in the ecosystem,mobile network operators are advised to take a keystone strategy.The key points of the strategy are summarized.Finally,suggestions for Chine...     

一种基于两级许可的过载控制改进算法

文中对智能网过载控制的三种典型算法进行了分析,根据仿真结果及其特点,总结了各算法的优点。针对适用于移动智能网的基于两级许可证的漏桶算法,提出了一种改进措施,并建立了系统模型。仿真结果表明,该算法在数据丢失率、平均呼叫等待时间等方面均要优于两级许可的单速率漏桶算法。     

Network planning for mobile multi‐hop relay networks

In this paper, the coverage problem of network planning in mobile multi‐hop relay networks is defined on the basis of integer linear programming. In order to provide desired utilities and also meet deployment limitations for network planning, we propose a supergraph tree algorithm to place base stations and relay stations at the lowest cost position. Furthermore, another algorithm for avoiding the interference between base stations, which is called interference aware tree algorithm is also proposed. Both the proposed algorithms are formulated on the basis of a graph theoretic technique and analyzed in the simulation results. The results show that the supergraph tree algorithm provides the lowest construction cost with different network scenarios, and the interference aware tree algorithm provides the highest communication quality for mobile multi‐hop relay infrastructure‐based communication network planning. Copyright © 2013 John Wiley & Sons, Ltd.     

An Improved Weighted Clustering Algorithm in MANET

The original clustering algorithms in Mobile Ad hoc Network(MANET)are firstly analyzed in this paper.Based on which,an Improved Weighted Clustering Algorithm(IWCA)is proposed.Then,the principle and steps of ouralgorithm are explained in detail,and a comparison is made between the original algorithms and our improved method inthe aspects of average cluster number,topology stability,clusterhead load balance and network lifetime.The experimentalresults show that our improved algorithm has the best performance on average.     

Non‐cooperative game‐based packet ferry forwarding for sparse mobile wireless networks

In sparse mobile wireless networks, normally, the mobile nodes are carried by people, and the moving activity of nodes always happens in a specific area, which corresponds to some specific community. Between the isolated communities, there is no stable communication link. Therefore, it is difficult to ensure the effective packet transmission among communities, which leads to the higher packet delivery delay and lower successful delivery ratio. Recently, an additional ferry node was introduced to forward packets between the isolated communities. However, most of the existing algorithms are working on how to control the trajectory of only one ferry work in the network. In this paper, we consider multiple ferries working in the network scenario and put our main focus on the optimal packet selection strategy, under the condition of mutual influence between the ferries and the buffer limitation. We introduce a non‐cooperative Bayesian game to achieve the optimal packet selection strategy. By maximizing the individual income of a ferry, we optimize the network performance on packet delivery delay and successful delivery ratio. Simulation results show that our proposed packet selection strategy improves the network performance on packet delivery delay and successful delivery ratio. Copyright © 2013 John Wiley & Sons, Ltd.     

移动WiMAX网络的移动IP机制分析

移动IP是移动WiMAX核心网络中的关键技术.本文分别从Client Mobile IP(CMIP)和ProxyMobile IP(PMIP)两种方式阐述移动IP在移动WiMAX网络中的实现原理,并对这两种方式进行了比较分析,最后从移动WiMAX网络运营的角度,对移动IP的具体实现进行了探讨并提出建议.