无线网状网路由协议的研究与对比

路由协议是网络一个很重要的课题,对无线网状网来说,由于无线网状网的复杂性,无线网状网路由协议的设计比有线网络的路由协议设计更加困难,因此,对无线网状网路由协议进行研究、改进十分必要。主要介绍无线网状网典型的路由协议,通过仿真实验比较它们的性能并展望路由协议发展的方向。     

无线自组织网络中动态源路由协议的移动性分析

针对移动性对无线网的影响,相关研究工作都需要定性、定量地对路由协议进行分析。由于动态源路由(DSR)协议在Ad hoc网络中应用广泛,对其进行实验分析就显得非常有意义。在实验的数据结果上,给出了无线网络吞吐量、平均端到端时延以及丢包率的性能对比,并且对协议改进进行了展望。     

无线网络中的动态源路由协议

在无线网络迅速发展的今天,为实现无线网络中节点间的正常通讯,路由技术成为研究的关键。本文介绍了新型的无线移动网络———Ad Hoc网络的工作原理;分析了Ad Hoc网络中常见的两种路由机制:表驱动路由协议(Table-Driven Routing)和按需驱动路由协议(On-Demand,DSR);着重对典型的按需(On-demand)AD Hoc网络路由协议(Dynamic Source Routing,DSR)进行了分析和研究,并详细介绍了DSR协议进行通讯的各节点需要维护的四个数据结构:路由缓存(route cache)、发送缓冲区(send Buffer)、路由请求表(route request)和路由应答表(route reply table)的设计与实现。     

基于路由生命期的动态源路由协议

无线Ad hoc网络拓扑结构的频繁变化以及无线信道的不稳定,使得如何提高路由可靠性成为无线Ad hoc网络路由协议研究的主要目标之一.在动态源路由协议(Dynamic Source Routing,以下简称DSR)基础上提出一个新的基于路由生命期估计的Ad hoc网络路由协议,REBDSR(Route-lifetime Estimation Based Dynamic Source Routing).该协议通过对链路状态预测估计路由生命期;路由发现算法同时使用路由生命期、路由跳数作为路径选择参数;当路由上的链路进入危险期后,启动主动式路由维护机制,发送路由失效警告以保证快速路由切换.REBDSR还以路由生命期为超时值进行路由缓存管理,解决了DSR路由缓存中存在较多过时路由的问题.大量仿真实验表明:在网络中载和重载情况下,REBDSR协议的整体性能要优于DSR协议,特别是在节点运动频繁的网络中,REBDSR协议的性能优势更为明显.     

无线传感器网络路由协议研究

无线传感器网络是由大量微型传感器节点组成的一个自组织的网络系统,路由协议是具关键技术之。在综合大量路由协议和算法文献的基础上,对现有的无线传感器网络路由协议进行了归纳,初步对其进行了分类,介绍了几个典型的方案,并对各种方案进行了分析,指出了其优缺点和发展趋势。     

基于802.11的多信道无线网状网络的路由

无线网状网络(WirelessMeshNetworks,WMNs)已经成为下一代无线网络的研究热点,其中采用何种策略进行路由选择以使网络吞吐量最大成为目前研究的关键问题。论文分析了现有的无线网状网络路由选择策略,并在此基础上综合考虑了跳数、信道质量、链路间的多信道必然干扰以及潜在干扰,提出了一种新的路由尺度WCETTR。仿真表明,该方法能够显著地提高网络吞吐量。     

无线传感器网络的路由协议

无线传感器网络是一种全新的信息获取和处理技术,路由协议是其组网的基础;在综合大量路由协议和算法文献的基础上,对现有的无线传感器网络路由协议进行了归纳,初步对其进行了分类,介绍了几个典型的方案,并对各种方案进行了对分析,指出了其优缺点和发展趋势.     

基于簇的动态源路由协议研究

AdHoc网络是一种自组织的、由移动节点组成的、动态变化的多跳无线网络。该文首先对簇进行了介绍,并提出CD-SR是基于WCA的DSR路由协议;然后讲解了CDSR的主要设计思想：路由发现是在簇头之间进行的,簇间的通信需要借助于簇头（不存在网关）;同时用GloMoSim模拟仿真工具,对CDSR与DSR的性能进行了分析和评价,并且得出CDSR协议较DSR协议具有高的投递率和吞吐率、低的延迟及较好的扩展性,更适合大规模自组无线网络;最后讨论了它的缺点。     

基于树形拓扑的无线Mesh网络路由协议研究

研究和分析了无线Mesh网络路由协议及其特点,提出了无线Mesh网络路由协议设计原则.遵循这些原则,充分利用Mesh网络全相连的优点构建出树形逻辑拓扑结构,该拓扑结构能满足无线Mesh网络业务特点的要求.在该拓扑树基础上设计了一种基于树形拓扑的无线Mesh网络路由协议(TTRP),该协议采用无开销的源地址学习方式构建路由相关表项,快速链路切换和路由重定向机制大大提高了TTRP路由协议的健壮性和网络的抗毁性.网络仿真结果表明了该路由协议的可行性.     

基于链路质量的无线传感器网络任播路由协议

无线传感器网络(WSN)中,由于无线链路的链路质量问题,经常有传递失败导致重传耗费能量的现象出现。传统任播路由协议只以路由距离作为路由判据,而没有讨论链路质量问题,将其应用在WSN中会造成路由权重设置不合理。提出了基于链路质量的WSN任播路由协议,该协议在讨论链路质量的计算之上,以能耗均衡和系统能耗最小这两个因素决定任播路径的路由权重,并以参数α来权衡两者之间的关系。实验证明,在WSN中,相比传统任播路由协议,该协议能更有效地均衡能耗,减少系统能耗,从而优化网络生存期。     

基于遗传算法的无线网状网QoS多播路由算法

探讨了基于遗传算法的无线网状网QoS多播路由算法,选用边集表示方式对多播树进行编码,其空间复杂度为O(N),给出了该编码方式下的初始种群生成算法RandWalkMT,同时对传统的遗传操作进行改进使子代个体中不会产生非法多播树,从而避免了复杂的惩罚机制或多播树修复算法。实验表明该算法收敛快且性能较好。     

A quality based routing protocol for wireless mesh networks

Wireless mesh networks can provide low-cost solutions for extending the reach of wireless access points by using multi-hop routing over a set of stationary wireless routers. The routing protocol for these networks may need to address quality considerations to meet the requirements of the user. In this paper, we present a quality based routing protocol for wireless mesh networks that tries to maximize the probability of successful transmissions while minimizing the end-to-end delay. The proposed routing protocol uses reactive route discoveries to collect key parameters from candidate routes to estimate the probability of success and delay of data packets transmitted over them. To achieve accurate route quality assessments, a new route quality metric is proposed that uses performance models of data packet transmissions as opposed to estimating route quality from the transmission of control packets, which have different transmission characteristics. These models are developed after careful evaluations of multi-hop wireless transmissions and validated by computer simulations. Relevant parameters that can be used to assess the route quality metric using these models are explained. Extensive performance evaluations of the proposed quality based routing protocol are presented and its benefits in comparison to some other known routing protocols are discussed.     

Wireless mesh networks based on CDMA

In this paper, we study hybrid contention-free/contention-based traffic management schemes in presence of delay-sensitive and delay-insensitive data in multihop CDMA wireless mesh networks. We suggest a greedy incremental contention-based ordering algorithm for contention-free schedules and also propose a time-scale-based framework for integration of contention and contention-free traffic management schemes. Further, for the contention-free phase, we propose a power control algorithm that gives an end-to-end throughput guarantee. With the aid of simulation, we observe the additional end-to-end throughput that can be achieved when scheduling and tight power control are applied.     

XCHARM: A routing protocol for multi-channel wireless mesh networks

Recent experimental results have pointed out the impact of physical layer multi-path fading and co-channel interference as the key factors influencing packet delivery among mesh routers (MRs) in wireless mesh networks. In addition, in a multi-channel environment, there exists significant power spectral overlap among channels used by MRs, leading to adjacent channel interference. In this paper, a cross-layer multi-radio, multi-channel routing protocol, XCHARM, is proposed in which the key contribution is the selection of the next hop, channel and transmission rate based on fading and interference concerns. The key features of our proposed protocol are as follows: (i) Routes are chosen based on the availability of channels that support high data rates, exhibit acceptable interference levels and long term resilience to fading related losses, (ii) The path latency is analytically calculated in advance for the candidate routes, accounting for channel induced errors, link layer contention, forward error correcting (FEC) codes, and the allowed data rates over the chosen channels, (iii) The route maintenance is performed by first attempting to identify and correct the point of failure before undertaking a global recovery action. An extensive performance evaluation, spanning the network, link and physical layers, reveals the benefits of adopting our cross-layer routing solution for wireless mesh networks.     

REUSE: A combined routing and link scheduling mechanism for wireless mesh networks

Increasing the capacity of wireless mesh networks has motivated numerous studies. In this context, the cross-layer optimization techniques involving joint use of routing and link scheduling are able to provide better capacity improvements. Most works in the literature propose linear programming models to combine both mechanisms. However, this approach has high computational complexity and cannot be extended to large-scale networks. Alternatively, algorithmic solutions are less complex and can obtain capacity values close to the optimal. Thus, we propose the REUSE algorithm, which combines routing and link scheduling and aims to increase throughput capacity in wireless mesh networks. Through simulations, the performance of the proposal is compared to a developed linear programming model, which provides optimal results, and to other proposed mechanisms in the literature that also deal with the problem algorithmically. We observed higher values of capacity in favor of our proposal when compared to the benchmark algorithms.     

基于协商机制的无线传感器网络路由协议

针对事件驱动型无线传感器网络（WSNs）中存在的次生驱动等问题,提出了一种基于分布式协商机制的WSNs路由协议。该协议通过抑制冗余节点发送数据来减少网内流量。仿真结果表明：该协议能够有效减少事件汇报的时间,减少系统能量消耗。     

基于负载均衡的DSR改进路由协议

提出了一种高效的双通道的源动态路由协议(DDSR),以适应NGN中各网融合、终端频繁移动、高速率传输的特点,满足MANET网络自身负载均衡的需求.DDSR使用两条有安全距离的独立路由,分别传输不同的数据包.OPNET网络仿真的性能指标分析表明:在较高负载的情况下,DDSR比DSR在吞吐量、有效数据包传输比率与网络生存时间上分别提高了20%,10%和28%.     

Optimal joint routing and link scheduling for real-time traffic in TDMA Wireless Mesh Networks

We investigate the problem of joint routing and link scheduling in Time-Division Multiple Access (TDMA) Wireless Mesh Networks (WMNs) carrying real-time traffic. We propose a framework that always computes a feasible solution (i.e. a set of paths and link activations) if there exists one, by optimally solving a mixed integer-nonlinear problem. Such solution can be computed in minutes or tens thereof for e.g. grids of up to 4 × 4 nodes. We also propose heuristics based on Lagrangian decomposition to compute suboptimal solutions considerably faster and/or for larger WMNs, up to about 50 nodes. We show that the heuristic solutions are near-optimal, and we exploit them to gain insight on the schedulability in WMN, i.e. to investigate the optimal placement of one or more gateways from a delay bound perspective, and to investigate how the schedulability is affected by the transmission range.     

一种基于AODV路由协议改进的无线Mesh路由协议

在分析经典路由协议AODV的基础上,结合Mesh网络的特点,提出了一种新的路由协议AODV-LS.新的路由协议根据节点带宽以及实时负载量这两个参数计算出节点权重值,根据节点权重值评估链路的性能,根据链路性能选择最优路径.实验结果表明,AODV-LS协议在数据分组投递率、端到端延时和标准化路由负载方面都优于AODV.     

无线Mesh网络路由协议的研究进展

在简要介绍无线Mesh网络特性的基础之上,对路由协议中若干关键技术的研究状况进行了总结和综述,重点讨论面向无线Mesh网络的路由度量的设计思路、多信道多无线接口环境下节点的自适应信道分配策略以及结合无线介质的广播特性的寻路算法的分析.详细讨论了上述因素对于路由协议性能的具体影响,深入分析了当前研究的优缺点.同时,鉴于无线链路上传输的不可靠和高误码率,详细介绍了跨层协议设计的相关内容.