无线网络中的协作路由机制研究

随着无线技术的发展,人们对无线高速通信提出了更高的要求,文中介绍的协作通信技术作为一种利用节点间的协作传输来提高网络的通信质量的新技术,可以显著提高现有网络资源的利用率和数据速率,而有线网络设计的路由协议不能直接应用于无线网络之中,必须有相应的无线路由协议的支持才能在无线网络中实现协作通信,本文通过对现有的路由协作算法进行研究,提出下一步研究的方向和方法,使其能尽快适用于今后的无线网络发展中。     

无线网络中基于位置的能量高效协作路由算法

为了降低无线网络中路由的整体发射功率,该文提出了一种基于位置的能量高效协作路由(LBCR)算法。首先分析了协作链路在一定中断概率要求下的发射功率性能,理论分析表明,合适的协作节点可以降低协作链路的发射功率。在自适应转发分群路由(AFCR)算法的基础上,LBCR算法利用节点位置信息为每跳选择合适的中继节点,然后结合多跳协作策略,建立从源节点到目的节点的协作路由。仿真结果表明,与无协作的AFCR算法和基于一跳协作的MPCR算法相比,LBCR算法可以明显改善路由的整体发射功率。     

一种基于ZigBee协议的DSDV改进型路由算法

大量的研究人员也投入精力研究和改进无线传感网。其中,ZigBee协议在无线传感网中扮演着举足轻重的角色,其可使大量传感器高效互连的能力,是有线网络所不能及的。提出了一种基于ZigBee协议DSDV路由算法的改进型路由算法,根据仿真,改进后的算法在处理存在移动节点通信时有一定的优势。     

无线网络中协作模式选择算法

在无线网络中选择合适的协作模式,可以带来更大的增益,显著提高系统性能。文章提出了一种新的协作模式选择算法,即最大吞吐量选择算法,推导了有碰撞时候的平均吞吐量的表达式,考虑了多种影响系统吞吐量的因素,包括传输出现的误码和碰撞概率,根据最大化系统的吞吐量来选择协作的模式,其中的模式包括直传,放大转发（AF）和编码转发（DF...     

基于位置信息的自组织网络路由算法研究

定位技术的快速发展使得获取位置信息的成本越来越低,此外利用位置信息可以有效降低路由开销,因此,基于位置信息的路由算法逐渐成为自组织网络路由算法的热点。在对现有基于位置信息的路由算法进行分析的基础上,对单播路由算法中贪婪转发算法及空洞处理算法进行研究,并对基于位置信息的多播路由算法及地理区域路由算法作了简要概述。     

移动自组织网络路由选择算法研究进展

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。     

基于博弈的协作路由算法

协作虚拟多输入多输出（VMIMO）传输是一种有效的无线传输性能优化技术。将物理层协作VMIMO技术和网络层路由选择技术相结合,设计跨层VMIMO路由选择方案可以利用VMIMO的分集增益,显著地降低网络传输能耗。如何设计VMIMO协作路由协议抵抗无线网络的自私节点和欺骗行为,保证高数据转发率和低传输能耗成为路由设计中的重大挑战。为了提高自私网络的VMIMO路由性能,提出了一种基于重复路由博弈的VMIMO协作路由算法。该算法将网络划分成多个Group、Group间使用VMIMO传输数据。将Group间路由选择过程建模为重复路由博弈过程。为了提高数据转发的成功率,提出适用度函数评估节点参与数据分组转发的信誉。以此为基础,提出基于适用度的路由选择子算法和路由转发子算法。理论证明所提重复路由博弈可达到帕累托最优。仿真实验结果表明本算法可以促进自私节点相互合作,可获得较高的数据转发率,较好地减少数据传输时延以及能量消耗。     

空间网络多路径路由算法

针对空间网络具有距离远、延时大、周期性间歇连接的特点,提出了一种适用于空间网络的多路径最大吞吐量的路由算法（SMMT）。该算法是对最小费用最大流算法的改进,经过多次最小费用路径查找和残留网络的构造过程,最终可以找出所有满足传输条件的转发路径。仿真实验表明,和传统的ASCOT和S-OSFP单路径路由算法相比,SMMT算法明显提高了网络的吞吐量,减少了数据包的传输时延,使得网络的资源得到充分的利用。     

一种基于演化博弈的分簇协作路由算法

现有的分簇协作路由没有依据协作通信的特点选择簇头,也没能根据簇头节点的服务能力均衡簇成员负载,因而不能充分发挥协作通信能量高效的优势.本文提出了一种基于演化博弈的分簇协作路由算法CCREG.算法首先定义虚节点剩余能量作为簇头确立的指标,然后通过动态演化博弈为簇联盟问题建立模型.簇成员节点选择不同簇头结成联盟,可获得不同的收益.收益由簇头的能力、簇成员节点个数等因素决定.簇成员节点都可以根据自身得到的信息有限理性的选择簇结成联盟,直到网络中所有节点改变簇联盟都不能获得更高的收益.实验结果表明,与协作多输入多输出路由算法CMIMO相比,CCREG算法的网络生存周期在两个簇头情况下延长14%到70%,三个簇头情况下延长5%到80%.     

无线网络中基于网络编码的路由算法

网络编码为无线网络带来了更高的可靠性,二者的结合已经引起了很多研究学者的关注,无线网络中基于网络编码的路由算法更是值得探讨和研究的问题,本文在网络编码的基础上分别对网络编码的多路径路由算法和编码感知的路由算法进行了分析和研究,以期实现提高无线传输效率的目标。     

Cooperative Routing in Static Wireless Networks

We study the problem of transmission-side diversity and routing in a static wireless network. It is assumed that each node in the network is equipped with a single omnidirectional antenna and that multiple nodes are allowed to coordinate their transmissions in order to obtain energy savings. We derive analytical results for achievable energy savings for both line and grid network topologies. It is shown that the energy savings of and are achievable in line and grid networks with a large number of nodes, respectively. We then develop a dynamic-programming-based algorithm for finding the optimal route in an arbitrary network, as well as suboptimal algorithms with polynomial complexity. We show through simulations that these algorithms can achieve average energy savings of about in random networks, as compared to the noncooperative schemes.     

无线传感器网络能量均衡路由算法

设计了一种能量均衡的路由算法.路由的建立分两个阶段,在簇头建立阶段,让候选节点在覆盖范围内以剩余能量的多少和所处位置为标准来竞选簇头,以使簇头分布均匀,平衡网络覆盖;在通信阶段,根据簇头节点的剩余能量大小和其距离基站的远近,采用多跳的簇间通信方式建立路由,以此来降低簇头节点的通信负载.仿真结果表明该算法能够有效降低网络能耗和延长网络生存时间.     

一种无线传感器网络自适应协同通信路由协议

无线传感器网络的重要应用特性是具有感测信息的传感节点形成一个自适应本地网络,由中心节点执行不同的协作信息处理任务。该文基于互信息量分析了不同中心节点选择机制的开销性能,证明了基于扩散计算的选择机制的开销有效性;提出一种自适应协同通信路由协议(ACCRP)：节点以分布式的方式选择中心节点并建立传输路径;分析讨论了ACCRP的性能参数;并通过实验验证了ACCRP是能源有效的、可扩展的自适应路由协议。     

Cooperative Protocols Design for Wireless Ad-Hoc Networks with Multi-hop Routing

Wireless ad-hoc networks can experience significant performance degradation under fading channels. Spatial diversity has been shown to be an effective way of combating wireless fading with the multiple-input multiple-output (MIMO) technique by transmitting correlated information through multiple antennas. The virtual MIMO technique, which allows multiple wireless stations with single antenna to form a virtual transmission array, is shown to be a viable solution from several recent studies. In this paper, we propose a complete system framework for wireless ad-hoc networks utilizing two different cooperative relaying techniques at the physical layer: the repetition coding and the space-time coding. In the data link layer, two medium access control protocols are proposed to accommodate the corresponding physical layer cooperative diversity schemes. In the network layer, diversity-aware routing protocols are proposed to determine the routing path and the relaying topology. Simulations with both constant bit rate and TCP (transmission control protocol) traffic show significant performance gains of the proposed cooperative relaying schemes.     

无线传感器网络基于梯度的分簇路由算法

无线传感器网络中节点的能量是有限的,而且一般不能补充能量.所以如何最大化节点能量的利用率,延长整个传感器网络的生命周期,一直是无线传感器网络的一个研究热点.本文针对Leach路由算法的不足,提出一种新的基于能量考虑的梯度分簇路由算法.最后通过OMNET++仿真试验,来验证新的路由算法的优越性.     

On Throughput Efficiency of Geographic Opportunistic Routing in Multihop Wireless Networks

Geographic opportunistic routing (GOR) has shown throughput efficiency in coping with unreliable transmissions in multihop wireless networks. The basic idea behind opportunistic routing is to take advantage of the broadcast nature and spacial diversity of the wireless medium by involving multiple neighbors of the sender into the local forwarding, thus improve transmission reliability. The existing GOR schemes typically involve as many as available next-hop neighbors into the local forwarding, and give the nodes closer to the destination higher relay priorities. In this paper, we show that it is not always the optimal way to achieve the best throughput. We introduce a framework to analyze the one-hop throughput of GOR, provide a deeper insight into the trade-off between the benefit (packet advancement and transmission reliability) and cost (medium time delay) associated with the node collaboration, and propose a local metric named expected one-hop throughput (EOT) to balance the benefit and cost. We also identify an upper bound of EOT and its concavity, which indicates that even if the candidate coordination delay were negligible, the throughput gain would become marginal when the number of forwarding candidates increases. Based on the EOT, we also propose a local candidate selection and prioritization algorithm. Simulation results validate our analysis and show that the EOT metric leads to both better one-hop and path throughput than the corresponding pure GOR and geographic routing.     

Joint Channel Assignment and Routing for Throughput Optimization in Multiradio Wireless Mesh Networks

Multihop infrastructure wireless mesh networks offer increased reliability, coverage, and reduced equipment costs over their single-hop counterpart, wireless local area networks. Equipping wireless routers with multiple radios further improves the capacity by transmitting over multiple radios simultaneously using orthogonal channels. Efficient channel assignment and routing is essential for throughput optimization of mesh clients. Efficient channel assignment schemes can greatly relieve the interference effect of close-by transmissions; effective routing schemes can alleviate potential congestion on any gateways to the Internet, thereby improving per-client throughput. Unlike previous heuristic approaches, we mathematically formulate the joint channel assignment and routing problem, taking into account the interference constraints, the number of channels in the network, and the number of radios available at each mesh router. We then use this formulation to develop a solution for our problem that optimizes the overall network throughput subject to fairness constraints on allocation of scarce wireless capacity among mobile clients. We show that the performance of our algorithms is within a constant factor of that of any optimal algorithm for the joint channel assignment and routing problem. Our evaluation demonstrates that our algorithm can effectively exploit the increased number of channels and radios, and it performs much better than the theoretical worst case bounds     

无线 Mesh 网络中多路径路由算法的研究

针对无线 Mesh 网络中传统单径路由协议的不足,提出一种基于动态源路由协议(DSR)的多路径路由算法(IDSR).该算法通过在路由发现过程引入带宽和最大转发次数等限制条件,保证了多条路由请求信息的获取;通过在节点不相交的多径选择过程中引入多 QoS 路由代价函数,有效地实现多路径的选择;通过提供多 QoS 保障,使算法具有较高的求解效率,避免了单径路由的不稳定等特点.实验结果表明,IDSR 算法在无线 Mesh 网络的路由中具有更好的 QoS 性能.     

一种能量有效的无线传感器网络路由算法

无线传感器网络中传感器节点能量有限,为了提高能量利用率,针对现有算法随机选择簇首、簇结构不合理等缺陷提出了一种新的能量有效的分簇路由算法EERA.EERA采用新的簇首选举、成簇,以及构建簇间路由算法,基于节点剩余能量与节点的相对位置选择簇首、成簇,使剩余能量较多的节点优先成为簇首并且各簇首能较均匀的分布在网络区域内;构建簇间路由时将最小跳数路由算法与改进的MTE算法结合起来,在簇间形成最小跳数、最小能耗路径.仿真结果表明,EERA算法可以均衡全网能量消耗,延长网络的生命周期.