最小跳数路由无线传感器网络中的节点距离测量

无线传感器网络中的间接距离测量是一种性价比极高的距离测量方法,但目前测量精度还有待进一步提高。根据最小跳数路由无线传感器网络的行为特征,提出了一种基于最小跳数路由及其路由重复数的节点距离测量算法,与DV-hop算法相比,借助路由重复数较大地提高了距离测量精度。理论分析及仿真结果表明,该算法在节点密集分布的无线传感器网络中具有很好的效果。     

最小跳数路由无线传感器网络行为特征研究

在无线传感器网络（WSN）中，一般借助消息的重复传送来提高网络的可靠性，但消息的重复传送会劣化网络的其他性能，为解决这一矛盾，有必要弄清具体网络运行时的特点。通过理论分析及仿真验证，揭示了最小跳数路由无线传感器网络的行为特征，找出了影响网络中消息重复传送程度的因素及其影响规律，为最小跳数路由无线传感器网络中消息重复传送程度的保证与控制提供了理论指导。     

最小跳数路由无线传感器网络仿真研究

为提高最小跳数路由(MHR)无线传感器网络的综合性能,通过仿真分析,揭示了传统最小跳数路由无线传感器网络存在的缺陷,极低开销地提取了改进传统最小跳数路由网络所需的相关信息,并讨论了可能的改进策略,给出了改进前后的性能比较.理论分析和仿真结果表明,利用廉价提取的网络行为特征信息对传统的最小跳数路由无线传感器网络进行改进,能提高网络的可靠性、能源有效性以及其综合性能.     

一种改进的无线传感器网络最小跳数路由协议

针对无线传感器网络最小跳数路由协议数据包多路径冗余传输,能量消耗不均衡等问题,提出了一种改进的无线传感器网络最小跳数路由协议。该协议通过引入侦听机制在网络中建立传输路径,同时采用一种新的能量均衡策略解决关键节点能耗过快的问题,以有效延长网络寿命。通过自主研发的无线传感器网络仿真平台进行仿真,比较最小跳数路由协议和改进协议的性能。实验结果表明:改进协议能够很好的均衡网络能量消耗,提高网络能量有效性,延长了网络寿命。     

一种改进的基于跳数的无线传感器网络路由算法

路由协议设计是无线传感器网络的一个重要研究领域,可靠性、低开销和易于维护是无线传感器网络路由协议的设计目标,其中基于跳数的路由协议以其简易、有效的设计思路,一直以来得到广泛关注。在详细分析基于跳数的无线传感器路由协议发展现状的前提下,对最小跳数路由算法的组网和数据传播阶段加以改进。通过在OMNeT++仿真环境中与原始最小跳数协议、定向扩散协议的比较,验证了改进后的算法在可靠性、负载均衡、延长网络生命周期和低路由开销方面的优势。     

低能耗最小阻力组播路由算法研究

阐述了跳频无线传感器网络的概念;综合考虑无线链路阻力和数据转发跳数因素,设计了一种适用于跳频无线传感器网络的组播路由算法,即低能耗最小阻力组播路由算法;最后对该组播路由算法的性能进行了分析。     

簇中基于最小跳数的路由方法

由于无线传感器网络节点能量有限和存储能力有限,因此节能高效的实现路由转发是其路由设计的一个关键点.它首先总结了目前已有的无线传感器网络的传输路由模式,在已有的基于簇的分层路由机制的基础上,结合平面路由基于最小跳数的思想,提出了一种新的路由转发模式,即在建立的簇中采用最小跳数路由法.节点只要记忆自己的转发节点集,就可以沿着最短路径向簇头发送数据.仿真结果显示新模式有更好的节能效果,延长了网络的生存时间.     

基于动态规划的无线传感器网络的路由算法

路由问题是无线传感器网络中的核心问题之一,其数据传送的多跳特点使得非常适合用动态规划的原理来设计传感器网络的路由算法.基于动态规划,通过节点跳数生成算法为传感器网络中的每个节点赋一个表示到Sink点跳数的节点跳数值,并分析了传感器网络的拓扑结构特点,然后给出了无线传感器网络中寻找从源到汇满足不同设计目标的最小跳数(MinH)、最小跳数最大剩余能量(MinHMaxRE)和最小跳数最小费用(MinHMinC)3种路由算法.探讨了最小跳数最小费用路由与最小费用路由之间的关系,并给出了判断最小跳数最小费用路径就是最小费用路径的一个充要条件.算法的能量消耗分析表明,所给路由算法能实现大幅度的能量节省.     

井下无线传感器网络最小跳数路由改进算法研究

针对经典无线传感器网络最小跳数路由算法存在节点能耗高、网络生存周期较短的问题,提出了一种最小跳数路由改进算法。该改进算法在梯度场建立阶段设置节点延时计时器;在数据传输阶段综合考虑节点能耗的有效性和均衡性,依据能量代价函数,动态选择唯一中继节点,构建一条从信源节点到Sink节点能量代价最小的路径。仿真结果表明,该改进算法进一步降低了节点能耗,延长了网络寿命,能够满足井下无线传感器网络路由需要。     

基于最小跳数的无线传感器网络路由协议

高效地实现路由转发是无线传感器网络路由设计的一个关键点。该文在现有基于簇的分层路由机制的基础上,提出一种基于最小跳数的路由转发模式,其核心是在建立的簇中采用最小跳数路由算法。该算法简单、易扩展,簇内节点只要记忆各自一跳范围内的转发节点集,就能沿最短路径向簇首发送数据。仿真结果表明,该模式节能效果较好,延长了网络寿命。     

基于图论模型的一类集成电路布线算法

针对具有曼哈顿模型的一类通道布线,提出了一个依据图论模型的最优轨道高度布线算法。算法根据通道上结点的水平约束图和垂直约束图,依次安排好每一个结点的布线轨道,进而通过通孔可以把所有的结点在2层轨道上布线完成。通过计算分析,该算法相对以前的算法能够达到更优的布线高度,并且其复杂性保持不变。     

Self-healing routing: failure,modeling and analysis

Network failures occur frequently, and self-healing ability of existing routing protocols cannot guarantee fast route convergence under these failures without impacting packet forwarding. During routing convergence, network routes may be incorrect and even routing black holes and loops occur, which will result in extensive packet loss and thus influence network performance. To solve this problem, several improved routing solutions have been proposed. In this paper, we propose the concept and model of self-h...     

Non-derivative algorithm design for efficient routing over unreliable stochastic networks

We study the question of routing for minimum average drop rate over unreliable servers that are susceptible to random buffer failures, which arises in unreliable data or manufacturing networks. Interestingly, we first reveal that the traditional Join-the-Shortest-Queue (JSQ) or optimal Randomized Splitting (RS) strategies are consistently outperformed by the Constant Splitting Rule (CSR) where the incoming traffic is split with a constant fraction towards the available servers.This finding motivates us to obtain the optimal splitting fraction under CSR. However, the objective function to be minimized depends on the mean queue length of the servers, whose closed-form expression is not available and often intractable for general arrival and service processes. Thus, we use non-derivative methods to solve this optimization problem by approximately evaluating the objective value at each iteration. To that end, we explicitly characterize the approximation error by utilizing the regenerating nature of unreliable buffers. By adaptively controlling the precision of this approximation, we show that our proposed algorithm converges to an optimal splitting decision in the almost sure sense. Yet, previous works on non-derivative methods assume continuous differentiability of the objective function, which is not the case in our setup. We relax this strong assumption to the case when the objective function is locally Lipschitz continuous, which is another contribution of this paper.     

基于环境感知的多路径路由算法

认知网络能够提高网络端到端的性能,确保服务质量(QoS)要求。而目前普遍使用的路由算法不具备网络认知能力。针对这一问题,提出一种具有认知能力的负载均衡多路径路由算法,该算法结合了Q学习算法和蚁群算法各自的优点,通过蚁群算法完成路径的建立和维护,Q学习算法实现拥塞规避和负载均衡。使用OPNET仿真比较,表明该算法在时延、带宽利用方面均具有较好的性能。     

Interval routing schemes

In this paper the problem of routing messages along shortest paths in a distributed network without using complete routing tables is considered. In particular, the complexity of deriving minimum (in terms of number of intervals) interval routing schemes is analyzed under different requirements. For all the cases considered NP-hardness proofs are given, while some approximability results are provided. Moreover, relations among the different cases considered are studied.This work was supported by the EEC ESPRIT II Basic Research Action Program under Contract No. 7141 Algorithms and Complexity II, by the EEC Human Capital and Mobility MAP project, and by the Italian MURST 40% project Algoritmi, Modelli di Calcolo e Strutture Informative.     

BGP路由冲突解决方案的研究

在分析BGP路由策略冲突问题的基础上,针对当前网络传输路由层面的发展要求,提出了基于优先池机制的BGP路由冲突解决方案,将路由的稳定性加入到BGP的判决过程中,同时引入了路由的相关性概念,对基于路由信息和通信数据进行转发的BGP路由环境展开了进一步的研究。仿真结果表明,该方法能够有效地缩短BGP路由的收敛时间,从而对整体网络环境下BGP路由冲突问题的解决起到了良好的促进作用。     

Multi-constraint QoS routing using a new single mixed metrics

Multi-constraint quality-of-service (QoS) routing has become increasingly important as the Internet evolves to support real-time services. It is well known, however, that optimum multi-constraint QoS routing is computationally complex, and for this reason various heuristics have been proposed for routing in practical situations. Among these methods, those that use a single mixed metric are the most popular. Although mixed metric routing discards potentially useful information, this is compensated for by significant complexity reduction. Exploiting this tradeoff is becoming increasingly important where low complexity designs are desired, such as in battery operated wireless applications. In this paper, novel single mixed metrics for multi-constraint routing are introduced. The proposed techniques have similar complexity compared with existing low complexity methods. Simulation and analytical results are presented which show that it can obtain better performance than comparable techniques in terms of generating feasible routes.     

Pseudo-cycle-based multicast routing in wormhole-routed networks

This paper addresses the problem of fault-tolerant multicast routing in wormholerouted multicomputers.A new pseudo-cycle-based routing method is presented for constructing deadlock-free multicast routing algorithms.With at most two virtual channels this technique can be applied to any connected networks with arbitrary topologies.Simulation results show that this technique results in negligible performance degradation even in the presence of a large number of faulty nodes.     

基于节点多样性的域内路由保护算法

已有的路由保护方案都没有考虑网络中节点的重要程度,然而在实际网络中不同节点在网络中的重要程度是不相同的。针对该问题,提出一种基于节点多样性的域内路由保护算法（intra-domain routing protection algorithm based on node diversity,RPBND）。计算节点构造以目的为根的最短路径树（shortest path tree,SPT）,从而保证RPBND算法和目前互联网部署的路由算法的兼容性;在该最短路径树的基础上构造特定结构的有向无环图（directed acyclic graph,DAG）,从而最大化路由可用性。实验结果表明,RPBND极大地提高了路由可用性,降低了故障造成的网络中断时间,为ISP部署域内路由保护方案提供了充分的依据。