一种新的动态流量疏导算法

文章主要研究WDM(波分复用)光网络中动态业务流量疏导的选路算法,提出了基于拓扑融合的动态流量疏导算法。该算法的最大特点在于融合了物理拓扑及其抽象出来的虚拓扑,利用最小权重优先方法进行选路。仿真结果表明,该算法在不增大建路时延的基础上,可以有效提高资源利用率,降低阻塞率,尤其是在高负载情况下,效果显著。     

WDM网络拓扑重构的均衡算法研究

针对WDM光网络中逻辑拓扑的重构迁移问题,提出一种均衡算法,以单条光通道为最小的计算单元,每次选择建立对当前的拓扑性能增益较多而中断的网络资源较少的光通道.仿真结果说明这样的做法有效降低了拓扑重构对网络的影响.     

基于最优刚性图的能量有效分布式拓扑控制算法

针对现有无线传感器网络拓扑控制算法无法平衡各节点能量消耗的问题,基于最优刚性图提出了一种具有平衡负载特性的能量有效分布式拓扑控制算法。算法引入综合反映能量消耗及剩余能量两方面因素的链路权值函数,能够根据当前节点剩余能量实时地动态优化拓扑结构,从而有效地平衡网络节点的能量消耗。从理论上证明了优化后的拓扑是2?连通的而且具有稀疏性;同时优化后拓扑中各节点的平均度趋于4。仿真结果表明,与其他算法相比,该算法能够有效地平衡各节点的能量消耗,进而延长网络生命期。     

An efficient load balancing method for ad hoc networks

Routing is the most basic and essential operation of any ad hoc network. A mobile ad hoc network presents many challenges, because of the severe resource limitations such as dynamic and varying topology, lack of centralized control, insecure medium, and limited battery power, among others. Therefore, optimization and conservation is the key to success of any ad hoc network operation. In this paper, we propose and define 2 new metrics for ad hoc networks: bandwidth utilization ratio and load index. These metrics can be used as an indicator to measure and monitor the network usability and to improve its efficiency by efficient load distribution. They can be used to predict the additional load that can be accommodated in the network, without causing any congestion or overflows. We also propose a new load balancing routing scheme for ad hoc networks, called efficient load balancing method. This method tries to offset the load on different paths using load index as a metric. Load index is defined as a measure of a node's degree of involvement in the message routing process, which is indicative of its load. To make this algorithm efficient, we limit our routes to a few efficient ones only. This number of alternate routes used, out of the pool of all available routes, is defined as degree of distribution. Simulation results adequately prove the efficiency of proposed method, vis‐à‐vis 2 other load balancing approaches, and these are verified statistically at 99% confidence interval. A p × q factorial design is used to verify that simulation results are the actual measurements and not due to some unknown errors.     

An improved algorithm for multicast topology discovery from end‐to‐end measurements

We present a new multicast topology inference algorithm called binary loss tree classification with hop count (HBLT). HBLT improves the previous algorithm of binary loss tree classification (BLT) not only in time complexity but also in misclassification probability and inference accuracy. The time complexity of HBLT is O(l²) instead of O(l³) required by BLT in the worst case, and O(l · log l) instead of O(l³) by BLT in the expected case, where l is the number of receivers in the multicast network. The misclassification probability of HBLT decreases more quickly than that of BLT as the number of probe packets increases. For correct classification, the inference accuracy of HBLT is always 1, i.e. the inferred tree is identical to the physical tree, whereas that of BLT is dependent on the shape of the physical tree and inversely proportional to the number of internal nodes with single child. We also show through simulation that HBLT requires fewer probe packets to infer the correct topology and hence has a lower misclassification probability and higher inference accuracy than BLT. Copyright © 2006 John Wiley & Sons, Ltd.     

基于拓扑感知的可重构服务承载网动态重构算法

可重构信息通信基础网络通过构建服务承载网的方式为业务提供自适应的承载服务。针对高效利用有限底层资源的问题,提出一种基于资源关键度进行动态映射的服务承载网构建算法。算法将通过节点或链路的最短路径数作为资源关键度的衡量指标,区别对待底层资源;并实时动态感知关键资源的使用状况,依据不同业务需求对服务承载网进行自适应调整。仿真结果表明,算法在构建成功率、收益花费比和资源均衡度等方面均具有良好性能。     

An energy‐efficient localized topology control algorithm for wireless ad hoc and sensor networks

Topology control plays an important role in the design of wireless ad hoc and sensor networks and has demonstrated its high capability in constructing networks with desirable characteristics such as sparser connectivity, lower transmission power, and smaller node degree. However, the enforcement of a topology control algorithm in a network may degrade the energy‐draining balancing capability of the network and thus reduce the network operational lifetime. For this reason, it is important to take into account energy efficiency in the design of a topology control algorithm in order to achieve prolonged network lifetime. In this paper, we propose a localized energy‐efficient topology control algorithm for wireless ad hoc and sensor networks with power control capability in network nodes. To achieve prolonged network lifetime, we introduce a concept called energy criticality avoidance and propose an energy criticality avoidance strategy in topology control and energy‐efficient routing. Through theoretical analysis and simulation results, we prove that the proposed topology control algorithm can maintain the global network connectivity with low complexity and can significantly prolong the lifetime of a multi‐hop wireless network as compared with existing topology control algorithms with little additional protocol overhead. Copyright © 2008 John Wiley & Sons, Ltd.     

网络虚拟化环境下基于预测的资源重配置算法

解决虚拟网动态加入、离开导致的底层网络资源占用不均衡问题,提出基于预测的资源重配置算法(FRRA)。FRRA用已知信息预测资源重配置时间间隔,代替已有算法中周期性时间间隔。采取两方面措施保证重配置时机全局最优:将资源划分为关键资源和普通资源并使用不同配置算法;根据资源迁移失败概率,推导重配置请求次数极限值。与算法VNA-II、PMPA实验比较表明,FRRA的重配置花费比VNA-II节省69%,比PMPA节省42%;FRRA的虚拟网请求接收率比VNA-II提高29%,比PMPA提高52%。     

高速局域网的简化CRMA协议性能分析

对现有的周期预留多址接入(CRMA)协议进行了简化和改进，提出了简化的CRMA协议(S-CRMA)。S-CRMA协议对时隙结构进行了重新定义，取消了原有协议的REJECT、CONFIRM等命令，通过自适应地改变预留时隙的间隔，实现了网络在接入时延和接入速率方面的公平性。通过仿真数据和曲线，说明了基于S-CRMA协议的网络在平衡突发业务和非平衡突发业务两种条件下，均保证了各个本地节点的公平接入。     

面向动态拓扑网络的深度强化学习路由技术

针对现有智能路由技术无法适用于动态拓扑的不足,提出了一种面向动态拓扑的深度强化学习智能路由技术,通过使用图神经网络近似PPO(Proximal Policy Optimization)强化学习算法中的策略函数与值函数、策略函数输出所有链路的权值、基于链路权值计算最小成本路径的方法,实现了路由智能体对不同网络拓扑的泛化....     

面向LEO卫星网络的高效路由算法

由于卫星星上处理以及存储能力有限,随着卫星网络的规模越来越庞大,迫切需要一种简单高效的路由算法.为此,提出了一种基于网络拥塞程度感知的路由策略(Network Congestion-Aware Routing Algorithm,NCARA).NCARA路由策略在网络处于非拥塞状态时采用Dijkstra算法寻路,网络拥...     

Mesh-connected rings topology for network-on-chip

With the feature size of semiconductor technology reducing and intellectual property （IP） cores increasing, on-chip interconnection network architectures have a great influence on the performance and area of system-on-chip （SoC） design. Focusing on trade-off performance, cost and implementation, a regular network-on-chip （NoC） architecture which is mesh-connected rings （MCR） interconnection network is proposed. The topology of MCR is simple, planar and scalable in architecture, which combines mesh with ring. A detailed theoretical analysis for MCR and mesh is given, and a simulation analysis based on the virtual channel router with wormhole switching is also presented. The results compared with the general mesh architecture show that MCR has better performance, especially in local traffics and low loads, and lower cost.     

An energy efficient clustering routing algorithm for wireless sensor networks

~~An energy efficient clustering routing algorithm for wireless sensor networks1. Mainwaring A, Polastre J, Szewczyk R, et al. Wireless sensor networks for habitat monitoring. Proceedings of the ACM International Workshop on Wireless Sensor Networks and A…     

An energy‐efficient utility‐based distributed data routing scheme for heterogenous sensor networks

A utility‐based distributed data routing algorithm is proposed and evaluated for heterogeneous wireless sensor networks. It is energy efficient and is based on a game‐theoretic heuristic load‐balancing approach. It runs on a hierarchical graph arranged as a tree with parents and children. Sensor nodes are considered heterogeneous in terms of their generated traffic, residual energy and data transmission rate and the bandwidth they provide to their children for communication. The proposed method generates a data routing tree in which child nodes are joined to parent nodes in an energy‐efficient way. The principles of the Stackelberg game, in which parents as leaders and children as followers, are used to support the distributive nature of sensor networks. In this context, parents behave cooperatively and help other parents to adjust their loads, while children act selfishly. Simulation results indicate the proposed method can produce on average more load‐balanced trees, resulting in over 30% longer network lifetime compared with the cumulative algorithm proposed in the literature. Copyright © 2014 John Wiley & Sons, Ltd.     

无线局域网中的负载均衡技术

随着无线局域网扩展服务集中的终端（STA）的移动和无线信道的时变，各个接入点（AP）上的负载会出现差异，需要加强负载均衡，平衡各个AP的差异，以达到最大化的网络资源利用。无线局域网中的负载均衡算法可以采用STA／AP主控负载均衡或接入式／切换式负载均衡技术。在时分双工的时分同步码分多址（TD—SCDMA）系统中，由于系统在最小资源单位和媒体访问机制等方面的差异，负载均衡可以在小到时隙和码道，大到终端和小区等不同的级别上进行，体现码分多址（CDMA）和时分双工（TDD）的特点，具体方式更加灵活多样。     

一种基于能耗均衡的ZigBee网络高效混合路由算法

针对目前ZigBee网络混合路由算法寻找开销偏大、能耗不均的问题,提出一种高效混合路由算法( EHCA)。通过采用跨层泛听与优先使用深度大、剩余能量多的节点进行路由的方式,减少部分泛洪寻路分组的转发,均衡节点能耗。仿真结果表明,EHCA的节点能耗均衡、路由开销和网络寿命等性能均优于混合路由算法和树路由算法。     

基于遗传聚类的无线传感器负载均衡路由算法

通常的无线传感器分簇网络存在节点负载不均衡的问题。为均衡各节点能量消耗,延长网络生存周期,将K均值算法与遗传算法相结合,提出一种负载均衡的无线传感器网络路由算法,算法利用遗传算法的全局寻优能力以克服传统K均值算法的局部性和对初始中心的敏感性,实现了传感器网络节点自适应成簇与各节点负载均衡。仿真实验表明,该算法显著延长了网络寿命,相对于其他分簇路由算法,其网络生存时间延长了约43%。     

A load balancing energy efficient clustering algorithm for MANETs

Nodes in mobile ad hoc Networks (MANETs) are characterized by their limited resources. Hence, the concept of clustering was introduced to allow spacial reuse of bandwidth and to minimize routing overhead. However, node mobility perturbs the stability of the network and affects the performance of other protocols such as scheduling, routing, and resource allocation, which makes re‐clustering the network to maintain up‐to‐date information at each node unavoidable. Consequently, clustering models for MANETS should be carefully designed while taking into consideration the fact that mobile nodes are energy constrained. In this paper, we propose a dynamic energy‐efficient clustering algorithm that prolongs the network lifetime by electing cluster‐heads taking into consideration, in addition to other parameters such as mobility, their residual energies and making them dynamically monitor their energy consumption to either diminish the number of their cluster‐members or relinquish their roles. We have evaluated the performance of the proposed clustering model and compared it with other related clustering approaches found in the literature. Obtained results show the efficiency of the proposed algorithm. Copyright © 2010 John Wiley & Sons, Ltd.     

基于OPNET的局域网拓扑建模仿真

为分析比较局域网中星形,环形和树形3种典型的点到点拓扑的优缺点,运用优化网络工程工具(Optimized Network Engineering Tools,简称OPNET)建立3种拓扑模型,并对其性能仿真.通过分析仿真数据,对3种拓扑的延时,通信量和负载进行比较,给出了3种拓扑各自优缺点,从而为网络规划选择的最佳拓扑提供了技术参考.     

基于最小跳数的无线传感器网络路由协议

在分析了最小跳数路由算法局限性的基础上对该算法进行了改进,充分考虑了无线传感器网络的跳数、能量、负载均衡等问题。改进后的算法使得传感器的某些节点不会因为频繁使用而迅速死亡,数据包可以沿着最优的路径向网关节点发送。仿真结果显示,改进后的算法可以有效地提高无线传感器网络的可靠性和稳定性,延长了网络的通信时间。