能量高效的ZigBee路由算法

研究无线网络能耗优化控制问题,传统的AODVjr路由算法通过洪泛路由请求分组(RREQ)来实现路由查找和记录,利用目标节点对最先到达的RREQ分组做出响应选择出最优路径.上述方法只有目的节点才能发送RREP分组,虽可避免无效的RREP分组出现和循环问题,但寻找路由方式需要大量的路由开销,造成网络拥塞,且没有保护剩余能量低的节点,引起通信效率低的问题.针对ZigBee传感网络路由算法的不足,为降低网络节点能量消耗,提出了一种能量高效的路由优化算法,充分利用邻居表信息及簇树分布式地址分配机制,转发数据分组并控制路由请求分组(RREQ)的传播方向,通过节点路由代价及能量等级避免关键节点的能量过度消耗,有效均衡网络能耗.仿真实验验证,改进算法有效地均衡了网络能耗,延长了网络的生命周期.     

基于改进萤火虫群优化的无线自组网路由算法

针对无线自组网络拓扑结构多变、网络生存时间受限及数据包分组传输效率低下等问题,借鉴萤火虫群优化算法,提出了一种改进萤火虫群优化的无线自组网络路由算法.路由算法将萤火虫优化算法中的荧光素强度更新与无线自组网络中的节点移动速度、拥塞程度、节点剩余能量、节点间距离等因素进行相互映射,同时改进萤火虫群优化算法中的搜索萤火虫、驻留萤火虫及回溯萤火虫用于完成无线自组网络中路由协议的路由发现、路由选择及路由维护等过程,整个协议无须传送大量的控制分组,即可实现无线自组网络的稳定传输.仿真实验结果表明,与AODV及基于蚁群优化的路由算法AntRouting协议相比,本文所提出的路由算法在端到端延时、分组数据传输率及网络生存时间上均有良好的性能.     

地理路由算法在三维传感器网络中应用

为解决三维传感器网络中应用地理路由算法引起的路由空洞问题,引入树型网络路由算法,提出一种新的地理路由算法———基于树型网络的贪婪算法（ GAT）。根据三维传感器网络拓扑结构信息,GAT生成一个树型网络拓扑,并为每个节点分配ID信息,当基于真实地理位置的贪婪算法遇到路由空洞时,采用树型网络路由算法作为恢复机制,保证了数据分组的可达性。GAT克服了三维空间中贪婪算法的路由空洞问题,可以保证三维传感器网络中任意节点之间数据分组的可达性。仿真实验验证了GAT在三维空间的可行性以及高效的路由性能。     

基于ODMRP的分布式核心稳定路由算法

在无人机网络中,由于节点具有较强的移动性,对于组播路由的建立以及组播组的划分提出更高要求,一般的组播路由协议往往无法满足网络需求.为此,提出了一种基于ODMRP的分布式核心稳定路由算法.该算法结合了改进贪婪机制,根据路由状况对路径进行优化,为了降低源节点的数据处理负担,提出了分布式核心节点选择机制,将组播组的信息储存在多个核心节点中,同时释放了转发节点的储存空间.文章通过路由抢修机制,监控路由状态变化,对即将断裂的路由提前修复,保证了路径的有效性.仿真表明,该算法与标准的ODMRP算法及改进算法VCMP算法相比,能够优化传输路径,降低端到端时延,提高分组交付率,提升网络性能.     

容迟网络路由算法

容迟网络泛指那些由于节点移动、能量管理、调度等原因而出现频繁中断、甚至长时间处于中断状态的一类网络.它涵盖了由于节点调度而处于间歇式连通的无线传感网络、移动Ad hoc网络、周期性连通的卫星网络、乡村网络、野生动物追踪网络以及个人设备交换网络等等.具有十分广阔的应用前景,引起了广泛的关注.与传统网络相比,容迟网络没有稳定的端到端传输路径,因而其路由问题更为复杂.已有的研究工作也主要集中于这一问题.并提出了许多的容迟网络路由算法.对这些算法的最新进展进行了综述.首先,介绍了容迟网络路由算法的性能评价标准.其次.给出了容迟网络路由算法的分类方法.按照路由策略来分.客迟网络路由算法可以分为基于复制策略的算法和基于转发策略的算法.按照网络模型来分,容迟网络路由算法又可以分为面向主动移动模型的算法和面向被动移动模型的算法.然后,针对每一分类.重点综述了其中具有代表性的一些容迟网络路由算法,并总结了各算法的优缺点.最后,讨论了未来的研究方向.     

GLFR：一种新的基于地理位置信息AdHoc网络路由算法

在经典的基于地理位置信息的Ad Hoc网络路由算法GPSR的基础上,为了提高数据分组成功传输率,提出了一种适用于无线网络的路由算法GLFR,该算法以RNG图作为无线网络的拓扑结构,利用节点中存储的邻节点位置信息和局部面上的节点位置信息实现了数据分组的转发,随着网络中节点数的增加以及节点移动性的增强,该路由算法具有良好的可扩展性和适应性.通过仿真可以看出GLFR算法在数据分组成功传输率方面具有良好的性能.     

一种基于组合量度的AODV路由协议

移动Ad hoc网络路由协议通常采用最短跳数算法选择路由.然而,随着网络负载的增加,采用最短跳数算法的路由协议,其性能会迅速下降.针对这一问题,本文提出了一种路由选择的组合量度(考虑了节点的负载、可用带宽和时延)替代最短跳数,并基于此量度和AODV设计了新的路由协议CMAODV(Combined Metric Based AODV).仿真结果表明,本文提出的协议提高了分组投递率,降低了分组传送的平均端到端时延,改善了网络性能.     

基于节点状态的无线Mesh网络路由算法

分析动态源路由(DSR)协议,提出一种基于节点状态的路由算法(NSBDSR),并将其作为WAM网络的路由协议。该算法能避免网络中间节点为转发分组而必须保持最新路由的问题,使节点仅维护与之通信的节点路由。在NS-2上的仿真结果表明,NSBDSR能有效降低路由中断概率,增加路由流量,减少网络时延和丢包率。     

一种基于跨层功率控制的Ad hoc网络路由算法*

在无线Ad Hoc网络路由协议中引入功率控制不但可以降低网络能量消耗,同时还能改善网络的吞吐量、投递率等性能,已成为当前Ad Hoc网络的一个研究热点.本文提出了一种基于跨层功率控制的按需路由算法CPC-AODV(Cross-layer Power Control Ad hoc On-demand Distance Vector).算法按需建立多个不同功率级的路由,节点选择到目的节点最小功率级的路由来传递分组,并对网络层的数据分组、路由分组和MAC层控制帧的传输采用不同功率控制策略来降低能量消耗.仿真结果表明:算法有利于降低通信能量开销,延长网络寿命,提高网络投递率及改善网络时延.     

基于分组索引增量交换的机会网络高效低时延路由算法

基于Epidemic机制的路由算法为机会网络提供了一类可靠的数据传送方式,但在相遇节点感知和分组交换的操作中存在冗余,导致开销和时延增加;对此,作者提出一种基于分组索引增量交换的机会网络路由算法--ERBEI,在分组索引的交换过程中只传递增量信息,并借助Request消息从节点缓存中删除已到达目的节点的分组,同时在相遇节点感知过程中只使用Hello消息,且优先发送位于最后1跳的数据分组,从而减少开销、降低分组时延.理论分析和仿真结果说明,与经典的Epidemic路由算法和它的一种改进算法ARER相比,ERBEI算法在控制开销、分组端到端时延、存储空间占用等方面的性能得到整体提升.     

QoS multicast routing using a quantum-behaved particle swarm optimization algorithm

QoS multicast routing in networks is a very important research issue in networks and distributed systems. It is also a challenging and hard problem for high-performance networks of the next generation. Due to its NP-completeness, many heuristic methods have been employed to solve the problem. This paper proposes the modified quantum-behaved particle swarm optimization (QPSO) method for QoS multicast routing. In the proposed method, QoS multicast routing is converted into an integer programming problem with QoS constraints and is solved by the QPSO algorithm combined with loop deletion operation. The QPSO-based routing method, along with the routing algorithms based on particle swarm optimization (PSO) and genetic algorithm (GA), is tested on randomly generated network topologies for the purpose of performance evaluation. The simulation results show the efficiency of the proposed method on QoS the routing problem and its superiority to the methods based on PSO and GA.     

Improving hybrid ad hoc networks: The election of gateways

The selection of an appropriate and stable route that enables suitable load balancing of Internet gateways is an important issue in hybrid mobile ad hoc networks. The variables employed to perform routing must ensure that no harm is caused that might degrade other network performance metrics such as delay and packet loss. Moreover, the effect of such routing must remain affordable, such as low losses or extra signaling messages. This paper proposes a new method, Steady Load Balancing Gateway Election, based on a fuzzy logic system to achieve this objective. The fuzzy system infers a new routing metric named cost that considers several networks performance variables to select the best gateway. To solve the problem of defining the fuzzy sets, they are optimized by a genetic algorithm whose fitness function also employs fuzzy logic and is designed with four network performance metrics. The promising results confirm that ad hoc networks are characterized by great uncertainty, so that the use of Computational Intelligence methods such as fuzzy logic or genetic algorithms is highly recommended.     

Reinforcement learning for resource allocation in LEO satellite networks.

In this paper, we develop and assess online decision-making algorithms for call admission and routing for low Earth orbit (LEO) satellite networks. It has been shown in a recent paper that, in a LEO satellite system, a semi-Markov decision process formulation of the call admission and routing problem can achieve better performance in terms of an average revenue function than existing routing methods. However, the conventional dynamic programming (DP) numerical solution becomes prohibited as the problem size increases. In this paper, two solution methods based on reinforcement learning (RL) are proposed in order to circumvent the computational burden of DP. The first method is based on an actor-critic method with temporal-difference (TD) learning. The second method is based on a critic-only method, called optimistic TD learning. The algorithms enhance performance in terms of requirements in storage, computational complexity and computational time, and in terms of an overall long-term average revenue function that penalizes blocked calls. Numerical studies are carried out, and the results obtained show that the RL framework can achieve up to 56% higher average revenue over existing routing methods used in LEO satellite networks with reasonable storage and computational requirements.     

Adaptation and Evaluation of the Multisplitting-Newton and Waveform Relaxation Methods Over Distributed Volatile Environments

This paper presents new adaptations of two methods that solve large differential equations systems, to the grid context. The first method is based on the Multisplitting concept and the second on the Waveform Relaxation concept. Their adaptations are implemented according to the asynchronous iteration model which is well suited to volatile architectures that suffer from high latency networks. Many experiments were conducted to evaluate and compare the accuracy and performance of both methods while solving the advection-diffusion problem over heterogeneous, distributed and volatile architectures. The JACEP2P-V2 middleware provided the fault tolerant asynchronous environment, required for these experiments.     

Scoped Bellman-Ford Geographic Routing for Large Dynamic Wireless Sensor Networks

Routing is a fundamental problem in wireless sensor networks. Most previous routing protocols are challenged when used in large dynamic networks as they suffer from either poor scalability or the void problem. In this paper,we propose a new geographic routing protocol,SBFR(Scoped Bellman-Ford Routing),for large dynamic wireless sensor networks. The basic idea is that each node keeps a view scope of the network by computing distance vectors using the distributed BellmanFord method,and maintains a cost for routing to the sink. When forwarding a packet,a node picks the node with minimum cost in its routing table as a temporary landmark. While achieving good scalability,it also solves the void problem in an efficient manner through the combination of Bellman-Ford routing and cost-based geographic routing. Analytical and simulation results show that SBFR outperforms other routing protocols not only because of its robustness and scalability but also its practicality and simplicity.     

互联网覆盖路由技术研究

对互联网覆盖路由相关研究工作进行了调研;按照Internet分层概念重点考查了网络层和传输层的覆盖路由的结构和方法;并且考查了覆盖路由其他相关问题的研究,包括覆盖路由性能的影响因素、多个覆盖网络路由之间的相互作用等.分析了已有研究工作的关键技术的优缺点.最后讨论了未来可能的研究方向,为互联网覆盖路由的研究提供参考.     

基于有线的Ad Hoc路由协议的性能评估方法

Ad hoc路由协议可以使用软件仿真、现场试验分析、理论分析等方法对其进行性能分析和评估。由于现场试验分析开销高及实验环境部署复杂等原因,目前,软件仿真是对ad hoc路由协议进行性能评估的主要方法,但这种方法对于一些需要通过实际应用场景对ad hoc网络进行研究的情况并不具有说服力。本文综合各种方法的优缺点,提出一种基于有线网络的ad hoc路由协议性能评估新方法：通过在应用层、网络层、链路层添加各种数据采集探针来采集性能数据。此外,设计并实现了可视化的数据采集分析平台,可以对采集的性能数据进行图形化的展示及分析评估。这种方法不仅弥补了在软件仿真过程中,未考虑操作系统、系统硬件、系统设计、通信环境等敏感因素带来的影响,使得测试结果更逼近真实,而且解决了现场试验分析中性能数据不易获取、开销巨大、场景搭建复杂等问题。最后,通过本文所提出的性能数据采集评估方法对3种典型的ad hoc路由协议进行性能对比分析。     

Congestion control based dynamic routing in ATM networks

In this paper we describe briefly a dynamic multi-path algorithm that has been considered for connection oriented asynchronous transfer mode (ATM) networks. Our scheme takes advantage of a cell multiplexing capability that has particular advantage in networks supporting variable bit rate (VBR) traffic. The fundamental objective of the scheme is to propose a congestion control based scheme that bridges the gap between routing and congestion control as the network becomes congested. The proposed routing scheme works as a shortest path first algorithm under light traffic conditions. However, as the shortest path becomes congested under unbalanced heavy traffic, the source uses multiple paths when and if available to distribute the calls and reduce cell loss. This mechanism will provide good Quality of Service for clients within the given constraints. We compare the performance of the proposed scheme with other competitive schemes. The throughput and cell loss performance are compared via simulations. These have been carried out concentrating on a five node network, each with varying traffic patterns, with the intention of gaining insight into the strengths and weaknesses of the various schemes.     

DRAD:一种基于异步休眠调度的无线传感器网络数据收集协议

数据收集是无线传感器网络的基本功能之一,被大量应用到环境监测。如何降低网络能耗、延长网络生命周期是环境监测中数据收集的首要问题。大多数应用都选择使用休眠调度,通过监听空闲侦听的时间来节省能量,而这通常是在MAC层进行。本文则在网络层路由中考虑休眠调度的影响,将路由和休眠调度综合起来考虑,提出了一种基于异步休眠调度的无线传感器网络数据收集协议DRAD。DRAD通过异步休眠调度避免了时间同步的消耗,节点只需维护与邻居节点间的时间差,通过顺带时间差修正机制解决时间偏移问题,降低了能量开销。实验用占空比来衡量系统能量消耗,结果显示DRAD可以稳定在预先设定的占空比,有效降低网络能耗,延长网络寿命。     

自组网中路由度量的研究

路由度量的选择对路由协议的设计和性能起着至关重要的作用。文章主要研究和定量分析各种路由度量和它们之间的组合对自组网拓扑性能的影响,其结果将有助于使用混合度量作为路径选择标准的自适应路由协议的建模和开发。首次通过使用基于快照的分析方法,该文隔离和定量分析了四种影响自组网拓扑性能的路由度量:跳数、信号强度、方位信息和移动速度。与其它研究成果的不同之处在于它专注于相对未曾研究的领域,即用静态方法研究选路度量对动态网络拓扑性能的影响。特别地,文章从下列性能指标:平均路径稳定时间、平均新增中间节点数和平均跳数来评估这些路由度量的影响。