Improved Multi-Path Routing for QoS on MANET

A Mobile Ad hoc NETwork(MANET)is a self-configuring network that is not reliant on infrastructure.This paper introduces a new multipath routing method based on the Multi-Hop Routing(MHR)technique.MHR is the consecutive selection of suitable relay nodes to send information across nodes that are not within direct range of each other.Failing to ensure good MHR leads to several negative consequences,ultimately causing unsuccessful data transmission in a MANET.This research work consists of three portions.The first to attempt to propose an efficient MHR protocol is the design of Priority Based Dynamic Routing(PBDR)to adapt to the dynamic MANET environment by reducing Node Link Failures(NLF)in the network.This is achieved by dynamically considering a node’s mobility parameters like relative velocity and link duration,which enable the next-hop selection.This method works more efficiently than the traditional protocols.Then the second stage is the Improved Multi-Path Dynamic Routing(IMPDR).The enhancement is mainly focused on further improving the Quality of Service(QoS)in MANETs by introducing a QoS timer at every node to help in the QoS routing of MANETs.Since QoS is the most vital metric that assesses a protocol,its dynamic estimation has improved network performance considerably.This method uses distance,linkability,trust,and QoS as the four parameters for the next-hop selection.IMPDR is compared against traditional routing protocols.The Network Simulator-2(NS2)is used to conduct a simulation analysis of the protocols under consideration.The proposed tests are assessed for the Packet Delivery Ratio(PDR),Packet Loss Rate(PLR),End-to-End Delay(EED),and Network Throughput(NT).

Multi-Path Routing and Resource Allocation in Active Network

An algorithm of traffic distribution called active multi-path routing (AMR)in active network is proposed. AMR adopts multi-path routing and applies nonlinear optimizeapproximate method to distribute network traffic among multiple paths. It is combined to bandwidthresource allocation and the congestion restraint mechanism to avoid congestion happening and worsen.So network performance can be improved greatly. The frame of AMR includes adaptive trafficallocation model, the conception of supply bandwidth and its' allocation model, the principle ofcongestion restraint and its' model, and the implement of AMR based on multi-agents system in activenetwork. Through simulations, AMR has distinct effects on network performance. The results show AMRisa valid traffic regulation algorithm.

MRBCH: A Multi-Path Routing Protocol Based on Credible Cluster Heads for Wireless Sensor Networks

Wireless sensor networks are widely used for its flexibility, but they also suffer from problems like limited capacity, large node number and vulnerability to security threats. In this paper, we propose a multi-path routing protocol based on the credible cluster heads. The protocol chooses nodes with more energy remained as cluster heads at the cluster head choosing phase, and then authenticates them by the neighbor cluster heads. Using trust mechanisms it creates the credit value, and based on the credit value the multi-path cluster head routing can finally be found. The credit value is created and exchanged among the cluster heads only. Theoretical analysis combined with simulation results demonstrate that this protocol can save the resource, prolong the lifetime, and ensure the security and performance of the network.

Fast and scalable routing protocols for data center networks

Data center networks may comprise tens or hundreds of thousands of nodes,and,naturally,suffer from frequent software and hardware failures as well as link congestions.Packets are routed along the shortest paths with sufficient resources to facilitate efficient network utilization and minimize delays.In such dynamic networks,links frequently fail or get congested,making the recalculation of the shortest paths a computationally intensive problem.Various routing protocols were proposed to overcome this problem by focusing on network utilization rather than speed.Surprisingly,the design of fast shortest-path algorithms for data centers was largely neglected,though they are universal components of routing protocols.Moreover,parallelization techniques were mostly deployed for random network topologies,and not for regular topologies that are often found in data centers.The aim of this paper is to improve scalability and reduce the time required for the shortest-path calculation in data center networks by parallelization on general-purpose hardware.We propose a novel algorithm that parallelizes edge relaxations as a faster and more scalable solution for popular data center topologies.

An Investigation on the Effect of Migration Strategy on Parallel GA-Based Shortest Path Routing Algorithm

Genetic algorithm (GA) is one of the alternative approaches for solving the shortest path routing problem. In previous work, we have developed a coarse-grained parallel GA-based shortest path routing algorithm. With parallel GA, there is a GA operator called migration, where a chromosome is taken from one sub-population to replace a chromosome in another sub-population. Which chromosome to be taken and replaced is subjected to the migration strategy used. There are four different migration strategies that can be employed: best replace worst, best replace random, random replace worst, and random replace random. In this paper, we are going to evaluate the effect of different migration strategies on the parallel GA-based routing algorithm that has been developed in the previous work. Theoretically, the migration strategy best replace worst should perform better than the other strategies. However, result from simulation shows that even though the migration strategy best replace worst performs better most of the time, there are situations when one of the other strategies can perform just as well, or sometimes better.

SOPA:Source Routing Based Packet-Level Multi-Path Routing in Data Center Networks

Many ＂rich - connected＂ topologies with multiple parallel paths between smwers have been proposed for data center networks recently to provide high bisection bandwidth, but it re mains challenging to fully utilize the high network capacity by appropriate multi- path routing algorithms. As flow-level path splitting may lead to trafl＇ic imbalance between paths due to flow- size difference, packet-level path splitting attracts more attention lately, which spreads packets from flows into multiple available paths and significantly improves link utilizations. However, it may cause packet reordering, confusing the TCP congestion control algorithm and lowering the throughput of flows. In this paper, we design a novel packetlevel multi-path routing scheme called SOPA, which leverag- es OpenFlow to perform packet-level path splitting in a round- robin fashion, and hence significantly mitigates the packet reordering problem and improves the network throughput. Moreover, SOPA leverages the topological feature of data center networks to encode a very small number of switches along the path into the packet header, resulting in very light overhead. Compared with random packet spraying （RPS）, Hedera and equal-cost multi-path routing （ECMP）, our simulations demonstrate that SOPA achieves 29.87%, 50.41% and 77.74% higher network throughput respectively under permutation workload, and reduces average data transfer completion time by 53.65%, 343.31% and 348.25% respectively under production workload.

Wormhole Routing──大规模并行处理系统中的一项关键技术

本文详细介绍了基于直接网络的大规模并行计算机的ＷｏｒｍｈｏｌｅＲｏｕｔｉｎｇ的原理。Ｗｏｒｍｈｏｌｅ寻径算法以及其它与通信性能有关的技术问题。

Reliable Braided Multipath Routing with Network Coding for Underwater Sensor Networks

Owing to the long propagation delay and high error rate of acoustic channels, it is very challenging to provide reliable data transfer for underwater sensor networks. Moreover, network coding is proved to be an effective coding technique for throughput and robustness of networks. In this paper, we propose a Reliable Braided Multipath Routing with Network Coding for underwater sensor networks （RBMR-NC）. Disjoint multi-path algorithm is used to build independent actual paths, as called main paths. Some braided paths on each main path are built according to the braided multi-path algorithm, which are called logic paths. When a data packet is transmitted by these nodes, the nodes can employ network coding to encode packets coming from the same group in order to further reduce relativity among these packets, and enhance the probability of successful decoding at the sink node. Braided multi-path can make the main paths to be multiplexed to reduce the probability of long paths. This paper mainly employs successful delivery rate to evaluate RBMR-NC model with theoretical analysis and simulation methods. The results indicate that the proposed RBMR-NC protocol is valuable to enhance network reliability and to reduce system redundancy.

Joint routing and rate allocation for multiple video streams in ad-hoc wireless networks

The support for multiple video streams in an ad-hoc wireless network requires appropriate routing and rate allocation measures ascertaining the set of links for transmitting each stream and the encoding rate of the video to be delivered over the chosen links. The routing and rate allocation procedures impact the sustained quality of each video stream measured as the mean squared error (MSE) distortion at the receiver, and the overall network congestion in terms of queuing delay per link. We study the trade-off between these two competing objectives in a convex optimization formulation, and discuss both centralized and dis- tributed solutions for joint routing and rate allocation for multiple streams. For each stream, the optimal allocated rate strikes a balance between the selfish motive of minimizing video distortion and the global good of minimizing network congestions, while the routes are chosen over the least-congested links in the network. In addition to detailed analysis, network simulation results using ns-2 are presented for studying the optimal choice of parameters and to confirm the effectiveness of the proposed measures.

基于改进蚁群优化算法的船舶管路布局设计

为了实现在多种约束和目标限制下,能以较短时间为工程师提供多种优质船舶布管方案,提出一种基于改进蚁群优化算法的新型船舶管路布局设计方法。该方法基于网格空间分解模型,将适应度函数中的优化目标进行规范化,对蚁群优化算法的关键步骤,如:蚂蚁行进方向选择、信息素更新机制、蚂蚁寻路过程等进行改进,采用最优解集合保存适应度相同但管路布局效果不同的多个优解,引入辅助点策略和并行计算机制提升算法整体寻优能力和效率。通过仿真算例验证了算法的有效性和先进性。

移动云系的平行条播方案与“S”型飞行航线设计研究

在人工影响天气作业过程中,飞机作业航线设计是整个飞机增雨过程中最重要的技术工作,科学的飞机作业航线设计是提高云系催化效率以及检验催化作业效果的关键。针对平行条播方案,在充分考虑云系移速移向、飞机性能等基础上,提出优化的“S”型飞行航线设计方法,给出飞机转弯部分的简化处理方法,可快速确定关键点的位置,同时给出在标准转弯速率下空中国王350和运12飞机的转弯时间计算方法,对飞机增雨作业方案设计有很好的指导意义。实际飞行试验表明,增雨飞机可以按照设计的航线进行增雨作业,并且可实现平行条播。

离线并行软件加载技术的研究

文章基于离线型并行软件加载技术的研究,从功能、性能架构,硬件需求,硬件设计方案,软件设计方案等方面为切入点,介绍了离线型并行软件加载技术的实现方案。通过多端口适配技术、多路路由技术、上位机软件开发,实现3种模块、7个接口、19个通道、20余种程序的并行加载。该研究对于其他集成化电子装备在大规模的软件加载环节建立适合自身产品特点的软件加载提供了一定借鉴。

基于大数据的电力通信通道智能路由推荐策略研究

面对规模庞大、结构复杂的电力通信网,针对通信调度如何根据业务需求准确、合理、高效地安排通信通道,提出了一种基于分布式图并行计算的大数据智能路由推荐方法。该方法根据电力通信网特点构建电力通信网络拓扑模型、建立优选路由指标模型,并采用基于分布式图并行计算框架实现并行路由推荐算法。实验证明,该方法具有快速迭代与收敛的特性,在大型复杂的电力通信网络路由推荐与规划中具有良好的应用前景。

All-To-All Personalized Communication in Wormhole-Routed 2D/3D Meshes and Multidimensional Interconnection Networks

All-to-all personalized communication,or complete exchange,is at the heart of numerous applications in paral-lel computing.It is one of the most dense communication patterns.In this paper,we consider this problem in a2D/3D mesh and a multidimensional interconnection network with the wormhole-routing capability.We propose complete ex-change algorithms for them respectively.We propose O(mn 2 )phase algorithm for2D mesh P m ×P n and O(mn 2 l 2 )phase algo-rithm for3D mesh P m ×P n ×P l ,where m,n,l are any positive integers.Also O(ph(G 1 )n 2 )phase algorithm is proposed for a multidimensional interconnection network G 1 ×G 2 ,where ph(G 1 )stands for complete exchange phases of G 1 and|G 2 |=n.

基于并行胶囊网络的声学场景分类

为解决卷积神经网络(CNN)忽略音频特征之间的空间关系、丢失姿态特征和时序性特征的问题,提出了基于并行胶囊网络的声学场景分类模型,选用胶囊网络和双向门控循环单元弥补CNN的缺陷。首先,该模型通过提取音频对数梅尔能量谱特征;然后,结合各模块优点对音频特征处理;最后,根据场景特征完成分类。通过在“国际声学场景和事件检测及分类(DCASE)挑战赛2019”挑战任务1数据集下进行实验,在开发集和验证集上分别获得了71.1%和70.2%的准确率,优于基线系统的准确率,证明了该网络模型适用于声学场景分类任务。

一种基于分段并行思想的PCB布线加速策略

基于网格的搜索布线方式是印制电路板PCB自动布线的主要手段.随着电路系统的规模不断增大、功能日益复杂,PCB布线设计的挑战也不断增大.针对PCB布线地图规模较大且元器件障碍物较多的布线场景,常用的Lees和A*等布线算法突显出着搜索空间迅速增大且无法有效解决多网络布线顺序的问题.由此,提出一种基于分段并行思想的布线加速策略以提升布线效率.其基本思路为:将一个较大区域内的搜索问题分解成多个小区域内的并行搜索问题,并且针对不同区域内障碍物的特征采用自适应的启发引导函数,从而实现有效减少搜索空间、加快搜索速度、优化布线效果.模拟实验表明,在150×150的网格布线场景中,所提方法与Lees算法和A*算法相比较,搜索速度分别可提升160倍和17倍.

面向大规模图数据的关键词覆盖最优路径规划方法

针对个性化自驾游路径规划中存在规划路径无法满足不同用户个性化需求的问题,提出了基于不同用户兴趣点的关键词覆盖最优路径规划方法。首先,建立路网信息预处理模型并通过路网信息预处理算法绘制路网信息查询图;其次,使用倒排索引算法根据用户设定的个性化需求对路网信息查询图进行剪枝,在减小大规模数据处理内存开销的同时提升了关键词覆盖最优路径规划方法的执行效率;最后,通过双向并行拓展方式的关键词覆盖最优路径拓展算法实现满足用户兴趣点的个性化旅游路径推荐。实验结果表明,关键词覆盖最优路径规划方法不仅实现了满足用户个性化需求的路径规划,而且通过剪枝和双向并行拓展的方式提高了方法的执行效率。

Toward path reliability by using adaptive multi-path routing mechanism for multimedia service in mobile Ad-hoc network

Traditional multi-path routing mechanisms aim to establish complete node or link disjoint paths. However, under some circumstances if multiple paths cannot be established based on the current network topology, the traditional multi-path routing mechanism will degenerate into single path routing mechanism, thus the advantages of multi-path routing cannot be exhibited. To enhance the end-to-end path reliability, an adaptive multi-path routing mechanism with path segment is proposed, in which multi-path can be established at part of the end-to-end path. In this way the reliability of the path can be enhanced. This path segment mechanism can divide the end-to-end path into several short segments, and a parallel forwarding mechanism is proposed for guaranteeing the quality of service of multimedia services over the wireless network. Simulations show that the network performance metrics such as the packet delivery ratio, the end-to-end delay and the number of route discoveries are all improved by using the adaptive multi-path routing mechanism.

Research of multi-path routing based on network coding in space information networks

A multi-path routing algorithm based on network coding is proposed for combating long propagation delay and high bit error rate of space information networks. On the basis of traditional multi-path routing, the algorithm uses a random linear network coding strategy to code data pack- ets. Code number is determined by the next hop link status and the number of current received packets sent by the upstream node together. The algorithm improves retransmission and cache mechanisms through using redundancy caused by network coding. Meanwhile, the algorithm also adopts the flow distribution strategy based on time delay to balance network load. Simulation results show that the proposed routing algorithm can effectively improve packet delivery rate, reduce packet delay, and enhance network performance.

Distributed Multi-hop Clustering Approach with Low Energy Consumption in WSN

The purpose of sensing the environment and geographical positions,device monitoring,and information gathering are accomplished using Wireless Sensor Network(WSN),which is a non-dependent device consisting of a distinct collection of Sensor Node(SN).Thus,a clustering based on Energy Efficient(EE),one of the most crucial processes performed in WSN with distinct environments,is utilized.In order to efficiently manage energy allocation during sensing and communication,the present research on managing energy efficiency is performed on the basis of distributed algorithm.Multiples of EE methods were incapable of supporting EE routing with MIN-EC in WSN in spite of the focus of EE methods on energy harvesting and minimum Energy Consumption(EC).The three stages of performance are proposed in this research work.At the outset,during routing and Route Searching Time(RST)with fluctuating node density and PKTs,EC is reduced by the Hybrid Energy-based Multi-User Routing(HEMUR)model proposed in this work.Energy efficiency and an ideal route for various SNs with distinct PKTs in WSN are obtained by this model.By utilizing the Approximation Algorithm(AA),the Bregman Tensor Approximation Clustering(BTAC)is applied to improve the Route Path Selection(RPS)efficiency for Data Packet Transmission(DPT)at the Sink Node(SkN).The enhanced Network Throughput Rate(NTR)and low DPT Delay are provided by BTAC.To MAX the Clustering Efficiency(CE)and minimize the EC,the Energy Effective Distributed Multi-hop Clustering(GISEDC)method based on Generalized Iterative Scaling is implemented.The Multi-User Routing(MUR)is used by the HEMUR model to enhance the EC by 20%during routing.When compared with other advanced techniques,the Average Energy Per Packet(AEPP)is enhanced by 39%with the application of proportional fairness with Boltzmann Distribution(BD).The Gaussian Fast Linear Combinations(GFLC)with AA are applied by BTAC method with an enhanced Communication Overhead(COH)for an increase in performance by 19%and minimize the DPT delay by 23%.When compared with the rest of the advanced techniques,CE is enhanced by 8%and EC by 27%with the application of GISEDC method.