无线传感网络移动分簇路由策略

无线传感网络(WSN)路由协议中,分簇路由具有拓扑管理方便、能量高效和数据融合简单等优点,成为当前重点研究的路由技术。通过研究各种环境下的移动传感器网络,有效地降低能耗则是研究移动无线传感器网络的重要目的之一。针对无线传感网络中移动性问题,基于LEACH协议,利用移动传感器网络中节点距离、速度和剩余能量等因素提出了能量高效的移动分簇路由算法。实验结果表明此算法能够较好地支持节点移动,从而降低网络能耗,延长网络生存时间。     

BGP-S: A Protocol for Terrestrial and Satellite Network Integration in Network Layer

To accomplish network layer integration of terrestrial and satellite IP networks, special exterior gateway protocols are needed. In this work, a new exterior gateway protocol called Border Gateway Protocol – Satellite version (BGP-S) is introduced that enables automated discovery of paths that go through the satellite network. This protocol is designed to work in only one terrestrial gateway in every Autonomous System and enables the forwarding of discovered paths in the Internet using the BGP-4 protocol. The performance of BGP-S is investigated through simulations.     

传感器网络中一种分布式数据汇聚层次路由算法

由于传感器网络具有能量约束,低速率冗余数据和多对一传输等特点,传统的端到端集中式路由算法一般不适合传感器网络.提出了一种分布式数据汇聚层次路由算法,该算法利用能量核的思想汇聚数据和减少传输到目的节点的信息.模拟结果表明:比较传统的端到端集中式路由算法,该算法可以显著减少能量消耗;与一般的数据汇聚算法相比,该算法在保证能量消耗少的条件下,具有复杂度低和可扩展性好的特点.     

BOIN:一种新型无缓存高性能计算机光互连网络

 现有的高性能计算机光互连网络大都需要对数据报文进行光-电-光转换并缓存,或者需要预先申请并建立从源节点到目的节点的光链路,这在一定程度上限制了网络性能.提出了一种既不需要对光数据报文进行缓存排队,也不需要预先申请并建立光链路的新型的光互连网络结构BOIN.给出了BOIN网络上的无死锁和无活锁路由算法,推导出BOIN网络中数据传输的延时上界,并通过模拟实验对比了BOIN网络与其它两种典型的网络的性能.实验结果表明,BOIN光互连网络具有良好的延时和吞吐率特性,能够很好地满足高性能计算机系统的要求.     

DACOR: A distributed ACO-based routing protocol for mitigating the hot spot problem in fog-enabled WSN architecture

Ant colony optimization (ACO) and unequal clustering algorithms in wireless sensor networks (WSNs) prove their efficiency in protracting the network lifetime. However, the existing ACO and unequal clustering algorithms, respectively, do not consider jointly energy efficiency and reliability and focus only on some normal parameters to adjust the cluster radius, then neglecting the cluster head (CH) neighborhood information as it is wise to reduce the cluster radius when there are more neighbor CHs in order to balance the load and energy consumption. To resolve these problems, we propose a fault-tolerant distributed ACO-based routing (DACOR) protocol for mitigating the hot spot problem in fog-enabled WSN architecture. To improve the performance of the network, we propose a multiple fog nodes (FNs) and unequal clustering-based network model. The proposed model is energy efficient as it avoids repetitive clustering and affects CHs to FNs based on distance. Also, unlike the existing works which use either single FN/sink-based unequal clustering or multiple FNs/sinks to mitigate hot spot problem, we propose to distribute unequal clustering to multiple FNs (partitions). Additionally, we formulate a different rule to calculate the cluster radius based on significant parameters ensuring energy efficiency and balancing. To route data from source to destination, we devise a new probabilistic formula which considers not only energy efficiency but also reliability. The performance of the proposed DACOR protocol has been investigated under different scenarios through simulations. The results show that the proposed DACOR protocol outperforms the existing protocols in terms of various main metrics.     

A Distributed Virtual Backbone Development Scheme for Ad-Hoc Wireless Networks

The virtual backbone is an approach for solving routing problems in ad-hoc wireless networks. The virtual backbone approach features low latency, moderate routing overhead and is a hybrid scheme that uses the table-driven and on-demand routing protocols. This work presents a distributed virtual backbone development scheme for ad-hoc wireless networks. Using clustering, distributed labeling and heuristic Steiner tree techniques, our scheme outperforms other schemes in terms of the size and stability of the virtual backbone and the virtual backbone change rate. Experimental results demonstrate that our scheme has lower overhead than traditional table-driven and on-demand routing schemes. This revised version was published online in July 2006 with corrections to the Cover Date.     

A Scalable and Reliable Multicast Routing Protocol for Ad-hoc Wireless Networks

Multicasting is an essential service for ad-hoc wireless networks. In a multicasting environment with multiple senders, receivers or meeting members, traditional multicast routing protocols must pay great overhead for multiple multicast sessions. This work presents a scalable and reliable multicasting protocol for ad-hoc wireless networks. A virtual backbone is used as a shared structure for multiple sessions. A clustering scheme is used to reduce the routing path length. A novel scheme is developed to effectively multicast packets using forwarding gates. Furthermore, a lost packet recovery scheme is developed for reliable packet transmission. This scheme can be used to improve the reliability of traditional non-acknowledged multicasting approach. Experiments were conducted to evaluate the proposed multicasting scheme and the results demonstrate that our scheme outperforms other schemes in terms of packet delivery ratio, packet delivery time, control overhead, multicast efficiency, and cost effect. Furthermore, our approach is stable for networks with high mobility and the lost packet recovery scheme is cost-effective. Chyi-Ren Dow was born in 1962. He received the B.S. and M.S. degrees in information engineering from National Chiao Tung University, Taiwan, in 1984 and 1988, respectively, and the M.S. and Ph.D. degrees in computer science from the University of Pittsburgh, USA, in 1992 and 1994, respectively. Currently, he is a Professor in the Department of Information Engineering, Feng Chia University, Taiwan. His research interests include mobile computing, ad-hoc wireless networks, agent techniques, fault tolerance, and learning technology. Jyh-Horng Lin was born in 1975. He received the B.S. and M.S. degrees in information engineering from Feng Chia University, Taiwan, in 1998 and 2000, respectively. He is currently a candidate for the Ph.D. degree in the Department of Information Engineering, Feng Chia University, Taichung, Taiwan. His research interests include mobile computing and ad-hoc wireless networks. Kun-Tai Chen was born in 1978. He received the B.S. and M.S. degrees in information engineering from Feng Chia University, Taiwan, in 2000 and 2002, respectively. He is currently an engineer in the VIA technologies, Inc. Hsinchu branch, Taiwan. His research interests include mobile computing, ad-hoc wireless networks and video decoding. Sheng-Chang Chen was born in 1979. He received his B.S. degree and M.S. degree in information engineering from Feng Chia University, Taiwan, in 2001 and 2002. He is currently a Ph.D. degree in information engineering from Feng Chia University, Taiwan. His research interests include mobile computing, ad-hoc wireless network and fault tolerance technique. Shiow-Fen Hwang was born in 1963. She received her B.S., M.S. and Ph.D. degrees in Applied Mathematics from National Chiao Tung University, Taiwan, in 1985, 1987 and 1991, respectively. Currently, she is an Associate Professor in the Department of Information Engineering, Feng Chia University, Taiwan. Her research interests include interconnection networks, mobile computing, and computer algorithms.     

HDF: Hybrid Debugging Framework for Distributed Network Environments

Debugging in distributed environments, such as wireless sensor networks (WSNs), which consist of sensor nodes with limited resources, is an iterative and occasionally laborious process for programmers. In sensor networks, it is not easy to find unintended bugs that arise during development and deployment, and that are due to a lack of visibility into the nodes and a dearth of effective debugging tools. Most sensor network debugging tools are not provided with effective facilities such as real‐time tracing, remote debugging, or a GUI environment. In this paper, we present a hybrid debugging framework (HDF) that works on WSNs. This framework supports query‐based monitoring and real‐time tracing on sensor nodes. The monitoring supports commands to manage/control the deployed nodes, and provides new debug commands. To do so, we devised a debugging device called a Docking Debug‐Box (D2‐Box), and two program agents. In addition, we provide a scalable node monitor to enable all deployed nodes for viewing. To transmit and collect their data or information reliably, all nodes are connected using a scalable node monitor applied through the Internet. Therefore, the suggested framework in theory does not increase the network traffic for debugging on WSNs, and the traffic complexity is nearly O(1).     

A cluster‐based fault‐tolerant routing protocol for wireless sensor networks

Energy conservation and fault tolerance are two critical issues in the deployment of wireless sensor networks (WSNs). Many cluster‐based fault‐tolerant routing protocols have been proposed for energy conservation and network lifetime maximization in WSNs. However, these protocols suffer from high frequency of re‐clustering as well as extra energy consumption to tolerate failures and consider only some very normal parameters to form clusters without any verification of the energy sufficiency for data routing. Therefore, this paper proposes a cluster‐based fault‐tolerant routing protocol referred as CFTR. This protocol allows higher energy nodes to become Cluster Heads (CHs) and operate multiple rounds to diminish the frequency of re‐clustering. Additionally, for the sake to get better energy efficiency and balancing, we introduce a cost function that considers during cluster formation energy cost from sensor node to CH, energy cost from CH to sink, and another significant parameter, namely, number of cluster members in previous round. Further, the proposed CFTR takes care of nodes, which have no CH in their communication range. Also, it introduces a routing algorithm in which the decision of next hop CH selection is based on a cost function conceived to select routes with sufficient energy for data transfer and distribute uniformly the overall data‐relaying load among the CHs. As well, a low‐overhead algorithm to tolerate the sudden failure of CHs is proposed. We perform extensive simulations on CFTR and compare their results with those of two recent existing protocols to demonstrate its superiority in terms of different metrics.     

基于蚁群的无线电源管理网络路由算法

蚁群算法(Ant Colony Algorithm,ACA)是一种新型的基于群体的仿生算法。采用蚁群算法实现了对无线电源管理网络的路由优化,为远程设备管理提供了新的解决思路。对原始蚁群算法进行了改进,提出了一种多蚁群的优化算法。基于蚁群算法及其并行搜索最优的特征,通过蚁群聚类和动态调整网络优化参数的方法,可作为一种面向无线电源管理网络的路由算法,经过仿真验证了该算法的有效性。     

RPSF: A Routing Protocol with Selective Forwarding for Mobile Ad-Hoc Networks

Many existing reactive routing algorithms for mobile ad-hoc networks use a simple broadcasting mechanism for route discovery which can lead to a high redundancy of route-request messages, contention, and collision. Position-based routing algorithms address this problem but require every node to know the position and velocity of every other node at some point in time so that route requests can be propagated towards the destination without flooding the entire network. In a general ad-hoc network, each node maintaining the position information of every other node is expensive or impossible. In this paper, we propose a routing algorithm that addresses these drawbacks. Our algorithm, based on one-hop neighborhood information, allows each node to select a subset of its neighbors to forward route requests. This algorithm greatly reduces the number of route-request packets transmitted in the route-discovery process. We compare the performance of our algorithm with the well known Ad-hoc On-demand Distance Vector (AODV) routing algorithm. On average, our algorithm needs less than 12.6% of the routing-control packets needed by AODV. Simulation results also show that our algorithm has a higher packet-delivery ratio and lower average end-to-end delay than AODV.     

7号信令系统电话用户部分(TUP)的仿真设计

7号信令网是通信网中专门用来传送各节点之间网络信令的共路信令网络。由于其信令容量大,误码率低,传输效率高以及具有极强的兼容性等优点,而被广泛的运用于电话网、ISDN、移动通讯、智能网等各种网络通信业务中。本文介绍了7号信令网用户部分(TUP)的仿真系统,该系统针对7号信令网的教学需要,模拟了正常通话情况下电话用户部分信令传送及处理的全过程以及各种异常通话的信令传送及处理过程。为便于演示,在系统中加入了主被叫用户控制;为提高信令传送效率,在设计中采用了信令编码库和对信令传输通道进行复用;为使系统具有更强的可重用性和稳定性,在程序中设置各种相关数据为可修改值。     

基于内容的无线传感器网络路由协议

针对无线传感器网络环境下低功耗路由问题,根据无线传感器网络是一种以数据为中心的网络的特点,提出了一种基于内容的低功耗路由协议CBP。其基本思想是:Sink节点根据上层应用构造谓词,并对谓词进行广播,网络中所有传感节点以Sink节点的谓词为依据建立路由表,实现数据路由。与现有无线传感器网络路由协议相比较,此路由协议具有低功耗,占用节点资源少,网络容错能力强等特点。仿真结果表明,在节点数量大于100的大规模网络中,基于内容的无线传感器网络路由协议功耗比定向扩散协议功耗降低19%。     

Integrating Heterogeneous Wireless Technologies: A Cellular Aided Mobile Ad Hoc Network (CAMA)

A mobile ad hoc network is a collection of wireless terminals that can be deployed rapidly. Its deficiencies include limited wireless bandwidth efficiency, low throughput, large delays, and weak security. Integrating it with a well-established cellular network can improve communication and security in ad hoc networks, as well as enrich the cellular services. This research proposes a cellular-aided mobile ad hoc network (CAMA) architecture, in which a CAMA agent in the cellular network manages the control information, while the data is delivered through the mobile terminals (MTs). The routing and security information is exchanged between MTs and the agent through cellular radio channels. A position-based routing protocol, the multi-selection greedy positioning routing (MSGPR) protocol, is proposed. At times due to the complicated radio environment, the position information is not precise. Even in these cases, the MT can still find its reachable neighbors (the association) by exchanging hello messages. This association is used in complement with the position information to make more accurate routing decisions. Simulation results show that the delivery ratio in the ad hoc network is greatly improved with very low cellular overhead. The security issues in the proposed architecture and the corresponding solutions are addressed. The experimental study shows that CAMA is much less vulnerable than a pure ad hoc network.     

主题特征格分析:一种用户生成文本质量评估方法

本文设计了一种用户生成文本的质量分析框架.首先,基于主题分析构建商品类别主题特征集合.其次,利用主题特征与商品分类的强关联关系,构建形式化概念分析的形式背景,将分类-主题概念格化简并生成主题特征格,以此构建五个质量特征并生成质量评估模型.最后,在真实评论数据上的实验结果表明新方法具有更高预测精度.     

MERIT: A Scalable Approach for Protocol Assessment

MERIT is a framework that can be used to assess routing protocols in mobile ad hoc networks (manets). It uses the novel concept of a shortest mobile path (SMP) in a mobile graph, a generalization of the shortest path problem for mobile environments. As a measure for routing protocol assessment, we propose the mean ratio of the cost of the route used by a protocol to the cost of the optimal mobile path for the same network history. The cost reflects that the route used in a session can change over time because of network dynamics such as topology changes. The aim is for the ratio to be an abstract, inherent measure of the protocol that is as implementation-independent as possible. The MERIT spectrum, which is the ratio expressed as the function of some parameters of interest, is a characterization of protocol effectiveness. MERIT, for MEan Real vs. Ideal cosT, provides a scalable assessment framework: rather than comparing performance measures of different protocols directly, we compare a protocol to the optimal solution. That is, rather than forcing the comparison to be in the same system, it is done once for each protocol in its own environment. Furthermore, we show that there is an efficient algorithm to solve the underlying SMP problem for important cases, making the approach practically feasible. We also investigate generalizations of and extensions within the MERIT framework. We show that the MERIT framework is rich, with much wider generality and potential applicability than assessing routing protocols.     

Fuzzy-based techniques for clustering in wireless sensor networks (WSNs): Recent advances,challenges, and future directions

A wireless sensor network (WSN) is a network of tiny sensors deployed to collect data. These sensors are powered with batteries that have limited power. Recharging and/or replacement of these batteries, however, are not always feasible. Over the past few years, WSN applications are being deployed in diverse fields such as military, manufacturing, healthcare, agriculture, and so on. With the ever-increasing applications of WSNs, improving the energy efficiency of the WSNs still remains to be a challenge. Applying fuzzy logic to the problem of clustering exploits the uncertainty associated with the factors that affect the lifetime of these sensors and enables the development of models that would improve their performance in real-world applications. We present a comprehensive review of various fuzzy-based techniques for clustering in WSNs whose main goal is to optimize energy usage in WSNs while simultaneously improving their overall performance.     

一种优化FPGA布线拥塞的FHO-BP网络

超大集成电路的高度复杂化造成的布线拥塞可能导致电路的不可布性,早期的布线拥塞预测对于提高集成电路的最终设计质量非常关键,因此针对现场可编程门阵列(Field Programmable Gate Array, FPGA),引入火鹰优化(Fire Hawk Optimizer, FHO)算法机制优化反向传播(Back Propagation, BP)神经网络,提出一种基于复杂网络和FHO-BP网络的布线拥塞优化方法,将电路布局的复杂网络特征向量应用到布线拥塞度预测模型中,并利用提出的优化算法改善电路布线拥塞。实验结果表明,与经典的BP网络相比,所提FHO-BP预测模型具有更高的预测精度和收敛速度,决定系数达到92.62%,模型的平均训练时间为94.55 s,平均预测时间为0.57 s,并且利用布线拥塞优化算法对布局进行优化后的布线实际拥塞程度明显缓和。     

A Combined Clustering and Neural Network Approach for Analog Multiple Hard Fault Classification

A new neural network-based fault classification strategy for hard multiple faults in analog circuits is proposed. The magnitude of the harmonics of the Fourier components of the circuit response at different test nodes due to a sinusoidal input signal are first measured or simulated. A selection criterion for determining the best components that describe the circuit behaviour under fault-free (nominal) and fault situations is presented. An algorithm that estimates the overlap between different faults in the measurement space is also introduced. The learning vector quantization neural network is then effectively trained to classify circuit faults. Performance measures reveal very high classification accuracy in both training and testing stages. Two different examples, which demonstrate the proposed strategy, are described.     

A Quality of Service Support Module (QASM) for a Wireless Multi-Segment Integrated 3G Network

Deployment of IP multimedia services with guaranteed Quality of Service (QoS) is a primary requirement for Beyond 3G (B3G) systems. In this paper we propose a new architecture to support Internet QoS-sensitive services (e.g., video-conferencing, voice over IP, interactive gaming), thus providing users with end-to-end QoS guarantees. In particular, the paper discloses a new hybrid Intserv/Diffserv scheme for handling IP packets and an interworking procedure with the RSVP protocol which allows to support QoS over an integrated, multi-segment network. Such scheme is implemented by means of a suitable Quality of service Support Module (QASM). Advantages and drawbacks of QASM are discussed and the impact on both system architecture and Multi-Mode Mobile Terminal is investigated. Performance evaluations, carried out via computer simulations, confirm the effectiveness of the proposed solution.