18 research outputs found

    Energy-efficient routing in the proximity of a complicated hole in wireless sensor networks

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    AbstractA quest for geographic routing schemes of wireless sensor networks when sensor nodes are deployed in areas with obstacles has resulted in numerous ingenious proposals and techniques. However, there is a lack of solutions for complicated cases wherein the source or the sink nodes are located close to a specific hole, especially in cavern-like regions of large complex-shaped holes. In this paper, we propose a geographic routing scheme to deal with the existence of complicated-shape holes in an effective manner. Our proposed routing scheme achieves routes around holes with the (1+ϵ\epsilon ϵ )-stretch. Experimental results show that our routing scheme yields the highest load balancing and the most extended network lifetime compared to other well-known routing algorithms as well

    A Survey on Energy Efficient Routing Protocols in Wireless Sensor Networks

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    Energy efficiency is one of the critical issues in the Wireless Sensor Networks (WSNs), since sensor devices are tiny and integrated with a limited capacity battery. In most of the advanced applications, WSNs operate in very harsh areas and not under supervision of human controls. Routing protocols play a significant role in energy balancing by incorporating the techniques that can reduce control overhead, proper data aggregation method and feasible path selection. It demands a unique requirement due to its frequent topology changes and distributive nature. One of the major concerns in the design of routing protocol in WSNs is efficient energy usage and prolonging Network lifetime. This paper mainly discusses different issues related to energy efficiency in routing protocols of all categories. It incorporates most recent routing protocols which improves the energy efficiency in various application environments. This paper also provides comprehensive details of each protocol which emphasize their principles and explore their advantages and limitations. These protocols belong to different classifications based on Network Structures, communication model, topology and QoS parameters. It also includes more relevant and prominent comparisons with all recent State-of-Art works

    GRACO: a geographic GReedy routing with an ACO-based void handling technique

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    Geographic routing has gained much attention as a basic routing primitive inwireless sensor networks due to its memory-less, scalability, efficiency and low overheadfeatures. Greedy forwarding is the simplest geographic routing scheme, it uses the distanceas a forwarding criterion. Nevertheless, it may suffer from communication holes, whereno next hop candidate is closer to the destination than the node currently holding thepacket. For this purpose, a void handling technique is needed to recover from the voidproblem and successfully deliver data packets if a path does exist between source anddestination nodes. Many approaches have been reported to solve this issue at the expenseof extra processing and or overhead. This paper proposes GRACO, an efficient geographicrouting protocol with a novel void recovery strategy based on ant colony optimization(ACO). GRACO is able to adaptively adjust the forwarding mechanism to avoid theblocking situation and effectively deliver data packets. Compared to GFG, one of the bestperforming geographic routing protocols, simulation results demonstrate that GRACOcan successfully find shorter routing paths with higher delivery rate, less control packetoverhead and shorter end-to-end delay

    Challenges and Solutions for Location-based Routing in Wireless Sensor Networks with Complex Network Topology

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    Complex Network Topologies (CNTs)–network holes and cuts–often occur in practical WSN deployments. Many researchers have acknowledged that CNTs adversely affect the performance of location-based routing and proposed various CNT- aware location-based routing protocols. However, although they aim to address practical issues caused by CNTs, many proposed protocols are either based on idealistic assumptions, require too much resources, or have poor performance. Additionally, proposed protocols are designed only for a single routing primitive–either unicast, multicast, or convergecast. However, as recent WSN applications require diverse traffic patterns, the need for an unified routing framework has ever increased. In this dissertation, we address these main weaknesses in the research on location- based routing. We first propose efficient algorithms for detecting and abstracting CNTs in the network. Using these algorithms, we present our CNT-aware location- based unicast routing protocol that achieves the guaranteed small path stretch with significantly reduced communication overhead. We then present our location-based multicast routing protocol that finds near optimal routing paths from a source node to multicast member nodes, with efficient mechanisms for controllable packet header size and energy-efficient recovery from packet losses. Our CNT-aware convergecast routing protocol improves the network lifetime by identifying network regions with concentrated network traffic and distributing the traffic by using the novel concept of virtual boundaries. Finally, we present the design and implementation details of our unified routing framework that seamlessly integrates proposed unicast, multicast, and convergecast routing protocols. Specifically, we discuss the issues regarding the implementation of our routing protocols on real hardware, and the design of the framework that significantly reduces the code and memory size to fit in a resource constrained sensor mote. We conclude with a proactive solution designed to cope with CNTs, where mobile nodes are used for “patching” CNTs to restore the network connectivity and to optimize the network performance

    Algorithmen für Topologiebewusstsein in Sensornetzen

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    This work deals with algorithmic and geometric challenges in wireless sensor networks (WSNs). Classical algorithm theory, with a single processor executing one sequential program while having access to the complete data of the problem at hand, does not suit the needs of WSNs. Instead, we need distributed protocols where nodes collaboratively solve problems that are too complex for a single node. First we analyze a location problem, where the nodes obtain a sense of the network topology and their position in it. Computing coordinates in a global coordinate system is NP-hard in almost all relevant variants. So we present a completely new approach instead. The network builds clusters and constructs an abstract graph that closely reflects the topology of the network region. The resulting topology awareness suits the needs of some applications much better than the coordinate-based approach. In the second part, we present a novel flow problem, which adds battery constraints to dynamic network flows. Given a time horizon, we seek a flow from source to sink that maximizes the total amount of delivered data. As there is no prior work on this problem, we also analyze it in a centralized setting. We prove complexity results for several variants and present approximation schemes. The third part introduces the WSN simulator Shawn. By letting the user choose among different geometric communication models and data structures for the resulting graph, Shawn can adapt to many different setups, including mobile ones. Due to its design, Shawn is much faster than comparable simulation environments.Die vorliegende Arbeit beschäftigt sich mit algorithmischen und geometrischen Fragestellungen in Sensornetzwerken. Im Gegensatz zur klassischen Algorithmik, bei der ein einzelner Prozessor sequenziell Anweisungen abarbeitet und vollen Zugriff auf die Probleminstanz hat, werden hier verteilte Protokolle benötigt, bei denen die Knoten gemeinsam eine Aufgabe bewältigen, zu der sie allein nicht in der Lage wären. Zuerst untersuchen wir das grundlegende Problem, wie Sensorknoten ein Bewusstsein für ihre Position erlangen können. Motiviert daraus, dass das Problem, Koordinaten für ein globales Koordinatensystem zu bestimmen, in fast allen Varianten NP-schwer ist, wird ein vollkommen neuer Ansatz skizziert, bei dem das Netzwerk selbständig geometrische Cluster bildet und einen abstrakten Graphen konstruiert, der die Topologie des zugrunde liegenden Gebiets sehr genau widerspiegelt. Das sich daraus ergebende Positionsbewusstsein ist für einige Anwendungen dem klassischen euklidischen Ansatz deutlich überlegen. Der zweite Teil widmet sich einem Flussproblems für Sensornetzwerke, dass klassische dynamische Flüsse um Batteriebeschränkungen erweitert. Gesucht ist ein Fluss, der für gegebenen Zeithorizont die Datenmenge maximiert, die von einer Quelle zur Senke geschickt werden kann. Dieses Problem wird auch im zentralisierten Modell untersucht, da keine Vorarbeiten existieren. Wir beweisen Komplexitäten von Problemvarianten und entwickeln Approximationsschemata. Der dritte Teil stellt den Netzwerksimulator Shawn vor. Da der Benutzer zwischen verschiedenen geometrischen Kommunikationsmodellen wählen kann und das Speichermodell für den daraus resultierenden Graphen an den verfügbaren Speicher sowie an Simulationsparameter wie eventuell mögliche Mobilität der Knoten anpassen kann, ist Shawn hochflexibel und gleichzeitig deutlich schneller als vergleichbare Simulationsumgebungen

    Mobile Ad-Hoc Networks

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    Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: vehicular ad-hoc networks, security and caching, TCP in ad-hoc networks and emerging applications. It is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks

    Bioinspired metaheuristic algorithms for global optimization

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    This paper presents concise comparison study of newly developed bioinspired algorithms for global optimization problems. Three different metaheuristic techniques, namely Accelerated Particle Swarm Optimization (APSO), Firefly Algorithm (FA), and Grey Wolf Optimizer (GWO) are investigated and implemented in Matlab environment. These methods are compared on four unimodal and multimodal nonlinear functions in order to find global optimum values. Computational results indicate that GWO outperforms other intelligent techniques, and that all aforementioned algorithms can be successfully used for optimization of continuous functions

    Experimental Evaluation of Growing and Pruning Hyper Basis Function Neural Networks Trained with Extended Information Filter

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    In this paper we test Extended Information Filter (EIF) for sequential training of Hyper Basis Function Neural Networks with growing and pruning ability (HBF-GP). The HBF neuron allows different scaling of input dimensions to provide better generalization property when dealing with complex nonlinear problems in engineering practice. The main intuition behind HBF is in generalization of Gaussian type of neuron that applies Mahalanobis-like distance as a distance metrics between input training sample and prototype vector. We exploit concept of neuron’s significance and allow growing and pruning of HBF neurons during sequential learning process. From engineer’s perspective, EIF is attractive for training of neural networks because it allows a designer to have scarce initial knowledge of the system/problem. Extensive experimental study shows that HBF neural network trained with EIF achieves same prediction error and compactness of network topology when compared to EKF, but without the need to know initial state uncertainty, which is its main advantage over EKF

    A bypassing void routing combining of geographic and virtual coordinate information for WSN

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