27 research outputs found

    Wireless Sensor Networks

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    The aim of this book is to present few important issues of WSNs, from the application, design and technology points of view. The book highlights power efficient design issues related to wireless sensor networks, the existing WSN applications, and discusses the research efforts being undertaken in this field which put the reader in good pace to be able to understand more advanced research and make a contribution in this field for themselves. It is believed that this book serves as a comprehensive reference for graduate and undergraduate senior students who seek to learn latest development in wireless sensor networks

    Preliminary Specification of Basic Services and Protocols

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    The objective of D5 is to provide a preliminary definition of basic services and protocols that will be necessary to program CORTEX applications made of sentient objects. Furthermore, the aim of D5 is also to provide an architectural view of the possible composition of services and relations among them. In this view, some services are intended to facilitate communication with certain required properties, others are fundamentally event-oriented services, providing extra functionality at a middleware level and, finally, the remaining services are essentially supporting services, which can be used by event and communication services, as well as directly by applications. More specifically, in terms of event and communication services the deliverable describes a content and cell based predictive routing protocol to provide predictability in mobile ad hoc environments as envisaged in CORTEX, it specifies the messages used by the TBMAC protocol and studies the inaccessibility of the latter, it specifies an event service that implements anonymous communication based on the publish-subscribe paradigm, it describes the deployment of event-channels on a CAN-bus network and, finally, it provides a preliminary specification of the interface of an adaptable timed event service (ATES). In terms of supporting services, the deliverable describes protocols for the implementation of all the basic services defined within the Timely Computing Base (TCB) and provides a specification of resource management services defined accordingly to a resource and task mode

    System support for client-server based interactive applications in ad hoc networks

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    With the emergence of wireless communications and mobile computing. new ways for people to interact with each other and their surrounding environment are emerging. Mobile devices, such as Personal Digital Assistants (PDAs) with wireless communication interfaces are able to communicate directly with each other if they are "close enough". If such devices are also able to act as message relays (routers), then a very powerful facility in the form of a mobile ad hoc network can be made available to applications. Although present day PDAs have sufficient networking and processing capabilities to support interesting interactive applications, as yet, there is hardly any software available for constructing and maintaining ad hoc networks and not many practical interactive applications have been built and tested. Rather, much of the research work is still at simulation and modelling stage. Thus it is difficult at this stage to decide what system support (middleware) for interactive applications a PDA should contain. This work is a step in the direction of remedying the situation by considering a class of applications where interactions between users can be supported by one of the nodes in the ad hoc network acting as a server. The thesis presents the design, implementation and evaluation of three such applications on PDAs, and based on that experience, describes what system support (middleware) for such applications is required. These applications are: Auction, Bingo game and Chatting that work over ad hoc networks. The work presented here can be used as a basis for deciding how the current generation of PDA operating systems can be extended for supporting ad hoc networking and what additional services are required for interactive applications.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    A wireless sensor network system for border security and crossing detection

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    The protection of long stretches of countries’ borders has posed a number of challenges. Effective and continuous monitoring of a border requires the implementation of multi-surveillance technologies, such as Wireless Sensor Networks (WSN), that work as an integrated unit to meet the desired goals. The research presented in this thesis investigates the application of topologically Linear WSN (LWSNs) to international border monitoring and surveillance. The main research questions studied here are: What is the best form of node deployment and hierarchy? What is the minimum number of sensor nodes to achieve k− barrier coverage in a given belt region? iven an appropriate network density, how do we determine if a region is indeed k−barrier covered? What are the factors that affect barrier coverage? How to organise nodes into logical segments to perform in-network processing of data? How to transfer information from the networks to the end users while maintaining critical QoS measures such as timeliness and accuracy. To address these questions, we propose an architecture that specifies a mechanism to assign nodes to various network levels depending on their location. These levels are used by a cross-layer communication protocol to achieve data delivery at the lowest possible cost and minimal delivery delay. Building on this levelled architecture, we study the formation of weak and strong barriers and how they determine border crossing detection probability. We propose new method to calculate the required node density to provide higher intruder detection rate. Then, we study the effect of people movement models on the border crossing detection probability. At the data link layer, new energy balancing along with shifted MAC protocol are introduced to further increase the network lifetime and delivery speed. In addition, at network layer, a routing protocol called Level Division raph (LD ) is developed. LD utilises a complex link cost measurement to insure best QoS data delivery to the sink node at the lowest possible cost. The proposed system has the ability to work independently or cooperatively with other monitoring technologies, such as drowns and mobile monitoring stations. The performance of the proposed work is extensively evaluated analytically and in simulation using real-life conditions and parameters. The simulation results show significant performance gains when comparing LD to its best rivals in the literature Dynamic Source Routing. Compared to DSR, LD achieves higher performance in terms of average end-to-end delays by up to 95%, packet delivery ratio by up to 20%, and throughput by up to 60%, while maintaining similar performance in terms of normalised routing load and energy consumption

    Radio Communications

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    In the last decades the restless evolution of information and communication technologies (ICT) brought to a deep transformation of our habits. The growth of the Internet and the advances in hardware and software implementations modified our way to communicate and to share information. In this book, an overview of the major issues faced today by researchers in the field of radio communications is given through 35 high quality chapters written by specialists working in universities and research centers all over the world. Various aspects will be deeply discussed: channel modeling, beamforming, multiple antennas, cooperative networks, opportunistic scheduling, advanced admission control, handover management, systems performance assessment, routing issues in mobility conditions, localization, web security. Advanced techniques for the radio resource management will be discussed both in single and multiple radio technologies; either in infrastructure, mesh or ad hoc networks

    MARIAN: A hybrid, metric-driven, agent-based routing protocol for multihop ad-hoc networks

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    Recent advances in technology provided the ground for highly dynamic, mobile, infrastructure-less networks, namely, ad-hoc networks. Despite their enormous benefits, the full potential cannot be reached unless certain issues are resolved. These mainly involve routing, as the lack of an infrastructure imposes a heavy burden on mobile devices that must maintain location information and route data packets in a multi-hop fashion. Specifically, typical adhoc routing devices, such as Personal Digital Assistants (PDAs), are limited in respect to the available throughput, life-time, and performance, that these may provide, as routing elements. Thus, there is a need for metric-driven ad-hoc routing, that is, devices should be utilised for routing according to their fitness, as different device types significantly vary in terms of routing fitness. In addition, a concrete agent-based approach can provide a set of advantages over a non-agent-based one, which includes: better design practice; and automatic reconfigurability.This research work aims to investigate the applicability of stationary and mobile agent technology in multi-hop ad-hoc routing. Specifically, this research proposes a novel hybrid, metric-driven, agent-based routing protocol for multi-hop ad-hoc networks that will enhance current routing schemes. The novelties that are expected to be achieved include: maximum network performance, increased scalability, dynamic adaptation, Quality of Service (QoS), energy conservation, reconfigurability, and security. The underlying idea is based on the fact that stationary and mobile agents can be ideal candidates for such dynamic environments due to their advanced characteristics, and thus offer state of the art support in terms of organising the otherwise disoriented network into an efficient and flexible hierarchical structure, classifying the routing fitness of participating devices, and therefore allow intelligent routing decisions to be taken on that basis

    MARIAN: A hybrid, metric-driven, agent-based routing protocol for multihop ad-hoc networks

    Get PDF
    Recent advances in technology provided the ground for highly dynamic, mobile, infrastructure-less networks, namely, ad-hoc networks. Despite their enormous benefits, the full potential cannot be reached unless certain issues are resolved. These mainly involve routing, as the lack of an infrastructure imposes a heavy burden on mobile devices that must maintain location information and route data packets in a multi-hop fashion. Specifically, typical adhoc routing devices, such as Personal Digital Assistants (PDAs), are limited in respect to the available throughput, life-time, and performance, that these may provide, as routing elements. Thus, there is a need for metric-driven ad-hoc routing, that is, devices should be utilised for routing according to their fitness, as different device types significantly vary in terms of routing fitness. In addition, a concrete agent-based approach can provide a set of advantages over a non-agent-based one, which includes: better design practice; and automatic reconfigurability.This research work aims to investigate the applicability of stationary and mobile agent technology in multi-hop ad-hoc routing. Specifically, this research proposes a novel hybrid, metric-driven, agent-based routing protocol for multi-hop ad-hoc networks that will enhance current routing schemes. The novelties that are expected to be achieved include: maximum network performance, increased scalability, dynamic adaptation, Quality of Service (QoS), energy conservation, reconfigurability, and security. The underlying idea is based on the fact that stationary and mobile agents can be ideal candidates for such dynamic environments due to their advanced characteristics, and thus offer state of the art support in terms of organising the otherwise disoriented network into an efficient and flexible hierarchical structure, classifying the routing fitness of participating devices, and therefore allow intelligent routing decisions to be taken on that basis

    Curracurrong: a stream processing system for distributed environments

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    Advances in technology have given rise to applications that are deployed on wireless sensor networks (WSNs), the cloud, and the Internet of things. There are many emerging applications, some of which include sensor-based monitoring, web traffic processing, and network monitoring. These applications collect large amount of data as an unbounded sequence of events and process them to generate a new sequences of events. Such applications need an adequate programming model that can process large amount of data with minimal latency; for this purpose, stream programming, among other paradigms, is ideal. However, stream programming needs to be adapted to meet the challenges inherent in running it in distributed environments. These challenges include the need for modern domain specific language (DSL), the placement of computations in the network to minimise energy costs, and timeliness in real-time applications. To overcome these challenges we developed a stream programming model that achieves easy-to-use programming interface, energy-efficient actor placement, and timeliness. This thesis presents Curracurrong, a stream data processing system for distributed environments. In Curracurrong, a query is represented as a stream graph of stream operators and communication channels. Curracurrong provides an extensible stream operator library and adapts to a wide range of applications. It uses an energy-efficient placement algorithm that optimises communication and computation. We extend the placement problem to support dynamically changing networks, and develop a dynamic program with polynomially bounded runtime to solve the placement problem. In many stream-based applications, real-time data processing is essential. We propose an approach that measures time delays in stream query processing; this model measures the total computational time from input to output of a query, i.e., end-to-end delay
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