1,234 research outputs found

    Dependable wireless sensor networks for in-vehicle applications

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    Intrusion tolerant routing with data consensus in wireless sensor networks

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    Dissertação para obtenção do Grau de Mestre em Engenharia InformáticaWireless sensor networks (WSNs) are rapidly emerging and growing as an important new area in computing and wireless networking research. Applications of WSNs are numerous, growing, and ranging from small-scale indoor deployment scenarios in homes and buildings to large scale outdoor deployment settings in natural, industrial, military and embedded environments. In a WSN, the sensor nodes collect data to monitor physical conditions or to measure and pre-process physical phenomena, and forward that data to special computing nodes called Syncnodes or Base Stations (BSs). These nodes are eventually interconnected, as gateways, to other processing systems running applications. In large-scale settings, WSNs operate with a large number of sensors – from hundreds to thousands of sensor nodes – organised as ad-hoc multi-hop or mesh networks, working without human supervision. Sensor nodes are very limited in computation, storage, communication and energy resources. These limitations impose particular challenges in designing large scale reliable and secure WSN services and applications. However, as sensors are very limited in their resources they tend to be very cheap. Resilient solutions based on a large number of nodes with replicated capabilities, are possible approaches to address dependability concerns, namely reliability and security requirements and fault or intrusion tolerant network services. This thesis proposes, implements and tests an intrusion tolerant routing service for large-scale dependable WSNs. The service is based on a tree-structured multi-path routing algorithm, establishing multi-hop and multiple disjoint routes between sensors and a group of BSs. The BS nodes work as an overlay, processing intrusion tolerant data consensus over the routed data. In the proposed solution the multiple routes are discovered, selected and established by a self-organisation process. The solution allows the WSN nodes to collect and route data through multiple disjoint routes to the different BSs, with a preventive intrusion tolerance approach, while handling possible Byzantine attacks and failures in sensors and BS with a pro-active recovery strategy supported by intrusion and fault tolerant data-consensus algorithms, performed by the group of Base Stations

    Achieving reliable and enhanced communication in vehicular ad hoc networks (VANETs)

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    A thesis submitted to the University of Bedfordshire in partial fulfilment of the requirement for the degree of Doctor of PhilosophyWith the envisioned age of Internet of Things (IoTs), different aspects of Intelligent Transportation System (ITS) will be linked so as to advance road transportation safety, ease congestion of road traffic, lessen air pollution, improve passenger transportation comfort and significantly reduce road accidents. In vehicular networks, regular exchange of current position, direction, speed, etc., enable mobile vehicle to foresee an imminent vehicle accident and notify the driver early enough in order to take appropriate action(s) or the vehicle on its own may take adequate preventive measures to avert the looming accident. Actualizing this concept requires use of shared media access protocol that is capable of guaranteeing reliable and timely broadcast of safety messages. This dissertation investigates the use of Network Coding (NC) techniques to enrich the content of each transmission and ensure improved high reliability of the broadcasted safety messages with less number of retransmissions. A Code Aided Retransmission-based Error Recovery (CARER) protocol is proposed. In order to avoid broadcast storm problem, a rebroadcasting vehicle selection metric η, is developed, which is used to select a vehicle that will rebroadcast the received encoded message. Although the proposed CARER protocol demonstrates an impressive performance, the level of incurred overhead is fairly high due to the use of complex rebroadcasting vehicle selection metric. To resolve this issue, a Random Network Coding (RNC) and vehicle clustering based vehicular communication scheme with low algorithmic complexity, named Reliable and Enhanced Cooperative Cross-layer MAC (RECMAC) scheme, is proposed. The use of this clustering technique enables RECMAC to subdivide the vehicular network into small manageable, coordinated clusters which further improve transmission reliability and minimise negative impact of network overhead. Similarly, a Cluster Head (CH) selection metric ℱ(\u1d457) is designed, which is used to determine and select the most suitably qualified candidate to become the CH of a particular cluster. Finally, in order to investigate the impact of available radio spectral resource, an in-depth study of the required amount of spectrum sufficient to support high transmission reliability and minimum latency requirements of critical road safety messages in vehicular networks was carried out. The performance of the proposed schemes was clearly shown with detailed theoretical analysis and was further validated with simulation experiments

    Supporting Cyber-Physical Systems with Wireless Sensor Networks: An Outlook of Software and Services

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    Sensing, communication, computation and control technologies are the essential building blocks of a cyber-physical system (CPS). Wireless sensor networks (WSNs) are a way to support CPS as they provide fine-grained spatial-temporal sensing, communication and computation at a low premium of cost and power. In this article, we explore the fundamental concepts guiding the design and implementation of WSNs. We report the latest developments in WSN software and services for meeting existing requirements and newer demands; particularly in the areas of: operating system, simulator and emulator, programming abstraction, virtualization, IP-based communication and security, time and location, and network monitoring and management. We also reflect on the ongoing efforts in providing dependable assurances for WSN-driven CPS. Finally, we report on its applicability with a case-study on smart buildings

    大規模システムLSI設計のための統一的ハードウェア・ソフトウェア協調検証手法

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    Currently, the complexity of embedded LSI system is growing faster than the productivity of system design. This trend results in a design productivity gap, particularly in tight development time. Since the verification task takes bigger part of development task, it becomes a major challenge in LSI system design. In order to guarantee system reliability and quality of results (QoR), verifying large coverage of system functionality requires huge amount of relevant test cases and various scenario of evaluations. To overcome these problems, verification methodology is evolving toward supporting higher level of design abstraction by employing HW-SW co-verification. In this study, we present a novel approach for verification LSI circuit which is called as unified HW/SW co-verification framework. The study aims to improve design efficiency while maintains implementation consistency in the point of view of system-level performance. The proposed data-driven simulation and flexible interface of HW and SW design become the backbone of verification framework. In order to avoid time consuming, prone error, and iterative design spin-off in a large team, the proposed framework has to support multiple design abstractions. Hence, it can close the loop of design, exploration, optimization, and testing. Furthermore, the proposed methodology is also able to co-operate with system-level simulation in high-level abstraction, which is easy to extend for various applications and enables fast-turn around design modification. These contributions are discussed in chapter 3. In order to show the effectiveness and the use-cases of the proposed verification framework, the evaluation and metrics assessments of Very High Throughput wireless LAN system design are carried out. Two application examples are provided. The first case in chapter 4 is intended for fast verification and design exploration of large circuit. The Maximum Likelihood Detection (MLD) MIMO decoder is considered as Design Under Test (DUT). The second case, as presented in chapter 5, is the evaluation for system-level simulation. The full transceiver system based on IEEE 802.11ac standard is employed as DUT. Experimental results show that the proposed verification approach gives significant improvements of verification time (e.g. up to 10,000 times) over the conventional scheme. The proposed framework is also able to support various schemes of system level evaluations and cross-layer evaluation of wireless system.九州工業大学博士学位論文 学位記番号:情工博甲第328号 学位授与年月日:平成29年6月30日1 Introduction|2 Design and Verification in LSI System Design|3 Unified HW/SW Co-verification Methodology|4 Fast Co-verification and Design Exploration in Complex Circuits|5 Unified System Level Simulator for Very High Throughput Wireless Systems|6 Conclusion and Future Work九州工業大学平成29年

    Revised reference model

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    This document contains an update of the HIDENETS Reference Model, whose preliminary version was introduced in D1.1. The Reference Model contains the overall approach to development and assessment of end-to-end resilience solutions. As such, it presents a framework, which due to its abstraction level is not only restricted to the HIDENETS car-to-car and car-to-infrastructure applications and use-cases. Starting from a condensed summary of the used dependability terminology, the network architecture containing the ad hoc and infrastructure domain and the definition of the main networking elements together with the software architecture of the mobile nodes is presented. The concept of architectural hybridization and its inclusion in HIDENETS-like dependability solutions is described subsequently. A set of communication and middleware level services following the architecture hybridization concept and motivated by the dependability and resilience challenges raised by HIDENETS-like scenarios is then described. Besides architecture solutions, the reference model addresses the assessment of dependability solutions in HIDENETS-like scenarios using quantitative evaluations, realized by a combination of top-down and bottom-up modelling, as well as verification via test scenarios. In order to allow for fault prevention in the software development phase of HIDENETS-like applications, generic UML-based modelling approaches with focus on dependability related aspects are described. The HIDENETS reference model provides the framework in which the detailed solution in the HIDENETS project are being developed, while at the same time facilitating the same task for non-vehicular scenarios and application

    In-band network telemetry in industrial wireless sensor networks

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    With the emergence of the Internet of Things (IoT) and Industry 4.0 concepts, industrial applications are going through a tremendous change that is imposing increasingly diverse and demanding network dynamics and requirements with a wider and more fine-grained scale. Therefore, there is a growing need for more flexible and reconfigurable industrial networking solutions complemented with powerful monitoring and management functionalities. In this sense, this paper presents a novel efficient network monitoring and telemetry solution for Industrial Wireless Sensor Networks mainly focusing on the 6TiSCH Network stack, a complete protocol stack for ultra-reliable ultra-low-power wireless mesh networks. The proposed monitoring solution creates a flexible and powerful in-band network telemetry design with minimized resource consumption and communication overhead while supporting a wide range of monitoring operations and strategies for dealing with various network scenarios and use cases. Besides, the technical capabilities and characteristics of the proposed solution are evaluated via a real-life implementation, practical and theoretical analysis. These experiments demonstrate that in-band telemetry can provide ultra-efficient network monitoring operations without any effect on the network behavior and performance, validating its suitability for Industrial Wireless Sensor Networks

    Provisioning Quality of Service of Wireless Telemedicine for E-Health Services: A Review

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    In general, on-line medical consultation reduces time required for medical consultation and induces improvement in the quality and efficiency of healthcare services. The scope of study includes several key features of present day e-health applications such as X-ray, ECG, video, diagnosis images and other common applications. Moreover, the provision of Quality of Service (QoS) in terms of specific medical care services in e-health, the priority set for e-health services and the support of QoS in wireless networks and techniques or methods aimed at IEEE 802.11 to secure the provision of QoS has been assessed as well. In e-health, medical services in remote places which include rustic healthcare centres, ships, ambulances and home healthcare services can be supported through the applications of e-health services such as medical databases, electronic health data and the transferring of text, video, sound and images. Given this, a proposal has been made for a multiple service wireless networking with multiple sets of priorities. In relation to the terms of an acceptable QoS level by the customers of e-health services, prioritization is an important criterion in a multi-traffic network. The requirement for QoS in medical networking of wireless broadband has paved the way for bandwidth prerequisites and the live transmission or real-time medical applications. The proposed wireless network is capable of handling medical applications for both normal and life-threatening conditions as characterized by the level of emergencies. In addition, the allocation of bandwidth and the system that controls admittance designed based on IEEE 802.16 especially for e-health services or wireless telemedicine will be discussed in this study. It has been concluded that under busy traffic conditions, the proposed architecture can used as a feasible and reliable infrastructure network for telemedicine
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