239 research outputs found

    Intelligent Municipal Heritage Management Service in a Smart City: Telecommunication Traffic Characterizationand Quality of Service

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    [EN] The monitoring of cultural heritage is becoming common in cities to provide heritage preservation and prevent vandalism. Using sensors and video cameras for this task implies the need to transmit information. In this paper, the teletraffic that cameras and sensors generate is characterized and the transmissions¿ influence on the municipal communications network is evaluated. Then, we propose models for telecommunication traffic sources in an intelligent municipal heritage management service inside a smart sustainable city. The sources were simulated in a smart city scenario to find the proper quality of service (QoS) parameters for the communication network, using Valencia City as background. Specific sensors for intelligent municipal heritage management were selected and four telecommunication traffic sources were modelled according to real-life requirements and sensors datasheet. Different simulations were performed to find the proper CIR (Committed Information Rate) and PIR (Peak Information Rate) values and to study the effects of limited bandwidth networks. Packet loss, throughput, delay, and jitter were used to evaluate the network¿s performance. Consequently, the result was the selection of the minimum values for PIR and CIR that ensured QoS and thus optimized the traffic telecommunication costs associated with an intelligent municipal heritage management service.This work was partially supported by Spanish Government Projects TIN2013-47272-C2-1-R and TEC2015-71932-REDTRodríguez-Hernández, MA.; Jiang, Z.; Gomez-Sacristan, Á.; Pla, V. (2019). Intelligent Municipal Heritage Management Service in a Smart City: Telecommunication Traffic Characterizationand Quality of Service. Wireless Communications and Mobile Computing (Online). 1-10. https://doi.org/10.1155/2019/8412542S11

    Portable mud remover

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    Basically, the only way to remove mud is by using shovel. The process of removing mud usually need us to shovel out the mud, put it into buckets and carry it outside and by using a garden sprayer or hose to wash away mud from hard surfaces [1]. This is because there are no specific tools or products to remove the mud in our industries. In that case, our group had come up with an idea to design a “Portable Mud Remover” which is inspired from a lawnmower and vacuum as shown in Figure 10.1. The idea of using concept of lawnmower is because to make is the product is portable and easy to handling. The smallest types of lawnmower are pushed by a human user and are suitable for small space. The problem occurs for the pool vacuum is that the product is not suitable to suck the mud because it is not designed for a heavy duty work

    A critical analysis of research potential, challenges and future directives in industrial wireless sensor networks

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    In recent years, Industrial Wireless Sensor Networks (IWSNs) have emerged as an important research theme with applications spanning a wide range of industries including automation, monitoring, process control, feedback systems and automotive. Wide scope of IWSNs applications ranging from small production units, large oil and gas industries to nuclear fission control, enables a fast-paced research in this field. Though IWSNs offer advantages of low cost, flexibility, scalability, self-healing, easy deployment and reformation, yet they pose certain limitations on available potential and introduce challenges on multiple fronts due to their susceptibility to highly complex and uncertain industrial environments. In this paper a detailed discussion on design objectives, challenges and solutions, for IWSNs, are presented. A careful evaluation of industrial systems, deadlines and possible hazards in industrial atmosphere are discussed. The paper also presents a thorough review of the existing standards and industrial protocols and gives a critical evaluation of potential of these standards and protocols along with a detailed discussion on available hardware platforms, specific industrial energy harvesting techniques and their capabilities. The paper lists main service providers for IWSNs solutions and gives insight of future trends and research gaps in the field of IWSNs

    Simulation, performance and interference analysis of multi-user visible light communication systems

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    The emergence of new physical media such as optical wireless, and the ability to aggregate these new media with legacy networks motivate the study of heterogeneous network performance, especially with respect to the design of protocols to best exploit the characteristics of each medium. This study considers Visible Light Communications (VLC), which is expected to coexist with legacy and future radio frequency (RF) media. While most of the research on VLC has been done on optimizing the physical medium, research on higher network layers is only beginning to gain attention, requiring new analyses and tools for performance analysis. The first part of the dissertation concerns with developing a new ns3-based VLC module that can be used to study VLC-RF heterogeneous networks via simulation. The proposed ns3 module is developed based on existing models for intensity modulated LED signals operating as lighting units transmitting to optical receivers at indoor scales (meters). These models and the corresponding simulation model are validated using a testbed implemented with a software-defined radio (SDR) system, photodetector, phosphor-converted “white” LEDs, and under PSK and QAM modulation. Two scenarios are used in the validation of the VLC module: (i) using a receiver placed right bellow the transmitter with varying range, and (ii) using a receiver with a fixed range and varying angle of acceptance. Results indicate good correspondence between the simulated and actual testbed performance. Subsequently, it demonstrates how the VLC module can be used to predict the performance of a hybrid WiFi/VLC network simulated using the ns3 environment with UDP, TCP, and combined network traffic. The second part of the dissertation focuses on modeling interference at VLC system level based on variable pulse position modulation (VPPM) and variable on-off keying (VOOK) which are used in VLC to simultaneously provide lighting with dimming control as well as communication. The bit error performance of these modulation schemes is evaluated at VLC systems consisting of multiple transmitters-receivers pairs, where co-channels interference exists. The BER is derived by providing an in depth analysis that captures the signal structure of the interference in terms of the number of transmitters. This work dispenses with the Gaussian interference model which is not suitable when the number of interferers are few and the central limit theorem (CLT) cannot be applied. The result shows that under realistic small-room scenario, the analytical results closely match with that of simulation

    Mobility-aware hierarchical fog computing framework for Industrial Internet of Things (IIoT)

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    The Industrial Internet of Things (IIoTs) is an emerging area that forms the collaborative environment for devices to share resources. In IIoT, many sensors, actuators, and other devices are used to improve industrial efficiency. As most of the devices are mobile; therefore, the impact of mobility can be seen in terms of low-device utilization. Thus, most of the time, the available resources are underutilized. Therefore, the inception of the fog computing model in IIoT has reduced the communication delay in executing complex tasks. However, it is not feasible to cover the entire region through fog nodes; therefore, fog node selection and placement is still the challenging task. This paper proposes a multi-level hierarchical fog node deployment model for the industrial environment. Moreover, the scheme utilized the IoT devices as a fog node; however, the selection depends on energy, path/location, network properties, storage, and available computing resources. Therefore, the scheme used the location-aware module before engaging the device for task computation. The framework is evaluated in terms of memory, CPU, scalability, and system efficiency; also compared with the existing approach in terms of task acceptance rate. The scheme is compared with xFogSim framework that is capable to handle workload upto 1000 devices. However, the task acceptance ratio is higher in the proposed framework due to its multi-tier model. The workload acceptance ratio is 85% reported with 3000 devices; whereas, in xFogsim the ratio is reduced to approx. 68%. The primary reason for high workload acceptation is that the proposed solution utilizes the unused resources of the user devices for computations

    Smart Sensor Technologies for IoT

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    The recent development in wireless networks and devices has led to novel services that will utilize wireless communication on a new level. Much effort and resources have been dedicated to establishing new communication networks that will support machine-to-machine communication and the Internet of Things (IoT). In these systems, various smart and sensory devices are deployed and connected, enabling large amounts of data to be streamed. Smart services represent new trends in mobile services, i.e., a completely new spectrum of context-aware, personalized, and intelligent services and applications. A variety of existing services utilize information about the position of the user or mobile device. The position of mobile devices is often achieved using the Global Navigation Satellite System (GNSS) chips that are integrated into all modern mobile devices (smartphones). However, GNSS is not always a reliable source of position estimates due to multipath propagation and signal blockage. Moreover, integrating GNSS chips into all devices might have a negative impact on the battery life of future IoT applications. Therefore, alternative solutions to position estimation should be investigated and implemented in IoT applications. This Special Issue, “Smart Sensor Technologies for IoT” aims to report on some of the recent research efforts on this increasingly important topic. The twelve accepted papers in this issue cover various aspects of Smart Sensor Technologies for IoT

    Wireless Channel Path-Loss Modelling for Agricultural and Vegetation Environments: A Survey

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    This work undertakes an extensive survey of the channel modelling methods and path-loss characterization carried out in agricultural fields and vegetation environments in an attempt to study the state-of-the-art in this field, which, though vastly explored, still presents extremely diverse opportunities and challenges. The interface for communication between nodes in a typical agricultural field is the wireless channel or air interface, making it imperative to address the impairments that are exclusive to such a communication scenario by studying the characteristics of the medium. The performance of the channel is a direct indicator of the quality of communication. It is required to have a lucid understanding of the channel to ensure quality in transmission of the required information, while simultaneously ensuring maximum capacity by employing limited resources. The impairments that are the very nature of a typical wireless channel are treated in an explicit manner covering the theoretical and mathematical models, analytical aspects and empirical models. Although there are several propagation models characterized for generic indoor and outdoor environments, these cannot be applied to agricultural, vegetation, forest and foliage scenarios due to the various additional factors that are specific to these environments. Owing to the wide variety, size, properties and span of the foliage, it also becomes extremely challenging to develop a generic predictive model for all kinds of crops or vegetation. The survey is categorized into fields containing specific crops, greenhouse environment and forest/foliage scenarios and the key findings are presented
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