1,086 research outputs found

    A Channel Model for Wireless Underground Sensor Networks Using Lateral Waves

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    Wireless Underground Sensor Networks (WUSNs) are an emerging type of wireless sensor networks (WSNs), where sensor nodes are located under the ground and communicate through soil. The major challenge in the development of efficient communication protocols for WUSNs is the characterization of the underground channel. So far, none of the existing models fully capture all the components of electromagnetic signal propagation in the soil medium. In this paper, three major components that influence underground communication are identified: direct, reflected, and lateral waves, where the latter has not been analyzed for WUSNs so far. Accordingly, a closed-form three-wave (3W) channel model is developed based on EM propagation principles of signals through soil. The 3W channel model is shown to agree well with both underground testbed experiments and EM analysis based on Maxwell’s equations, which cannot be represented in closed-form

    A Channel Model for Wireless Underground Sensor Networks Using Lateral Waves

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    Wireless Underground Sensor Networks (WUSNs) are an emerging type of wireless sensor networks (WSNs), where sensor nodes are located under the ground and communicate through soil. The major challenge in the development of efficient communication protocols for WUSNs is the characterization of the underground channel. So far, none of the existing models fully capture all the components of electromagnetic signal propagation in the soil medium. In this paper, three major components that influence underground communication are identified: direct, reflected, and lateral waves, where the latter has not been analyzed for WUSNs so far. Accordingly, a closed-form three-wave (3W) channel model is developed based on EM propagation principles of signals through soil. The 3W channel model is shown to agree well with both underground testbed experiments and EM analysis based on Maxwell’s equations, which cannot be represented in closed-form

    Channel Characterization for Wireless Underground Sensor Networks

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    Wireless Underground Sensor Networks (WUSNs) are natural extensions of the established Wireless Sensor Network (WSN) phenomenon and consist of sensors buried underground which communicate through soil. WUSNs have the potential to impact a wide variety of applications including precision agriculture, environmental monitoring, border patrol, and infrastructure monitoring. The main difference between WUSNs and traditional wireless networks is the communication medium. However, a comprehensive wireless underground channel model for WUSNs has not been developed so far. In this thesis, the Soil Subsurface Wireless Communication (SSWC) channel model is developed based on an extensive empirical study in a large agriculture field. The results of the experiments provide important insights for the model, which have not been available in the wireless communication literature. The SSWC channel model captures the signal attenuation and bit error rate (BER) in underground settings based on five components: (1) The dielectric soil model estimates the soil permittivity based on soil parameters including soil moisture. (2) The direct wave model captures the attenuation of the line-of-sight signal between sender and receiver. (3) The reflected wave model considers the attenuation on the signal which is reflected at the soil surface before reaching the receiver. (4) The lateral wave model estimates the attenuation of a third front of waves that potentially reach the receiver. Due to the fact that a significant portion of the lateral waves’ propagation occurs over-the-air, this form of transmission is an excellent option to extend the communication range without increasing the power consumption. (5) The signal superposition model captures the phase shifting between the mentioned waves, the resulting attenuation, and the bit error rate. The SSWC model is validated through extensive underground experiments. To the best of our knowledge, this is the first channel model for the underground to underground communication in WUSNs with comprehensive set of features. The SSWC channel model is fundamental for the development of cross-layer communication solutions for WUSNs and for the development of underground to aboveground and aboveground to underground channel models for WUSNs

    Impacts of Soil Type and Moisture on the Capacity of Multi-Carrier Modulation in Internet of Underground Things

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    Unique interactions between soil and communication components in wireless underground communications necessitate revisiting fundamental communication concepts from a different perspective. In this paper, capacity profile of wireless underground (UG) channel for multi-carrier transmission techniques is analyzed based on empirical antenna return loss and channel frequency response models in different soil types and moisture values. It is shown that data rates in excess of 124 Mbps are possible for distances up to 12 m. For shorter distances and lower soil moisture conditions, data rates of 362 Mbps can be achieved. It is also shown that due to soil moisture variations, UG channel experiences significant variations in antenna bandwidth and coherence bandwidth, which demands dynamic subcarrier operation. Theoretical analysis based on this empirical data show that by adaption to soil moisture variations, 180% improvement in channel capacity is possible when soil moisture decreases. It is shown that compared to a fixed bandwidth system; soilbased, system and sub-carrier bandwidth adaptation leads to capacity gains of 56%-136%. The analysis is based on indoor and outdoor experiments with more than 1; 500 measurements taken over a period of 10 months. These semi-empirical capacity results provide further evidence on the potential of underground channel as a viable media for high data rate communication and highlight potential improvements in this area

    Internet of underground things in precision agriculture: Architecture and technology aspects

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    The projected increases in World population and need for food have recently motivated adoption of information technology solutions in crop fields within precision agriculture approaches. Internet Of Underground Things (IOUT), which consists of sensors and communication devices, partly or completely buried underground for real-time soil sensing and monitoring, emerge from this need. This new paradigm facilitates seamless integration of underground sensors, machinery, and irrigation systems with the complex social network of growers, agronomists, crop consultants, and advisors. In this paper, state-of-the-art communication architectures are reviewed, and underlying sensing technology and communication mechanisms for IOUT are presented. Moreover, recent advances in the theory and applications of wireless underground communication are also reported. Finally, major challenges in IOUT design and implementation are identified

    A First Look at Forensic Analysis of sailfishos

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    SailfishOS is a Linux kernel-based embedded device operation system, mostly deployed on cell phones. Currently, there is no sufficient research in this space, and at the same time, this operating system is gaining popularity, so it is likely for investigators to encounter it in the field. This paper focuses on mapping the digital artifacts pertinent to an investigation, which can be found on the filesystem of a phone running SailfishOS 3.2. Currently, there is no other known publicly available research and no commercially available solutions for the acquisition and analysis of this platform. This is a major gap, as the adoption of this OS is accelerating in emerging markets on low-cost devices. This paper presents many of the major forensics points of interest, such as call and text, log, phonebook, web browser artifacts as well as hardware-specific features
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