Internet Of Underground Things Research Articles

Internet of Underground Things in Agriculture 4.0: Challenges, Applications and Perspectives.

Internet of underground things (IoUTs) and wireless underground sensor networks (WUSNs) are new technologies particularly relevant in agriculture to measure and transmit environmental data, enabling us to optimize both crop growth and water resource management. The sensor nodes can be buried anywhere, including in the passage of vehicles, without interfering with aboveground farming activities. However, to obtain fully operational systems, several scientific and technological challenges remain to be addressed. The objective of this paper is to identify these challenges and provide an overview of the latest advances in IoUTs and WUSNs. The challenges related to the development of buried sensor nodes are first presented. The recent approaches proposed in the literature to autonomously and optimally collect the data of several buried sensor nodes, ranging from the use of ground relays, mobile robots and unmanned aerial vehicles, are next described. Finally, potential agricultural applications and future research directions are identified and discussed.

Estimating Volumetric Water Content in Soil for IoUT Contexts by Exploiting RSSI-Based Augmented Sensors via Machine Learning.

This paper aims at proposing an augmented sensing method for estimating volumetric water content (VWC) in soil for Internet of Underground Things (IoUT) applications. The system exploits an IoUT sensor node embedding a low-cost, low-precision soil moisture sensor and a long-range wide-area network (LoRaWAN) transceiver sending relative measurements within LoRaWAN packets. The VWC estimation is achieved by means of machine learning (ML) algorithms combining the readings provided by the soil moisture sensor with the received signal strength indicator (RSSI) values measured at the LoRaWAN gateway side during broadcasting. A dataset containing such measurements was especially collected in the laboratory by burying the IoUT sensor node within a plastic case filled with sand, while several VWCs were artificially created by progressively adding water. The adopted ML algorithms are trained and tested using three different techniques for estimating VWC. Firstly, the low-cost, low-precision soil moisture sensor is calibrated by resorting to an ML model exploiting only its raw readings to estimate VWC. Secondly, a virtual VWC sensor is shown, where no real sensor readings are used because only LoRaWAN RSSIs are exploited. Lastly, an augmented VWC sensing method relying on the combination of RSSIs and soil moisture sensor readings is presented. The findings of this paper demonstrate that the augmented sensor outperforms both the virtual sensor and the calibrated real soil moisture sensor. The latter provides a root mean square error (RMSE) of 3.33%, a virtual sensor of 8.67%, and an augmented sensor of 1.84%, which improves down to 1.53% if filtered in post-processing.

A Top-Down Survey on Optical Wireless Communications for the Internet of Things

The Internet of Things (IoT) is a transformative technology marking the beginning of a new era where physical, biological, and digital worlds are integrated by connecting a plethora of uniquely identifiable smart objects. Although the Internet of Terrestrial Things (IoTT) has been at the center of our IoT perception, it has been recently extended to different environments, such as the Internet of Underwater Things (IoWT), the Internet of Biomedical Things (IoBT), and Internet of Underground Things (IoGT). Even though radio frequency (RF) based wireless networks are regarded as the default means of connectivity, they are not always the best option due to the limited spectrum, interference limitations caused by the ever-increasing number of devices, and severe propagation loss in transmission mediums other than air. As a remedy, optical wireless communication (OWC) technologies can complement, replace, or co-exist with audio and radio wave-based wireless systems to improve overall network performance. To this aim, this paper reveals the full potential of OWC-based IoT networks by providing a top-down survey of four main IoT domains: IoTT, IoWT, IoBT, and IoGT. Each domain is covered by a dedicated and self-contained section that starts with a comparative analysis, explains how OWC can be hybridized with existing wireless technologies, points out potential OWC applications fitting best the related IoT domain, and discusses open communication and networking research problems. More importantly, instead of presenting a visionary OWC-IoT framework, the survey discloses that OWC-IoT has become a reality by emphasizing ongoing proof-of-concept prototyping efforts and available commercial off-the-shelf (COTS) OWC-IoT products.

Self-Sensing Antenna for Soil Moisture: Beacon Approach.

On the way from the Internet of things (IoT) to the Internet of underground things (IoUT) the main challenge is antenna design. The enabling technologies still rely on simple design and low cost, but the systems are more complex. The LoRa-based system combined with a machine learning approach can be used for the estimation of soil moisture by using signal strength data, but for the improvement of the system performance we propose the optimization of the antenna for underground use. The soil properties are frequency-dependent and varying in time, which may cause variations in the signal wavelength and input impedance of the antenna underground. Instead of using wideband antenna design or standard helical antenna provided in LoRa module, which are typical in the IoUT research community for communication links, we propose a narrow-band antenna design for the application in soil moisture sensing. It is shown that the approach of simply matching the antenna buried in dry sand can provide a substantial signal level difference, ranging from approximately 10 dB (achieved by proof-of-concept measurements) to as much as 40 dB (calculated by a full wave simulator) in reflection coefficient when the moisture content is being increased by 20%. This can ensure more reliable radio sensing in novel sensorless technology where soil moisture information is extracted from the signal strength of a transmitting device.

Soil Fertility Monitoring With Internet of Underground Things: A Survey

Soil Fertility Monitoring With Internet of Underground Things: A Survey

Radio frequency identification in internet of underground things using a soil dielectric attenuator and microstrip antenna as tag sensor

AbstractThis work proposes an underground things (UT) based on radio frequency identification for internet of UT (IoUT) systems. The UT is formed by a microstrip antenna encapsulated in a soil dielectric attenuator (SDA). The dimensions of the antenna and SDA are designed through simulations and a prototype is manufactured for experimentation in two types of soil. Reflection coefficient (S11) and received signal strength indicator (RSSI) measurements were performed to verify the viability of the prototype. The measured results of S11 showed satisfactory agreement with the simulations and the antenna encapsulated in the SDA has small variations in the resonance frequency in the presence of moisture. The RSSI results indicated the potential of UT as a soil moisture sensor.

Internet of underground things‐assisted performance evaluation for underbalanced drilling telemetry systems

AbstractThis paper presents recent developments with an emphasis on communication technologies, problems with networks, and localization techniques on the Internet of Underground Things (IoUT). Presently, Underground (sensors), communications and network protocols are enabled to allow IoUT validation in an effective way. A new IoUT model is designed to detect and incorporate communications between various industries, such as oil and gas, forestry, earthquake mapping, and the underground boundary protection. Such applications require data collection from the underground resources deployed. While, the challenging underground climate, including sand, rock and water drainages, does not allow a single system of communication. Hence, a new advanced distance‐based approach and Channel Modeling have been developed for performance analysis and the ideal selection of the drilling telemetry system has been potentially analyzed for the development of an extended reservoir region. The predictive value of research is to build a structured and user‐friendly framework for assessing telecommunications efficiency and supporting the decision optimization process. The proposed system has been validated and used for an adequate range of telemetry techniques in under‐balanced drilling operations on a developed reservoir. Expert evaluations show the results and needs of telemetry systems achieve better results.

A Theoretical Model of Underground Dipole Antennas for Communications in Internet of Underground Things

The realization of Internet of underground things (IOUT) relies on the establishment of reliable communication links, where the antenna becomes a major design component due to the significant impacts of soil. In this paper, a theoretical model is developed to capture the impacts of the change of soil moisture on the return loss, resonant frequency, and bandwidth (BW) of a buried dipole antenna. Experiments are conducted in silty clay loam, sandy, and silt loam soil, to characterize the effects of soil, in an indoor testbed and field testbeds. It is shown that at subsurface burial depths (0.1–0.4 m), the change in soil moisture impacts communication by resulting in a shift in the resonant frequency of the antenna. Simulations are done to validate the theoretical and measured results. This model allows system engineers to predict the underground antenna resonance and also helps to design an efficient communication system in IOUT. Accordingly, a wideband planar antenna is designed for an agricultural IOUT application. Empirical evaluations show that an antenna designed considering both the dispersion of soil and the reflection from the soil–air interface can improve communication distances by up to five times compared to antennas that are designed based on only the wavelength change in soil.

Di-Sense: In situ real-time permittivity estimation and soil moisture sensing using wireless underground communications

Internet of Underground Things (IOUT) communications have the potential for soil properties estimation and soil moisture monitoring. In this paper, a method has been developed for real-time in situ estimation of relative permittivity of soil, and soil moisture, that is determined from the propagation path loss, and velocity of wave propagation of an underground (UG) transmitter and receiver link in wireless underground communications (WUC). The permittivity and soil moisture estimation processes (Di-Sense, where Di- prefix means two) are modeled and validated through an outdoor UG software-defined radio (SDR) testbed, and indoor greenhouse testbed. SDR experiments are conducted in the frequency range of 100–500 MHz, using antennas buried at 10 cm, 20 cm, 30 cm, and 40 cm depths in different soils under different soil moisture levels, by using dipole antennas with over the air (OTA) resonant frequency of 433 MHz. Experiments are conducted in silt loam, silty clay loam, and sandy soils. By using Di-Sense approach, soil moisture and permittivity can be measured with high accuracy in 1–15 m distance range in plant root zone up to depth of 40 cm. The estimated soil parameters have less than 8% estimation error from the ground truth measurements and semi-empirical dielectric mixing models.

3D Localization for Internet of Underground Things in Oil and Gas Reservoirs

Magnetic Induction (MI) is an efficient wireless communication method to deploy operational internet of underground things (IoUT) for oil and gas reservoirs. The IoUT consists of underground things which are capable of sensing the underground environment and communicating with the surface. The MI-based IoUT enable many applications, such as monitoring of the oil rigs, optimized fracturing, and optimized extraction. Most of these applications are dependent on the location of the underground things and therefore require accurate localization techniques. The existing localization techniques for MI-based underground sensing networks are two-dimensional and do not characterize the achievable accuracy of the developed methods, which are both crucial and challenging tasks. Therefore, this paper proposes a novel three-dimensional (3D) localization technique based on Isometric scaling (Isomap) for future IoUT. Moreover, this paper also presents the closed-form expression of the Cramer Rao lower bound (CRLB) for the proposed technique, which takes into account the channel parameters of the underground magnetic-induction. The derived CRLB provides the suggestions for an MI-based underground localization system by associating the system parameters with the error trend. Numerical results demonstrate that localization accuracy is affected by different channel and networks parameters such as the number of underground things, ranging error variance, size of the coils, and the transmitting power. The root mean square error performance of the proposed technique shows that increase in the number of turns of the coils, transmitting power, and the number of anchors improves the performance. Results also show that the proposed technique is robust to the ranging error variance in the range of 10 to 30 %; however, a further increase in the ranging error variance does not allow to achieve acceptable accuracy. Also, the results show that the proposed technique achieves an average of 30 % better localization accuracy compare to the traditional methods.

Toward the Internet of Underground Things: A Systematic Survey

This paper provides recent advances in the area of Internet of Underground Things (IoUT) with emphasis on enabling communication technologies, networking issues, and localization techniques. IoUT is enabled by underground things (sensors), communication technology, and networking protocols. This new paradigm of IoUT facilitates the integration of sensing and communication in the underground environment for various industries, such as oil and gas, agriculture, seismic mapping, and border monitoring. These applications require to gather relevant information from the deployed underground things. However, the harsh underground propagation environment including sand, rock, and watersheds do not allow the use of single communication technology for information transfer between the surface and the underground things. Therefore, various wireless and wired communication technologies are used for underground communication. The wireless technologies are based on acoustic waves, electromagnetic waves, magnetic induction and visible light communication while the wired technologies use coaxial cable and optical fibers. In this paper, state-of-art communication technologies are surveyed, and the respective networking and localization techniques for IoUT are presented. Moreover, the advances and applications of IoUT are also reported. Also, new research challenges for the design and implementation of IoUT are identified.

Application Specific Internet of Things (ASIoTs): Taxonomy, Applications, Use Case and Future Directions

As more and more applications are deployed using the Internet of Things (IoT) technologies, the fragmentation of general purpose IoT technologies to target particular sectors with different requirements is becoming necessary. In this paper, we summarize the latest developments of application-specific IoTs (ASIoTs) (a term to conceptualize the development of IoTs targeted toward specific domains, communications mediums, and industry sectors) in eight representative studies (Internet of Battlefield Things (IoBT), Internet of Medical Things (IoMT), Internet of Animal Things (IoAT), Internet of Waste Things (IoWT), Internet of Underwater Things (IoUWT), Internet of Underground Things (IoUGT), Internet of Nano Things (IoNT), and Internet of Mobile Things (IoMobT) such as the Internet of Vehicles). The paper gives contributions to ASIoTs from three perspectives: First, we offer a basic classification taxonomy for ASIoTs and discuss various representative studies and applications which can be found in the literature; Second, we discuss a use case for a biometrics-based ASIoT (termed IoBioT) for illustration and experiments of face-based biometric recognition on IoBioT are also performed; and Third, we give discussions and future directions for ASIoTs. An objective of this paper is to spur researchers and facilitate the development of ASIoTs for the different user-defined domains, communication mediums, and technology constrained platforms.

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

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.