1,064 research outputs found
On Capacity of Active Relaying in Magnetic Induction based Wireless Underground Sensor Networks
Wireless underground sensor networks (WUSNs) present a variety of new
research challenges. Magnetic induction (MI) based transmission has been
proposed to overcome the very harsh propagation conditions in underground
communications in recent years. In this approach, induction coils are utilized
as antennas in the sensor nodes. This solution achieves longer transmission
ranges compared to the traditional electromagnetic (EM) waves based approach.
Furthermore, a passive relaying technique has been proposed in the literature
where additional resonant circuits are deployed between the nodes. However,
this solution is shown to provide only a limited performance improvement under
practical system design contraints. In this work, the potential of an active
relay device is investigated which may improve the performance of the system by
combining the benefits of the traditional wireless relaying and the MI based
signal transmission.Comment: This paper has been accepted for presentation at IEEE ICC 2015. It
has 6 pages, 5 figures (4 colored), and 17 reference
Magneto-inductive wireless underground sensor networks: novel longevity model, communication concepts and workarounds to key theoretical issues using analogical thinking
This research has attempted to devise novel workarounds to key theoretical issues in magneto-inductive wireless underground sensor networks (WUSNs), founded on analogical
thinking (Gassmann & Zeschky 2008). The problem statement for this research can be summarized as follows. There has been a substantial output of research publications
in the past 5 years, devoted to theoretically analysing and resolving the issues pertaining to deployment of MI based WUSNs. However, no alternate solution approaches to such
theoretical analyses have been considered. The goal of this research was to explore such alternate solution approaches.
This research has used the principle of analogical thinking
in devising such alternate solution approaches. This research has made several key contributions to the existing body of work. First, this research is the first of its kind to demonstrate by means of review of state-of-the-art
research on MI based WUSNs, the largely theoretical genus of the research to the exclusion of alternate solution approaches to circumvent key theoretical issues. Second, this research is the first of its kind to introduce the notion of analogical thinking as a solution approach in finding viable workarounds to theoretical impediments in MI based WUSNs, and validate such solution approach by means of simulations. Third, this research is the first of its kind to explore novel communication concepts in the realm of MI based WUSNs, based on analogical thinking. Fourth, this research is the first of its kind to explore a
novel longevity model in the realm of MI based WUSNs, based on analogical thinking. Fifth, this research is also the first to extend the notion of analogical thinking to futuristic directions in MI based WUSNs research, by means of providing possible indicators drawn from various other areas of contemporary research.
In essence, the author believes that the findings of this research mark a paradigm shift in
the research on MI based WUSNs
Signals in the Soil: An Introduction to Wireless Underground Communications
In this chapter, wireless underground (UG) communications are introduced. A detailed overview of WUC is given. A comprehensive review of research challenges in WUC is presented. The evolution of underground wireless is also discussed. Moreover, different component of UG communications is wireless. The WUC system architecture is explained with a detailed discussion of the anatomy of an underground mote. The examples of UG wireless communication systems are explored. Furthermore, the differences of UG wireless and over-the-air wireless are debated. Different types of wireless underground channel (e.g., In-Soil, Soil-to-Air, and Air-to-Soil) are reported as well
A Survey on Subsurface Signal Propagation
Wireless Underground Communication (WUC) is an emerging field that is being developed continuously. It provides secure mechanism of deploying nodes underground which shields them from any outside temperament or harsh weather conditions. This paper works towards introducing WUC and give a detail overview of WUC. It discusses system architecture of WUC along with the anatomy of the underground sensor motes deployed in WUC systems. It also compares Over-the-Air and Underground and highlights the major differences between the both type of channels. Since, UG communication is an evolving field, this paper also presents the evolution of the field along with the components and example UG wireless communication systems. Finally, the current research challenges of the system are presented for further improvement of the WUCs
On Achievable Accuracy of Localization in Magnetic Induction-Based Internet of Underground Things for 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 presents the expression of
the Cramer Rao lower bound (CRLB) for three-dimensional MI-based IOUT
localization which takes into account the channel parameters of the underground
magnetic-induction. The derived CRLB provide 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
anchors, noise variance, frequency, and the number of underground things.Comment: Submitted to IEEE Internet of Things Journa
On-Site and External Energy Harvesting in Underground Wireless
Energy efficiency is vital for uninterrupted long-term operation of wireless underground communication nodes in the field of decision agriculture. In this paper, energy harvesting and wireless power transfer techniques are discussed with applications in underground wireless communications (UWC). Various external wireless power transfer techniques are explored. Moreover, key energy harvesting technologies are presented that utilize available energy sources in the field such as vibration, solar, and wind. In this regard, the Electromagnetic(EM)- and Magnetic Induction(MI)-based approaches are explained. Furthermore, the vibration-based energy harvesting models are reviewed as well. These energy harvesting approaches lead to design of an efficient wireless underground communication system to power underground nodes for prolonged field operation in decision agriculture
A Computational Channel Model for Magnetic Induction-Based Subsurface Applications
There are many underground applications based on magnetic fields generated by an oscillating magnetic source. For them, a magnetic dipole in a three-layered region with upper semi-infinite air layer can be a convenient idealization used for their planning, development, and operation. Solutions are in the form of the well-known Sommerfeld integral expressions that can be evaluated by numerical methods. A set of field expressions to be numerically evaluated by an efficient algorithm are not collected comprehensively yet, or at least in a directly usable form. In this paper, the explicit magnetic field solutions for the vertical magnetic dipole and the horizontal magnetic dipole for a general source-observer location are derived from the Hertz vector. They can be properly combined to model the problem of a tilted magnetic dipole source for horizontally or inclined stratified media. As a result, a complete set of integral equations of the Sommerfeld type valid from the near zone to the far zone are formulated. A method for numerical evaluation of the field expressions for high accurate computations is described. The numerical results are validated using the finite element method for all the possible source-receiver configurations and three well-spanned frequencies of typical subsurface applications. Both numerical solutions agree according to the normalized root-mean-square error-based fit metric. Numerical results for two cases of study are presented to see its usefulness for subsurface applications. A MATLAB implementation of the mathematical description outlined in this paper and the proposed evaluation method is freely available for download
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