Abstract
Wireless sensor networks (WSNs) especially with sensor nodes communicating with each other in medium other than air have been naive area of research since the last few years. In comparison to underwater communication, wireless underground sensor networks (WUSNs) are now being used in a large number of applications ranging from environmental observation, estimating chances of earthquake, communicating in underground tunnels or mines, and infrastructure monitoring to soil monitoring for agricultural purposes. In spite of all such promising applications, due to harsh and dynamically changing soil characteristics including soil type, water content in soil, and soil temperature, underground communication with conventional electromagnetic (EM) wave-based technology could not prove to be feasible for long-distance communication. Alternatively, due to magnetic permeability of soil being similar to air, magnetic induction- (MI-) based approach was adopted using magnetic coils as antenna for sensor nodes. Subsequently, MI waveguide and 3D coil mechanisms were considered to improve the system efficiency. Attributing to different characteristics of underlying transmission channels, communication protocols as well as architecture of MI-based WUSNS (MI-WUSNs) have been developed with different approaches. In this review paper, in addition to the latest advancements made for MI-WUSNs, closely associated areas of MI-WUSNs have also been explored. Additionally, research areas which are still open to be worked upon have been detailed out.
Highlights
The communication between sensing nodes in an underground medium is a difficult job, and researchers have been still trying to improvise it for the last more than four decades
This study considers the major developments in protocols used in Wireless sensor networks (WSNs) which indicate the directions of research in WSN
Underground WSNs being a special class of WSNs cater to a large range of application areas making it an attractive destination area for researchers
Summary
The communication between sensing nodes in an underground medium is a difficult job, and researchers have been still trying to improvise it for the last more than four decades. Separate operational cost of every node ends up in large exploitation cost, which is generally not possible to be supported economically It has been established by Akyildiz et al [3] that coordinated effort of multiple sensor nodes organized in a network reduces the energy requirements and enhances the reliability of measurements. The study on how signals propagate through the soil for wireless underground sensor nodes (WUSNs) is investigated by [5]. They proposed a two-phased coefficient model, one for a near-field region and other for a far-field region.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
