Empowering Wireless Sensor Networks below Ground Surfaces

A group of scientist led by Dr. Ian F, Akyildiz, Ken Byers Chair Professor in Telecommunications of the Broadband Wireless Networking lab, School of Electrical and Computer Engineering, Georgia Institute of Technology (Ga Tech) and collaborators have come up with a project known as ‘The MOLES: Enabling Wireless Sensor Networks in Underground’ supported by the National Science Foundation lasting from 2013 – 2016.

MI-based wireless communications.
The terms ‘Wireless Underground Sensor Networks (WUSNs)’ are networks of wireless sensor nodes operating below the ground surface, which are envisioned to provide real-time monitoring capabilities in challenging underground environments including soil medium, oil reservoirs, and underground mines and tunnels.’ According to the vision, the realization of WUSNs will lead to many emerging applications, such as intelligent agriculture, underground pipelines and power grid monitoring, oil reservoir monitoring, concealed border patrol, earthquake and landslide forecasting, underground mine disaster prevention and rescue, amongst others.

akyildiz_2012Despite their potential advantages, the realization of WUSNs is challenging according to the team. The main problem lies in the realization of efficient and reliable underground links to establish multi-hop underground communication and localization, and efficiently disseminating and collecting the data for continuous operation. This is due to the hostile underground environments that tend to prevent the direct use of most, if not all, existing wireless communication and networking solutions, because of the extremely high path loss, small communication range, and high dynamics of electromagnetic (EM) waves when penetrating the soil, sand, rock, water, and crude oil medium in the underground environment.

The team intends to address these unique and important challenges for the realization of wireless sensor networks in challenging underground environments. The idea of this project was initiated from the expertise and outcomes achieved throughout the Prof. Akyildiz’s four-year NSF project “Fundamentals of Efficient Communication in Wireless Underground Sensor Networks (2007-2011)“. The researchers proposes to use Magnetic-Induction-based Wireless Underground Sensor Networks (MI-based WUSNs) to enable reliable and efficient communication and localization in the underground environment.

The proposed research is built on top of novel Magnetic Induction (MI)-based communication mechanisms as well as system architectures in underground soil medium, oil reservoirs, and mines and tunnels.

This is because the MI-based communication and localization have the following unique advantages for the wireless sensor networks in underground environments:
 The MI-based communication has reliable channel conditions in the dynamic environment:
 The MI-based communication solves the antenna size problem of the EM wave-based technique:
 The MI waveguide technique can significantly enlarge the wireless communication ranges in the underground environment:
 The MI-based localization is not affected by the extreme environmental parameters in underground environments:
 The MI-based devices can be recharged by the inductive charging techniques

According to the article, this particular project has contributions along four major thrusts.

 Leveraging the promising propagation properties of MI waves in the underground environment, a cross-layer communication framework based on the MI channel characteristics is proposed to achieve high-throughput, energy-efficient, and reliable underground communications by means of jointly optimizing different system parameters.
 A new Received Magnetic Field Strength (RMFS)-based localization paradigm is proposed to exploit the unique multi-path and fading-free propagation properties of MI-based signals, which guarantees the accuracy, simplicity, and convenience of the localization strategy.
 An optimal MI-based network deployment strategy is proposed for different WUSNs applications with the objective to minimize the coil density while maintaining the required bandwidth constraint and reliability requirements.
 Finally, a physical MI-based WUSN testbed is developed, which consists of our own designed MI-based sensor devices and an engineered underground environment, to validate our proposed solutions.

Feel free to contact Prof Ian Akyildiz for details of this project