Underground communication is keeping pace with surface communication

No Abstract.

Advanced diagnostic system for underground communication networks with ventilation on demand

In this thesis, a novel diagnostic system has been developed to increase the realibility of leaky feeder communication systems in underground mines. The new system is based on three main parts: 1) Diagnostic Receiver Unit (DRU) located in the control room above ground; 2) several Diagnostic Transponder Units (DTU) connected to amplifiers, Power Supply Units (PSU), fans and sensors; and 3) Communication protocol that was designed for this specific system. The amplifiers, PSU, fans, and sensors in the system cascade will be able to communicate freely with the control room through the leaky cable to send information about their current conditions, and receive configuration messages. A new concept is also presented that provides energy saving in mines; Ventilation-on-Demand where the fans will operate according to the current situation of each section in the mine. This is made possible through a series of interrupt messages that is sent from the DTU attached to the fan/sensor to the DRU in the control room.

Advanced diagnostic system for underground communication networks with ventilation on demand

In this thesis, a novel diagnostic system has been developed to increase the realibility of leaky feeder communication systems in underground mines. The new system is based on three main parts: 1) Diagnostic Receiver Unit (DRU) located in the control room above ground; 2) several Diagnostic Transponder Units (DTU) connected to amplifiers, Power Supply Units (PSU), fans and sensors; and 3) Communication protocol that was designed for this specific system. The amplifiers, PSU, fans, and sensors in the system cascade will be able to communicate freely with the control room through the leaky cable to send information about their current conditions, and receive configuration messages. A new concept is also presented that provides energy saving in mines; Ventilation-on-Demand where the fans will operate according to the current situation of each section in the mine. This is made possible through a series of interrupt messages that is sent from the DTU attached to the fan/sensor to the DRU in the control room.

Li-Fi technology: A Era of New Data Transmission

The main focus of this paper is to clarify the concept and working of Li-Fi technology. In present era, wireless communication plays an important role in day to day life. Wifi is the most used wireless technology which transmits data through radio frequencies. However, during multiple accesses WiFi is facing many challenges related to speed, security and efficiency. Also, WiFI emits radio waves which are harmful in hospitals for patients and cannot be used in underground communication and airplanes. These limitations of WiFi are overcome by Li-Fi technology. The term Li-Fi stands for Light Fidelity which uses visible light communication (VLC) to transfer data at high speed. In this paper, a detailed study on Li-Fi technology, its working and future scope is discussed.

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-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.

Wireless Underground Communications in Sewer and Stormwater Overflow Monitoring: Radio Waves through Soil and Asphalt Medium

Storm drains and sanitary sewers are prone to backups and overflows due to extra amount wastewater entering the pipes. To prevent that, it is imperative to efficiently monitor the urban underground infrastructure. The combination of sensors system and wireless underground communication system can be used to realize urban underground IoT applications, e.g., storm water and wastewater overflow monitoring systems. The aim of this article is to establish a feasibility of the use of wireless underground communications techniques, and wave propagation through the subsurface soil and asphalt layers, in an underground pavement system for storm water and sewer overflow monitoring application. In this paper, the path loss analysis of wireless underground communications in urban underground IoT for wastewater monitoring has been presented. The dielectric properties of asphalt, sub-grade aggregates, and soil are considered in the path loss analysis for the path loss prediction in an underground sewer overflow and wastewater monitoring system design. It has been shown that underground transmitter was able to communicate through thick asphalt (10 cm) and soil layers (20 cm) for a long range of up to 4 km.