A line-of-sight propagation performance study for underground mining in an arched-shaped tunnel environment

ABSTRACT

This article investigates the effect of antenna polarization, directivity and placement on the line-of-sight wideband radio channel characteristics of an arch-shaped underground mine tunnel over the 2.4 GHz frequency band. Access point-to-access point and access point-to-mobile wireless communication configurations were examined for linearly and circularly polarized antennas mounted in the center, on the wall and ceiling. The circularly polarized directional antennas offer higher coherent bandwidth, whereas the linearly polarized omni-directional antennas offer lower attenuation rate. A higher directive antenna enhances coverage area, coverage reliability and channel coherent bandwidth. For access point-to-mobile communication, a circularly polarized directional antenna with a horizontally polarized omni-directional antenna gives the best performance in terms of attenuation rate and coherent bandwidth.

KEYWORDS:

• Wireless communication
• radio propagation
• digital mine
• through-the-air (TTA)
• channel modeling
• antenna
• systems
• deep mines

Acknowledgement

The authors gratefully acknowledge the reviewers for their comments toward the improvement of this article. The author thanks all the support of the University of Witwatersrand's Sibanye-Stillwater Digital Mining Laboratory and Sibanye – Stillwater for funding the research.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Intikhab Hussain

Intikhab Hussain received the BSc degree in Information and Communication System Engineering (with distinction) from the School of Electrical Engineering and Computer Science (SEECS), National University of Science and Technology (NUST), Islamabad, Pakistan, and the MSc degree from the University of the Witwatersrand (WITS), Johannesburg, South Africa. He was a visiting student at IMPACT research laboratory, King Abdullah University of Science and Technology (KAUST) Saudi Arabia; where he designed and tested antennas for real-time indoor and outdoor tracking devices. His current research interests include wireless communication, channel propagation, multifunctional systems, and reconfigurable RF front-end architectures.

Frederick Cawood

Frederick Cawood is Professor of Mine Surveying, Director of WITS Mining Institute (WMI) and Coordinator of WITS Digital Mine Project. He has a Master's and Doctorate in Mining Engineering and an LLM in (International) Mineral Law and Policy, along with his qualifications in Mine Surveying. He has 34 years in mining which includes research project execution and research project management. He serves on the Editorial Boards of the South African Journal of Geomatics, Resources Policy, SAIMM Journal, Mining Mirror and African Mining.

Rex van Olst

Rex van Olst studied at Wits and at UNISA and graduated with an MSc (Information Engineering) and a Master of Business Leadership (MBL). He was a mentor (2005–2010) to ICT start-up companies at the country's Innovation Hub in Pretoria. Rex was also the interim Executive Director of the Joburg Centre for Software Engineering (JCSE) from 2005 to 2007. Rex joined the Witwatersrand University staff of the School of Electrical and Information Engineering in 2002 after 25 years in the ICT industry in South Africa. At present Rex is the Associate Professor of Telecommunications Engineering Research and Academic at the School of Electrical & Information Engineering and is responsible for the School's Centre of Excellence in Telecommunication Access and Services (CeTAS).