Reliable communications has always been challenging in underground environments due to harsh and dynamic conditions. A crucial component of the underground communication system is the antenna, which can improve the wireless connectivity in the underground environment for operational efficiency & safety. Modern underground operations use communication systems to enable secure voice communications, to locate both people and machines, remote control of vehicles and systems, and site access and security. Given the recent standardization of autonomous mining vehicular communication and the wide presence of traditional WiFi in mines, two carrier frequencies- 2.4GHz and 5.9GHz – are most commonly used.
In the past, mining was one of the toughest jobs due to its physically intense nature and dangerous working conditions. Over time, mining has evolved dramatically with the introduction of machinery replacing human presence in mines in order to increase safety. Recent advancements in robotics, artificial intelligence and machine learning, are leading mining equipment manufacturers to envision a fully autonomous mine. The need for through-the-air (TTA) in the underground mining industry has evolved from person-to-person and person-to-machine to M2M (machine-to-machine) real-time voice, video and data transmission. Today, high bandwidth communication systems perform a vital role in the safety and productivity in mining operations. This concept reduces human presence in harsh environments while at the same time allowing continuous operation around the clock.
In the context of mining & tunneling, the goal is to create a wireless audio transition channel through the earth that can meet the energy requirements of mine safety. To solve this problem, historically RF designers have worked on improving performance of the coupling circuit, using a very low penetration of 30 baud rates for transmission through communication & low data rate. Under normal circumstances, data collection is time-consuming where transmission is relatively simple & straight-forward. Data collection & storage can require 9600 baud, through a low baud rate transmission. Given the aforementioned challenges, RF designers have sought to isolate the power & sound signals needed for the RC coupling circuit which has often required software to ensure error-free signal transmission.
Because the antenna required for the low baud rate transmission uses a narrow band, the audio data must be compressed & packaged tightly to reduce the rate through the transmission medium. In these cases, receivers serve the role of audio quality restoration by amplifying the signal for processing, at a low frequency.
Unictron has a long history of designing and supplying specialist circular polarized and WiFi antennas that are optimized for communication in tunnels and mines (including versions for mounting antennas in hazardous areas). We offer a complete (dual-band) WiFi, LoRa, Sigfox and LTE range of Mining Antenna Solutions which are used worldwide. Numerous customer tests in mines have been performed over the past 10 years showing that these unique antenna solutions achieve ranges 3x-4x to those obtained with a similar gain linear polarized antenna.
If reliable and clear underground communications are critical to your mining operations, feel free to reach out to discuss your project!