## 1 Introduction  
Innovative technologies at the forefront of the fourth industrial revolution include artificial intelligence (AI), drones, the Internet of Things (IoT), 3D printing, robotics, autonomous driving, and big data. These technologies are spreading throughout the industry to improve its productivity and efficiency and are causing major social and economic changes [1, 2]. As the fourth industrial revolution has begun in the mining industry, significant changes are taking place in the traditional mining value chain--from mineral exploration to exploitation, processing, and sales [3]. Smart mining is at the center of this change. Smart mining refers to the introduction of cutting-edge information and communication technology (ICT) such as the IoT, big data, mobile, AI, and augmented reality (AR), preparing the way for the fourth industrial revolution and new climate change regimes, and to realize eco-friendly, high-efficiency, low-cost, and disaster-free mining sites. Smart mining technology consists of hardware (H/W) technology, such as data acquisition sensors, wired and wireless communications devices, power supplies, control devices, data processing servers, and software (S/W) technology that can analyze and effectively visualize collected field data [4, 5]. Moreover, an ideal smart mine can be built by gradually utilizing IoT technology [6]. The IoT refers to a virtual world in which all types of objects existing in the world can be connected to each other in various ways to provide new services. In the mining industry, the IoT can be particularly useful for workers' safety management, field environment monitoring, work efficiency improvement, and transport system improvement; consequently, related technologies have been developed by various researchers [7]. Regarding the safety management of mining workers, technologies have been developed that detect changes in the environment around workers by attaching various sensors, which can detect a worker's location, movement, heart rate, temperature, humidity, and the gas concentration, to helmets [8; 9; 10; 11]. Solutions have also been developed that allow workers to directly identify environmental changes using wearable devices such as smart glasses or smartwatches [12]. Moreover, a number of sensors with wireless communication functionality have been used to evaluate a mine's overall performance and secure stability, as well as acquire data that are difficult to obtain directly from people [13; 14; 15; 16]. Recently, attempts have been made to improve the transportation system by managing the safety of mines and improving work efficiency using beacons based on Bluetooth low-energy technology. [PERSON] et al. [17] used Bluetooth beacons for monitoring the transport of ore or waste. [PERSON] and [PERSON] [18] studied the possibility of using Bluetooth wireless technology for tracking and mapping of personnel and equipment in underground mines. Additionally, they analyzed the costs associated with installing these systems in underground mines and evaluated the performance of the system [18]. [PERSON] et al. [19] designed a Bluetooth-based underground mine-monitoring system to detect changes in the gas concentration in real time and transmit measurement data through a wireless communication network. [PERSON] and [PERSON] [20] proposed a Bluetooth beacon-based proximity warning system that could prevent collisions in underground mines. A smartphone installed in a vehicle received signals from Bluetooth beacons attached to the operator or equipment, providing a step-by-step response depending on the received signal strength. [PERSON] and [PERSON] [21] measured and analyzed the transport time of trucks dispatched to the transport system of an underground mine. Field experiments demonstrated that Bluetooth beacons could conveniently and accurately measure truck transport times. [PERSON] et al. [22] developed a Bluetooth beacon-based underground navigation system that could display optimum transport routes and truck locations in underground mines on a mobile device.