## 1 Introduction  
The underground mining industry is considered a priority industry for many governments worldwide, so it has made great technological advances in its infrastructure and work environment [1]. However, there are problems related to the mining environment that make work difficult and endanger the lives of mining workers, such as the presence of poisonous substances, toxic gases, and corrosive water, as well as dust. Another latent problem in underground mines occurs when there are landslides and it is necessary to know the location of workers who need to be rescued [2]. A way to mitigate these problems is by designing specific communications systems for underground mining environments. Therefore, among the characteristics that these communication systems must have are: transmission of reliable and real-time information on the location and tracking of workers when a disaster occurs, transmission of smoke and hazardous gas detection data, information monitoring of mining machinery, and so on [3,4]. These details added to the hostile environment of a mining company, make the design of underground mine communications systems a challenging task, which, if properly implemented, would guarantee work safety and optimize the productivity of the mines. Based on the mining environment's features, the transmission priorities and the behavior of the transmission method, there are several categories studied in underground mining communications, among which are wired communication systems (coaxial, fiber-optic, and twisted pair), radio communication systems, carrier current communication systems and the combination of some of these systems (hybrid systems) [5,6]. It is understood that the underground mining environment is hostile; thus, wired communication systems are susceptible to damage and cannot be a reliable mode of communication in underground mines. Furthermore, radio communication systems and carrier current communication systems also cannot be used in underground mines due to attenuation of the signal. Even though, the underground mining environment needs good lighting that meets international standards, this problem remains without efficient solutions. All these challenges are presented as opportunities for proposals for emerging and complementary communications systems that optimize communication and lighting of underground mining environments. To fulfill these requirements, the concept of visible light communication (VLC) has been introduced for underground mining communication [7, 8, 9]. There are several benefits of using VLC technology compared to other wired and wireless communication techniques: unlicensed spectrum in which visible light operates; reasonable prices of the components that make up the VLC system; high data transfer rates; and, the most important VLC characteristic, the resistance to electromagnetic interference, providing reliable communication in addition to reducing the risk of accidents due to poor ambient lighting [10,11]. Another important characteristic of VLC systems is the security that it presents in the data transmission, specifically in the physical layer [12,13]. As is well known, several current research outputs presents VLC system models for indoor environments, which, due to their characteristics [14], are perfectly applicable to mining environments. The main components of an underground mining VLC system are, first; light-emitting diodes (LEDs), which are cold light sources; as well as having a long service life, they are used to form LED lamps that could be installed on the top surface of underground mines; and second, photo-diodes (PDs) that could be installed on the worker's helmet, to create a VLC link between workers and mining infrastructure, or between workers, depending on the required application. Channel modeling is also an important stage for efficient, reliable, and robust VLC system design.