Characteristic Study of Visible Light Communication and Influence of Coal Dust Particles in Underground Coal Mines

Abstract

The critical environment of the underground mines is a risky zone for mining applications and it is very hazardous to engage the miners without a sophisticated communication system. The existing wired networks are susceptible to damage and the wireless radio systems experience severe fading that restricts the complete access to the entire assembly of a mine. Wireless optical communication is a better approach that can be incorporated in the erratic atmosphere of underground mines to overcome such issues, as lights are already used to illuminate the mine galleries. This study is focused on investigating the characteristics of visible light communication (VLC) in an underground coal mine. The entire scope of VLC is elaborated along with the influence of coal dust particles and the scattering model. The impact of coal dust clouds on visibility and attenuation is analyzed for visible light transmission. The shadowing effect generated by the pillars and mining machinery is estimated by employing the bimodal Gaussian distribution (BGD) approach in coal mines. The characteristic model of VLC for underground coal mines is presented by classifying the area of the mine into mine gallery and sub-galleries. The transmission links of VLC are categorized as the line of sight (LOS) link for direct propagation and the non-LOS (NLOS) link for reflected propagation. The scenarios of LOS and NLOS propagation are considered for each evaluating parameter. Furthermore, the performance of the proposed framework is examined by computing the received signal power, path loss, delay spread (DS), and signal to noise ratio (SNR).

Channel Characteristics and Link Adaption for Visible Light Communication in an Industrial Scenario

“…Finally, only small rays can reach the RX, i.e., a larger PLE can be observed. In addition, the OPL in [ 28 ] is also examined by considering LOS and NLOS links. The computed values of the PLE (n) are 1.2 for LOS and 1.4 for the NLOS sub-gallery link, respectively.…”

Recent Advancements in Indoor Positioning and Localization

“…Sensor Approach [1] Positioning Acoustic Time difference of arrival [2] Channel modeling Visible light Bimodal Gaussian distribution in line of sight and non-line of sight [3] Energy optimization -Macro model for energy optimization [4] Positioning Wireless Improved K nearest neighbor [5] Positioning Smartphone sensors Analytical review…”

“…The authors investigate the characteristics of visible light channels for the underground hazardous environment of coal mines in [2]. Communicating with and locating the people working in the high-risk environment of coal mines is very important, and traditional wired communication channels are susceptible to damage, fading, and complete failures in case of gaseous explosions, and other potential alternatives should be explored to locate the workers.…”

A study on the VLC security at the physical layer for two indoor scenarios

“…The visibility into underground spaces is an important parameter to be considered while modelling the visible-light wireless communication and its PLS. Therefore, since the gallery of a coal mine is composed of coal dust particles, they can dramatically affect the friendly environment for optical transmission and induces a strong reduction of visibility, therefore an important path loss [23].…”