The terahertz-wave communications are sensitive to the propagation environment. Line-of-Sight (LOS) is considered crucial in maintaining reliable connections between transmitters and receivers, providing high quality of service and estimating the terminals’ locations accurately. Therefore, maximizing LOS availability improves performance and the localization process in the future systems. In this paper, we propose a general framework to investigate the impact of blockages’ characteristics on the probability of a terminal of interest provided with a number of LOS links simultaneously by taking into consideration the correlation among these links. A comparison among three scenarios, namely correlation, no correlation and two-dimensional is presented to validate the accuracy of these scenarios in different environment densities. The simulation results validate the accuracy of our analysis and show that considering different values of the base station (BS) number and height can improve the system performance. Maximizing the LOS availability can be achieved by considering a higher number of BSs in low and medium environment densities and by increasing the height of BSs for dense environments. Furthermore, unlike in the low environment densities, the correlation between links needs to be addressed carefully when studying LOS availability in dense environments in order to meet the future requirements.