The performance of wireless links and channels in indoor home environments at 140 GHz for communications beyond 5G is the focus of this study. Sub-terahertz bands have recently become crucial to “beyond 5G”networks, which aim to improve speed and coverage for a range of wireless applications. In this work, MATLAB and the NYUSIM simulator were used to perform channel simulations while studying an antenna array operating at 140 GHz. In order to analyses the speed, simulations take human obstruction effects into account, as well as the delay. MATLAB is used to examine the path loss in the implementation of Reconfigurable Intelligent Surfaces (RIS), a revolutionary “beyond 5G”technology that can actively alter electromagnetic wave propagation. The same environment as in NYUSIM is created delay spread, SNR, and path loss across a range of T-R separation values. The outcome displays the graphs for direct and RIS paths comparing various characteristics such as SNR, distance, path loss, and PDP.