Implementation of Outdoor to Indoor Path Loss Model at 1.8 GHz and 2.1 GHz with a Transmitter Placed on Top of The Building

Nowadays, the use of mobile communication devices has become a necessity in the lecture environment. This is evidenced by the increase in wireless communication traffic in the lecture building. Generally, users inside the building receive radio waves from transmitters placed outside the building to support wireless communication. Thus, an adequate received signal level (RSL) is required to ensure smooth wireless communication in the building. However, the power level received by the user will decrease along with the increase in distance and obstacles inside the building. This problem can generally be solved by using a power amplifier (repeater device) or wireless fidelity (WiFi) network, but nowadays most buildings do not have these devices.Therefore, an accurate path loss model is needed to predict the path loss of radio wavesfrom outdoors to indoors. Thus, the prediction of path loss can be a reference for designing transmitters that can support smooth wireless communication in the building. This study has compared three outdoor to indoor path loss models, namely the 3GPP Model, the WINNER+Model, and the COST231 Model. Based on the results of research data analysis, it is known that the COST231 Model is the most accurate of the other path loss models used. This is evidenced by the lowest dominant Mean Error (ME), Root Mean Square Error (RMSE), and Standard Deviation Error (SDE) values.