This article introduces an efficient analysis of indoor 4.5 GHz radio wave propagation by using a proposed three-dimensional (3-D) ray-tracing (RT) modeling and measurement. The attractive facilities of this frequency band have significantly increased in indoor radio wave communication systems. Radio propagation predictions by simulation method based on a site-specific model, such as RT is widely used to categorize radio wave channels. Although practical measurement provides accurate results, it still needs a considerable amount of resources. Hence, a computerized simulation tool would be a good solution to categorize the wireless channels. The simulation has been performed with an in-house developed software tool. Here, the 3-D shooting bouncing ray tracing (SBRT) and the proposed 3-D ray tracing simulation have been performed separately on a specific layout where the measurement is done. Several comparisons have been performed on the results of the measurement: the proposed method, and the existing SBRT method simulation with respect to received signal strength indication (RSSI) and path loss (PL). The comparative results demonstrate that the RSSI and the PL of proposed RT have better agreements with measurement than with those from the conventional SBRT outputs.Electronics 2019, 8, 750 2 of 17 of transmitter, and the propagation environment [4]. It is also challenging to optimize the actual position of the transmitter (Tx) by measurement to ensure acceptable system performance. Therefore, radio-propagation using a simulation tool for the indoor environment based on RSSI and PL has become a significant research tool [5].Weather conditions-such as floods, rains, clouds, or snowfall-have no effect on the indoor radio propagation; however, it can be influenced by the interior walls, furniture, doors, windows, and other household objects. These influences need to be considered for better indoor radio wave propagation modeling. Therefore, the indoor scenario has these objects, with Tx waves reaching the receiver (Rx) through multipath channels [6].Although practical measurement enables actual assessment of onsite performance, it requires a sizable amount of resources and effort. On the other hand, software simulation tools are easy to use and are an inexpensive way to obtain accurate results [7]. Nowadays, many researchers recommend the use of the RT technique for radio propagation prediction modeling [8].Based on the fundamental geometric optics (GO) theory and uniform theory of diffraction (UTD) principles, RT is extensively used in radio wave modeling, and is widely used in indoor WCS [9]. The RT full cycle has three steps: ray launching (RL), ray path sensing, and ray capturing by receivers [10]. The RL is the method of propagating straight rays in all directions in space. Normally, the rays are launched from the source of a Tx to the destination Rx by following the principle of GO and UTD. The complete ray path is traced, bearing the additional propagation features of transmission, reflection, and diffraction [...