Overview of Radio Propagation Models in the Millimeter Wave Range for Cellular Networks

This paper presents a review of recent published articles on the propagation path loss measurements and results in the Millimeter-wave radio spectrum range and compares with known propagation models commonly applicable in the sub-6 GHz range. The review shows that path loss is a function of the extent of wireless network coverage. With heightened interest in the application of millimeter wave range as solution to the low wireless data rate, various propagation models have been modified and new ones developed across the industry and academia. It is observed that the known propagation models in the sub 6 GHz cannot be directly applied in the millimeter wave range without introducing some parameter modifications to the models. In the outdoor, the physical structures, like type of buildings, materials of the built and vegetation exact influence on the propagation models. Types of walls, metallic and wood structures in confinements also exhibited profound influence on the propagation models in indoor environments. In the papers reviewed, mobility was not considered.