Coverage Analysis for Ground and Aerial Users in mmWave Cellular Networks in Urban Settings

The fifth generation (5G) mobile technology is being developed to meet the ever-increasing demands for cellular capacity. 5G is poised to be a critical enabler in various verticals. Millimeter waves (mmWaves), massive multi input multi output (MIMO) antenna arrays, and unmanned aerial vehicles (UAVs) are three key components that are being investigated in the context of 5G, which can jointly be used to support applications such as cellular-connected drones. To support such use cases, it is essential to study the propagation characteristics of ground to air (GA) mmWave links, for which there are very limited studies in the existing literature. In this work, we perform ray tracing simulations using Remcomm Wireless Insite software to compare ground and aerial coverage using mmWave communication links. Two sets of sectored antennas were used at the base station (BS), both of which use the same frequency spectrum. One antenna set was tilted up to serve aerial users while the other was tilted down to serve ground users. Our findings indicate that coverage is determined by shadowing due to buildings, path loss, and the angular interference between the beams of the two antenna sets. It was also observed that the coverage for aerial users is approximately twice that for ground users. Further, using sharper beams, of width 10 or less, is desirable as it makes spectrum reuse between aerial and ground users more feasible, enables users to be placed closely to each other and also increases the range, particularly for ground users. Along with narrower beams, MIMO beamforming techniques may be used to increase network capacity in dense urban areas.