etting dif- ferent requirements on the network features, new applications will drive a wide variety of deployment scenarios. The different physical characteristics of various spectrum bands (e.g., range, path loss, penetration into structures, propagation) make some applications more suitable in certain frequency bands [46]. While sub-1 GHz spectrum has very good propagation properties that make it the most suitable option for large area coverage, it has limited capacity due to lack of available spectrum and component design considera- tions. The sub-6 GHz spectrum provides a type of coverage that is more suitable for urban deployment, with increased capacity. The above 6 GHz spectrum is more limited in coverage but can provide very high capacity due to potentially very large bandwidth available at these frequencies. In late 2015, WRC-15 agreed that ITU-R should conduct sharing and compatibility studies for a number of frequency bands between 24.25 and 86 GHz prior to WRC-19 in late 2019. Some of these frequency bands enable wide contiguous bandwidths, which would allow sat- isfaction of the stringent requirements of bandwidth-demanding applications. Although the band 27.5-29.5 GHz was not selected for ITU-R studies, the United States and Korea have continued to make progress with trials in this band for 5G which could, when combined with the band 24.25-27.5 GHz (which was selected at WRC-15 for ITU-R studies), provide a good solution for a global implementation of 5G systems. The following frequency bands in sub-6 GHz range have been identified for IMT in ITU-R radio regulations since 1992 [6]: 450-470 MHz 470-698 MHz 694/698-960 MHz 1427-1518 MHz 1710-2025 MHz 2110-2200 MHz Ixxxvi Introduction and Background 2300-2400 MHz 2500-2690 MHz 3300-3400 MHz 3400-3600 MHz 3600-3700 MHz 4800-4990 MHz As shown in Table 5, there are two frequency regions which are playing an important role in 5G NR deployments. In the 3-6 GHz band, there is generally globally available spec- trum in the range of 3.3-3.8, 3.8-4.2, and 4.4-4