 specification at WRC-19 in different regions of the world [40]. The smaller coverage areas of higher frequencies, when employed terrestrially, provide more frequency reuse opportunities with limited inter-cell interference issues. As such, 5G services in urban areas may be able to occupy the same bands as other wireless services (e.g., satellite and fixed links) which operate in different geographical areas (e.g., rural) Sub-10 GHz 10-20 GHz 20-30 GHz 30-40 GHz 40-50 GHz 50-60 GHz 60-70 GHz 70-80 GHz 80-90 GHz Frequency bands proposed by regional groups Europe Commonwealth of Independent States (Russia) Arab Spectrum Management *No specific frequency bands submitted, opinions that above 31 GHz should be targeted. Group (ASMG) Africa 26.5 27.5 7.057 23.6 24.25 Americas 23.15 10.45 24.25 45.5 47 Asia-Pacific 25.25 Frequency bands to be studied before WRC-19 24.25 Figure 19 Frequency bands under study for ratification in WRC-19 40]. Introduction and Background Ixxxv when suitable interference mitigation techniques such as beamforming are in place. The potential for spectrum sharing will be explored through sharing studies being conducted by ITU-R, in preparation for WRC-19. Adopting viable sharing methods is particularly impor- tant as many of the bands above 24 GHz that are being considered for 5G access are or will be used for 4G/5G mobile backhaul especially in rural areas where fiber links might not be available or practical [30]. As we mentioned earlier, the wide bandwidth requirements for some 5G applications have necessitated comprehensive study of frequency bands above 6 GHz for utilization in various 5G deployment scenarios and use cases. There are ongoing global activities to identify and specify suitable spectrum including frequency bands that can be used in as many countries as possible to enable global roaming and economies of scale. While not very successful for 4G and previous generations, various efforts around the world are underway to achieve spectrum harmonization in 5G networks. In addition to s