 into the suburban and rural areas, while the older mobile genera- tions (e.g. 3G, 4G, and even GPRS, in respect to 5G) are used to provide macrocellular coverage. However, spectrum management is carried out by governments and regulators to ensure that there is sufficient frequency spectrum for those services most in demand among their citizens, and in such a way that provides the highest possible socio- economic benefits [19]. The spectrum for terrestrial mobile and wireless networks is typically divided into two main types: Licensed spectrum. This is given to telecom operators on the basis of individual licenses, which specify the bands for exclusive use by that operator. Such spectrum provides the best possible QoS controls because it is dedicated to the operator for defined radio access technology (or technologies). The recent trend is to provide bands for the IMT spectrum, which includes 2G, 3G, 4G, and 5G. The operators that have licenses for certain spectrum bands can use them according to their network design and planning, through the given requirements on the spectrum use (antenna's output power, interference, etc.) Unlicensed spectrum. This can be used by everyone at their own location (e.g. home, office, public place) without a need for licenses to be issued by the government or regulator. Such bands are license-free and are located on 2.4 GHz (the most used), 5 GHz, and lately 60 GHz. However, unlicensed bands can become crowded with higher interference ratio when many wireless/mobile networks are overlapping (e.g. in neighboring homes, offices). Therefore, QoS cannot be strictly guaranteed as with licensed bands. Typically, WiFi is the technology used in all three unlicensed bands, although the 3GPP mobile network (e.g. LTE-Advanced-Pro, 5G) has defined standards for use in these bands, besides their use in traditional licensed bands. However, the 3GPP technologies in unlicensed bands offer the possibility of better QoS because they are based on the TDMA scheme in the RAN (unlike WiFi, which is not),