. The spectrum allocation for legacy technologies could be minimized, or the legacy networks could be closed down. One option for 5G low band in the United States is also 600 MHz. It is also possible to share spectrum between LTE and 5G with dynamic spectrum sharing. Millimeter wave at 24, 28, and 39 GHz is used to provide extremely high local data rates for smartphone users and for fixed wireless users. 4 Spectrum Millimeter Wave Spectrum Above 20 GHz Millimeter wave spectrum above 20 GHz will be essential in 5G for providing the required increase in capacity and data rates for the future requirements. Regulatory bodies around the world are currently working toward opening up new spectrum bands from 6 to 100 GHz. These higher frequencies provide much more bandwidth than the current spectrum below 6 GHz. If only a fraction of that 94 GHz of spectrum were made available to the mobile industry, it could easily be 20-30 GHz of new spectrum, which is significantly higher than all the spectrum available below 6 GHz. In practice, up to 800 MHz bandwidth per operator can be provided in the early phase below 40 GHz and up to 2 GHz above 50 GHz frequencies later. All these spectrum blocks use TDD technology. The following spectrum blocks will be available in millimeter wave and are illustrated in Figure 4.4: 24-29 GHz band. The upper part of this band, known as the 28 GHz band, covers 26.5-29.5 GHz, and the lower part, known as the 26 GHz band, covers 24.25-27.5 GHz. 37-43.5 GHz, known as the 40 GHz band. 57-64 GHz band, also known as the V-band or 60 GHz band. 71-76 GHz and 81-86 GHz bands, also known as the E-band or 70 and 80 GHz band. 92-95 GHz band, also known as the W-band or 90 GHz band. The first millimeter wave spectrum for 5G will be at the 28 GHz band in the United States, which is called Band n261 in 3rd Generation Partnership Project (3GPP) at 27.5-28.35 GHz. A few other countries, including Korea and Japan, use band n257, covering 26.5-29.5 MHz. Korea allocated 800 MHz for all three opera- tors at 26.5-28.9 