Some parts of the spectrum are only suitable for certain uses. Cell phone providers prefer frequencies in the MHz range because they penetrate buildings well. H

Some parts of the spectrum are only suitable for certain uses. Cell phone providers prefer frequencies in the MHz range because they penetrate buildings well. Higher or lower frequencies wouldn't be suitable for this purpose. In addition, a lot of Tx and Rx equipment moves around. A quiet part of the spectrum in a rural area might be crowded in a city, for example, and poorly designed equipment could be subject to harmful interference