Mobile Radio Transmission System -1.Securing Channels in Narrow Frequency Bandwidths
Radio waves are part of the family of electromagnetic waves that can convey information and energy. By utilizing differences in ways of transmission and energy conveyance effects depending on frequencies, electromagnetic waves are used for various purposes in accordance with frequencies.
Among radio waves, the VHF and UHF bandwidths used in broadcasting are also the most frequently used bandwidths in mobile communications. In particular, the frequency bandwidths of 1 GHz and below are used for a multitude of purposes, and available frequencies in these bandwidths are rapidly being used up. As a consequence, the quasi-microwave bandwidth between 1 to 3 GHz has been developed to deal with the new mobile communications demand. This quasi-microwave bandwidth is used for digital portable telephones, automobile telephones and PHS.
What Are Radio Waves?