demodulate the signal . It connect one computer to another through ordinary telephone lines .
Fax ( Facsimile Telegraphy )
The electronic reproduction of a document at a distant place is called FAX
Radio Waves
The radio waves are the electromagnetic waves of frequency ranging from 500 kHz to about 1000 MHz . These \ V8VeS are used In the field of radio communication . With reference to the frequency range and wavelength range , the radio waves have been divided into various categories shown in table .
Frequency Range and Wavelength Range of Radio Waves
Propagation of Radio Waves
The three modes are discussed below :