Telecommunication
The other meaning of the term "channel" in telecommunications is seen in the phrase communications channel, which is a subdivision of a transmission medium so that it can be used to send multiple streams of information simultaneously. For example, one radio station can broadcast radio waves into free space at frequencies in the neighborhood of 94.5 MHz (megahertz) while another radio station can simultaneously broadcast radio waves at frequencies in the neighborhood of 96.1 MHz. Each radio station would transmit radio waves over a frequency bandwidth of about 180 kHz (kilohertz), centered at frequencies such as the above, which are called the "carrier frequencies". Each station in this example is separated from its adjacent stations by 200 kHz, and the difference between 200 kHz and 180 kHz (20 kHz) is an engineering allowance for the imperfections in the communication system.
Radio y Televisión Martí
Today, Radio Marti broadcasts a 24-hour radio program over short-wave transmitters in Delano, California, and Greenville, North Carolina, and a medium-wave transmitter in Marathon, Florida (GC: ). Its studios are located in Miami, Florida. Cuba jams both the medium-wave and shortwave signals, but the shortwave program is heard in Canada and throughout Central America and South America. On occasion, the medium-wave transmitter at 1180 kHz can be heard as far north as Washington, D.C.