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.
Valley Public Radio
Despite having no translators, the two stations' combined signal covers most of California's San Joaquin Valley, including the cities of Fresno, Bakersfield, Visalia, Madera, Tulare, Clovis, Merced, and Hanford; however, much of this area gets only grade B coverage. KPRX operates with its maximum allowed U.S. Federal Communications Commission power (11,000 watts) for a Class B1 station with an antenna height of 152 meters; likewise KVPR broadcasts with its maximum allowed power (2,450 watts) and an antenna height of 576 meters for a Class B FM station. In FM broadcasting effective radiated power is inversely proportional to antenna height.