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.
Campus radio
Most of the FM radio stations received higher-class licenses than ten watts, typically a few hundred watts. A few got several kilowatts, and a small handful got licenses in the range of tens of thousands, sometimes reaching up to maximum-power 100-kilowatt outlets. WRAS 88.5 FM and WREK 91.1 FM in Atlanta are the most powerful college radio station, operating at 100,000 watts. Still, due to strict class D regulations, some radio stations were prohibited from a wattage upgrade for possible signal interference with adjacent radio stations, such as KWUR 90.3 FM interfering with KWMU 90.7 FM in St. Louis, Missouri. KTUH 90.3 FM in Honolulu, Hawaii has had many increases in its wattage since they started broadcasting at 10 watts as a Non-commercial educational FM radio station in 1969. In 1984 KTUH received permission from the Board of Regents to increase to 100 watts of power. More recently, in 2001, KTUH began transmitting at 3000 watts of power. KTUH is heard on an island wide frequency in Honolulu, Hawaii from 90.1 FM, as well as online at KTUH.ORG and on digital cable channel 866.