Frequency and Bandwidth:
Let us try to understand a little about how information is transmitted. The information may be in the form of sound (human voice, music) or it may be visual (printed page, microfilm, video picture) or it may be digital data. Whatever may be the form, it must be converted to electrical signals (electromagnetic waves) before it can be transmitted over a given medium. Such signals very often cannot be sent over a channel as they are, but must be modulated in some way to fit them into the carrying medium. The frequencies of the electromagnetic waves are normally radio frequendies which range from low frequencies capable of carrying only small amounts of information to millimeter waves, which can carry very large amounts. Above the radio frequencies lies light frequency, which can be modulated to carry even larger amounts of information. In other words, the amount of information that can be sent over a given channel in a given time is dependent on the bandwidth. The bandwidth available increases with increasing carrier frequency. Thus, generally speaking the wider the bandwidth, the larger the amount of information which can be carried and the faster its speed.