Bandwidth is the capacity of a transmission media. Though this capacity can be measured in many ways; we consider the frequency to be the best metric of bandwidth.
The bandwidth of a media can simply be defined as the range between lowest and highest supported frequencies by that media.
We can calculate the bandwidth as:
Bandwidth = highest supp. Frequency – lowest supp. Frequency
For example, a media that can carry signals as low as on 100KHz and as high as 400 KHz will have the bandwidth:
(400KHz – 100KHz) = 300KHz.
Bandwidth is utilized in any of the following ways:
When entire bandwidth is being used for just one single signal, this transmission is called baseband transmission. For example: Ethernet.
In this method, the entire bandwidth is distributed in many channels and every channel carries different signal simultaneously. For, Ex: Mobile communication and TV Channels.