Welcome to our world of Data transmission. We learn that Data transmission is known as digital transmission, or digital
communications. We should also know that Data transmission is the physical transfer of data over a point-to-point or point-
to-multipoint communication channel.
You are introduced to examples of communication channels used in data transmission such as copper wires, optical fibres,
wireless communication channels, and storage media.
On Data transmission planet, the data are represented as an electromagnetic signal, such as an electrical voltage, radiowave,
microwave, or infrared signal.
Data transmitted may be digital messages originating from a data source, for example a computer or a keyboard. It may also
be an Analog signal such as a phone call or a video signal, digitized into a bit-stream for example using pulse-code
modulation (PCM) or more advanced source coding (analog-to-digital conversion and data compression) schemes.