Data transmission

[sukishan]

Data transmission, digital transmission or digital communications is the physical transfer of data (a digital bit stream) over a point-to-point or point-to-multipoint transmission medium.

Examples of such media are copper wires, optical fibers, wireless communication media, and storage media. The data is often represented as an electro-magnetic signal, such as an electrical voltage signal, a radiowave or microwave signal or an infra-red signal.

While analog communications represents a continuously varying signal by a continuously varying signal, a digital transmission can be broken down into discrete messages. The messages are either represented by a sequence of pulses by means of a line code (baseband transmission), or by a limited set of analogue wave forms (passband transmission), using a digital modulation method.

According to the most common definition of digital signal, both baseband and passband signals representing bit-streams are considered as digital transmission, while an alternative definition only considers the baseband signal as digital, and the passband transmission as a form of digital-to-analog conversion.

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 (data compression) schemes. This source coding and decoding is carried out by codec equipment.

[albertadesoza]

These transmission channels are made up of several segments that acquiesce the abstracts to circulate in the form of electromagnetic, electrical, light or even acoustic waves. So, in fact, it is a vibratory phenomenon that is propagated over the physical medium. The term tele transmission involves the analog as well as digital communication.

[pradeep prem]

this used for physical transfer of data

they have given more example for data transmission

it can easily transfer from one point to another point