telecommunications Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that fe ...

, transmission is the process of sending or propagating an analog or

digital signal A digital signal is a signal that represents data as a sequence of discrete values; at any given time it can only take on, at most, one of a finite number of values. This contrasts with an analog signal, which represents continuous values; at ...

via a

medium Medium may refer to: Science and technology Aviation *Medium bomber, a class of war plane * Tecma Medium, a French hang glider design Communication * Media (communication), tools used to store and deliver information or data * Medium of ...

that is wired,

wireless Wireless communication (or just wireless, when the context allows) is the transfer of information between two or more points without the use of an electrical conductor, optical fiber or other continuous guided medium for the transfer. The most ...

, or fiber-optic. Transmission technologies typically refer to

physical layer In the seven-layer OSI model of computer networking, the physical layer or layer 1 is the first and lowest layer; The layer most closely associated with the physical connection between devices. This layer may be implemented by a PHY chip. The ...

protocol duties such as

modulation In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the ''carrier signal'', with a separate signal called the ''modulation signal'' that typically contains informatio ...

demodulation Demodulation is extracting the original information-bearing signal from a carrier wave. A demodulator is an electronic circuit (or computer program in a software-defined radio) that is used to recover the information content from the modulated ...

, line coding, equalization, error control, bit synchronization and

multiplexing In telecommunications and computer networking, multiplexing (sometimes contracted to muxing) is a method by which multiple analog or digital signals are combined into one signal over a shared medium. The aim is to share a scarce resource - a ...

, but it may also involve higher-layer protocol duties, for example, digitizing an analog signal, and data compression. Transmission of a digital message, or of a digitized analog signal, is known as data transmission. Examples of transmission are the sending of signals with limited duration, for example, a block or packet of data, a phone call, or an email.

References

Telecommunications engineering {{telecom-stub

See also

References