In telecommunications,
transmission (abbreviation:
Tx) is the process of sending and propagating an
analogue or
digital information signal over a physical point-to-point or point-to-multipoint
transmission medium, either wired, optical fiber or wireless. One example of transmission is the sending of a signal with limited duration, for example a block or packet of data, a phone call, or an email. Transmission technologies and schemes typically refer to
physical layer protocol duties such as
modulation,
demodulation,
line coding,
equalization,
error control,
bit synchronization and
multiplexing, but the term may also involve higher-layer protocol duties, for example,
digitizing an analog message signal, and source coding (compression).