The transmission speed indicates the speed at which messages are transmitted electronically.

In Morse telegraphy, the speed is specified in ZpM (CpM, characters per minute) or WpM (words per minute, counted in the usual groups of five in military encrypted transmission).

In (radio) teletype traffic, usually the baud rate is indicated, the number of symbols (letters, coded with a 5-bit code) transmitted per minute. This is not identical to the bit rate, the number of 1 - 0 character steps transmitted per minute.