In telecommunication, the term transposition has the following meanings:

  1. In data transmission, a transmission defect in which, during one character period, one or more signal elements are changed from one significant condition to the other, and an equal number of elements are changed in the opposite sense.
  2. In outside plant construction, an interchange of spatial positions of the several conductors of a cable between successive concatenated sections.

Note: Transposition is usually used to minimize inductive coupling and thus reduce interference in communications circuits.

Source: from Federal Standard 1037C and from MIL-STD-188

In music transposition is moving a note or collection of notes up or down in pitch by a constant interval. This could be tranposing a piece of music into another key, transposing a tone row or an unordered collection of pitches such as a chord so that it begins on another pitch. See also Transposing instrument. Transpositional equivalency is the concept that intervals and chords are the same when transposed. It is similar to enharmonic equivalency and octave equivalency. Transpositional equivalency is generally supposed by most music theory in that chords which may be transposed onto one another share something in common. However, taking them to be identical or near-identical is only assumed in musical set theory.

In mathematics, a transposition is a permutation which exchanges two elements and keeps all others fixed. For example (1 3) is a transposition which exchange 1 and 3. A transposition is a cycle of length two.

In cryptography, a transposition is an elementary cryptographic operation somewhat related to the mathematical permutations. See transposition (cryptography).