ITU-T O.81 APP.1-1998
Group-Delay Measuring Equipment for Telephone-Type Circuits - Appendix I: A Measuring Signal (Multitone Test Signal) for Fast Measurement of Amplitude and Phase for Telephone Type Circuits - Series O: Specifications of Measuring Equipment - Equipment for

Standard No.

ITU-T O.81 APP.1-1998

Release Date

1998

Published By

International Telecommunication Union (ITU)

Status

Withdraw

Latest

ITU-T O.81 APP.1-1998

Scope

The multitone test signal (MTTS) consists of a spectrum of N discrete signals separated by frequency spacing of 100 Hz in the low frequency range. The spectral lines are all of equal amplitude; their phase relationship to each other is chosen on the basis of mathematical considerations so that the energy of the test signal is distributed approximately evenly across the entire period of the test signal. The transmission characteristics, i.e. the amplitude and phase distortion of a telephone line, produce changes in the test signal. On the receive side, these changes are measured and evaluated, e.g. by means of a Fourier analysis. The results may be displayed on a screen in the form of an amplitude andor phase graph and also, for example, the group delay may be derived from this.

ITU-T O.81 APP.1-1998 history

• 1998 ITU-T O.81 APP.1-1998 Group-Delay Measuring Equipment for Telephone-Type Circuits - Appendix I: A Measuring Signal (Multitone Test Signal) for Fast Measurement of Amplitude and Phase for Telephone Type Circuits - Series O: Specifications of Measuring Equipment - Equipment for