Measurements of Dual-tone Multifrequency Dialling Signals with the Audio Analyzers R&S®UPL and R&S®UPD

In modern telephoning, dual-tone dialling is used more and more often. Every symbol to be transmitted is coded by two frequencies which are sent at the same time. To ensure a trouble-free call setup, transmission has to be done within defined tolerances. For measuring these kind of dialling signals, the measurement equipment has to fulfill high requirements. This application note describes how the measurements can be carried out by using the Audio Analyzers UPL or UPD. It also presents a measuring program for this application.