What Does Multi-Frequency Mean - What is dtmf and how does it work? Web add to word list. Able to operate at different frequencies (= the number of times a light, sound, or radio wave is produced each. It is a technology used in communication systems, specifically in. In the 1950s, the bell system, led by at&t, began research into different.
Web add to word list. Able to operate at different frequencies (= the number of times a light, sound, or radio wave is produced each. It is a technology used in communication systems, specifically in. In the 1950s, the bell system, led by at&t, began research into different. What is dtmf and how does it work?