[WEBINAR] The New Normal: Dealing with the Reality of an Unsecure World

Dual-Tone Multifrequency (DTMF)

Definition - What does Dual-Tone Multifrequency (DTMF) mean?

Dual-tone multifrequency (DTMF) is a method used to dial telephone numbers or to issue commands to switching systems. DTMF is widely used for telecommunication signaling between telephone handsets and switching centers over analog telephone lines in voice-frequency bands.

DTMF is used in push-button telephones for tone dialing. This version of DTMF is an AT&T registered trademark and is called Touch-Tone.

Techopedia explains Dual-Tone Multifrequency (DTMF)

DTMF signaling was developed to signal the destination telephone number of calls without requiring a telephone operator. It was standardized by the International Telecommunication Union (ITU) Telecommunication Standardization Sector recommendation Q.23.

DTMF tones are also used by cable television broadcasters to indicate the start and stop times of commercial insertion points during station breaks for cable company benefit. The frequencies used prevent harmonics from being incorrectly detected by receivers as other DTMF frequencies.

DTMF keypads are laid out on a 4x4 matrix, in which each row represents low frequency and each column represents high frequency. With DTMF, each key pressed on a phone generates two tones of specific frequencies. One tone is generated from a high-frequency group of tones, while the other is from a low-frequency group. DTMF systems use eight different frequency signals transmitted in pairs to represent 16 different numbers, letters and symbols.

Techopedia Deals

Connect with us

Techopedia on Linkedin
Techopedia on Linkedin
"Techopedia" on Twitter

Sign up for Techopedia's Free Newsletter!

Email Newsletter

Join thousands of others with our weekly newsletter

Free Whitepaper: The Path to Hybrid Cloud
Free Whitepaper: The Path to Hybrid Cloud:
The Path to Hybrid Cloud: Intelligent Bursting To Amazon Web Services & Microsoft Azure
Free E-Book: Public Cloud Guide
Free E-Book: Public Cloud Guide:
This white paper is for leaders of Operations, Engineering, or Infrastructure teams who are creating or executing an IT roadmap.
Free Tool: Virtual Health Monitor
Free Tool: Virtual Health Monitor:
Virtual Health Monitor is a free virtualization monitoring and reporting tool for VMware, Hyper-V, RHEV, and XenServer environments.
Free 30 Day Trial – Turbonomic
Free 30 Day Trial – Turbonomic:
Turbonomic delivers an autonomic platform where virtual and cloud environments self-manage in real-time to assure application performance.