 Autovon keypads were one of the few production units to include all 16 DTMF signals. The red keys in the fourth column produce the A, B, C, and D DTMF events. | |
| Abbreviation | DTMF |
|---|---|
| Status | Active |
| Year started | 1963 |
| Committee | ITU-T |
| Website | www |
Dual-tone multi-frequency signaling (DTMF) is a telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers.[1] DTMF was first developed in the Bell System in the United States, and became known under the trademark Touch-Tone for use in push-button telephones supplied to telephone customers, starting in 1963. DTMF is standardized as ITU-T Recommendation Q.23.[2] It is also known in the UK as MF4.
Touch-tone dialing with a telephone keypad gradually replaced the use of rotary dials and has become the industry standard in telephony to control automated equipment and signal user intent.[3] Other multi-frequency systems are also used for signaling on trunks in the telephone network.
- ^ Z., Dodd, Annabel (2012). The essential guide to telecommunications (5th ed.). Upper Saddle River, NJ: Prentice Hall. ISBN 9780137058914. OCLC 779863446.
{{cite book}}: CS1 maint: multiple names: authors list (link) - ^ Technical features of push-button telephone sets (Report). Recommendation. ITU. Q.23.
- ^ "What is DTMF (dual tone multi-frequency) and how does it work?". Networking. Retrieved 2024-05-23.