5 Cause of DTMF generation

03.143GPPSupport of Dual Tone Multi-Frequency Signalling (DTMF) via the GSM SystemTS

A user may cause a DTMF tone to be generated by depression of a key in the Mobile Station (MS). Optionally (on a MS basis) manufacturers of mobile equipment may choose to allow DTMF to be controlled from a remote terminal.

The man-machine interface questions associated with this facility are not discussed further in this GTS.