Discontinuous transmission (DTX) is a means by which a mobile telephone is temporarily shut off or muted while the phone lacks a voice input.
[1][2] A common misconception is that DTX improves capacity by freeing up TDMA time slots for use by other conversations.
In packet radio systems such as GPRS/EDGE, it is possible to combine DTX with capacity increase when VoIP is used for telephony.
Systems that use voice codecs such as AMR can reduce vocoder rate adaptively to better combat interference.
As with the packet radio systems above, when one side of the conversion is silent, the amount of transmitted data is minimized.