Technical information

Chapter 2: Hardware Interface Description
December 15, 2009 G30 - Module Hardware Description 39
Audio Programming Interface
The G30 incorporates a unique audio programming interface, through AT commands, which
controls the following audio features:
• Audio Path - Defines the input and output devices for speech, DTMF tones, rings and alerts.
• Audio Gain - Defines the amplification (gain) level for input and output audio devices.
• Audio Algorithm - Defines the speech processing features for voice calls.
Figure 2-22 describes the audio programming interface options, which are defined by AT
commands.
Figure 2-22: Audio Programming Interface
Audio Algorithms
The G30 audio interface features advanced speech processing algorithms for echo suppression,
noise suppression and side-tone feedback.
Enabling or disabling the algorithms can be configured separately for each audio path and
operating mode through the AT command interface.
The G30 also supports full rate (FR), half rate (HR), enhanced full rate (EFR) and adaptive
multi-rate (AMR) speech coding algorithms, which are used by the GSM network. These
algorithms are configured and operated by the GSM network provider.