Chapter 6
Tools
Audio measurements
4460 GSM System Option and 4468 EDGE System Option
Version 12.20
233
–
Signal Destination
provides a selection of where the generated audio
signal shall be sent to. This field is accessible only for system options
providing a voice codec (vocoder) option.
–
Status
gives an overview of the current signaling status while working in
call mode.
AF generator settings
This area of the menu gives access to the main parameters of the audio gener-
ator.
Frequency —
Entry field to set the frequency of the audio generator.
Entry range: 20 Hz to 20 kHz in increments of 0.1 Hz.
Level (AF out) —
Entry field to set the RMS-valued output voltage of the AF
signal on the
“AF out”
connector.
Entry range: 0.0 V(rms) to 5.599 V(rms) in increments of 1 mV.
Level (Codec in) —
Entry field to set the volume of the audio signal, when it is
transmitted over the air interface and therefore connected internally to the input
of the 4400’s codec.
Entry range: –55.0 dB(F.S.) to 0.0 dB(F.S.) in increments of 0.1 dB.
sine —
Check box. If ticked, the output signal will have a sinusoidal waveform.
NOTE
When using audio signals for transmission over the air interface, the audio
frequency should be set in a range between 300 to 3200 Hz as any voice
codec will only operate in this frequency range (just like a normal telephone
line, where the audio signal transmitted is also limited to this frequency
range).
NOTE
The physical unit dB relative to full scale (dB(F.S.)) means a level relative to
the nominal maximum input level at the voice codec.