Hi,<br>
<br>
I have noticed that most mobile phones (GSM and CDMA at least) seem to
have a tendency to interrupt the incoming audio stream when the
microphone levels get louder than a certain threshold (such as when you
are speaking into it). I do not know exactly why this happens, nor
whether it is something that happens in the handset (the handset mutes
the incoming audio, which doesn't make much sense) or in the network
(maybe to try to save bandwidth?). <br><br>
Also, the GSM codec is intended to intelligibly encode human speech,
not general audio signals such as music. GSM uses approximately 6-8
times less bandwidth than G.711u/a, and the degradation in the quality
of music and other non-speech signals is one of the tradeoffs that we
make in order to not have the cost of mobile calls increase 6-8 times
over.<br>
<br>
Maybe if Europe was as backward with its mobile systems as the United
States currently is, you could try to get your users to call your
system from analog mobile phones... They don't use digital compression
(by definition, I suppose) and would probably work much better for your
specific application ;).<br>
<br>
-Rusty<br>
<br>
<br>
<br><div><span class="gmail_quote">On 11/25/05, <b class="gmail_sendername">Esteban Maestre</b> <<a href="mailto:emaestre@iua.upf.es">emaestre@iua.upf.es</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Hi all!<br><br>I have a strange problem when using asterisk. I have configured asterisk<br>to receive calls (FX0). In my configuration, I want asterisk to play music<br>while I record the caller's speech. If the caller does the call from a
<br>fixed line telephone, there is no problem, but in case the caller does the<br>call from a mobile GSM phone, the quality of the music he hears becomes so<br>bad, and even more when he speaks.<br>I have tried several codecs.
<br>Any idea or advice?<br><br>thanks in advance,<br><br>-esteban-<br><br>_______________________________________________<br>--Bandwidth and Colocation sponsored by <a href="http://Easynews.com">Easynews.com</a> --<br><br>
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