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Topic: how does GSM work? (Read 24434 times) previous topic - next topic

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  • jmvalin
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how does GSM work?
Reply #25
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Nowadays, he focuses on speech recognition since speech coding has virtually reached its limits.

That's true if you consider the limits of cramming phone quality content into less and less bits. It isn't if you consider things like wideband, variable bit-rate, and all the research that goes into being able to encode speech and music efficiently using the same codec.

  • QuantumKnot
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how does GSM work?
Reply #26
Quote
Quote
Nowadays, he focuses on speech recognition since speech coding has virtually reached its limits.

That's true if you consider the limits of cramming phone quality content into less and less bits. It isn't if you consider things like wideband, variable bit-rate, and all the research that goes into being able to encode speech and music efficiently using the same codec.

According to B.S. Atal (the guy who invented Linear Prediction), research in speech coding should now focus on the applications side....eg. voice over IP, robustness of speech coding to packet loss, etc.  The main focus has always been on achieving the lowest bitrate without consideration on the application and channel, thanks to Shannon's separation principle.  But now, joint design of speech coders is the next big challenge.

how does GSM work?
Reply #27
OK  Let me first apologize for bringing this old thread up. I would like to know how I can play GSM audio files.  (although it was mentioned it was not a format one could play or encode into)

http://www.voip-info.org/wiki/view/Asteris...s+international

Some GSM Sets such as this http://www.g7ltt.com/VoIP/vmukmale.tgz have their WAV counterparts but others do not.

Any info guys?

Thanks!

Kieran Mullen