Hi!
I experience a slight decrease in audio quality when switching from plain APCO25 (unencrypted) to DES-OFB. This should not happen, as the encryption happens when the signal already is digital, so what is the reason for that? I have made a sample, although in german language you should be able to hear the difference. The first transmission is in clear, the second one in DES-OFB...
http://dk5ras.dyndns.org/samples/APCO25.wav
XTS5k - audio quality difference in P25 with and without DES
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XTS5k - audio quality difference in P25 with and without DES
regards - Ralph, dk5ras
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Those are quite old 123abc radios, 2.20, encryption module 5.13 or something like that. With newer "true" XTS it sounds similar, but I do not have them by hands and can not verify the exact versions.grem467 wrote:what version host/dsp and emc are you running in the radios?
regards - Ralph, dk5ras
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Ralph A. Schmid http://www.bclog.de ralph@schmid.xxx
Tel./SMS +49-171-3631223
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Ralph A. Schmid http://www.bclog.de ralph@schmid.xxx
Tel./SMS +49-171-3631223
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I mean DES-OFB, and as you can hear, there is an difference :( Securenet is another thing :)Bruce1807 wrote:I assume you mean DES-OFP
There should be no difference between encryption and clear in a digital system.
Now clear and securenet that was another story.
But with each DSP release the quality has improved.
Anyway, in case I can find someone who is willing to sell upgrade licences to germany, I will flash my old radios, too.
regards - Ralph, dk5ras
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Ralph A. Schmid http://www.bclog.de ralph@schmid.xxx
Tel./SMS +49-171-3631223
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Ralph A. Schmid http://www.bclog.de ralph@schmid.xxx
Tel./SMS +49-171-3631223
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