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Posted by =?iso-8859-15?Q?Tekkie=AE?= on September 12, 2006, 9:32 pm
Mo Hoaner posted for all of us...
> > Test
>
> BER, while a useful end-to-end metric of a signal, is NOT the appropriate
> measurement to be making here - modulation fidelity is.
> Yes - a high BER will cause your signal to fall on its face. But what causes
> a high BER? It is the radio's inability to distinguish between symbols. And
> what is the measurement of how "hard" symbols are to distinguish? Modulation
> fidelity. You will see pretty much the same BER for a 10% modulation
> fidelity error as you will for a 0.7% error, but if you see a 10% MFE you
> can know the system is NOT performing well - you have lost most of your
> margin for decode, and any increase at all in the distortion of the signal
> will start causing errors.
>
> Think of it as the difference between SINAD and intelligibility - you can
> have a 20 dB SINAD or a 12 dB SINAD, and still understand what the other guy
> is saying 100% - but if you are at a 12 dB SINAD coming out of the repeater,
> any additional noise is going to start causing a whole lot of "What did you
> say? Say again?" traffic.
>
> The advantage of regenerating the digital signal, even if you don't apply
> the forward error correction at that point, is that you can go from a 10%
> MFE to a 0.7% MFE, and thus improve the odds of correctly decoding the
> signal.
>
> AND, if you then apply the FEC to the signal, you can further clean it up,
> so that you can once again pick up bit errors without the radio being unable
> to decode.
>
> From MOL Astro25 Readme file:
>
> New Radio Features Supported:
> =============================
> NOTE: Firmware version R08.00.00 or greater is required for all features
> -Quik Call II Encode/Decode
> -DTMF Encode/Decode
> -In-Call Alert Operation for ASTRO, MDC, QCII, DTMF and Trunking
> -'Failsoft Connect Tone'
> -MDC Emergency Alarm Indication
> -Smart Rugged Battery for the XTS 2500 and XTS 1500 radios
> -Rotary Switch Lock for Channels
> -Scan Lists have been increased to a maximum of 64
>
> New CPS features supported:
> ===========================
> - The CPS is now capable of upgrading the PR 1500 and the MT 1500 radios
> using FLASHport.
> - The CPS is now capable of upgrading from rebanded XTS models to the
> traditional APCO 25 capable XTS models using FLASHport. An XTS 1500 RB model
> can be upgraded to a
> traditional XTS 1500 model and an XTS 2500 RB model can be upgraded to a
> traditional XTS 2500 model.
> Please note that a new FLASHkey will be needed for this operation.
> -Please note that new field 'Failsoft Connect Tone' can only be Advance
> System Key protected if 'Connect Tone' is also protected. Specific
> protection just for this field is not supported.
>
> Looks like that's it.
>
>
>
Stay out of my trunked system
--
Tekkie "There's no such thing as a tool I don't need."
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