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Re: ISS Full Duplex Default-On or Off?



Yes FULL DUP is assumed off.  But since no one anywhere has reported any
"bunching" of multiple packets in a single burst then this is proof, that
transmit-holdoff (because of FULLDUP Off) is *not* a problem (now).  Bob

In fact, as long as bunching (if it were to occur) was say under 10
packets, it would actually be better this way by amortizing the TXD delay 
of the ISS transmitter over many packets.

The only time FULLDUP would be a bad problem would be if the TNC in use
was just a carrier detector and not a full DCD detector.  I think the TNC
on the ISS uses DCD and so all the QRM on the uplink makes hardely
anything look like a valid packet so the channel does not appear to be
very busy at all.  So again, this does not appear to be a probelm...

Bob

 On Sat, 21 Apr 2001, Bruce Kille
(Mindspring) wrote:

> I have been following the discussions of the merits of the
> full duplex mode on ISS, and immediately had this question.
> If the TNC has reverted to default values, as was shown by
> the fall back to the NOCALL, then wouldn't the unit also have
> reverted to Full Duplex OFF?  It has been my experience that
> this is the default for this mode, and if this is the case for the
> ISS's TNC, then couldn't some of the 'logjam' be due to the
> unit reverting to this mode?  Now, I understand there is a lot
> of QRM on the uplink, but I was just wondering if this, and
> what ever other settings that were lost when the unit defaulted
> might be making things worse. BTW the thread on this was
> very long, and if this was addressed before, I apologize.
> 73, Bruce WA4JAV
> 
> 
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de WB4APR@amsat.org, Bob

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