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Re: TDMA - Reading the mail

on 12/20/00 11:10 PM, Franklin Antonio at antonio@qualcomm.com wrote:

> You're thinking about only one layer of the cake.
> The idea is to have a protocol that controls the user terminal
> behavior.  In a TDMA system, the user's terminal (or radio or whatever you
> call it) would get assigned a time slot, and these assignments would be
> made in a such a way that people don't fall on top of one
> another.  Whatever the multiplexing scheme (CDMA, TDMA, XYZMA, etc), the
> protocol would be a set of rules governing user terminal behavior designed
> (among other things) to avoid transmissions which destroy one another.

I understand what you are saying.  And in a one person to one person or
point to point QSO this works great.  But in a point to multi-point
environment where those "multi" points are not necessarily "well behaved",
how can you do that?  If P51AA (North Korea for those who don't chase DX)
says, "QRZ this is P51AA", then how will he know what time slot to listen on
or how will the processor that determines who gets what time slot select who
gets to make it through to the DX?  It's a far more complicated system than
a one on one QSO or even a nicely controlled rountable where everyone takes
their turns.  In a pileup you have hundreds and potentially thousands of
stations all wanting to talk to the same station at the same time.  So how
are you going to divvy that up?  What in the protocol will determine how the
pileup works?



Jon Ogden
NA9D (ex: KE9NA)



"A life lived in fear is a life half lived."

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