Re: [amsat-bb] TDMA - Reading the mail

["Edward R. Cole" <al7eb@xxxxxxxxxxxxx>]

>From: Jon Ogden <na9d@mindspring.com>
>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?

{Just getting caught on my reading so still a day behind} 

How's this for a DX/contest digital "protocall":
Stations would be logged at the time they first called and placed into a
que.  There turn to "bag" the rare one would be controlled by the
protocall.  In case of simultaneous calls, I guess some alphabetic call
ranking or maybe just a pseudo-random que routine {role of the dice}.  Now
of course we could just move all alaskan stations automatically to the
front of the que :-)  Contest sponsors could even tailor the protocall as
part of the contest design/challenge!

Now it would seem to me that some voice/data mode would be useful.  In the
contest the call, section, grid, state, county, country info would be
exchanged as data sort of like a signature line on e-mail.  the voice part
of the exchange would be names and reports, possibly.  Then of course you
could have total data contests that you program the computer-radio in
advance and print the result at the end of the contest!  {hmm what's the
point?}

Well, enough of my musing.  Good topic.  This group is poised to lead the
way, if desired!
Ed


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