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TCP-group 1991


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MAC sublayer protocol



> Some trivial solutions:
>
> 1) put the repeater lower (saves $ too)
> 2) run lower power and/or more squelch (another $ saver)
> 3) okay, put up ten times as many repeaters.  Why assume
>    a scarcity when none need exist ?

Did you notice that all of these attempt to reduce the cell/cluster
size?  However, in a real environment (including the variability of the
troposhpere and terrain) it is not easy to "bound" a cell.  This is
demonstrated by such things as California hams being able to work(or QRM)
Hawaiian 2M repeaters on occasion.....

> and a slightly less trivial solution

describing algorithimic discrimination of the signals once "unwanted"
ones are present....

> 4) The above discussion assumes a "no-brains" full duplex repeater.
> Ok, maybe it's doing some regeneration.  Now let's assume a few more
> smarts:

> that's logically needed.  If the packets are of a good size (a
> given, since otherwise all the other latencies are going to kill us)
> this won't hurt much, and if not - well, it's *still* better than the
> alternative :-).

But it's not better than the alternative of not hearing (having to
contend with) "unwanted/QRM" packets to begin with... It would be better
to reuse the spectrum and therby increase the aggregate capacity.

> Mind you, I find the concept of a closed repeater to be one of the most
> distasteful ideas in hamdom.  If the ham population is dense enough
> (in the *spatial* sense of the word) to require this sort of
> technique, I suppose keeping track of who can use the repeater would
> be a bearable administrative overhead (sigh).  If the other sense of
> the word applies, ghods help us.

 This is getting close to what I see as the crux of matters.  How do we
equitably share our resources without alienating the world by "telling
them what they have to do"?  If we are going to get effective at sharing
we have to coordinate and cooperate.  However this means that people are
going to have to avoid some kinds of actions which "are their rights".

  My own conclusion is that the way to do this is by showing that an
alternative is available and works so much better that everyone will
agree to abide.  We don't have too many people driving on the wrong side
of the roads just to excercise their freedom or demonstrate their
individuality (well at least not in most parts of the country, I admit
California is something of an exception).

  We increasingly need to use architectures which reduce interference to
others and see this as vital to improving the performance available
to us.  Since we probably can't get the masses to do it on principle I
think we need to get them to do it because it works.

 If it's any concilation, there doesn't have to be a "black list" and a
"white list" for a local cluster...just a maximum number of users
supported at any given time.  This is part of how hubmaster helps
maintain an acceptable degree of service.

 When things get too busy/crowded and delays are experienced in gaining
service there is more incentive to join up with similarly disgruntled
users and add another (small) cluster.

 I'm very interested in any ideas for a better way.

Glenn n6gn





Document URL : http://www.a00.de/tcpgroup/1991/msg00083.php
Ralf D. Kloth, Ludwigsburg, DE (QRQ.software). < hostmaster at a00.de > [don't send spam]
Created 2004-12-21. Last modified 2004-12-21. Your visit 2020-10-30 15:41.34. Page created in 0.0507 sec.
 
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