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PA2AGA > HDDIG 22.06.00 03:00l 163 Lines 7184 Bytes #-9426 (0) @ EU
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Subj: HamDigitalDigest 2000/171E
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Sent: 000621/1818Z @:PI8HGL.#ZH1.NLD.EU #:53644 [Den Haag] FBB $:HD_2000_171E
From: PA2AGA@PI8HGL.#ZH1.NLD.EU
To : HDDIG@EU
Date: Wed, 21 Jun 00 18:52:36 MET
Message-Id: <hd_2000_171E>
From: pa2aga@pe1mvx.ampr.org
To: hd_broadcast@pa2aga.ampr.org
X-BBS-Msg-Type: B
found wanting for one reason or another. There's plenty of detail, plenty of
documentation of the nature of the radio environment (hidden terminal
problems, exposed terminal problems, multipath, noise, legal proscriptions
on bandwidth or content, site acquisition problems, routing in a sparse
network, etc, etc, etc), and the amateur radio social, demographic and
economic environments, and how they have shaped what is feasible with
regard to amateur radio digital networks.
Hank makes much of the old message passing system of BBS's loosely linked
together by various tenuously maintained slow radio links. But it was never a
network in the sense you or I (or anyone else seriously connected to
networking
in the last 10-15 years) mean when we talk of digital networks. It is most
similar
to the old dial up uucp usenet distribution, but with the dial ups replaced by
less
reliable and slower radio links.
The sort of real packet switched end to end digital network that you or I
would
mean when speaking of digital networking has only existed in amateur radio in
a few limited areas where careful network engineering, and a hell of a lot of
hard
work and politics, have been practiced to get it built and maintained.
Technical,
social, demographic, geographic, and economic factors have prevented any real
amateur radio digital network from expanding to become the worldwide network
that Hank would lead you to believe once existed.
There are basically three ways we can go from here. One way is to throw up our
hands and abandon the idea of amateur radio in the context of digital networks
altogether. Most everyone posting here (with a few exceptions) eschews that
solution. We all want to do digital radio of one sort or another, and many of
us
would like to do at least part of that in a networked manner.
A second way is to cling to the past and try to rejuvenate a message passing
system that was already an obsolescent concept in the days when it was
most active (then rail at amateurs because most of us don't want to do that
again). That way is a dead horse. It isn't going to come back to life on any
sort of major scale.
The third way is to concentrate on what is feasible within the amateur scope.
That includes moderate size medium to high speed radio LAN structures. It
is practical and feasible, albeit a lot of hard work, to build and maintain
packet
switched radio networks of metropolitan scope, and in some cases of a
somewhat larger scope, which have a reasonable degree of performance.
(The biggest amateur network of which I'm aware that meets the criteria for
a modern end to end packet switched network spans parts of four states.
It is pretty much as large as it will ever be because amateurs are too thin
on the ground to expand it much further while keeping it coherently linked
and reliable.)
If there is a need to intertie these networks with other networks (and there
often isn't a good reason to do so since a metropolitan scope is often
sufficient
for amateur purposes), we will need to use whatever means is practically at
hand to do that part of the job, because we aren't going to be able to do it
purely
by amateur radio. We're too thin on the ground, and don't have the financing
or
the number of skilled amateurs to put up and maintain the necessary
infrastructure
for a pure radio packet switched digital network on a national or
international scope.
(It is possible that we can do something that is very low speed, and/or very
high
latency, on a large scale. That sort of network might fill some useful niche.
But
we aren't even in your wildest dreams going to construct a viable alternative
to
the wired internet on a large scale. There are too many miles and too few
amateurs.)
This is all fairly old ground. It has been chewed over here and elsewhere
many times, often in much greater detail. I found myself alternately chuckling
and grimacing while reading some of your suggestions. You haven't been there
yet, but a number of us have trod that ground, and in many cases found out
the hard way what works and what doesn't in the amateur radio context.
Most of the technical issues have viable solutions, though those solutions
are often very different from what works in the wired world because radio
propagation in the real world is very different from a wire. It is the
demographic,
geographic, economic, and political issues that are the hard problems. For
example, give a thought to the fact that most amateurs reside in the
metropolitan
areas, and there are wide expanses between metropolitan areas where there is
little or no amateur presence.
Who is going to acquire the sites, build, and more importantly who is going
to maintain, the links needed to cross those expanses? It isn't feasible to
expect
amateurs to drive for hours, time and again, year after year, to maintain a
link
out in the middle of nowhere. (Some of us did it back in the beginning, but it
burned
virtually all of us out in the end.) Amateurs have lives and other
obligations. The
reality is, if you don't have a local presence, you can't maintain a reliable
link site
of even medium performance over the long term.
That means there are going to be many situations where you just can't get
there from here via packet radio, because the necessary links in between
either don't exist, or are down. (HF isn't a viable alternative, it is too
slow
to handle the sort of volume a metropolitan intertie, much less a national
or international trunk, would be called upon to support.)
If we scale our expectations to the feasible, there is still a lot we can do
with
amateur radio digital networks that's desirable enough to attract a sufficient
following to support it. But don't be fooled, national and international scope
amateur radio packet switched networks aren't part of the picture.
Gary
Gary Coffman KE4ZV | You make it |mail to ke4zv@bellsouth.net
534 Shannon Way | We break it |
Lawrenceville, GA | Guaranteed |
------------------------------
Date: Tue, 20 Jun 2000 08:20:35 +1000
From: "David Findlay" <nedz@bigpond.com>
Subject: Packet Radio
> Bingo. Speed is 75% of the problem, the other 20% is the people, and the
> last 5% is legal. We just recently were given access to modern technology
> on the Ham bands. Before, you had to do everything with what was
> designed before 1985.
NASA is developing a new protocol for interplanetary internet which uses
much smaller headers. They can't afford to waste all those bits for headers.
So maybe a similar simplified header could be used on a new protocol.
> Yes, alternative to the Internet. The only way things get done
historically,
> is that a Ham or club will show a solution at Dayton, or in the Ham
magazines,
> and hundreds of other Hams are excited by that.
Or from an internet site outlining the benefits.
> The uni operates mostly with Government and State grants. What you
To be continued in digest: hd_2000_171F
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