"Hank Oredson" wrote in message
k.net...

We have done some test links, to verify path issues.
Then we did the cost analysis.
About $2k per endpoint for the paths we need to cover.
So we have some short links, but any interesting links require
investment from a group of hams instead of a single ham.
That has not happened.

The problem is cost.

By interesting, I assume you are talking about links that can be located a
reasonable distance apart.

I've been curious about this for quite a while. I use ethernet cable at home
so I have no experience with WIFI equipment.

Charles Brabham, N5PVL

Director: USPacket http://www.uspacket.org
Admin: HamBlog.Com http://www.hamblog.com
Webmaster: HamPoll.Com http://www.hampoll.com
Weblog: http://www.hamblog.com/blog_n5pvl.php

Charles,

Did some background reading, guess I've used the wrong terminology.
I've had a few networking classes but I'm no expert. The partially
meshed topology is definitely the way to go. But the issues of selling
the concept and handling funding and logistics that I mentioned are
still a factor in any large-scale network implementation. As other
posters have mentioned, we have the bandwidth available to get this
done but money is the major obstacle. I'm just glad this conversation
is happening here. The original poster hit a nerve and clearly there is
interest in moving digital amateur radio networking forward. I'm going
to look at what I can do within my club, using our facilities - some
kind of happy medium between setting up a network in my house and
covering 500 square miles. Gotta walk before you can run.

Matt, N3SOZ

Charles Brabham wrote:
The Star network topology has been tried with Packet. It was called
TexNet.

The TexNet network did something that no other large-scale ax25
packet
network ever did - It disappeared completely, leaving hardly any
trace
behind to show that it once existed.. From 100+ linked nodes to none
in just
a few years.

I suppose that would qualify TexNet as the worst disaster in the
history of
digital amateur radio. It's untimely demise was directly related to
the use
of the obsolete Star network topology. All the other large-scale
packet
networks used the same Partially-Meshed network topology that the
Internet
utilizes, and I notice that all of those are still around to this
day.

Charles Brabham, N5PVL

Director: USPacket http://www.uspacket.org
Admin: HamBlog.Com http://www.hamblog.com
Webmaster: HamPoll.Com http://www.hampoll.com
Weblog: http://www.hamblog.com/blog_n5pvl.php

"Marty Albert" wrote in message
...
TDM = Time Domain Multiplexing

WDM = Wide Dimensional Multiplexing

SDM = Statistical Domain Multiplexing.

TDM and, to a limited degree, WDM have been around and used for several
decades in high performance networking. SDM is relatively new, about 5
years.

There are far more ways to multiplex intelligence on a medium than PSK and
FSK, although both are used in high performance systems.

You are 100% correct... I may very well a few decimal places off... The
mathematical models show that 100 Mbps should be possible in as little as
10
KHz.


The model is wrong.
Post it and I'll be glad to explain why.

--

... Hank

http://home.earthlink.net/~horedson
http://home.earthlink.net/~w0rli

"Charles Brabham" wrote in message
...

"Hank Oredson" wrote in message
k.net...

We have done some test links, to verify path issues.
Then we did the cost analysis.
About $2k per endpoint for the paths we need to cover.
So we have some short links, but any interesting links require
investment from a group of hams instead of a single ham.
That has not happened.

The problem is cost.

By interesting, I assume you are talking about links that can be located a
reasonable distance apart.

Five to fifty miles.
All costs included, things like towers, etc. as well as the dishes and
amplifiers.

I've been curious about this for quite a while. I use ethernet cable at
home so I have no experience with WIFI equipment.

It can be very easy to set up, played with it here, but ordinary
WiFi won't even get from one end my house to the other. So
there are a few hundred feet of CAT5 instead :-)

--

... Hank

http://home.earthlink.net/~horedson
http://home.earthlink.net/~w0rli

"Hank Oredson" writes:
Five to fifty miles.
All costs included, things like towers, etc. as well as the dishes and
amplifiers.

What are you using for the underlying RF? Ordinary wifi cards?
How did you get them to operate outside the part 15 band?

"Paul Rubin" wrote in message
...
"Hank Oredson" writes:
Five to fifty miles.
All costs included, things like towers, etc. as well as the dishes and
amplifiers.

What are you using for the underlying RF? Ordinary wifi cards?

Ordinary WiFi cards.

How did you get them to operate outside the part 15 band?

Look at your favorite frequency allocation chart.

--

... Hank

http://home.earthlink.net/~horedson
http://home.earthlink.net/~w0rli

"Radio Active" wrote in message
...
On Fri, 20 May 2005 14:33:20 GMT, "Hank Oredson"
was heard mumbling in the corner:

"Radio Active" wrote in message
. ..
On Wed, 18 May 2005 03:45:42 GMT, "Marty Albert"
was heard mumbling in the corner:

You are 100% correct... Lack of interest is, in my opinion, the largest
single factor.

The speed is also a big deal, as you say... 1200 bps vs. a 2-4 Mbps
cable
connection seems to be a slam dunk.

The higher the speed the more the bandwidth needed to support it. We
don't have the bandwidth in any of the spectrum we have to support 2-4
Mbps.

What ??? You are joking, right?

Not in the least. We don't have MHz of bandwidth to give up for
something that only a few would use. Of the 700,000 US hams, how many
do you think would be interested in such a thing?

Ah, never mind, a really ignorant troll.

But, keep in mind that we are talking about is an easy to build and use
device that, with a 15+ year old design, was known to 80 Mbps over a
fairly
short path.

How much bandwidth did it use?

That sort of makes mucking about with 802.11 junk sort of a wasted
effort.

ROFLOL!

The mistake was made about 15 years ago when the drive was to
effectively
duplicate the Internet on the ham bands. Simply put, there are not,
never
have been, and likely never will be enough hams in the world to do that.
Besides, why try to duplicate a defective system?

The internet is defective? Interesting. So, your idea of what amateur
radio should be is a national digital communications network? You have
no room for other modes of communications? No SSB? No CW?

For the life of me, I can see no reason why Frank's device could not be
re-designed today to well over 512 Mbps, perhaps very close to gigabit
speeds. If you make the jump to the new copper solutions for 10 Gbps, we
may
even be able to get close to that...

Look at the bandwidth 1200 bps or 9600 bps uses and then figure out
what 512 Mbps would take up. Then read Part 97.

What's the problem?

If you can figure it out, I doubt anyone would be able to explain it
to you.

See above comment.

Imagine a large metropolitan area, like maybe Dallas/Fort Worth, ringed
by
an 8 Gbps nodes with spokes at 8 Gbps "dropping" into and through the
city.
A series of 1 Gbps nodes come off of the spokes to feed into the
neighborhood. In the neighborhoods, picture a bridge node that users can
connect to at, say, 100 Mbps. Lastly, picture these "City Wheels" being
connected to other city wheels at 10 Gbps.

And just where are you going to get that much radio spectrum to do
that?

SHF. We already have the spectrum.

Oh? We do?

Yes.

Are you drooling yet?

No, I'm laughing.

Clueless but happy.

Ah, here we go with the insults.

Plonk!

Ah yes, place hands firmly over ears.
Imagine how much we will miss you.
Next time post using your callsign in your sig.

--

... Hank

http://home.earthlink.net/~horedson
http://home.earthlink.net/~w0rli

I will see if the University that I am using to develop the model will allow
that at this point... It is actually their intellectual property.

I doubt, however that you will find any major errors in the algorithms....
There have been many professors, PhDs, and grad students looking at it to
find those errors as well as engineers from Motorola, Maxim, and TI.

Take Care & 73
--
From The Desk Of
Marty Albert, KC6UFM


"Hank Oredson" wrote in message
ink.net...

The model is wrong.
Post it and I'll be glad to explain why.

"The mathematical models show that 100 Mbps
should be possible in as little as 10 KHz."

If that is what it shows, there is an error.

The error is either with the model itself, or with the
assumptions fed into the model.

Basic Thermo 101 ... Shannon ... etc.

However, if you can get me 100 Mbps in 10 KHz,
I'll be glad to buy a whole bunch of 'em :-)

--

... Hank

http://home.earthlink.net/~horedson
http://home.earthlink.net/~w0rli
"Marty Albert" wrote in message
om...
I will see if the University that I am using to develop the model will
allow
that at this point... It is actually their intellectual property.

I doubt, however that you will find any major errors in the algorithms....
There have been many professors, PhDs, and grad students looking at it to
find those errors as well as engineers from Motorola, Maxim, and TI.

Take Care & 73
--
From The Desk Of
Marty Albert, KC6UFM


"Hank Oredson" wrote in message
ink.net...

The model is wrong.
Post it and I'll be glad to explain why.

In article "Marty Albert" writes:
I will see if the University that I am using to develop the model will allow
that at this point... It is actually their intellectual property.

I doubt, however that you will find any major errors in the algorithms....
There have been many professors, PhDs, and grad students looking at it to
find those errors as well as engineers from Motorola, Maxim, and TI.

Take Care & 73
--
From The Desk Of
Marty Albert, KC6UFM


"Hank Oredson" wrote in message
link.net...

The model is wrong.
Post it and I'll be glad to explain why.


A few things come to mind:

1) Multiplexing does not increase the bandwidth capability of a channel.
You mention various forms of multiplexing, but these will not increase
the channel capacity. They are just different ways of utilizing what
is available.

2) The Hartley-Shannon Law gives the maximum bandwidth of a channel as
C = B log2(1+(s/n)) bits/second; where B is bandwidth (Hz) and s/n is
expressed as a value, not in dB.

Given this, to get 80 megabits of signal in a 100 kilobit channel, you
will need a signal/noise ratio of about 2408 dB. Since you were only
starting with a 10 watt signal, with about 100 dB path loss (after including
the two j-poles), and a terrrestrial noise floor of about -124 dBm for the
100 kHz wide channel, you get only about 60 - 64 dB s/n in your receiver
(assuming things like lossless coax, etc.).
Thus you are about 2340 dB short on signal to accomplish the task as
described. See http://encyclopedia.laborlawtalk.com/Shannon_limit for more
discussion of this.


Your numbers are a bit too far from what can reasonably be believed.


Alan
wa6azp