I've been a ham for almost eleven years. The year I got started (1994)
was the same year the Web became open to commercial traffic, and I
guess the decline of packet began around that time. I keep an APRS
beacon on the air, and I use the local packet infrastructure. I edit my
club's newsletter, and write a monthly column about digital topics.
There is a small but active group of packet enthusiasts in the region
that keep the nodes running, but all the same I've seen a node and a
full-service BBS go dark in the last year or so.

One reason for digital's decline from my point of view is a lack of
interest. Obviously if the choice is reading bulletins at 1200 baud vs.
DSL or even fast dialup, most folks will go with the more attractive
alternative. It's too bad though that we as amateurs don't have a
viable nationwide digital network. I've given the topic a lot of
thought, and locally I'm trying to stir up interest in APRS since its
the 'hottest' digital application we currently have that is available
to most hams cheaply.

From an emergency communications perspective, we could potentially make
a better case for our existence if we had a national network that was
100% independent of the wired public infrastrucure (including the
Internet). Now, the ARRL is pushing Winlink 2000. I sat through a forum
on the topic two or three years ago at the Timonium, MD hamfest. I know
about the controversy surrounding it, but at least it provides a way to
pass email traffic via the client programs that people are accustomed
to using.

Besides lack of interest, there is always the cost factor. I don't know
what it costs to operate a typical node, but for a hobby it must be
expensive. Its obviously a labor of love for the sysops out there,
given the small amount of traffic and small number of users. A local
node/BBS seems to have gone out of service. It was a TCP/IP and AX.25
board, as well as an Internet gateway node. Maybe the connectivity
costs got to be too much, I don't know. Without users, even the most
dedicated packet sysop must eventually question the reason for
maintaining his or her system. I also understand that tower space is
getting more difficult to obtain and hold onto.

I think establishing high-speed backbones on a regional basis, using
802.11 technology under Part 97 rules, or maybe the Icom D-Star system,
would be useful. The problem there is cost and the tremendous effort
that would be involved. In theory, a group of clubs with repeaters that
have line-of-sight could get together and build a backbone linking
those repeater sites. Now I'm talking TCP/IP, so there is another
problem. I'm interested in doing amateur TCP/IP, but when I emailed my
regional Amprnet coordinator for an IP address, I received zero
response.

Imagine the value the ham community could offer if we had networks
ringing the major cities. I don't believe we need to recreate the
Internet or try to compete with anything that exists currently. But to
support emergency services effectively with a robust network would
really go a long way to justifying our continued existence.

Matt, N3SOZ











Marty Albert wrote:
I have been floating in and of this news group for about 12-15
years...
Sometimes I have been an active poster and other times I am content
to just
lurk.

What amazes me is really two things that have a very close connection
(no
pun intended):

1) The amount of useful and meaningful traffic in the digital
modes has
dropped dramatically.

2) The amount of useful and meaningful traffic on this news group
has
dropped dramatically.

Yes, there are a few APRS nodes and some traffic there... A node
simply
repeating ad infinitum where it is located, what time it is, and what
the
temperature is at the site. Not very useful, but it is better than
dead air,
I suppose.

While it really does not fit the definition of digital radio 100%, of
much
more interest are the EchoLink system and similar ideas. At least
there is a
combining of digital services (VoIP) and radio happening.

And yes, there are a few pockets of digital services that are
surviving,
perhaps even thriving. But this is not the norm... Just look at the
traffic
in this news group or check your local BBS (if you have one) and, if
you
have been around for more than about 10 years or so, you will see the
overall decline.

I am curious as to what people attribute the (apparent) death of
digital
systems overall.

I, of course, have my own ideas that have, by the way, not changed
for more
than a decade.

So, what say you about the life of digital services?

Take Care & 73

From The Desk Of
Marty Albert
KC6UFM

"n3soz" wrote in message
oups.com...

Imagine the value the ham community could offer if we had networks
ringing the major cities. I don't believe we need to recreate the
Internet or try to compete with anything that exists currently. But to
support emergency services effectively with a robust network would
really go a long way to justifying our continued existence.

Matt, N3SOZ

Exactly what we are doing here in Portland, OR.
Lots of fun.

--

... Hank

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

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.

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.

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

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?

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...

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.

Are you drooling yet?

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



"n3soz" wrote in message
oups.com...
I've been a ham for almost eleven years. The year I got started (1994)
was the same year the Web became open to commercial traffic, and I
guess the decline of packet began around that time. I keep an APRS
snipped for space's sake

Marty Albert wrote:

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...

What was the on-the-air bandwidth of Frank's 80Mbps signal?


Dana K6JQ

As I recall, at 23 cm and 80 Mbps we had an effective bandwidth of around
100 KHz on the "final" design... That design incorporated TDM, limited SS,
and WDM of the signals.

Obviously, with multiple forms of simultaneous multiplexing, the bandwidth
would through the roof, most likely to around 100-150 MHz.

Today, we could use TDM, WDM, SDM, high-end SS, and a few other tricks and,
assuming a target data-rate of 100 Mbps, get the on air bandwidth down to
around 50-75 KHz, maybe even a little less.

With a similar set up except for a target data-rate of 10 Gbps, my
back-of-the-envelope calculations are coming up with an on air bandwidth on
the order of 30-50 MHz.

There may be as much as a 10-15% decrease in bandwidth by using a well
designed DSP.

Essentially we would need to look carefully at the Ethernet 10+ Gbps over
copper and copy those concepts... I have my upper division and grad students
looking at ways to do just that.I am hoping in the next month or so, I can
reach an agreement with EE department and the RF engineering department to
bring in some of their students to help out with those aspects... My
students have already found one thing... BASIC Stamps and PIC processors
will only work up to about 115 Mbps. Beyond that, they are just too slow.

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



"Dana H. Myers" wrote in message
...
What was the on-the-air bandwidth of Frank's 80Mbps signal?

Dana K6JQ

Marty Albert wrote:
As I recall, at 23 cm and 80 Mbps we had an effective bandwidth of around
100 KHz on the "final" design... That design incorporated TDM, limited SS,
and WDM of the signals.

What exactly does this all mean?

Passing 80,000,000 bits/sec in 100,000Hz of bandwidth sounds
pretty fantastic - to the extent that makes me question the
validity of the measurements.

Today, we could use TDM, WDM, SDM, high-end SS, and a few other tricks and,
assuming a target data-rate of 100 Mbps, get the on air bandwidth down to
around 50-75 KHz, maybe even a little less.

Whoa. Hold on. Help me understand what units and methods
of measurement you're using. Right now, you're off by several
decimal places in even the most generous way.

Dana K6JQ

"Dana H. Myers" wrote in message
...
Marty Albert wrote:
As I recall, at 23 cm and 80 Mbps we had an effective bandwidth of around
100 KHz on the "final" design... That design incorporated TDM, limited
SS,
and WDM of the signals.

What exactly does this all mean?

Passing 80,000,000 bits/sec in 100,000Hz of bandwidth sounds
pretty fantastic - to the extent that makes me question the
validity of the measurements.

This in 100 Hz of bandwidth we can obtain 80 Kbps.
Shannon twirling in his grave.

Today, we could use TDM, WDM, SDM, high-end SS, and a few other tricks
and,
assuming a target data-rate of 100 Mbps, get the on air bandwidth down to
around 50-75 KHz, maybe even a little less.

Whoa. Hold on. Help me understand what units and methods
of measurement you're using. Right now, you're off by several
decimal places in even the most generous way.

Lost a decimal point for sure.

BTW ... why does everyone always mention 1200 baud?
Doesn't everyone use at least 9600 for local links, and
PACTOR II / III on HF?

Think I have a 1200 baud TNC around here ... yeah there it is
over in that cabinet. Big black box, says TAPR TNC-1 on it.

--

... Hank

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

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.

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


"Dana H. Myers" wrote in message
...
Marty Albert wrote:
As I recall, at 23 cm and 80 Mbps we had an effective bandwidth of
around
100 KHz on the "final" design... That design incorporated TDM, limited
SS,
and WDM of the signals.

What exactly does this all mean?

Passing 80,000,000 bits/sec in 100,000Hz of bandwidth sounds
pretty fantastic - to the extent that makes me question the
validity of the measurements.

Today, we could use TDM, WDM, SDM, high-end SS, and a few other tricks
and,
assuming a target data-rate of 100 Mbps, get the on air bandwidth down
to
around 50-75 KHz, maybe even a little less.

Whoa. Hold on. Help me understand what units and methods
of measurement you're using. Right now, you're off by several
decimal places in even the most generous way.

Dana K6JQ

"Marty Albert" writes:
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.

Yes, you are a few decimal places off, but in the wrong direction ;-).

"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