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To : APRDIG@WW
Subject: Re[4]: Re: Re[2]: Re: Trains, planes and APRS autom obiles. was:
Kenwood APRS radio
From: Danny <danny@messano.net>
Date: Tue, 15 Jun 2004 17:09:58 -0400
X-Message-Number: 52
That wasnt my question..
Was there anyone withing 120 miles of there with a dialup connection that
could have set up an IGATE?
Danny
KE4RAP
Tuesday, June 15, 2004, 4:45:48 PM, you wrote:
EHC> Not during this event... The nearest IGATE was about 120+ miles away...
----------------------------------------------------------------------
Subject: Re[4]: Trains, planes and APRS automobiles. was: Kenwood APRS radio
From: Danny <danny@messano.net>
Date: Tue, 15 Jun 2004 17:17:50 -0400
X-Message-Number: 53
Tuesday, June 15, 2004, 4:28:34 PM, you wrote:
SM> And really, if we want to provide communications in an emergency, we'd
SM> better be able to offer something besides commercial comms that everyone's
SM> got already.
Thats what you are missing. APRS is a hybrid system. Trying to make it ALL
RF or ALL internet defeats its purpose. I think APRS-IS access is crucial
in an emergency. As i've said in other messages, if you give me a 9600 APRS
RF backbone, then what? If you give me APRS-IS access within even 2 or 3
digi hops, you have given me a great asset.
--
Danny
----------------------------------------------------------------------
Subject: Re: Trains, planes and APRS automobiles
From: "Eric H. Christensen" <kf4otn@earthlink.net>
Date: Tue, 15 Jun 2004 17:09:36 -0400
X-Message-Number: 54
Yes but our digis are located on hardened sites. These towers and sites
don't just go down. They are located at State tower sites, Federal
buildings, etc. They are on generator backup. If we would have had a high
speed RF backbone that was carrying APRS, TCP/IP, BBS Traffic, etc, then we
would have been able to keep weather information coming in and out, kept
email going, and really been able to serve our EOC.
73s,
Eric KF4OTN
kf4otn@amsat.org
----------------------------------------------------------------------
Subject: Re[4]: Re[2]: Re[2]: Re: Re[2]: Re: Trains, planes and APR S
automobiles. was: Kenwood APRS radio
From: Danny <danny@messano.net>
Date: Tue, 15 Jun 2004 17:23:17 -0400
X-Message-Number: 55
Thats the problem..
Everyone is so quick to point out how utlilities CAN go down and will go
down. Generators fail.. towers fall. If we are going to call this a
disaster, lets do it right!
Like I said.. During an ice storm here, I lost 2 of my tower sites.. Both
had generators. If I had an APRS backbone at either one (both would be good
candidates), I would have been SOL.
Now, not all of our area lost power.. MOST did. Had I wanted to, I could
have had an IGATE set up and been able to pass traffic in and out of the
area with APRS-IS using that IGATE. My IGATE was SOL because I lost power,
but I could have had IGATES set up potentially anywhere in just a short
time.
----------------------------------------------------------------------
Subject: RE: Re[4]: Re: Re[2]: Re: Trains, planes and APRS autom obiles. was:
Kenwood APRS radio
From: "Eric H. Christensen" <kf4otn@earthlink.net>
Date: Tue, 15 Jun 2004 17:23:25 -0400
X-Message-Number: 56
I don't think so. No one did. Our regional network was pretty much
covering an area that was under severe duress. We are adding more I-Gates
now so that in the event of another large event maybe we will still have
coverage.
Plus using the APRS-IS to link two RF networks is not the best way. Unless
you have it tied directly to the digi, you are adding to the network traffic
and taking away some of the bandwidth. Backbones would be linked directly
into the WIDEs.
The APRS-IS IS a good way to link all the RF networks together for use on
the internet AND to disseminate information to large areas...
73s,
Eric KF4OTN
kf4otn@amsat.org
-----Original Message-----
From: Danny [mailto:danny@messano.net]
That wasnt my question..
Was there anyone withing 120 miles of there with a dialup connection that
could have set up an IGATE?
Danny
KE4RAP
----------------------------------------------------------------------
Subject: RE: Re[4]: Re[2]: Re[2]: Re: Re[2]: Re: Trains, planes and APR S
automobiles. was: Kenwood APRS radio
From: "Eric H. Christensen" <kf4otn@earthlink.net>
Date: Tue, 15 Jun 2004 17:31:15 -0400
X-Message-Number: 57
CE> Yes but our digis are located on hardened sites. These towers and
CE> sites don't just go down. They are located at State tower sites,
CE> Federal buildings, etc. They are on generator backup. If we would
CE> have had a high speed RF backbone that was carrying APRS, TCP/IP,
CE> BBS Traffic, etc, then we would have been able to keep weather
CE> information coming in and out, kept email going, and really been
CE> able to serve our EOC.
Which would have been impossible because you had no internet access within
120 miles. ;)
CAPS TO DEPICT MY RESPONSE:
NO, THAT IS EXACTLY THE REASON FOR THE BACKBONE! TO GET THE TRAFFIC TO AN
AREA WHERE THERE IS INTERNET CONNECTIVITY.
Seriously, we are not talking about an APRS backbone anymore. If we are
talking about e-mail, and internet access and all that, then we are talking
about a 19.2k or 56k Amateur TCP/IP system. You would definitely have to
consider building quite a few RELIABLE sites as well, because with your
access to utilities being lost in a 120 radius from ground zero, you would
need to build out quite a bit in at least one or more directions. (I mean,
if you are going to invest in that sort of network, you wouldnt want losing
1 site to take you down)
ABSOLUTELY!!!!!!!! THINK ABOUT WHAT THE EUROPEANS ARE DOING. I AM VERY
IMPRESSED. THERE USED TO BE A SIMILAR NETWORK IN WESTERN GEORGIA.
ERIC KF4OTN
(SORRY FOR THE CAPS)
----------------------------------------------------------------------
Subject: Re[4]: Re[2]: Re[2]: Re: Re[2]: Re: Trains, planes and APRS
automobiles. was: Kenwood APRS radio
From: Drew Baxter <droobie@maine.rr.com>
Date: Tue, 15 Jun 2004 17:41:07 -0400
X-Message-Number: 58
At 05:05 PM 6/15/2004, Danny wrote:
>Well, thats what DIGIS are for. You still need to access a tower site if
>your backbone is gonna work. Why create a new pipe on RF when we are a
>couple hops from the HIGH speed internet (remember that even DIALUP is
>high speed compared to what we have).
>
>It doesnt take an EXTRA computer. You can set up any existing APRS
>station as an IGATE with just a dialup connection.
Station? I have a D700A (one of 38%, hi hi) .. :) Many of us are using
generic trackers and Kenwood devices for connection to the APRS network..
>I just dont understand why you wanna replace APRS-IS with an RF
>backbone. We have greater bandwidth accessible to us that most of us
>(everyone on this sig has at least dialup access) are ALREADY paying for.
>The backboning of APRS is DONE.. Steve invented it, Pete and Dale made
>building the infrastructure accessible to anyone with a linux or windows
>PC. We are much better off investing our time in improving the user ports
>and making APRS-IS accessible to anyone, even during an emergency.
I didn't say I did.. You're missing my idea entirely. I'm saying we have
no high speed packet network on Amateur Radio at all! We should have
SOMETHING that we could use for multiple things. We can't always trust the
Internet, or have access to the Internet.. In my idea there'd be redundancy
amongst the stations via RF as well as could lower the flood of cross-digi
traffic to another network.
>Seems to me like you are trying to recreate the entire internet using
>RF. Good luck.
Once again, you're misreading what I'm saying. I'm saying that there
should be a standardized high-speed approach for a multi-use amateur radio
network. A place where any technology (APRS, Internet over RF, etc.) can
exist together because the pipe is ridiculously fat to allow it.
I am NOT suggesting removing the IS, I am NOT suggesting moving APRS away
from 1200bps. I am saying however that we could have high speed nodes for
everything from voice conferencing, to statewide APRS backbones
(Non-Internet) all through a single group of frequencies through
standardized hardware.
--Droo, K1XVM
----------------------------------------------------------------------
Subject: emergency care package
From: Wes Johnston <wes@johnston.net>
Date: Tue, 15 Jun 2004 17:45:28 -0400
X-Message-Number: 59
This idea is kinda neat... a box which contains radio gear, water
purification equipment, food, etc....
http://www.popsci.com/popsci/care/carecube.html
.....Rose and Hillis's aircraft-deployable station comes equipped with a
water-purification unit, a computer and PDA-like networked communication
devices, and a Stirling engine and power generator. An induction hose sucks
in river water for purification. Users can borrow PDAs, which ping messages
to one another and, when close enough to home base, into cyberspace. To
make electricity, users either hop onto a stationary bike and pedal,
hamster-style, or they can burn wood, rice husks or other combustibles.
Weather permitting, the station's Stirling engine can also run on solar
power.....
I read about this in the current issue of popsci at home, and noticed the
PDAs... they appearently zap messages to/from pdas like a fire bucket
brigade. Each PDA collects emails from all parties it comes into contact
with and as the pda's sync with one another via IR, they all end up with
more and more messages until one of the PDAs reaches this care box. Then
all messages are uplinked. Kinda like a "sneaker net" for aprs? Maybe
they should throw a D7 ht in there for good measure?
Wes
----------------------------------------------------------------------
Subject: Re: Re[2]: Re[2]: Re: Re[2]: Re: Trains, planes and APRS automobiles.
was: Kenwood APRS radio
From: "Scott Miller" <scott@opentrac.org>
Date: Tue, 15 Jun 2004 14:45:00 -0700
X-Message-Number: 60
>I think we have seen demonstrated that APRS paths of 5 or 7 hops will
work. NO, I AM NOT ADVOCATING IT!!! My point is, you could certainly digi
hop 2 or 3 times to a local LAN with APRS-IS access easily in the event your
area is so heavily damaged that you lose all your local IGATES.
Your reliability and capacity both drop dramatically after the first hop or
so. 9600 baud can carry a large portion of the APRS-IS, and should be more
than adequate for a regional feed. What we need is a simple way to build
the backbone network, though - software that can handle regional filtering,
traffic aggregation, multiple AX.25 interfaces, and client subscriptions.
It's on the to-do list for OpenTRAC, but we haven't gotten any further than
BSing about what we'd like it to do.
No, an RF backbone overlay network isn't critical for emergency use. But it
wouldn't hurt.
Scott
N1VG
----------------------------------------------------------------------
Subject: Re: UI-Network, not on 2m? Yeah, and monkeys might fly outta.... (was
Trains, planes, and APRS)
From: Jeff King <jeff@aerodata.net>
Date: Tue, 15 Jun 2004 16:56:20 -0500 (CDT)
X-Message-Number: 61
MFSK would work better then AFSK. Give the folks at CMX a call (ask for
David if he still works there) and they can explain it better then I.
Also, don't forget, the choice of Bell 202, just like just about every
other major ham decision, was a choice of convience rather then technical
soundness. Back in the late 70's, one of the groups in Montrial was using
2400 baud on the air.
Quoting Scott Miller <scott@opentrac.org>:
>>non-2m VHF or UHF band network for UI-frames in general, at 9.6 kbps?
>>Are there issues with mobile 9.6k, any more so than with fixed stations?
>
>What about 2400 bps MSK? Does it survive pre/de-emphasis? I've seen it
>used on commercial AVL systems, but I've never looked into running it
>through normal audio inputs. And for re-using old equipment, that's a big
>requirement.
>
>Scott
>N1VG
----------------------------------------------------------------------
Subject: MFJ-1270B schematic
From: "Scott Miller" <scott@opentrac.org>
Date: Tue, 15 Jun 2004 14:47:56 -0700
X-Message-Number: 62
Does anyone have a schematic of the MFJ-1270B? I'd like to take a look at
the filter it uses on the XR2211. I'm building a new device based on the
same chip, and I've read that the MF10 filter in the original TNC-2's
actually did more harm than good by restricting the dynamic range, but
apparently the 1270B's got a simple passive filter that does a better job.
Thanks,
Scott
N1VG
----------------------------------------------------------------------
Subject: Re: Re[2]: Re[2]: Re: Re[2]: Re: Trains, planes and APRS automobiles.
was: Kenwood APRS radio
From: "Eric H. Christensen" <kf4otn@earthlink.net>
Date: Tue, 15 Jun 2004 17:59:39 -0400
X-Message-Number: 63
Heck! After Isabel, the only thing that was NOT damaged was Amateur Radio!
The Public Service antennas were laying all over the roof (including the
SATCOM)...
73s,
Eric KF4OTN
kf4otn@amsat.org
-----Original Message-----
From: Scott Miller [mailto:scott@opentrac.org]
>As fragile as our ham radio rag-tag networks can be, they're not
>dependent on the telco, and if something gets broken there's a good
>chance we can get off our rears and at least try to fix it, rather than
>sit around on our hands waiting for the local telco to fix things. And
>I
THAT is the big difference - being able to fix it. You can rig up an
emergency TV-twinlead J-pole held up with tie-wraps and thumbtacks, swap out
a bad radio with a spare mobile, or whatever. 2-meter packet is a pretty
forgiving and hackable technology.
Sure, use Internet bandwidth when you've got it. But don't count on it
being there when you need it...
Scott
N1VG
----------------------------------------------------------------------
Subject: Re[6]: Re: Re[2]: Re: Trains, planes and APRS autom obiles. was:
Kenwood APRS radio
From: Danny <danny@messano.net>
Date: Tue, 15 Jun 2004 18:06:47 -0400
X-Message-Number: 64
Tuesday, June 15, 2004, 5:23:25 PM, you wrote:
EHC> I don't think so. No one did. Our regional network was pretty much
EHC> covering an area that was under severe duress. We are adding more I-Gates
EHC> now so that in the event of another large event maybe we will still have
EHC> coverage.
I dont understand..
If no one had even had so much as a dialup connection within 120 miles,
what good will adding more IGATES do? You said yourself that it wont work,
yet you are planning IGATES.
EHC> Plus using the APRS-IS to link two RF networks is not the best way. Unless
EHC> you have it tied directly to the digi, you are adding to the network
trafficEHC> and taking away some of the bandwidth. Backbones would be linked
directly
EHC> into the WIDEs.
Hmm.. If I send a beacon, it gets repeated by the digi on 144.39 and passed
down the backbone. I have generated 2 packets on 144.39. If I send my
beacon and it's repeated by the digi so the IGATE hears it, I have
generated the same 2 packets on 144.39.
If someone sends me a one line message, the IGATE tranmsits it, the digi
repeats it. They have generated 2 packets on 144.390. If someone sends a
message down the backbone, it's transmitted by the digi on 144.390. 1
packet.
THAT is the bandwidth we are saving? Seems worth it to me.
I don't know that you have really thought this out.
EHC> The APRS-IS IS a good way to link all the RF networks together for use on
EHC> the internet AND to disseminate information to large areas...
It's a good way to link all the RF networks together, period.
I still havent seen the overwhelming need to have an RF backbone to replace
anything that cant be done with an on-the-fly IGATE.
Lets face it, the internet is everywhere. In the event of a disaster, you
cant be more than a couple hops to an IGATE. Replacing what we already have
with APRS-IS with our own MUCH SLOWER and LESS RELIABLE backbone system
doesnt make sense.
Danny
KE4RAP
----------------------------------------------------------------------
Subject: Re: Re[4]: Trains, planes and APRS automobiles. was: Kenwood APRS radio
From: Drew Baxter <droobie@maine.rr.com>
Date: Tue, 15 Jun 2004 18:08:58 -0400
X-Message-Number: 65
You do know what 'radio' means, right? This isn't called Amateur Internet.
The IS isn't meant to replace RF, it's meant as a means to supplement. I'm
proposing we have a localized high speed packet network in hopes of
fulfilling the data needs of now and new technology in the future. The
APRS-IS is critical to the APRS network, and shouldn't change. However, I
try not to rely on the Internet because my friend 90 miles away might not
get me on Internet but he could with the right terrestrial network on RF.
I'm not proposing to remove or negate the IS.. However the IS is NOT as
important to some of us (SAR, etc.) as a high speed packet backbone would
be for LOCAL (APRS was meant for LOCAL) traffic.
It sounds to me like you have entirely too much interest in reducing the
Amateur Radio Service to an Internet-based Network with the occasional RF
traffic. That's a very sad state of affairs if that is really how you see
things.
--Droo, K1XVM
At 05:17 PM 6/15/2004, Danny wrote:
>Thats what you are missing. APRS is a hybrid system. Trying to make it
>ALL RF or ALL internet defeats its purpose. I think APRS-IS access is
>crucial in an emergency. As i've said in other messages, if you give me a
>9600 APRS RF backbone, then what? If you give me APRS-IS access within
>even 2 or 3 digi hops, you have given me a great asset.
>
>Danny
----------------------------------------------------------------------
Subject: Re[6]: Re[2]: Re[2]: Re: Re[2]: Re: Trains, planes and APR S
automobiles. was: Kenwood APRS radio
From: Danny <danny@messano.net>
Date: Tue, 15 Jun 2004 18:17:43 -0400
X-Message-Number: 66
EHC> CAPS TO DEPICT MY RESPONSE:
EHC> NO, THAT IS EXACTLY THE REASON FOR THE BACKBONE! TO GET THE TRAFFIC TO AN
EHC> AREA WHERE THERE IS INTERNET CONNECTIVITY.
Which is more than likely a digi hop or two away. The internet is
everywhere. If a disaster takes it down in your local LAN, digi an extra
hop or two to the next LAN.
EHC> Seriously, we are not talking about an APRS backbone anymore. If we are
EHC> talking about e-mail, and internet access and all that, then we are talking
EHC> about a 19.2k or 56k Amateur TCP/IP system. You would definitely have to
EHC> consider building quite a few RELIABLE sites as well, because with your
EHC> access to utilities being lost in a 120 radius from ground zero, you would
EHC> need to build out quite a bit in at least one or more directions. (I mean,
EHC> if you are going to invest in that sort of network, you wouldnt want losing
EHC> 1 site to take you down)
EHC> ABSOLUTELY!!!!!!!! THINK ABOUT WHAT THE EUROPEANS ARE DOING. I AM VERY
EHC> IMPRESSED. THERE USED TO BE A SIMILAR NETWORK IN WESTERN GEORGIA.
I think that goes way beyond a discussion of APRS and the need for
backbones. Your really dreaming of an amateur TCP/IP netowrk for your area,
which is MUCH more than you would need to just make APRS work.
Danny
KE4RAP
----------------------------------------------------------------------
Subject: Re[5]: Re[2]: Re[2]: Re: Re[2]: Re: Trains, planes and APRS
automobiles. was: Kenwood APRS radio
From: Danny <danny@messano.net>
Date: Tue, 15 Jun 2004 18:26:52 -0400
X-Message-Number: 67
DB> Station? I have a D700A (one of 38%, hi hi) .. :) Many of us are using
DB> generic trackers and Kenwood devices for connection to the APRS network..
I find it hard to believe that no one in your area runs a home APRS station.
DB> I didn't say I did.. You're missing my idea entirely. I'm saying we have
DB> no high speed packet network on Amateur Radio at all! We should have
DB> SOMETHING that we could use for multiple things. We can't always trust the
DB> Internet, or have access to the Internet.. In my idea there'd be redundancy
DB> amongst the stations via RF as well as could lower the flood of cross-digi
DB> traffic to another network.
Well, good luck building an amateur network with the same redundancy as the
internet.
DB> Once again, you're misreading what I'm saying. I'm saying that there
DB> should be a standardized high-speed approach for a multi-use amateur radio
DB> network. A place where any technology (APRS, Internet over RF, etc.) can
DB> exist together because the pipe is ridiculously fat to allow it.
Well, go for it. If and when you find the equipment to build that pipe, let
me know. Id rather plan to put myself a few hops from the internet over a
low speed link than to try and build a whole new high speed network to
"backup" what we have with the internet. Again, we would need to do this
with as much redundancy as the internet, and make sure that "fat pipe"
doesnt get overloaded with garbage so it can actually be used in an
emergency.
Danny
KE4RAP
----------------------------------------------------------------------
Subject: Re: Re[4]: Re[2]: Re[2]: Re: Re[2]: Re: Trains, planes and APR S
automobiles. was: Kenwood APRS radio
From: "Scott Miller" <scott@opentrac.org>
Date: Tue, 15 Jun 2004 15:21:31 -0700
X-Message-Number: 68
>I think we are well on our way to rebuilding the internet using RF now.
That's AMPRnet. They've been doing it for a long time, and I think a level
of integration with APRS would be a good thing.
Scott
N1VG
----------------------------------------------------------------------
Subject: Re: emergency care package
From: "Scott Miller" <scott@opentrac.org>
Date: Tue, 15 Jun 2004 15:37:18 -0700
X-Message-Number: 69
>This idea is kinda neat... a box which contains radio gear, water
>purification equipment, food, etc....
>http://www.popsci.com/popsci/care/carecube.html
That's really cool. Might be just the ticket for when the zombies take
over: http://www.straightdope.com/mailbag/mzombiepower.html
I'm not really sure about the utility of the PDA gadgets. Seems like a
phone headset with a direct line to a control center would be more
practical.
Scott
N1VG
----------------------------------------------------------------------
Subject: Re[2]: Re: Re[2]: Re[2]: Re: Re[2]: Re: Trains, planes and APRS
automobiles. was: Kenwood APRS radio
From: Danny <danny@messano.net>
Date: Tue, 15 Jun 2004 18:33:01 -0400
X-Message-Number: 70
SM> Your reliability and capacity both drop dramatically after the first hop or
SM> so.
Agreed.. But if you are cut off from the world and it's your lifeline, it's
not too shabby.
9600 baud can carry a large portion of the APRS-IS, and should be more
SM> than adequate for a regional feed.
What size region are we talking about?
The APRS-IS stream gets fatter and fatter as we go. By the time we get any
backbone system in place at 9600 baud, APRS-IS will probably double in
size.
...What we need is a simple way to build
SM> the backbone network, though - software that can handle regional filtering,
SM> traffic aggregation, multiple AX.25 interfaces, and client subscriptions.
SM> It's on the to-do list for OpenTRAC, but we haven't gotten any further than
SM> BSing about what we'd like it to do.
Personally, I think we're better off improving the delivery of information
back and forth to APRS-IS, even over slow, emergency degraded links.
SM> No, an RF backbone overlay network isn't critical for emergency use. But it
SM> wouldn't hurt.
I would just like to see how it rivals being a hop or two from an IGATE and
APRS-IS.
Just think its a lot more infrastructure involved with setting up a
backbone, which is another asset to be taken out during your disaster.
Danny
KE4RAP
----------------------------------------------------------------------
Subject: Re[2]: Re[4]: Trains, planes and APRS automobiles. was: Kenwood APRS
radio
From: Danny <danny@messano.net>
Date: Tue, 15 Jun 2004 18:39:34 -0400
X-Message-Number: 71
DB> You do know what 'radio' means, right? This isn't called Amateur Internet.
Yes, but I am not close minded enough to put all my eggs into one basket.
As an engineer and amateur radio operator, I use all the resources
available to me.
DB> The IS isn't meant to replace RF, it's meant as a means to supplement. I'm
DB> proposing we have a localized high speed packet network in hopes of
DB> fulfilling the data needs of now and new technology in the future. The
DB> APRS-IS is critical to the APRS network, and shouldn't change. However, I
DB> try not to rely on the Internet because my friend 90 miles away might not
DB> get me on Internet but he could with the right terrestrial network on RF.
and 90 miles away he can set up your emergency IGATE and you now have
access to APRS-IS and the WORLD.
DB> I'm not proposing to remove or negate the IS.. However the IS is NOT as
DB> important to some of us (SAR, etc.) as a high speed packet backbone would
DB> be for LOCAL (APRS was meant for LOCAL) traffic.
APRS-IS is what you make of it. APRS-IS carries local traffic just as it
does traffic from Australia.
Why does it matter whether the pipe is RF or internet? With the internet
you have MUCH more bandwidth that ALREADY exists and that is accessible to
anyone with a dialup internet connection.
DB> It sounds to me like you have entirely too much interest in reducing the
DB> Amateur Radio Service to an Internet-based Network with the occasional RF
DB> traffic. That's a very sad state of affairs if that is really how you see
DB> things.
No Droo.. I see the internet as a potential extension of Amateur Radio...
Just like Echolink is, or Telnet DX Clusters, etc.
Like I said, I use what technologies are available to me. In an emergency,
who gives a damn if your network is 100% RF or not.. If part of your
traffic is carried on the internet and completed its mission, then the JOB
WAS DONE!
Danny
KE4RAP
----------------------------------------------------------------------
Subject: Re: Trains, planes and APRS automobiles. was: Kenwood APRS radio
From: Wes Johnston <wes@johnston.net>
Date: Tue, 15 Jun 2004 18:44:12 -0400
X-Message-Number: 72
Here's a novel idea.... we've all agreed that kenwoods comprise 38% of the
stations... how many _total_stations are mobile(percentage wise)... for the
sake of this argument, let's say out of all of the APRS stations it's 38%
mobile. That means that 62% are fixed assets. You take those 62% of the
stations and put them on an alternate frequency at 9600. Now that leaves
the mobiles on 144.39 at 1200 baud.... 1200 is reliable, and now the
mobiles don't have to compete with so many stations... particularly
non-local stations. All their packets are gated to the alternate frequency
where they are seen by all the fixed stations. Now, this leaves the
mobiles kind of in the dark as to what is going on.... the trick is that
the digipeaters must allow them to "subscribe" to data products via a
standard APRS message. Then the selected data products are gated down from
the backbone to the local area for the benefit of that requesting mobile
operator.
What if the digipeater fails? the mobile operators simply spin their dials
to the alt frequency and change to 9600. All the kenwoods can do this
easily. Will work in a pinch. I guess my point here is that we can allow
the fixed stations to vacate 144.39 leaving it for the legacy mobiles...
get traffic off the mobile frequency so there is less for the mobiles to
compete with.
Another way to reduce congestion is to have the local digi strip the path
of the mobile packet's station to nothing on the legacy (144.39)
frequency. A packet from a mobile will be digipeated two places... onto
the alt frequency with it's indicated path, and also digipeated onto the
legacy frequency by the digipeater in such a way that it will _not_ be
digipeated by any other nearby digipeater. By keeping non-local packets
off 144.39, the mobiles can get in better... and they can see each
other. How busy is your 144.39 digipeater everyday digipeating traffic
from >50 miles away that you could care less about? This method could
maintain THAT digipeater for mobiles wilst the fixed stations who do want
to see traffic from >50 miles can tune to the backbone (which should have
separate a user input frequency so that the users aren't competing with DX
stations. For example, digipeaters on the backbone always TX on 444.000
and have a 2nd tnc on site listening on 449.000. Digipeaters can hear each
other and pass traffic using the current WIDEn-n scheme simplex on 444.000,
while the users can simply set their rigs to the standard 5mhz split and
talk to the second TNC at the digi site. This TNC passes it's packets to
the 444.000 tnc which transmits the packet on the digi - digi frequency.
If we're gunna redesign the network, let's do it right... What I'm
proposing here will a) keep 144.39 active for out of towners who don't know
the local alt frequency, b)reduce congestion on 144.39 by moving approx 60%
of the users off frequency, c)provide for a simple backbone, d)provide a
reliable local access port for the users.
It means each digi site having 3 tncs... 3 radios (144.39, a 440 tx/rx and
a 440 rx)and a 70cm duplexer. Also, this _doesn't_ have to happen at 9600,
but it could/should. if done at 9k6, the digi should probably queue
packets for 5 to 10 seconds to save on TXD time.
Just my thoughts....
Wes
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