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Last August San Diego Section ARES ran a
Simulated Emergency Test in San Diego and Imperial County where we simulated the
effects of a 7.9 earthquake next door in Imperial County ( a likely scenario)
which destroyed most of the local infrasture.
Due to the simulated outages of local
infrastructure, repeaters and power sources, we were unable to establish
VHF/UHF/Cell Phone or Land Line voice communications between the San Diego EOC
and the Imperial County EOC.
The only communications that proved reliable was HF
Winlink. San Diego EOC was able to connect into a Winlink Node in Texas
and Imperial County was able to connect to another HF node and we established
and maintained both Critical, Tactical and H&W communications through
Winlink Email.
I might note that the success of HF Winlink when
everything else failed during the SET really changed the minds of a lot of died
in the wool Winlink Haters around here.
Could we have accomplished the same with HF voice
Relays?..
We tried HF voice without much success (they were
in a HF dead zone)... however in an real (non SET) disaster with more HF
stations around for relays...Likely... but definitely not with the same ease of
use or reliability...
So there definitely is a place for Winlink
EMCOMM in our bag of tricks...
__________________________________________________________ Howard S.
White Ph.D. P. Eng., VE3GFW/K6 ex-AE6SM KY6LA Website: www.ky6la.com "No Good Deed Goes
Unpunished" "Ham Antennas Save Lives - Katrina, 2003 San Diego Fires,
911"
----- Original Message -----
Sent: Wednesday, February 22, 2006 12:19
PM
Subject: Re: [digitalradio] Re: NTS and
traffic handling and digital
Tim,
I think we all understand your position on
this. If you take it very
far, I would have to say that 95% or more hams
would recommend that any
kind of automatic operation be prohibited on
amateur radio frequencies.
As I said earlier, subbands may be a solution
for now, but long term,
maybe not. Nothing is perfect.
For example,
if I am monitoring a frequency and start calling a digital
CQ or answer a
digital CQ and an automatic digital station comes on
frequency, I have no
way of knowing if they were there first unless I
happen to be using their
mode. If a Pactor station comes up, I would
know that they are interfering
with my Q because, they are going to be
operating as an ARQ mode.
This is another significant benefit to ARQ
modes, since they insure that a
station coming up on the frequency knows
right away whether the frequency
is busy or not. And it doesn't have to
occur on a special part of the
band.
Now if I am monitoring a frequency and start calling a digital CQ
or
answer a digital CQ or try to connect with an automated system and a
human op somewhere starts transmitting on the frequency, I would often
consider them to be encroaching. If they were using a different mode, I
would have no way of knowing if they were there first. Does this happen
very often? Pretty rare, but it does happen. If I am on the same mode, I
may be able to read the mail if they are stronger and maybe not. This is
one of the limitations of digital modes at this time. With CW or voice
you can more easily determine who was there first. QRL in CW as some
suggest is going to be of less value due to the fewer and fewer hams who
will even know CW, but if they hear it, even if they can not understand
it, they will know the frequency is being used, so that has value in
ID'ing a busy channel.
As far as using e-mail during emergencies,
you only use e-mail for large
files of data. You NEVER, EVER, use e-mail
for critical, tactical
messaging. Any emergency operations MUST always
have a solid voice link
first. This is one of the most basic tenents of
emergency communication.
It is only after you have tactical communications
that you even consider
having e-mail linking. But e-mail links can be
useful in emergency
situations.
One of the best object lessons
(apparently true) about e-mail was when
e-mail was used to call for an
emergency test for an organization. The
message was sent out at the end of
the week so that everyone would know
of the participation on Saturday
morning. Unfortunately, the e-mails did
not get delivered to the
recipients until Sunday :( Big problem.
I know of a Winlink 2000
situation where the system was to be used to
demonstrate its effectives
for emergency use and it utterly failed. Some
of the messages came through
much later, but it showed that you can not
absolutely rely on any of these
systems to work 100% of the time. But
often they do work rather well. When
we were testing SCAMP, I was able
to link between my station in SW
Wisconsin, to a station in Nova Scotia,
transfer a letter size document in
a few minutes and have the message
back on my desktop as e-mail a few
seconds later. The idea is to have
alternate systems, but always have
tactical voice available.
The American Red Cross fiasco with them
preventing hams from sending
Health and Welfare is shocking and you are
very correct that ARRL needs
to negotiate a complete change in thinking
within the leadership of ARC.
I still can not believe how many really bad
decisions were made at so
many levels, by so many people who were in
positions of authority.
73,
Rick, KV9U
Tim Gorman
wrote:
> On Tuesday 21 February 2006 18:45, KV9U wrote:
> >
With the unfolding technologies we won't be needing subbands. For the
>
> older technology such as PK-232 equipment the stop gap is to keep
the
> > automatic operation areas in place for now. Ideally, they
would
> > eventually not be needed. At this time I am not sure that
the SCS modem
> > is a solution. It would require improved software
to go with the modem.
> > But there is no reason that this could not
be developed as a retrofix.
>
> I think you missed my point. Even
with the new technology, sub-bands
> will be
> needed. You are
only fooling yourself if you think busy detection by
> itself
>
will eliminate the QRM from the hidden transmitter problem. Let me
>
emphasize,
> *THE COMMERCIAL INDUSTRY* could not solve this problem
during FCC
> hearings on
> the smart radio
concept.
>
> It doesn't matter what kind of busy detection the
automatic station
> has. If it
> can't hear anyone on the
frequency it will, sooner or later, respond to a
> query. If you force
the protocol to use an extended leaky bucket type of
> timing to respond
to queries when activity has been detected at a
> prior time
>
then you only load the channel up further with connection requests
thus
> causing even more congestion than occurred before. This hurts the
channel
> efficiency tremendously. If you program the protocol so that a
session is
> stopped whenever another station is detected, you
tremendously lower the
> throughput.
>
> When you make the
channel less efficient you force more channels to be
> used to
>
carry the traffic load. This causes even more opportunities for
>
interference
> to happen. It's a merry-go-round with no way
off.
>
> The only answer is to establish sub-bands where this kind
operation
> can exist
> in an efficient manner so as to maximize
spectrum efficiency and minimize
> impacts on the rest of the
spectrum.
>
> >
> > From everything I have been
discovering, there is very little support
> > (or even knowledge of )
the NTS/D. The current direction seems to be to
> > move toward the
internet as the solution for handling e-mail traffic
> > with minimal
ham activity. This is partially due to the desire for
> > timely
traffic handling (one hour maximum delivery time that can not be
> >
done by NTS/D) and partially due to the desire to reduce the number of
>
> automatic stations operating on HF.
>
> Have you listened to
the latest testimony in front of Congress
> concerning the
> use
of email for handling tactical traffic? It's not good. It's what
> so
many
> have been saying for a long time but can't get anyone to hear -
> especially
> the ARRL. When Mike Brown said he sent emails to a
number of people in
> Washington about the situation in New Orleans, the
answer was "Email?
> Who can
> dig out information like this when
I get 600 emails a day?" (I'm
> paraphrasing
> of course - but
this was the bottom line meaning!) There was one
> witness, I
>
belive a vice-admiral, who said that there should have been telephone
or
> radio contact to pass this kind of message - i.e. human to human
contact.
>
> If the ARRL doesn't rethink their priorties after
this testimony,
> there isn't
> any hope for amateur radio to be
a useful entity in the future, at
> least for
> important types
of messages. It is important for a system with human
> intervention for
delivery to be available for handling priority traffic -
> there just
isn't anything else that works. You can't tell a computer
> to
run
> down the hall and wake someone up to get them a
message.
>
> That shouldn't be the only lesson learned either. In
talking with a
> couple of
> people who were in the Superdome, a
vast, vast majority of the people
> there
> could not have used
email to notify anyone of their situation even if
> computers had been
available. Even in this day and age there is a large
> majority of our
population that do not use email let alone even have
> enough
>
computer training to make use of it. Winlink and the ARRL would be
>
useless to
> thses people. Only the NTS with its use of telephone
numbers for
> delivery and
> with an established delivery network
manned with actual personnel is
> set up
> to handle this --
assuming the ARRL ever gets off their behind and
> negotiates
>
agreements that actually lets amateur radio help these
victims.
>
> The automatic stations in the NTS-D aren't a problem.
As far as I
> know, all
> operation by stations in the system
occurs inside the automatic subbands.
> Those subbands just aren't big
enough to cause a problem to most of the
> amateur radio community - as
long as people are aware that they exist.
>
> >
> >
This is the basic philosophy of the Winlink 2000 system: only use
ham
> > radio for a short distance to bridge a gap in the
internet, (unless
> > longer distances are needed for wide spread
disasters or for isolated
> > stations such as boaters), keep
HF stations off the air as much as
> > possible to avoid HF
forwarding due to the lack of bandspace as it is,
> > and handle most
of the short distance traffic via VHF/UHF packet to
> > further keep
messages off of HF, and also because an increasing number
> > of new
entrants do not have HF capability.
>
> As I said earlier, this
only works for email. It doesn't work for
> messages
> delivered
to telephone numbers or which need to be delivered by a
> human to
a
> human. Winlink doesn't have a delivery network capable of providing
these
> functions. The NTS does.
>
> >
> > For
casual types of operation, I think this is a good thing. I do not
> >
consider such systems true emergency communications systems because
with
> > certain single point failures, the system becomes
inoperative. The
> > decentralized NTS system can still get through,
albeit with inaccuracies
> > in the information and not necessarily
in a timely manner. Sometimes
> > that is still better than nothing
getting through at all.
>
> Based on current testimony, it may in
fact be the best thing of all. The
> inaccuracies can be addressed
through other means. The ARRL started to do
> that several years ago and
then dropped it. Moving to high
> intelligibility
> SSB systems
would be a start for voice messages. Keeping messages on the
> NTS-D
most of the way would help as well.
>
>
> >
> >
As far as Winlink 2000's content or any other newer e-mail systems,
>
> there is no broadcasting to my knowlege. All the connections are
from
> > one station to the other station. In fact, it would be very
difficult
> > (not impossible, but very difficult) for anyone to even
monitor the
> > transmission content. Since the content is not
transparent to the
> > amateur community, unlike almost any other
amateur mode, this is a root
> > problem that we have not come to
grips with.
> >
>
> If you don't like the broadcast
analogy, then consider if an ARES
> group in St.
> Louis decided
to send the entire current NWS weather forecast on 3963khz
> everytime
someone requested it. They would staff the frequency 24/7 with
>
operators and would just play the NWS radio through the mic whenever
>
someone
> requested it.
>
> How long would it be until they
got a letter from Riley outlining all the
> complaints that this is
third party traffic being sent on a regular
> basis and
> is
tying up amateur frequencies for a purpose that can be met by other
>
radio
> services (i.e. the NWS broadcasts).
>
> tim
ab0wr
>
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