-->Reliability - I don't think there is any data to present regarding the
reliability of the all in one repeater in a box concept over a commercial
analog repeater. The Icom 'repeater' is clearly two mobiles stuck in a box.
However, can you keep it running and repair it if needed?

You repair as any other radio. Just because you have a bunch of unused
spares doesn't make a FM repeater any more reliable. And there are MANY
commercial repeaters that are "two mobiles stuck in a box"


** that is completely wrong.  Do you have a service monitor that allows you
to inject a calibrated signal into the Dstar repeater?  In fact, do you have
ANY test equipment to measure sensitivity, BER, etc. on the Dstar repeater?
I have the service manual for the Dstar VHF repeater, anything in there I'm
going to be able to replace and retune in the field?  Could you purchase the
interface board between the two mobiles and replace it in the field?  As I
stated, there is a difference between reliability and serviceability.  The
product has not been on the market long enough to speak to the
'reliability', but having hot standby systems and spare parts that CAN be
changed in the field do increase serviceability, and ultimately reliability.
If you Dstar repeater goes down, for the most part, you need to swap out the
rack mount box and send it in.  That is just not the case with 90% of the
analog FM repeaters out there.


-->Same as FM - sounds like you have swallowed the blue pill from Icom. Our
'terrain' includes very few locations that are line of sight to the site.

Sound as if you might have a malfunctioning system, because as others have
indicated, that isn't the general case for D-STAR. We've got a number of
repeaters here in Georgia that are covering very similar to the high site FM
repeaters that are collocated.



** the difference is likely terrain.  I can easily work my VHF dstar
repeater 80+ miles out when in a nice spot with virtually LOS to the
hilltop.  However, come back 20 miles away behind some big mountains and
trees, and it doesn't work.  Analog does, nicely.  I often talk on the VHF
dstar until it gets too rough while mobile, then switch to the UHF analog on
the same tower, same height, and it is just fine.  My point has been all
along that the GMSK stuff is adequate (even though compressed and ugly
sounding audio) when the signal isn't torn up with multipath.  However, tear
it up a bit, and it just doesn't decode well.

 

-->Voice and slow speed data 'over the same links' - this one has me
wondering. Assuming the gateway is down, what links are you referring to?

If the gateway is down, I can talk to ALL of the local users, which is often
the primary target for data communications anyway.

So with a handheld or mobile and a computer, I can send voice and data.



** Yup, but that isn't a link.  The original post claimed he could talk to
everyone 'over the links' even though the gateway was down.


-->Yup.with my D7 and a laptop, I can carry on a voice conversation or send
and receive email or download lists of data via packet. I don't tie up the
net control discussion when I send and receive email.

But you will need to have two infrastructures online. The voice repeater and
the digipeater. I can do the same thing that the D7 can. BUT, if desired, I
can do it on a single channel, with a single infrastructure.



** So what you are telling me.is that while a voice net is fully functioning
and you are not part of it, you are monitoring it, you can transmit data to
send email and the like with the internet connectivity down and all this
without disrupting the voice net?  Not possible my friend.


BUT, if Internet access IS available, then I can provide all of the above,
as well as direct communications with remote locations such a State EOCs,
FEMA EOCs, and other government organizations in DC such as the Red Cross.

-->Yes, assuming all those agencies have Dstar (all of those agencies by
default quite likely already have analog FM)

Many of them do. And for those that don't, all I have to do is to get a
DVDongle into one and I've got instant communications. And I'm never saying
to rip out FM for D-STAR. D-STAR is another tool in the toolbag.



** it's a great tool for the tool box, provided the internet is up.  The
dongle won't do squat without connectivity.  I'm not trying to tell anyone
that the Dstar system is a flop or not useful, what I was pointing out is
that there is a HUGE discrepancy between what the brochures offer and what
can actually be done.


So if I compare the common non-linked FM repeater to the commonly Internet
connected D-STAR repeater, the D-STAR repeater at it's worst does a heck of
a lot more, and at the best, just blows the functionality of a FM repeater
away.

-->Hmmm..you do get NOAA weather alerts over your D-Star repeater? We do on
analog. You get site telemetry (battery voltage, VSWR, etc.) over your
D-star? We do with analog. You have remote control of any of the site
features like turning the power down, switching to the backup antenna,
manually starting the generator, etc on your D-Star repeater? We do with
analog. And guess what, with data on a separate network, I can send and
receive email at the same time I'm listening to the emergency net without
having to occupy their channel for data.

Yup, Yup, Yup, Yup, Yup, all of that is easily doable for anyone that wants
to do it. There are some systems that do, others that don't just as FM
repeaters. Does you FM repeater identify with every transmission? No, just
because it doesn't, doesn't make it less useful. Just because a specific
D-STAR repeater doesn't have a capability doesn't make it worthless.



** please help me understand, shoot me to someone who is doing any of the
above?


And guess what, on my D-STAR stack and I can have 3 nets (with or without
data) and send high-resolution pictures, and look at the current weather
radar, and check out our ARES database and send and receive email and
Instant Message and a bunch more stuff. With the high-speed IP connection of
the ID-1, I've got so much more capability that will ever exist on a FM or
12/24/96 packet network.



No question that the ID-1 as an ethernet bridge is valuable, never was part
of the debate.  We have an ID-1 on the same site, we've pushed it 70+ miles
in testing.but it won't go 8 miles to our control ops house because..there
is no line of sight.  In fact, probably 80+ or better of the area served
from the hilltop is not LOS.  We just don't live in that kind of area, we
have mountains, hills, canyons and trees and believe it or not, digital GMSK
stuff does NOT work better than analog in that environment.


-->Awesome. PLEASE explain to me how you have been able to make the gateway
work via cellular modem and wifi. Having only done one installation and
worked hard to get the Icom required addressing scheme implemented and
having to be very close to the backbone to keep the jitter down enough to
provide reliable communications I would be in awe if you have managed to
make it actually work as simply as you make it sound.

You just roll in, connect to a wifi hot spot, and you are authenticated with
the trust server and the gateway just hums along? Please Share!

It's a piece of cake, a Sprint modem is the best right now because it
doesn't NAT the address. There are hundreds of people on this list that have
seen the KJ4BDF repeater in action. It has been online at Dayton,
Huntsville, and a number of Georgia Hamfests and events. The WD4HRO repeater
is also capable of operating mobile. It was at the Atlanta hamfest a few
weeks ago.

In the past I've operated off of hotspots in hotels, but because of some
security concerns, that's been temporarily discontinued. I'm hoping that the
DPLUS software will enable the functionality in the future. But even without
it, I can still do it because I just VPN into another network with a public
IP and I'm online.



** I'd love to see this in practice, after watching and listening to the
packet reliability needed to keep the stream stable, I'm in awe.  I'll do my
part and research these folks.  Seems like if it was that easy we'd all have
much better luck with the connectivity.  I've only got one installation to
base it on, and that was nowhere near as forgiving as you are explaining.
Furthermore, there was no internet access anywhere in our area when we were
out of services.


-->I'm not saying D-star isn't novel and fun. I'm saying that there are many
pitfalls in implementing it, servicing it, fixing it and actually doing what
the brochures lead you to believe it does. I would MUCH rather have a voice
radio so I can monitor a couple of nets during the emergency and a radio/TNC
to send data WHEN I want to WHERE I want (i.e. winlink) rather than be
trapped on the Dstar 'network' with no onramp to the email system (except
what Dan has done with Drats which is awesome!). My tool box includes both,
todate the analog side get's 99% of the usage because it meets the need even
if the internet backbone is down.

"pitfalls in implementing" Hmmm, let me think. Have I heard that somewhere
before? I think so, I believe those were some of the same types of
statements that was used when SSB started, when FM started, essentially when
any technology started. The first FM repeaters were a pain to install until
someone figured out duplexors. Before that you had to worry about antenna
isolation.

Oh, as to being stuck in the D-STAR system, well you are indeed entitled to
your own opinion, but that's definitely not mine.

When "I'm stuck" in D-STAR, I can do my email over my ID-1. I'm not limited
to Winlink, I can do that as well as Hotmail, Gmail, and Yahoo Mail. I can
easily send and receive 2MB high resolution pictures. I can fire up Instant
Messenger client and talk to millions of people.



** yes..and all that hinges on a local (VERY LOCAL ON 1.2 gHz)
infrastructure that is operating.  Two years ago, we were out of power, land
line telephone, internet and cellular service for almost 3 days on the North
Oregon Coast.  Guess what, we shot hundreds of winlink messages out.  If we
had already setup the Dstar VHF with gateway then, it would have been
useless as we had no internet for the gateway.  The nearest hilltop with
internet still working was far too far away to support 1.2 gHz signals.


Without my ID-1, I can flip over to the Southeastern Weather Net where we
have over 25 repeaters connecting weekly with systems from Texas to North
Carolina and every state in-between.

And most importantly, I can switch to FM and hookup a TNC if I desire.



** My point has been, and remains, that while this coverage can easily be
expected and utilized in many terrains..it is not the case in many others.
The folks that seem to be 'selling' the Dstar solution as so much better
than analog seem to be in areas where line of sight access to the repeater
gives them reasonably good signals and throughput.  Please understand.that
dog won't hunt in our terrain.  We've tried, we know what works and what
doesn't work, and it is different from what may work in big flat states.

 

73

 

Daron N7HQR





 



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