Date   
Re: Internet Fail & Cell Weakness = Need for Ham Network?

Matthew Pitts <daywalker_blade_2004@...>
 

Tony,

I'm not so sure it needs to work as you're describing; what I see is that the mesh networks should back up the Internet in areas where they are practical, and link to other areas using other means in case the Internet is down, ss well as linking in smaller node clusters where such exist.

As far as Winlink goes, there are even ways to cope with a loss of Internet there; it all comes down to a desire to be less dependant on commercial networks that may not be a priority in a specific incident case and having the alternative tested and working.

Matthew Pitts
N8OHU


Sent from Yahoo! Mail on Android



From: Tony Langdon, VK3JED ;
To: ;
Subject: Re: [UniversalDigitalRadio] Internet Fail & Cell Weakness = Need for Ham Network?
Sent: Tue, Jul 31, 2012 1:13:42 PM

 

At 10:51 PM 7/31/2012, you wrote:
>The same applies here - there must be long-distance linking
>backbones to bridge those gaps - temporarily it could be
>the Internet but long-term it needs to be wireless.

Again, why? The wireless becomes infrastructure also, it's going to
be prone to failure, unless you haul it out. Again, I believe a
flexible approach of using the Internet when its available, and
bypassing it when it's not is better than spending $$$$ on more
infrastructure that could also fail. The real strangth of hams is
their flexibility and decentralised nature. Setup wireless links,
and you're creating another telco of sorts, with more or less similar
issues. One of the most likely disasters in this part of the world
is wildfire, and that has a habit of taking out infrastructure
perched on mountains. Guess what! We're back to hauling out the HF
radios (which is often what I'd first grab for comms out of the local
area anyway :) ). Oh, I should mention that the telcos here are
extremely quick in setting up temporary exchanges and portable cell
sites to restore services after a disaster.

Even testing and practice, because I'm outside the major metropolitan
areas, the only choice I have of communicating with the rest of the
emcomm guys here are the Internet (email or IRLP/Echolink), one 2m
and one 70cm repeater that's on a mountain midway between us, or (as
is most commonly used) good old HF.

As for the utility of the Internet, I have been involved in nets
which successfully combine the Internet (for reliable long haul
comms) with HF (for penetrating into an affected area). Winlink is
an example of a whole system that does exactly that for email.

73 de VK3JED / VK3IRL
http://vkradio.com

Re: Internet Fail & Cell Weakness = Need for Ham Network?

"John D. Hays" <john@...>
 



On Tue, Jul 31, 2012 at 5:51 AM, qrv@... 

If we could get back the piece of 220 here that UPS took, then
wasted, perhaps that could be dedicated to the purpose?

I don't know, nor do I know what's available elsewhere.


We received the equivalent of 1/2 of what was taken at 219-220 Mhz.(about 1996) specifically for point-to-point linking.  97.303l  (http://www.w5yi.org/page.php?id=202)


John D. Hays
K7VE
PO Box 1223, Edmonds, WA 98020-1223 
  

 

Re: Internet Fail & Cell Weakness = Need for Ham Network?

"qrv@..." <qrv@...>
 

Would 1MHz be adequate for what is needed?

It sounds impractical to use near the coast and one would have to
avoid TV stations on Channels 11 & 13.

We received the equivalent of 1/2 of what was taken at 219-220
Mhz.(about 1996) specifically for point-to-point linking. 97.303l
(http://www.w5yi.org/page.php?id=202)
John D. Hays



--

Thanks! & 73, KD4E.com
David Colburn nevils-station.com
I don't google I SEARCH! duckduckgo.com
Network: groups.yahoo.com/group/qrv
Restored to design-spec at Heaven's gate 1Cor15:22

Re: Internet Fail & Cell Weakness = Need for Ham Network?

"Tony Langdon, VK3JED" <vk3jed@...>
 

At 01:50 AM 8/1/2012, you wrote:


Tony,

I'm not so sure it needs to work as you're describing; what I see is that the mesh networks should back up the Internet in areas where they are practical, and link to other areas using other means in case the Internet is down, ss well as linking in smaller node clusters where such exist.
What I'm saying is that mesh networks have a low probability of success anywhere here, and permanent PrP links have the same weaknesses as the telcos and regular repeaters in some of the more common disaster scenarios, and probabilities (Black Saturday did take out some repeaters).


As far as Winlink goes, there are even ways to cope with a loss of Internet there; it all comes down to a desire to be less dependant on commercial networks that may not be a priority in a specific incident case and having the alternative tested and working.
Agree. I'm playing Devils advocate here, because I'm sensing a bit of a "religious" argument creeping in, and I'm saying there's other ways to work without having to build infrastructure. Down here, we can go a lot further, sometimes all that's needed is a supply of skilled operators to man agency radios, so people with hands on skills can be out in the field dealing with the emergency. That is one of the ham roles in this part of the world.

73 de VK3JED / VK3IRL
http://vkradio.com

Re: Internet Fail & Cell Weakness = Need for Ham Network?

Nate Bargmann <n0nb@...>
 

* On 2012 31 Jul 08:00 -0500, qrv@... wrote:

If we could get back the piece of 220 here that UPS took, then
wasted, perhaps that could be dedicated to the purpose?
Wasn't a portion of replacement bandwidth allocated at 219-220 MHz? I
know for certain that the American Association of Railroads is using
220-222 MHz for Positive Train Control on a national basis. The
railroad I work for is rolling it out now. It will not be allocated
back to amateur radio.

73, de Nate >>

--

"The optimist proclaims that we live in the best of all
possible worlds. The pessimist fears this is true."

Ham radio, Linux, bikes, and more: http://www.n0nb.us

Bridging the digital voice and data gap

Matthew Pitts <daywalker_blade_2004@...>
 

This topic seems more appropriate to this group than any of the others that I'm in here, as the hardware should support at least the three main modes in use. I know some folks might get their knickers in a twist over this, but interoperability between DMR, D-Star and NXDN is something I feel would be of benefit to all digital voice hams, and would eliminate the (intentional) animosity I've seen in certain groups if someone brings up connecting certain "incompatible" hardware together.

I know that the DMR core network standard implies that it is possible to connect a Hytera repeater to a Motorola Mototrbo repeater even though they use incompatible manufacturer specific functions; there are similar potential issues with connecting Icom IDAS repeater to Kenwood NEXEDGE repeaters. D-Star is semi-unique in that it's network protocol is the same as it's over the air protocol, and this is what attracted me to it in the first place, from a hardware and software design perspective. Is anyone else interested in discussion on this subject?

Matthew Pitts
N8OHU


Sent from Yahoo! Mail on Android

Re: Bridging the digital voice and data gap

Tyrell Berry <kd7kuj@...>
 

Not trying to start a flame war (but probably will...  I'm sorry in advance), but I feel it's important to point out.  Anytime you go from analog to digital, audio quality/information is lost.  If you go from D* to DMR, you are taking spoken voice (analog) and making it digital (IMBE) in your radio, the repeater receives the bits and spits out audio again (digital to analog), and encodes it AGAIN as digital (AMBE) to be sent to the received, where it once again gets converted to analog.  That's two A-D conversions...  each loses quality, and at these bit rates, we don't have much budget for dropping additional audio info.  People already complain about it sounding tinny!

SO, for me it's not a religious "thou shalt not inter-connect technologies" argument, it's more of a "the sacrifices made MAY make such a project technically unfeasible"

Just food for thought.

On Jul 31, 2012 6:05 PM, "Matthew Pitts" <daywalker_blade_2004@...> wrote:
 

This topic seems more appropriate to this group than any of the others that I'm in here, as the hardware should support at least the three main modes in use. I know some folks might get their knickers in a twist over this, but interoperability between DMR, D-Star and NXDN is something I feel would be of benefit to all digital voice hams, and would eliminate the (intentional) animosity I've seen in certain groups if someone brings up connecting certain "incompatible" hardware together.

I know that the DMR core network standard implies that it is possible to connect a Hytera repeater to a Motorola Mototrbo repeater even though they use incompatible manufacturer specific functions; there are similar potential issues with connecting Icom IDAS repeater to Kenwood NEXEDGE repeaters. D-Star is semi-unique in that it's network protocol is the same as it's over the air protocol, and this is what attracted me to it in the first place, from a hardware and software design perspective. Is anyone else interested in discussion on this subject?

Matthew Pitts
N8OHU


Sent from Yahoo! Mail on Android

Re: Bridging the digital voice and data gap

"Tony Langdon, VK3JED" <vk3jed@...>
 

At 04:34 PM 8/1/2012, you wrote:


Not trying to start a flame war (but probably will... I'm sorry in advance), but I feel it's important to point out. Anytime you go from analog to digital, audio quality/information is lost. If you go from D* to DMR, you are taking spoken voice (analog) and making it digital (IMBE) in your radio, the repeater receives the bits and spits out audio again (digital to analog), and encodes it AGAIN as digital (AMBE) to be sent to the received, where it once again gets converted to analog. That's two A-D conversions... each loses quality, and at these bit rates, we don't have much budget for dropping additional audio info. People already complain about it sounding tinny!

SO, for me it's not a religious "thou shalt not inter-connect technologies" argument, it's more of a "the sacrifices made MAY make such a project technically unfeasible"
While the codec conversions are unavoidable, you do NOT have to go all the way back to analog, if you are able to build some suitable hardware. That's already been done for D-STAR, with the DV Dongle being suitable for such a transcoder.

73 de VK3JED / VK3IRL
http://vkradio.com

Re: Bridging the digital voice and data gap

Matthew Pitts <daywalker_blade_2004@...>
 

Tony,

Exactly; all of the DV technologies I mentioned use some form of AMBE, so it's a matter of conversion of bit rates and constructing the proper carrier code for the target system. We already have code for D-Star amd can write code for DMR and NXDN as well. The hardest part will be converting from FDMA to TDMA and back, as the time slots could both have information on them that needs to be handled in some way.

Matthew Pitts
N8OHU

Sent from Yahoo! Mail on Android

Re: Bridging the digital voice and data gap

"Tony Langdon, VK3JED" <vk3jed@...>
 

At 07:53 PM 8/1/2012, Matthew Pitts wrote:

Tony,

Exactly; all of the DV technologies I mentioned use some form of AMBE, so it's a matter of conversion of bit rates and constructing the proper carrier code for the target system. We already have code for D-Star amd can write code for DMR and NXDN as well. The hardest part will be converting from FDMA to TDMA and back, as the time slots could both have information on them that needs to be handled in some way.
Agree totally, all the supervisory information needs to be handled properly. I'd like to see this sort of work happen. As for the technologies, I'm wary of TDMA, because it has inherent range limits (since the speed of light is finite), and over here, distance is king.

73 de VK3JED / VK3IRL
http://vkradio.com

Re: Bridging the digital voice and data gap

"Reid" <reid.crowe@...>
 

Will the UDR56K4 be able to support the switching speeds required for DMR?

-Reid N0RC

--- In UniversalDigitalRadio@..., Matthew Pitts <daywalker_blade_2004@...> wrote:

This topic seems more appropriate to this group than any of the others that I'm in here, as the hardware should support at least the three main modes in use. I know some folks might get their knickers in a twist over this, but interoperability between DMR, D-Star and NXDN is something I feel would be of benefit to all digital voice hams, and would eliminate the (intentional) animosity I've seen in certain groups if someone brings up connecting certain "incompatible" hardware together.

I know that the DMR core network standard implies that it is possible to connect a Hytera repeater to a Motorola Mototrbo repeater even though they use incompatible manufacturer specific functions; there are similar potential issues with connecting Icom IDAS repeater to Kenwood NEXEDGE repeaters. D-Star is semi-unique in that it's network protocol is the same as it's over the air protocol, and this is what attracted me to it in the first place, from a hardware and software design perspective. Is anyone else interested in discussion on this subject?

Matthew Pitts
N8OHU


Sent from Yahoo! Mail on Android

Re: Bridging the digital voice and data gap

Bryan Hoyer <bhhoyer@...>
 

Hi Reid,

DMR is NOT one of the modes supported at launch. There has been some interest in DMR mostly in a future duplex repeater configuration which doesn't require turning the PA around.

As a client, the architecture is able to support the timing for TDMA in the FPGA (software lacks the required granularity). and the TX/RX switch is well under the 1.5ms switch time.

So that makes this a definite maybe.

Bryan

Re: Bridging the digital voice and data gap

Tyrell Berry <kd7kuj@...>
 

Maybe your all confused...  audio doesn't have to come out a speaker to be analog.  To be perfectly clear, the dv-dongle is still converting a digital signal to an  analog one...  and a second chip is required to go into any another digital code. Even if a lossless digital codec is used in between (like wave or similar), the conversion to a lossy format like AMBE is the troublesome one...  not the conversion to analog. Yes, less signal is lost vs going out a speaker and into a  microphone, but the principles I stated before are largely the same, and I'm not convinced the resulting stream of bits will be legible audio.

As for the conversion from fdma to tdma, if NAT can convert ip addresses, this should be easy.

On Aug 1, 2012 7:54 AM, "Reid" <reid.crowe@...> wrote:
 

Will the UDR56K4 be able to support the switching speeds required for DMR?

-Reid N0RC

--- In UniversalDigitalRadio@..., Matthew Pitts wrote:
>
> This topic seems more appropriate to this group than any of the others that I'm in here, as the hardware should support at least the three main modes in use. I know some folks might get their knickers in a twist over this, but interoperability between DMR, D-Star and NXDN is something I feel would be of benefit to all digital voice hams, and would eliminate the (intentional) animosity I've seen in certain groups if someone brings up connecting certain "incompatible" hardware together.
>
> I know that the DMR core network standard implies that it is possible to connect a Hytera repeater to a Motorola Mototrbo repeater even though they use incompatible manufacturer specific functions; there are similar potential issues with connecting Icom IDAS repeater to Kenwood NEXEDGE repeaters. D-Star is semi-unique in that it's network protocol is the same as it's over the air protocol, and this is what attracted me to it in the first place, from a hardware and software design perspective. Is anyone else interested in discussion on this subject?
>
> Matthew Pitts
> N8OHU
>
>
> Sent from Yahoo! Mail on Android
>

Test

john@...
 

AW: Test

"siegfried jackstien" <siegfried.jackstien@...>
 

- . ... -

..--..

-----Ursprüngliche Nachricht-----
Von: UniversalDigitalRadio@...
[mailto:UniversalDigitalRadio@...] Im Auftrag von
john@...
Gesendet: Mittwoch, 1. August 2012 17:25
An: UniversalDigitalRadio@...
Betreff: [UniversalDigitalRadio] Test






Re: Bridging the digital voice and data gap

"Tony Langdon, VK3JED" <vk3jed@...>
 

At 01:43 AM 8/2/2012, you wrote:


Maybe your all confused... audio doesn't have to come out a speaker to be analog. To be perfectly clear, the dv-dongle is still converting a digital signal to an analog one... and a second chip is required to go into any another digital code. Even if a lossless digital codec is used in between (like wave or similar), the conversion to a lossy format like AMBE is the troublesome one... not the conversion to analog. Yes, less signal is lost vs going out a speaker and into a microphone, but the principles I stated before are largely the same, and I'm not convinced the resulting stream of bits will be legible
No, the DV dongle converts a PCM bitstream to an AMBE coded bitstream and vice-versa. There is no analog audio near a DV Dongle (have you ever managed to get an analog signal down a USB bus? ;) ).

Conversions between codecs are better when there is no intervening A/D and D/A pair to go through, so running a DV Dongle (or equivalent) back to back with an IMBE equivalent will give the best result possible. You are right in one thing, the result won't be perfect, may not be pretty, but it may be functional. Only one way to find out! :) If the number of transcodes is limited to the bare minimum (i.e. 1), then you may get along with it.

Oh, and a case in point, telephony systems (e.g. Asterisk) do convert between codecs when necssary, so that you can attach any phone to the system, regardless of what code the network is running. The phone just needs to be capable of using at least one of the codecs Asterisk supports. Asterisk also decodes and recodes any participants in a conference call. Of course, most of the codecs used in telephony are a lot less "aggressive", but the principle works rather well.


73 de VK3JED / VK3IRL
http://vkradio.com

Re: Test

"Tony Langdon, VK3JED" <vk3jed@...>
 

At 03:24 AM 8/2/2012, you wrote:



------------------------------------
Little bit of power supply hum there, and some signs of RF feedback. ;)

73 de VK3JED / VK3IRL
http://vkradio.com

Re: Bridging the digital voice and data gap

"qrv@..." <qrv@...>
 

This one tickled my fancy ...

Perhaps one could modulate the 5v line?

Just sayin' ... ;-)

Tony Langdon, VK3JED wrote: (have you ever managed to get an analog
signal down a USB bus? ;) ).
--

Thanks! & 73, KD4E.com
David Colburn nevils-station.com
I don't google I SEARCH! duckduckgo.com
Network: groups.yahoo.com/group/qrv
Restored to design-spec at Heaven's gate 1Cor15:22

Re: Bridging the digital voice and data gap

"Howard Small" <howard@...>
 

Hmm. Not sure how they do it but the IC-7200 passes the audio over a USB connection in parallel with the CI-V commands.

 

Howard

VK4BS

 

From: UniversalDigitalRadio@... [mailto:UniversalDigitalRadio@...] On Behalf Of qrv@...
Sent: Thursday, 2 August 2012 12:01
To: UniversalDigitalRadio@...
Subject: Re: [UniversalDigitalRadio] Re: Bridging the digital voice and data gap

 

 

This one tickled my fancy ...

Perhaps one could modulate the 5v line?

Just sayin' ... ;-)

> Tony Langdon, VK3JED wrote: (have you ever managed to get an analog
> signal down a USB bus? ;) ).

--

Thanks! & 73, KD4E.com
David Colburn nevils-station.com
I don't google I SEARCH! duckduckgo.com
Network: groups.yahoo.com/group/qrv
Restored to design-spec at Heaven's gate 1Cor15:22

Re: Bridging the digital voice and data gap

Ian Wade G3NRW <g3nrw-radio@...>
 

___Original Message_________________________________________
From: "Tony Langdon, VK3JED" <vk3jed@...>
Date: Thu, 2 Aug 2012 Time: 07:32:08

There is no analog audio near a DV Dongle (have you
ever managed to get an analog signal down a USB bus? ;) ).
Yup. I do it every day. On my TS-590S. Mostly analog data tones, but sometimes analog DV tones. Audio codec in the radio, codec driver in the PC. USB cable in between. Works very well.

:-)

--
73
Ian, G3NRW

The TS-590S Resources Page:
http://homepage.ntlworld.com/wadei/ts-590s.htm

The TS-990S Resources Page:
http://homepage.ntlworld.com/wadei/ts-990.htm