[App_rpt-users] RTCM Commands

[Wayne]

@David,

If RTCM's are appropriate for voting/simulcast, in your opinion what is?
Surely not a URI.

-----Original Message-----
From: David McGough [mailto:kb4fxc at inttek.net] 
Sent: Saturday, April 19, 2014 3:25 AM
To: Wayne
Subject: RE: [App_rpt-users] RTCM Commands


Wayne,

Please see inline, below.



On Fri, 18 Apr 2014, Wayne wrote:

<snip>
> 
> To address your specific questions, below:
> 
> 1) Selling RC-210's should be simple enough (E-bay?).
> 
> 
> [ I thought I saw something about not reselling them. At a minimum they
have
> to buy the software. ]
> 

Well, the manufacturer can't stop you from reselling (unless you sign a 
draconian license agreement!) in the USA. You can't make extra copying of 
software. But, you can resell what you got, verbatim.


> 2) Since you've got a private network and a public network involved, 
> that's fine. But, this is a somewhat complex networking task. You'll need 
> to get everything "talking together." I'm suspecting you'll want to 
> implement some VPN's (Virtual Private Networks) to accomplish this. I use 
> OpenVPN under Linux. It works great. BTW, I'm not sure RTCM's are the best

> solution. And, you don't need a Windows box at each site.
> 
> [ My intent is to vote/simulcast two of three sites and bring in a third
> site on a different pair. Site 1-2 require a RTCM and Site 3 a URI,
correct?
> ][ I've never done anything with a VPN and don't know how to implement it.
I
> thought that given to IP's by my site vendor the RTCM's would talk on the
> same network, albeit a VLAN. But how do I access it to control? How can I
> bridge the public IP I have been given with the private VLAN? ]
> 

You must have a Linux PC, running the AllStar software, on your network
somewhere. URI boards attach via a USB interface (just like mice,
keyboards, etc.). So, any place you have a URI you must also have a Linux
PC.  Note that if your Linux PC becomes unavailable (broken network,
etc.), your RTCM's will go down, too! The RTCM's do have a very limited 
"failover" mode which should allow the repeater to stay on-line. But, it 
will be very crippled.

As for the computer networking, I really recommend that you find
knowledgeable local person to help. I've been doing this for 30 years and
own a Internet software company that has VPN's in 70+ countries. Networks
can get complex in a hurry! BTW, this isn't a sales pitch. My plate is
already full and overflowing. But, some others on the mailing list might
be able to help.

If you don't mind, may I ask where these repeaters are that you're trying 
to get upgraded? How high are they (coverage radius?)? And, what 
frequencies? Which ones will be voted/simulcast and which stand-alone? 
I'll keep this in confidence. I trying to better understand your needs.


> 2) There is an small, unavoidable audio delay from audio input to output
> with AllStar. This is typical with any VoIP radio system, including full
> digital systems like D-Star and DMR, etc. This delay isn't like the delay
> found in traditional analog linked repeater systems, however. In older
> linked systems, you'd have to hold the PTT down for a second or so to
> allow all the transmitters to come on-line or you'd loose that initial
> audio. AllStar digitally buffers the audio during propagation from any
> member receiver to all member transmitters. So, the audio could be
> buffered and delayed as much as several hundred milliseconds (a big
> network!). But, not typically lost.
> 
> [ I can deal with the delay. ]

okay, and this isn't a problem in my experience.

> 
> 3) As for persistent kerkhunkers and other issues, no hardware is going to
> solve that. That is an etiquette problem. Over time, (most) users can be
> trained to behave. Yes, I know you're saying: "Yeah, right. I hear you."
> But, I help with several wide-coverage repeater systems, so, I've been
> there, too.
> 
> [ Jammer's that kerchunk to annoy cannot be trained. ]

Jammers are a difficult subject. I am the president of a local ham club
with some wide-coverage repeaters. By that, I mean we've got several
repeaters, some with antennas as high as 1830 feet on a 2000ft tower, with
flat surrounding terrain. Two of these systems have roughly 60+ mile HT
coverage and 85+ mile mobile coverage area. We regularly have hams 110+
miles out hitting these repeaters with decent, but modest, base setups.
Thankfully, we've got a number of technically competent hams who are good
fox-hunters. Someone who regularly mis-behaves *will* get located and
contacted appropriately.

Unfortunately, this is part of life these days. On a positive note, the
AllStar software can be configured to record all audio passing thru the
system. The logs show the input source, etc., all timestamped. This helps
a lot, too. IMO, much of the time, a jammer will give themselves
away--accidentally giving their callsign, etc., at some point during the
day; perhaps before they begin their jamming activity.

Note that if you're already having serious jamming issues, 
simulcast/voting will likely only make this worse!

> 
> 4) Yes, you can hook various systems together (WX radios, remote bases,
> etc.) into a single network quite easily with AllStar. But, it will likely
> take some complex scripting and networking to do, just like with any
> controller. I don't fully understand the scope of what you're wanting and
> as I mentioned above, trying to build the system here is beyond the scope
> of this mailing list. 
> 
> [ I don't mean to be rude but this should be an easy task to do and
> understand. We are an ECOMM repeater(s) and each site needs a WX receiver
on
> it. The commercial WX receivers have audio, COR, PTT and COS. I don't see
> how this is beyond the scope of the mailing list. Can I connect such a
> device using a URI? ]
> 

Yes, you can certainly connect a WX receiver via a URI. But, remember 
that, except for possible redundancy, you only need one WX radio in the 
network. The exception to this would be if your network is so broad that 
the different WX alert messages are broadcast in different geographic 
locations. Again, remember that where there is a URI, there must be a 
Linux host running AllStar.


> I understand your overwhelm! I would recommend getting started in small 
> steps, if possible. First, only put up a test repeater or remote base with

> AllStar and get a grasp of how that is setup. Then, add a second AllStar 
> box and network the two together--take small steps. Now, if that's not a 
> possibility--meaning you've got to have the whole system on-line "like 
> tomorrow", you probably need to locate some expert help ASAP; due to the 
> big learning curve with this (or any other) complex VoIP system.
> 
> [ I have plenty of time. I don't see our needs as complex at all. Two
> voted/simulcast repeaters and a third repeater linked in. A WX receiver
and
> an Earthquake Alarm receiver on each repeater. ]

True simulcast, even for a small system, is non-trivial.  I say this with
personal experience. Ask the tech folks for any municipality doing
simulcast for public safety. It's quite easy to spend $millions$ making
these systems truly work.

I really, really recommend starting small. Get a single test system going 
and then start expanding.


> Anyway, I hope this helps some.
> 
> 73, David KB4FXC
>