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Re: p25 trunking with SDR?

 

After many attempts I finally got a red tx led and MMDVMHost showing voice frames!! .. and.... dmrtc crashed the moment voice started. Segmentation fault. Debian 11, 4gb ram, 4 cores intel x64....


Re: p25 trunking with SDR?

 

Got little closer - used fixed hunt plan and base freq and shift. Now I get 'call set up' then a countdown timer, but after 5 seconds it resets, regardless of holding PTT.


Re: p25 trunking with SDR?

 

Also, trying to attach a scan group (of at least 1 tg) results in segmentation fault in dmrtc. Willing to help debugging.


Re: p25 trunking with SDR?

 

Okay, developer config, switched from hytera methods to self-adaptive. Now groups attach. But still can't setup call (setting up... timeout). Do I need a second radio on the net?


Re: p25 trunking with SDR?

 

Radio either says 'unattached group', or (with attach off in dmrtc) it tried to set up call but times out.


Re: p25 trunking with SDR?

 

Okay, my PD785 register on the system. And even able to do private calls (and get sms).
But I can't get attached to any group.
What settings do I use radio side? I tried everything...
Log from dmrtc:
----
[4/Aug/2024 18:26:08.534] [Info] Status of radio 1111111, for talkgroup 2716900 is 26
[4/Aug/2024 18:26:09.207] [Info] Received status transport request to TG from 1111111, slot 1 to destination 2716900
[4/Aug/2024 18:26:09.208] [Info] Status of radio 1111111, for talkgroup 2716900 is 26
[4/Aug/2024 18:26:09.749] [Info] Received status transport request to TG from 1111111, slot 1 to destination 2716900
[4/Aug/2024 18:26:09.749] [Info] Status of radio 1111111, for talkgroup 2716900 is 26
[4/Aug/2024 18:26:10.344] [Info] Received status transport request to TG from 1111111, slot 1 to destination 2716900
[4/Aug/2024 18:26:10.344] [Info] Status of radio 1111111, for talkgroup 2716900 is 26
---


Re: p25 trunking with SDR?

 

On Friday, 2 August 2024 18:05:13 EEST you wrote:
Great. Will test thoroughly. I got many more questions but for now I'm good
haha. My testing radios are SL4000e and DP4801e.

Well, good luck. The learning curve is pretty steep, but once you've configured
everything it's smooth sailing.
Keep me posted if your radios work, I'll add them to the list of supported
devices.

Adrian


Re: p25 trunking with SDR?

 

Great. Will test thoroughly. I got many more questions but for now I'm good haha.
My testing radios are SL4000e and DP4801e.


Re: p25 trunking with SDR?

 

On Thursday, 1 August 2024 17:17:06 EEST you wrote:
Oh, okay, I see. Thank you. I understand that dmrtc setting is for freq data
broadcasted to radios.

What if it's the other way around? Can I put negative value into the dmrtc
(as I can - verified - into qradiolink)? Or just drop the minus? As in
classic setup - site's rx is higher than site's tx?

Yes, you should be able to put in a negative split, no problem.
If you can't then that's a bug in the code.


Re: p25 trunking with SDR?

 

Oh, okay, I see. Thank you. I understand that dmrtc setting is for freq data broadcasted to radios.

What if it's the other way around? Can I put negative value into the dmrtc (as I can - verified - into qradiolink)? Or just drop the minus? As in classic setup - site's rx is higher than site's tx?


Re: p25 trunking with SDR?

 

On Thursday, 1 August 2024 17:03:37 EEST you wrote:
Sorry by dvm I meant mmdvm-sdr.

Can I use negative value in dmrtc if I have negative value in qradiolink? My
radio's TX (mmdvm rx) needs to be below radio's RX (mmdvm tx).

Well, in that case the split is positive, not negative in both qradiolink and
dmrtc.
If the radio transmits at a frequency lower than it receives, then qradiolink
receives at a frequency lower than it transmits so the split is positive.
The same split value needs to be entered in dmrtc.
Mathematically, RX_freq + split = TX_freq. It does not matter if split is
positive or negative, this equation always applies for qradiolink.


Re: p25 trunking with SDR?

 

Sorry by dvm I meant mmdvm-sdr.

Can I use negative value in dmrtc if I have negative value in qradiolink? My radio's TX (mmdvm rx) needs to be below radio's RX (mmdvm tx).


Re: p25 trunking with SDR?

 

On Thursday, 1 August 2024 04:04:54 EEST you wrote:
Also.. How do I make dmrtc work when my base TX freq is higher than base
RX?
Right now I have, e.g. -20000000 tx split in qradiolink. E.g. dvm
broadcasts cc on 440mhz, and listens on 420mhz. You mentioned that dmrtc
split value must be positive?

dmrtc will work even if the split value is wrong, but the various PDUs which
contain frequency information will be wrong (absolute channel grants,
frequency broadcasts etc.)
Just put in the split value in dmrtc the same as you put it in qradiolink.
I'm not sure what you mean by dvm, but I assume it's a custom system
component.


Re: p25 trunking with SDR?

 

Also.. How do I make dmrtc work when my base TX freq is higher than base RX?
Right now I have, e.g. -20000000 tx split in qradiolink. E.g. dvm broadcasts cc on 440mhz, and listens on 420mhz.
You mentioned that dmrtc split value must be positive?


Re: p25 trunking with SDR?

 

Yes, silly me, LimeSDR uses independent tx/rx paths. Great.

I was able to reach CC data transmitted on air stage, pre DMRGateway and pre Controller.

My question right now: if, hypothetically, I just want to run a local micro-site, with, say, 4 freq pairs (1cc+7vc total), without any linking to anything remote, how could I achieve that? Host-SDR wants a gateway operating.

Thank you. Amazing project.


Re: p25 trunking with SDR?

 

On Monday, 29 July 2024 19:39:15 EEST you wrote:
Understood! Thanks for reply.
One more question while I'm setting up my test lab:
Limesdr-mini - what max tx/rx split can I use for T3 mode? Can it be +10mhz
so I get up to 7 duplex chans at, say 446rx/456tx? It's not clear in
documentation.
You can use any duplex split value as long as both frequencies are within the
limits that the device supports. So you can have even 1 GHz split without any
problems. The TX and RX LO are completely independent.

Adrian


Re: p25 trunking with SDR?

 

Understood! Thanks for reply.
One more question while I'm setting up my test lab:
Limesdr-mini - what max tx/rx split can I use for T3 mode? Can it be +10mhz so I get up to 7 duplex chans at, say 446rx/456tx?
It's not clear in documentation.


Re: p25 trunking with SDR?

 

On Monday, 29 July 2024 01:35:58 EEST you wrote:
Hey all and thanks for great work.
I'm wondering if I'm dreaming if I want to have LimeSDRmini with DVM-SDR in
P25 trunking mode (as dvmhost does)?

Thank you!
It's probably possible technically, but not out of the box. Some code might
need to be written for that. You'd have to ask the software authors, I don't
know any specifics here unfortunately.

Best,
Adrian


p25 trunking with SDR?

 

Hey all and thanks for great work.
I'm wondering if I'm dreaming if I want to have LimeSDRmini with DVM-SDR in P25 trunking mode (as dvmhost does)?

Thank you!


Re: private calls, SMS etc.

 

Hi Christian,

I can confirm that -h works - stupid error on my side.

My trunk mode repeater is running for evereral days now and only once
needed a restart for unknown reason.

Roaming between two tier II repeaters (DB0BR/DM0BT) here in Bayreuth and
my Tier III repeater at home works flawlessly.

Registraration: ok

Talkgroup Attachment works. I programmed button TK1 with "Scan Group
List" to get rid of annoying ongoing background calls if I want to talk
on my selected talkgroup. Unfortunately, I cannot find any indication in
the UI of the radio if the scan group list feature is on or off. In
dmrtc, you can see additional TGs being subscribed once the feature is
active.

I have make quite a few QSOs with a local OM working on a Brandmeister
DMR repeater near Kulmbach - works flawlessly.
Great, thanks for letting me know. I'll put your radio model in the list as
supported now.


Private Voice calls: Had not yet had an opportunity for thourough
testing. The terms OACSU and FOACSU are nowhere to be found in my CPS.

I did test a lot calling 9990 on brandmeister. I can say that this only
works sometimes, but unreliably, and usually with very bad audio
quality. weird.
Private calls are a bit of a problem, same as private SMS, from a routing
perspective. If you have only one DMR system (eg. Brandmeister) connected,
private calls can be passed on using PassAllPC in DMRGateway.ini for that
network configuration.
The situation gets trickier if you are connected to multiple systems (DMR+,
Brandmeister, etc.). Then it is pretty much impossible to know where a
particular private call should be routed to. This is a pretty bad limitation
of the current system that needs to be worked on in the future, but I'm open
to pretty much any architecture changes that enable more features.


SMS: No test yet. Try to send me one: DB9CR, my device is logged in most
of the time I am at home in homeoffice.
SMS should only work between two Tier III sites and radios, the UDT message
protocol is only standardized in TS 102 361-4 so Tier II radios will not be
able to receive them. In addition, I remember that I needed to modify
something in MMDVMHost for UDT short data message support, so classical
hotspots might not even be able to pass them on to RF.
I'm not sure what the situation is on the reflector software side and if it
will support passing through this type of messages. Brandmeister may be able,
other networks may not. So needs further testing and maybe additional code.


Also the rest of the items still needs some testing.

I did have a chat with Ralph DK5RAS - he pointed me to


Seems to me that this could completey replace the ugly^h^h^h^hcreative

:-) multi DMRgatway setup. Technically it's probably a SIP trunk with

AMBE2 codec, but I did not have a chance to look at the relevant
original DMRA paper
(). Will
try to dig deeper into this. Also, having a generic SIP implentation
could make it possible to attach to an asterisk VOIP server - we have
one here on db0bt.ampr.org in the HAMNET.
Yes, that seems like the ideal. Unfortunately other DMR networks don't support
this system, and many people use other networks, myself included. It would be
nice it there was some standards group among us amateurs that aimed at
compatibility between implementations.
Anyway there is really no need for complications like a SIP trunk. A simple
limitation being removed on the reflector side would be enough. And that
limitation is the blocking at reflector-side of any calls coming on a timeslot
if there is already a call ongoing in that timeslot. Then you can define one
Tier III site as one connection only. A call is basically a sequence of UDP
packets with a stream id, and as long as you have enough bandwidth there is no
reason not to have hundreds of calls at the same time on one UDP socket
connection.

73, Adrian