SDR# TETRA Demodulator Trunk Tracking Demonstration

[DRL-XM43]

Folks.. a quick question. Forgive me.... I'm not familiar at all with the technical workings of Tetra so I have a simple, brief question regarding this plugin. I already successfully use the other SDR# Tetra plugin, it does what I want.. I tune a Tetra signal and I hear speech (if it's not encrypted). Will the plugin available here do that ? It's all I need .. I'm not bothered about tracking other network channels etc.

Thanks.

Terry

Yes - That is how I use it. The advantage of the plug is the info panels where you can have alias and so forth plus a bunch of neat features

 

[Haax]

just a quickie, if i may,
a couple weeks back i started using Tetra demodulator plugin in SDR# and it receives clear tetra. all very nice.
I'd just like to know if i am using it correctly, am i hearing all i am able to from these sites ?
because there are several clear networks here. It doesn't receive our DMO QSOs either

In SDR# - i tune to a good strong main TETRA control channel (in wide FM about 30Kc bandwidth) -
and in the Tetra demodulator plugin on the side, the red text 'Receiving' illuminates,
in the plugin - all slots / channel tick-boxes are set to 'auto' - and in the net info i get 'current cell' data and 'neighbour cell' data,
i also get other data, calls and TG listed in the other tabs. It all works amazingly and as it should.

But - Is this set for optimal listening to my local clear, unencrypted TETRA sites ?
I am concerned that i am missing voice calls, as there is very little activity.

When there is voice, i hear it very well indeed, but there's just *not much* activity... am i missing a setting ?
i know these sites arent huge miles-wide sites and lots of activity, but i'm sure there should be more, i can leave the SDR on for days on some freq and hear nothing. - are there conversations taking place that i can't hear ? or are these sites just not using their radios very much ?

-Thanx-

 

[thewraith2008]

Folks.. a quick question. Forgive me.... I'm not familiar at all with the technical workings of Tetra so I have a simple, brief question regarding this plugin. I already successfully use the other SDR# Tetra plugin, it does what I want.. I tune a Tetra signal and I hear speech (if it's not encrypted). Will the plugin available here do that ? It's all I need .. I'm not bothered about tracking other network channels etc.

Thanks.

Terry

Why can't you not just create a new SDR# folder and copy this version of TETRA Demodulator plug-in and try it for yourself.
It's the only way to see if it meets your needs.

I'm not bothered about tracking other network channels etc.

Why? How do you know the calls of interest are not going to be on those 'channels' as well.

just a quickie, if i may,
a couple weeks back i started using Tetra demodulator plugin in SDR# and it receives clear tetra. all very nice.
I'd just like to know if i am using it correctly, am i hearing all i am able to from these sites ?
because there are several clear networks here. It doesn't receive our DMO QSOs either

Did you enable DMO mode to listen to those types of calls?

In SDR# - i tune to a good strong main TETRA control channel (in wide FM about 30Kc bandwidth) -
and in the Tetra demodulator plugin on the side, the red text 'Receiving' illuminates,
in the plugin - all slots / channel tick-boxes are set to 'auto' - and in the net info i get 'current cell' data and 'neighbour cell' data,
i also get other data, calls and TG listed in the other tabs. It all works amazingly and as it should.

But - Is this set for optimal listening to my local clear, unencrypted TETRA sites ?
I am concerned that i am missing voice calls, as there is very little activity.

When there is voice, i hear it very well indeed, but there's just *not much* activity... am i missing a setting ?
i know these sites arent huge miles-wide sites and lots of activity, but i'm sure there should be more, i can leave the SDR on for days on some freq and hear nothing. - are there conversations taking place that i can't hear ? or are these sites just not using their radios very much ?

-Thanx-

If you are only using the plug-in stand alone and your network is using more than one carrier for each LA, then yes you are probably missing calls.
This call activity would be seen in the 'Calls' tab of the 'Network Info' window.
e.g. If your main carrier is 1000 and if calls appear in 'Calls' tab of the 'Network Info' window that are not on 'Carrier' 1000, then they are on different carriers that belong to the current LA and you will not hear those calls.



Latest version (v1.7.0.0) can be found here: Release post

 

[Haax]

Hi - Thanks for the reply,

i wasn't aware that SDR# with the Tetra demodulator plugin was able to hear decode DMO calls

I like to keep ithe SDR here very simple, and i use the Tetra demodulator as a plugin in SDR#
and with only one RTL SDR dongle I understand that i am not receiving the other sites.

Ii have no plans (yet) to buy more SDR devices and install the Trunk tracker in order to tune and hear the entire
voice traffic from this agency automatically (if i understand it's operation correctly), although that would be way cool.

To use it, I just manually tune to one of their (several) control channels and wait for whatever comes from that particular transmitter
and I'm quite happy doing it that way, for now, and i know i could be, or very likely *am* missing calls coming from one of the other transmitters.
even so, voice traffic still sems low,

I'm not sure what you mean as ' LA ' -

>e.g. If your main carrier is 1000 and if calls appear in 'Calls' tab of the 'Network Info'
>window that are not on 'Carrier' 1000, then they are on different carriers that belong to the current LA
>and you will not hear those calls.

When you say 'main carrier is 1000' do you mean the constant tetra data control channel frequency would be like on 1000 mhz as an example ?
i've not seen any 'carriers' mentioned in the SDR# or it's GUI or in the tetra demodulator plugin, is this something i should be looking for in the
tabs of the 'net info' window ?

Thanks, and apologies for showing my ignorance of how TETRA and SDRing of it, works,

 

[thewraith2008]

Hi - Thanks for the reply,

i wasn't aware that SDR# with the Tetra demodulator plugin was able to hear decode DMO calls

One only needs to read the supplied documentation.

I like to keep ithe SDR here very simple, and i use the Tetra demodulator as a plugin in SDR#
and with only one RTL SDR dongle I understand that i am not receiving the other sites.

Ii have no plans (yet) to buy more SDR devices and install the Trunk tracker in order to tune and hear the entire
voice traffic from this agency automatically (if i understand it's operation correctly), although that would be way cool.

With one dongle you can use SDR# + TETRA Demodulator plug-in and TTT in single mode to follow calls. Pretty simple stuff.
You already have all that you need to at least try it out. Not sure why you wouldn't

To use it, I just manually tune to one of their (several) control channels and wait for whatever comes from that particular transmitter
and I'm quite happy doing it that way, for now, and i know i could be, or very likely *am* missing calls coming from one of the other transmitters.
even so, voice traffic still sems low,

I'm not sure what you mean as ' LA ' -

A network (MNC) can be made up of multiple LA's.
- Each LA is made up of one 'Main carrier' (Control channel) and maybe multiple traffic carriers.

LA = Location Area.
- These are used to extend coverage around an area larger than one LA can do by itself.

Carrier is the frequency where traffic occurs on. There are 4 timeslots to each carrier.
- The more that are used for each LA depends on load from it's users.
- There is one 'main carrier' and maybe multiple other carriers per LA.
- Each carrier is assigned a number which is based on it's frequency (base freq,offset, spacing)
- Each carrier points to it's main carrier (for LA).

>e.g. If your main carrier is 1000 and if calls appear in 'Calls' tab of the 'Network Info'
>window that are not on 'Carrier' 1000, then they are on different carriers that belong to the current LA
>and you will not hear those calls.

When you say 'main carrier is 1000' do you mean the constant tetra data control channel frequency would be like on 1000 mhz as an example ?
i've not seen any 'carriers' mentioned in the SDR# or it's GUI or in the tetra demodulator plugin, is this something i should be looking for in the
tabs of the 'net info' window ?

Thanks, and apologies for showing my ignorance of how TETRA and SDRing of it, works,

See above.
The values for Network (MNC), Location Area (LA), Main carrier and current carrier are shown in plug-in and are used in various parts to indicate where a call is taking place.



Latest version (v1.7.0.0) can be found here: Release post

 

[Ubbe]

If you want to keep your existing SDR# simple, do what are suggested and copy the whole folder to another folder and run the plugin and its additional files only in that copy.

I run only one RTL-SDR and TTT jumps out of conversations to instead follow a higher priority one in the system I monitor.
Most settings are done automaticly for you, so you only set SDR# to WFM and click on a tetra carrier in the spectrum display and click start in the TTT window.

/Ubbe

 

[BackHive67]

Why can't you not just create a new SDR# folder and copy this version of TETRA Demodulator plug-in and try it for yourself.
It's the only way to see if it meets your needs.

Why? How do you know the calls of interest are not going to be on those 'channels' as well.

I've already tried the plugin on more than one occasion and I have never received any clear voice.. just silence. I guess I should let it sit for a bit longer this time.... (on a channel that I know is un-encrypted). I'm quite happy to keep it simple and just listen to any activity on a specific frequency/channel.

In any case, many thanks for your work so far.

Terry

 

[Haax]

Hi and Thanks for the help thewraith2008, it is much appreciated and certainly helps me wade through the terminology,
as I'm primarily a HF SSB Guy, and have been for about 30 years, and i only got into digital voice via P25 some years back,
Much of the terminology associated with TETRA seems, somewhat unsurprisingly, to be more GSM speak than
the P25, DMR and VSELP world i'm more familiar with.

I will indeed try TTT then, as time permits, and will actually read the docs this time too, as i was under the
impression it would be all in Russian.

The SDR aspect has certainly come on amazingly in recent years, i think i still have an old mechanical HD
for my old Linux laptop somewhere, with a lovingly compiled Telive and GNUradio on.. hats off to the coders
for making it much less of a chore for end users to get going. Never thought it would happen on Windows either...

I find it a interesting side of the hobby, i like my old P25 phase 1 gear, we use it daily, it's good quality, but it's old
and TDMA is where it's at, and having pretty much given up with Amateur DMR (and never found any of that almost obscure
3 slot eDMR stuff) it seemed time to revisit TETRA, and decoding it on SDR.

Thanks

 

[thewraith2008]

So, with the latest release I added the ability to see the encrypted activity in the 'Calls' tab.
Has anyone tried this? What do you think? Is this feature of any interest to anyone?
I thought adding this would be of interest to those who see only encrypted traffic or see mixed (clear, encrypted) traffic.

This is a tough crowd to get feedback.



Latest version (v1.7.0.0) can be found here: Release post

 

[hamradionl]

@thewraith2008,
After your release it, send PM with feedback about matters and questions

 

[AOD999]

So, with the latest release I added the ability to see the encrypted activity in the 'Calls' tab.
Has anyone tried this? What do you think? Is this feature of any interest to anyone?
I thought adding this would be of interest to those who see only encrypted traffic or see mixed (clear, encrypted) traffic.

This is a tough crowd to get feedback.



Latest version (v1.7.0.0) can be found here: Release post

Would like the feature if the one Tetra network here does start the Big E

 

[FERRAINAELENA]

Thanks for this great job you did, I who live in ITALY where everything is encrypted I find it very interesting.

thank you very much

 

[AJCarrick]

So, with the latest release I added the ability to see the encrypted activity in the 'Calls' tab.
Has anyone tried this? What do you think? Is this feature of any interest to anyone?
I thought adding this would be of interest to those who see only encrypted traffic or see mixed (clear, encrypted) traffic.

This is a tough crowd to get feedback.



Latest version (v1.7.0.0) can be found here: Release post

Hello. Thanks for this. I find this latest step very appealing. Easy to set up and use.

 

[LA6FRA]

So, with the latest release I added the ability to see the encrypted activity in the 'Calls' tab.
Has anyone tried this? What do you think? Is this feature of any interest to anyone?
I thought adding this would be of interest to those who see only encrypted traffic or see mixed (clear, encrypted) traffic.

This is a tough crowd to get feedback.



Latest version (v1.7.0.0) can be found here: Release post

I have been running it for 6-7 hours in an encrypted network and there is not much information displayed. Before with the firsts versions remember wrong I could see call id, group and much more I think.

if I do not

 

[DarkAngelT]

So, with the latest release I added the ability to see the encrypted activity in the 'Calls' tab.
Has anyone tried this? What do you think? Is this feature of any interest to anyone?
I thought adding this would be of interest to those who see only encrypted traffic or see mixed (clear, encrypted) traffic.

This is a tough crowd to get feedback.



Latest version (v1.7.0.0) can be found here: Release post

Greetings God Tetra!

I'm testing and everything seems to be ok. As for cryptography, I cannot say anything about it, because in my area the signals are not encrypted.

 

[LA6FRA]

This network is encrypted wwith TEA 2

 

[thewraith2008]

I have been running it for 6-7 hours in an encrypted network and there is not much information displayed. Before with the firsts versions remember wrong I could see call id, group and much more I think.

if I do not

Do you have it enabled in 'Config' in the plug-in?
NOTE: TTT will not show anything to do with encrypted calls.
NOTE: Showing encrypted details may work better when NOT using TTT or when using TTT in dual mode.
I've have only been able to do limited testing with this feature. (using user supply IQ samples where encryption is used.)



Latest version (v1.7.0.0) can be found here: Release post

 

[badyunior]

This is a tough crowd to get feedback.



Latest version (v1.7.0.0) can be found here: Release post

Hi, I tried to send you a PM, but I don't have permission to do that. I got some idea for you.

Regards
Darek

 

[Kasmus]

I upgraded to v1.7.0.0 from 1.0.15.8 and recording is no longer working.

There are no wav files created at all. The 'Record' folder exists but stays empty. I can hear call audio by listening to the virtual audio pipeline, just as I used to in the past. The SDR# plugin that comes with the 1.7.0.0 package has been installed. Logging appears to work as intended.

What can I do to troubleshoot this issue?

 

[Ubbe]

Check the error.txt file if that says anything.
You don't have the Record folder to deep into the folder structure as it needs the full path name from root to not exceed a certain number of characters?

/Ubbe