SDR# TETRA Demodulator Trunk Tracking Demonstration

[Marco192]

Is that a voice announcement or text? What do they say or write? How often do they make those announcements? High GSSI numbers can be reserved for special use, like patches or phone calls. Are the GSSI's in the 14000000 range or higher?

/Ubbe

It is a voice announcement with important information for all the drivers (public transport). For instance that a certain street is closed for all traffic or similar. Announcements are made only when needed, so they are not regular (maybe once a day)
GSSIs are in the 14000000 range, but it is a normal group call (no phone call or similar).

 

[Ubbe]

GSSIs are in the 14000000 range, but it is a normal group call (no phone call or similar).

Then it's TG patches. If they patch TG1 to TG2 it will create a common TG in the 14000000 range that the users use instead of their TG1 and TG2. Each time there's a new patch the 14000000 TG will change and when it reaches the highest TG there can be for patches it will start over again.

On the control channel there will be sent out info to all users that have TG1 or TG2 selected that they instead need to use that 14000000 TG. The actual users will not see or note any difference on their radio, it's all done in the internal CPU in the radio.

/Ubbe

 

[boyradio]

Hello and greetings to this great radio forum, I am desperate with TTT, I can't get it to work, it throws me an error related to TCP and I can't solve it. Can someone help me please?

 

[Marco192]

Then it's TG patches. If they patch TG1 to TG2 it will create a common TG in the 14000000 range that the users use instead of their TG1 and TG2. Each time there's a new patch the 14000000 TG will change and when it reaches the highest TG there can be for patches it will start over again.

On the control channel there will be sent out info to all users that have TG1 or TG2 selected that they instead need to use that 14000000 TG. The actual users will not see or note any difference on their radio, it's all done in the internal CPU in the radio.

/Ubbe

This is a great insight into the way the system is being used. Thanks!

Is there a way to see in TTT, from the control channel traffic, which TGs are patched together on a certain "announcement call"?

 

[dannyllama0564]

Dear @thewraith2008 firstly let me give my heartfelt thanks for your many years of hard work, and really what you have given back to the radio community. Thank you so much.

I don't know if it is a bug, or I am doing somehting wrong? I am attempting to enter the LRRP path in TTT. Even if I enter the absolute correct path, TTT never seems to save the location - or at least display the path to LRRP.EXE. I am using the free version that came with DSD. Am I doing something stupid? Thanks.

 

[thewraith2008]

Dear @thewraith2008 firstly let me give my heartfelt thanks for your many years of hard work, and really what you have given back to the radio community. Thank you so much.

I don't know if it is a bug, or I am doing somehting wrong? I am attempting to enter the LRRP path in TTT. Even if I enter the absolute correct path, TTT never seems to save the location - or at least display the path to LRRP.EXE. I am using the free version that came with DSD. Am I doing something stupid? Thanks.

The defined path you set must also have the file LRRP.exe in it. (the exception is when the field is left blank and the TTT root folder is used)
When the folder has LRRP.exe in it, the label "DSDPlus.LRRP save path" will turn green and the path will be saved.



Latest version (v1.8.6.0) can be found here: MEGA - Download
Release post here

 

[Ubbe]

Is there a way to see in TTT, from the control channel traffic, which TGs are patched together on a certain "announcement call"?

TTT are more of a voice program and tries to keep it as clean as possible. But if you use any of the Linux versions with GnuRadio you will be able to see pretty much all the info there are from the control channel. There's a version of Telive that you put on a USB stick and boot from it that will give you a lot of info without installing anything on the PC.

/Ubbe

 

[thewraith2008]

TETRA from a observer point of view (of the downlink), the system does not identify any signalling as been 'patches'
Calls are set-up targeting MS radio's of a TG on a LA.
If there are users of the same TG on another LA(s), then the downlinks of the (2+) LAs are routed via whatever link LAs use and sent to the respective LAs as needed. This control signalling happens in the network BS infrastructure and you won't see it on a downlink.

TETRA demodulator available here, decodes all of the layers and protocols. (I don't think anything else does this)
The plug-in does not display every element of a PDU because seizure modes are pointless for trying to see whats going on.
You will find in one of the many display panels the most interesting parts of the signalling.

TTT as Ubbe says, "tries to keep it clean". It's always been focused on call control for voice traffic only (with exception to LIP and SDS).



Latest version (v1.8.6.0) can be found here: MEGA - Download
Release post here

 

[sammycookie]

Hello, why on private call i just receive voice from 1010609, i don't hear 712048 ?

 

[thewraith2008]

Hello, why on private call i just receive voice from 1010609, i don't hear 712048 ?

View attachment 113461

Because the two MS in the call are on different LAs.
The voice bursts of the MS who is on the current LA (which you are monitoring) is not sent back on the current LA's downlink.
It's sent via the LA to LA inter-link. This is why you don't hear the local MS.
What you are actually hearing is the MS from the other LA.
The same type of (one way) call is occurring on the other LA.
This saves resources on the network.

You can turn OFF these types of (one way) call set-ups in TTT.



Latest version (v1.8.6.0) can be found here: MEGA - Download
Release post here

 

[sammycookie]

Because the two MS in the call are on different LAs.
The voice bursts of the MS who is on the current LA (which you are monitoring) is not sent back on the current LA's downlink.
It's sent via the LA to LA inter-link. This is why you don't hear the local MS.
What you are actually hearing is the MS from the other LA.
The same type of (one way) call is occurring on the other LA.
This saves resources on the network.

You can turn OFF these types of (one way) call set-ups in TTT.



Latest version (v1.8.6.0) can be found here: MEGA - Download
Release post here

Thank you Thewraith2008 for your explaination

 

[Angelo2021]

Hi,
I'm having problems in the new version with the TETRA_GSSI.txt and TETRA_SSI.txt files.
Each time that starts TTT, both files are restarted, deleting the data. I haven't find a solution in the documents.
I would appreciate your help.

 

[thewraith2008]

Maybe there is an issue writing to path where files are saved. If settings are been saved then I would expect not.
Are there any messages in the status window? Every 10 minutes or so TTT saves these files, is it reporting that saving is OK?

Are you running TTT through a sandbox? This may see saved files wiped clean on every start.

Not really much to go on here to help further.



Latest version (v1.8.6.0) can be found here: MEGA - Download
Release post here

 

[Ubbe]

Each time that starts TTT, both files are restarted, deleting the data.

I've had that problem when the files where corrupt, just some extra space or characters in the file that TTT didn't like and started the files blank. Check the files using Notepad or similar that there's no illegal characters or out of place spaces. Start blank and save a couple of records using F4 and then add your data to those files keeping the exact format intact.

/Ubbe

 

[Angelo2021]

I've had that problem when the files where corrupt, just some extra space or characters in the file that TTT didn't like and started the files blank. Check the files using Notepad or similar that there's no illegal characters or out of place spaces. Start blank and save a couple of records using F4 and then add your data to those files keeping the exact format intact.

@Ubbe @thewraith2008 thanks for your comments. The problem has been solve reinstalling TTT and deleting some characters in the tetra_GSSI.txt file

/Angelo

 

[thewraith2008]

The problem has been solve reinstalling TTT and deleting some characters in the tetra_GSSI.txt file

Which part of 'tetra_GSSI.txt' was affected?
What 'characters' where deleted?
This file has each line delimited which contains: GSSI ; MCC ; MNC ; LABEL ; PRIORITY ; LOCKOUT

It would be helpful when you see this problem again to send (via PM) the unmodified file to me so I can investigate this more.



Latest version (v1.8.6.0) can be found here: MEGA - Download
Release post here

 

[Angelo2021]

Which part of 'tetra_GSSI.txt' was affected?
What 'characters' where deleted?
This file has each line delimited which contains: GSSI ; MCC ; MNC ; LABEL ; PRIORITY ; LOCKOUT

It would be helpful when you see this problem again to send (via PM) the unmodified file to me so I can investigate this more.

I have seen that characters ñ, ç and some accented letters like "é" were not well identified in notepad.
The fomat of the file is ok:
0;214;8;UNID;0;True

 

[thewraith2008]

Thanks for getting back to me.

OK so the "label" is where the problem is.
So the program is not generating these characters but seems to be tripping up on them somewhere.

If I get so time I'll see if I can add these characters here and see if I can reproduce the error (and hopefully find and fix it)



Latest version (v1.8.6.0) can be found here: MEGA - Download
Release post here

 

[Marco192]

Hi guys!
Is there a way to change the sound output device for TTT program (for call setup sounds)?

 

[thewraith2008]

Sounds are played via whatever the default system sound device is.



Latest version (v1.8.6.0) can be found here: MEGA - Download
Release post here