Tetra decoding

[grahampaull]

hey folks not sure if this has been asked but is it possible to run the telive live boot image on a RaspPI? wondering as this would make it a more portable solution rather than lug my laptop around in the car anyone?

No, I would be 99.99% sure this won't run on an RPI. Tetra is pretty resource hungry.

Sent from my SM-G950F using Tapatalk

 

[enCrypt]

hey folks not sure if this has been asked but is it possible to run the telive live boot image on a RaspPI? wondering as this would make it a more portable solution rather than lug my laptop around in the car anyone?

Hi welshevo,
I've long wanted to make this a reality with a Pi as it would make it a very portable option with a standard RTL stick. Unfortunately Telive needs quite a bit of CPU horsepower.
I originally tried running it in (bare metal) Debian Linux on an HP Mini netbook with Intel Atom 1.6 CPU and 2GB RAM.
It struggled badly and the audio was very very choppy.
I then tried it on an AMD 2.4Ghz laptop, 2GB RAM running on a Debian VM inside VirtualBox on top of Windows 7.
This also struggled although not as badly and I put it down to being on a VM.
I then rebuilt the same AMD laptop with bare metal Debian Linux, set it all up on that and it runs fine.

I've since gone back to the VM option on a much more powerful laptop for convenience and its fine this time.

So, given that even the latest Pi (3) is a quad core 1.2GHz with 1GB RAM, I think it would struggle...

It is a real shame and I wish it would work too

 

[welshevo]

its a shame isnt it....and i would love a totally portable solution i run Telive on an AMD laptop and seems alright ...but having a smaller machine like a PI would make life easier lol i am considering a small form factor in car PC in the boot and run a touch screen at the front of car ...but will see what else is out there before i spend some cash

 

[grosminet]

Hi welshevo,
I've long wanted to make this a reality with a Pi as it would make it a very portable option with a standard RTL stick. Unfortunately Telive needs quite a bit of CPU horsepower.
I originally tried running it in (bare metal) Debian Linux on an HP Mini netbook with Intel Atom 1.6 CPU and 2GB RAM.
It struggled badly and the audio was very very choppy.
I then tried it on an AMD 2.4Ghz laptop, 2GB RAM running on a Debian VM inside VirtualBox on top of Windows 7.
This also struggled although not as badly and I put it down to being on a VM.
I then rebuilt the same AMD laptop with bare metal Debian Linux, set it all up on that and it runs fine.

I've since gone back to the VM option on a much more powerful laptop for convenience and its fine this time.

So, given that even the latest Pi (3) is a quad core 1.2GHz with 1GB RAM, I think it would struggle...

It is a real shame and I wish it would work too

I made good tests with 1.5 version with funcube pro + . On QTHID 4.1 (only for funcube) , you can change received frequency very easy . So telive batches can be run with >/dev/nul : no diplay . It can run on old laptop or slow PC . it is gnuradio GUI wich is CPU consumer .

I tried to contact GQRX or cubicsdr , in order to run a multi SDR common interface but they never did any change . That would be the best solution to run on slow PC

Maybe one day ....

 

[grosminet]

I tried to re install last telive version on Xubuntu using install_telive.sh . Running script

#!/bin/sh
export TETRA_HACK_PORT=7380
export TETRA_HACK_RXID=$1
FIFO=/tmp/fifo$1
mkfifo $FIFO
ulimit -c unlimited

./osmo-tetra-sq5bpf/src/demod/python-3.7/fcdp-tetra_demod_fft_plus.py -D hw:1,0 -o /dev/stdout | ./osmo-tetra-sq5bpf/src/float_to_bits /dev/stdin /dev/stdout | ./osmo-tetra-sq5bpf/src/tetra-rx /dev/stdin

I have this message


gr::digital::mpsk_receiver_cc block is deprecated.

I saw on trl.com that this quest have been already asked but no one answer it . Is this due to gnuradio more recent version ?

Any answer would be welcome

 

[lgrangeia]

Hi guys,

I've been playing around with telive (great program), and I've managed to record what appear to be encrypted voice messages.

by opening the raw PCM file created by telive with audacity I get something really close to a good looking voice sample, but it still sounds garbled:

Imgur: The most awesome images on the Internet

I have a few ideas on maybe deducing a valid keystream for this sample. One interesting tidbit on the published TETRA documents:

http://www.etsi.org/deliver/etsi_tr/102500_102599/102512/01.01.01_60/tr_102512v010101p.pdf

"All TETRA encryption algorithms for use with pi/4-DQPSK modulation generate a key stream of up to 432 bits using an
input Cipher-Key and Time Variant Parameter derived from the timing sequence of the TDMA broadcast. "

This means that the keystream is at most 432 bits, and then recycles? For stream ciphers we could deduce parts of the keystream from silences or intelligible sound samples.

Let me know if someone is interested in discussing this further or if this is the right forum.

 

[trashbag]

No, the KSG uses a 29 bit IV (the "Time variant parameter") which changes with every burst. So it's not just the same 432 bit keystream over and over again.

 

[Matof35]

Hello everyone,

I am new to the forum and am very happy to be part of your community.

I have a problem with Telive and the Tetra transit network in my city. I know that the problem has already been exposed on page 71, but I prefer to post it again so that you can answer my question.

I explain my problem: I have been listening to the network of my city in France for several months. I managed to find the network of the relay Tetra of my city thanks to the scan on Telive. There are several relays, but the main one is used by different organizations like the city's cleanliness services, the municipal police or even the transit service.

It is the latter that poses a problem to me. Indeed, there are several actors in this network like the dispatcher, the field agents, the garage and to finish the drivers. When the regulator speaks with the field agents or the garage, there is no problem because they use portable tetra (https://www.hostingpics.net/viewer.php?id=973490eadsstar.png).
It is then possible to listen to the conversation with Telive. On the other hand, when the controller speaks with the bus conductors, it is then possible to hear only the regulator, not the driver. On some conversations, it is possible to hear a small voice, that of the driver, but that is not at all audible. The only time it is possible to hear the driver correctly is when the distress call is triggered. But it is very rare.
Calls between the drivers and the regulator are made by the SAE (Operations Support Service). In other words, it is a device embedded in buses, and connected permanently to the regulator by Tetra. Regulators use an EADS portable, with a remote microphone to communicate between maintenance and field agents. They also use a Funktronic control panel, connected to their computer, on which is installed a transit operating software (Navinéo). It is with this software that he establishes communication between him and the driver of the bus.

In this video showing the backstage of the public transport network in my city, it is possible to see several times the radio stations and the control room: youtu.be/GtZ0ONkfEwg

If you have any answers to my question, do not hesitate to post the answer.

Thank you in advance for your help !

 

[grosminet]

Some french transportation networks are using Simplex /half duplex or full duplex . In some cases, you won't be able to listen to both sides because uplink and downlink are not on the same transmitter .
SAE tetra communications are based on TETRA SDS but not readable with telive software
On many networks all voice and data trafic aren't splited over the all network but only on some cells . Some talkgroups are for the complete network like general annoucement , some only under the bus or metro lines transmitters

 

[Matof35]

Thank you "grosminet" for your answer.
Indeed, I happen to see the SDS messages in the log of Telive. The latter partially decodes the sent messages. I have already tried to listen to the 10MHZ frequency below the main frequency, yet I do not hear anything, there is not a frame. Voice traffic that is sent over the entire network is on the same frequency as individual calls. But then, why is it possible to hear regulators when making an individual call?

 

[grosminet]

Because individual call are DMO in TMO infrastructure .

 

[Matof35]

Ok I understand now

 

[Matof35]

But then, how come I sometimes hear (truly weakly) the voice of the driver in an individual call?

 

[Matof35]

Ok I understand now

But then, how come I sometimes hear (truly weakly) the voice of the driver in an individual call?

 

[CanesFan95]

I thought TETRA systems were encrypted? What is the benefit of decoding TETRA when it's encrypted?

 

[ET-NL]

I thought TETRA systems were encrypted? What is the benefit of decoding TETRA when it's encrypted?

Tetra systems CAN be encrypted, but most systems are just plain Tetra without encryption.

 

[oz1jua]

StrTelive

I have created a GUI program that can start Telive.
If some would like to try out this GUI program, it can be retrieved from the following address: https://github.com/oz1jua/StrTelive

 

[grosminet]

I have created a GUI program that can start Telive.
If some would like to try out this GUI program, it can be retrieved from the following address: https://github.com/oz1jua/StrTelive

What is the purpose of this program ? assuming telive can be run in an easy way .

As I said for years now , the best way to monitor TETRA is to use Funcubepro + +QTHID + telive . You set the exact frequency on QTHID and gain and it is starting immediatly .

We you use an airspy or RTLSDR , we have to set frequency, gain , and most of the time , we have to take many time to ajust settings (and poor level signals) to decode TETRA .

The best way would have to use GQRX or cubicsdr as a front end and send IQ results to telive . I asked to both developpers many years ago , to adapt their IQ output for TETRA but without any success .

 

[oz1jua]

What is the purpose of this program ? assuming telive can be run in an easy way .

As I said for years now , the best way to monitor TETRA is to use Funcubepro + +QTHID + telive . You set the exact frequency on QTHID and gain and it is starting immediatly .

We you use an airspy or RTLSDR , we have to set frequency, gain , and most of the time , we have to take many time to ajust settings (and poor level signals) to decode TETRA .

The best way would have to use GQRX or cubicsdr as a front end and send IQ results to telive . I asked to both developpers many years ago , to adapt their IQ output for TETRA but without any success .

I have never been a fan of Funcubepro. I use AirSpy becouse I have transmitter under 100 meter from my receiver that send with 50 Watt. This can destroy every receiver. But AirSpy run perfect under these condition.
But the main purpose of this program is a simple start Telive Receivers and Tetrad when testing lots of receivers and freq.
In my City in close we have about 50-60 sites with different freq. and different networks. And to create script for starting all this is cumbersome. What I do is to use this program to start Telive with Receivers and then start allready setup GRC compile to pyton code. Below is a Picture of my program.

 

[sq5bpf]

i've been to a radio conference today, and some nice people let me play with their tetra equipment there, and play with status messages.

i've pushed a simple update for osmo-tetra-sq5bpf to parse D-STATUS messages

in the logs this will look like this:
FUNC: DSTATUSDEC SSI:1111 SSI2:2222 STATUS:9876 RX:1
(status 9876 sent from 2222 to 1111, note that i assume that the calling SSI is a simple tetra address)

and in tetra-rx output it will look like this:
CPTI:1 CalledSSI:1111 CallingSSI:2222 CallingEXT:0 Status:9876 (0x2694)

the status messages are unique to the network.

common ones:
0 - Emergency (orange panic button on a motorola handheld radio)
65024 - reply when the called device acknowledges receiving a status message
65028 - reply when the called device doesn't exist (bad SSI etc). motorola shows "destination not found"
65029 - not sure what this is, but also an error message. got this a few times when the message was sent to a wrong address

replies are sent with calling ssi 16777213

now i could make a modification to have the status messages appear also in the telive status window, but i'm not sure if it might produce to much output. could people with busy tetra networks test the patch and see what is the maximum amount of status messages in one minute?


EDIT: other status messages are in this document on page 148: http://aeroflex-cdip.ru/eng/pdf/3900-manual3.pdf