Tagged: TETRA

Wintelive YouTube Demo

Over on YouTube use radiosification has uploaded a video showing the Windows TETRA decoder ‘wintelive’ in action. Wintelive is a Windows port of the popular RTL-SDR compatible Linux based ‘telive’ TETRA decoder. Back in October 2016 we posted about its release and we have a tutorial for telive and the RTL-SDR available here

The install instructions for wintelive are available on the authors webserver.

https://www.youtube.com/watch?v=AiMJbyw8Bi0

TETRA Decoding on Windows with Telive

TETRA is a type of digital voice and trunked radio communications system that stands for “Terrestrial Trunked Radio”. It is used heavily in many parts of the world, except for the USA. Telive is a decoder for TETRA which is compatible with RTL-SDR dongles, and has been around and in use for almost 2 years now. If you have unencrypted TETRA signals available in your area it can be used to listen in on them.

Telive is dependent on GNU Radio, so it is normally installed and used on a Linux system. Previously we wrote a tutorial on it’s installation and use, and other users have also made bootable Linux images of telive available.

However, now a TETRA experimenter by the handle of “cURLy bOi” has released a new prototype of a telive modification that works on Windows systems. It makes use of the GNU Radio for Windows development. The telive Windows file can be downloaded from curly’s webserver. His reademe file shows how to install and use the software and it reads:

This has been put together as lowest-effort configuration
to run telive on Windows system. I have also optimized to process (for example adding the CQPSK block to GRC since the python code in the original telive package is IN FACT some unused part of GNU Radio)

Warning:
———
This package contains pre-compiled binaries that work on my 64-bit system. I have compiled them inside the M-SYS2 package. If you don’t trust me, you can follow the installation guide from telive docs, just be prepared you are going to need a lot of packages for the M-SYS2 (pacman -S gcc automake git wget, etc.)

Install:
———
1) Download GNU Radio for Windows from http://www.gcndevelopment.com/gnuradio/downloads.htm
and install
2) Copy contents of gnuradio_mod to c:\Program Files\GNURadio-3.7\
3) Download and install M-SYS2 from https://sourceforge.net/projects/msys2/ and install
4) Copy contents of msys_root to your M-SYS2 installation directory
5) Download FFmpeg for Windows (64-bit Shared) from https://ffmpeg.zeranoe.com/builds/
and extract everything from bin to usr\bin in your M-SYS2 installation directory
6) In M-SYS2 shell execute “pacman -S socat”
7) Get GNU Radio Companion (GRC) projects from original telive package at
https://github.com/sq5bpf/telive/tree/master/gnuradio-companion
(only udp or xmlrpc, pipes won’t work)
8) Open whatever GRC project you want to use and edit it:
– Delete the link between (all) Fractional Resampler and UDP Sink
– From the modules on the right (ctrl-f to search) drag CQPSK Demod to project
(If you don’t see CQPSK Demod then you have messed up #2)
– Connect Fractional Resampler -> CQPSK Demod -> UDP Sink
– Change UDP Sink Input Type to Float in its properties
– Save

Use:
——
1) Open GRC project of your choice (already with the CQPSK Demod box)
2) Use the Project/Execute to run the project from the GRC
– OR –
If you had headless (without GUI) project, use Project/Generate option
to generate top_block.py file in the GRC project directory.
Then open GNURadio Command Prompt from Start menu, the use this command
c:\Program Files\GNURadio-3.7\gr-python27\python.exe -u c:\path\to\grc\project\top_block.py
This will enhance performance.
3) Open new M-SYS2 shell for every channel in that project and execute
command “receiver1udp X” where X is the number of each channel in GRC project
4) Open new M-SYS2 shell, resize it to 203×60 and execute:
– cd /tetra/bin
– ./rxx OR ./rxx_xmlrpc (if you are using XMLRPC GRC project)
You can edit these files to match your preferences
5) That’s it, should work.

Note that we have not tested this out ourselves yet and can’t guarantee the file safety or that it works, but we have no reason to believe that it wouldn’t be safe or not work.

TETRA Decoding (with telive on Linux)
TETRA Decoding (with telive on Linux)

Kukuruku: A new SDR client that supports RTL-SDR

A new general purpose SDR software package called “Kukuruku” has recently been released. It appears to be a Linux only based client which is based on GNURadio. The authors write that they have several interesting features which we quote below:

Network transparency. Process the data remotely and send to the client only waterfall pixels and filtered narrowband channels instead of the entire SDR baseband. With this, you can use the SDR remotely over WAN.

Multiple demodulators running at once. How the hell can this be missing?

History browsing. It happens to me all the time: I see a new station scrolling on the waterfall. Before I manage to tune to it, it disappears (or at least the callsign is over). I have 8 GB of RAM, so why can’t I store the last minute of the entire SDR baseband for future reference?

Pluggable demodulators. Why is it so much pain to add GSM, Tetra, Tetrapol and other modes to existing software? I just want to provide a binary and have the data piped to stdin.

Squelch sucks. The squelch should not care about absolute signal level, but about level relative to surrounding channels. Additionally, it should have hysteresis and a small buffer, so when it triggers, it correctly replays the beginning of the conversation. Oh, and when recording, the squelch should timestamp the parts of conversation.

Histogram. It is difficult to see clipping on the FFT output. Why don’t we have histogram of samples?

Autotune/AFC. Obvious.

Scanner. Both for automatic demodulating all peaks in the spectrum and for retuning the SDR and finding stations. Even the crappiest rtl-sdr has 2 MHz bandwidth and can retune in 50 ms. This means 1600 channels per second. Compare this with commercial scanners.

At the moment one interesting plugin for Kukuruku is the TETRA plugin. The plugin appears to use tetra-listener and TERAPOL-kit as the demodulators, and simply passes the signal data to them for decoding and audio output.

The installation instructions can be found on the user guide. So far we unfortunately haven’t been able to install and test the software due to several compilation errors occurring, so if anyone tries this out and gets it to work, please post any installation tips in the comments. 

Kukuruku running and demodulating TETRA audio with a plugin.
Kukuruku running and demodulating TETRA audio with a plugin.

A new TETRA voice and multiframe SDS decoder

Recently Marek Sebera of ITDS Consulting wrote in to let us know about two new TETRA decoders that they have released. TETRA is a trunked radio communications system that stands for “Terrestrial Trunked Radio”. It is used heavily in many parts of the world, except for the USA.

The first piece of software released is called TETRA Listener and is from the Brmlab hackerspace in Prague. They write that Tetra-Listener is a new program (based on osmo-tetra) that can decode unencrypted voice and data traffic. They also write that it is very easy to set up and install since it uses Vagrant, which is a system that can be used to automatically set up a VMWare or VirtualBox Virtual Machine that has everything set up and ready to go. The instructions for using the software can then be found in the readme of the main tetra-listener page on GitHub.

The second software they have written is what they believe is the world’s first open source TETRA Multiframe SDS decoder. SDS stands for short data service and is the TETRA equivalent to SMS text messages used on a GSM network. They write that their solution can assemble long multiframe SDS messages.

Previously we showed how unencrypted TETRA messages could be listened to using telive in our tutorial. It is good to see alternative solutions now coming out, and in the future we hope to test this new software out.

TETRA SDS Example
TETRA SDS Example

RTL-SDR Tutorial: Listening to TETRA Radio Channels

TETRA is a trunked radio communications system that stands for “Terrestrial Trunked Radio”. It is used heavily in many parts of the world, except for the USA. Recently, a software program called Tetra Live Monitor (telive) was released on GitHub. This software can be used along with the (patched) Osmo-TETRA software to monitor and listen to unencrypted TETRA communications.

Below we show a tutorial on how to listen to TETRA communications using a RTL-SDR RTL2832U software defined radio. This tutorial is based heavily on the telive_doc.pdf file that is written by the author of telive and included in the telive git download. Please refer to that pdf file for further details on how the software works. We have modified their tutorial slightly to make it a little easier to understand. As this code is still under heavy development if you have trouble please check their PDF file for modifications to the procedures.

Again, we reiterate: This tutorial is not a substitute for a thorough reading of the documentation. If you have trouble setting this software up, please refer to the telive documentation first, before asking any questions. It contains a comprehensive FAQ section which solves most of the common problems. The documentation can be found directly at https://github.com/sq5bpf/telive/raw/master/telive_doc.pdf. There is also a discussion at http://forums.radioreference.com/digital-voice-decoding-software/302347-tetra-decoding.html.

Decoding and Listening to TETRA Tutorial

Most of this tutorial is performed in Linux and we assume that you have some decent Linux experience. We also assume you have some experience with the RTL-SDR dongle and have a decent antenna capable of picking up TETRA signals in your area. If you don’t have a RTL-SDR dongle yet see our Buy RTL-SDR dongles page.

Note: As of October 2016 there is now a Windows port of the Telive decoding software available. This may be an option for you if you prefer to run in Windows. More information here.

First, we will need to find some TETRA signals. The easiest way to do this is to open SDR# or another program like GQRX and look for them. TETRA signals are continuously broadcasting with a bandwidth of around 25 kHz. In most European countries they can be found at 390 – 470 MHz. In some countries they may be found around 850 MHz or 915 – 933 MHz. There may be several TETRA signals grouped in close proximity to one another. See the example images below.

 
A Zoomed in TETRA Signal
A Zoomed in TETRA Signal
 
TETRA Signals Zoomed Out
A Grouping of TETRA Signals Zoomed Out

An example audio clip of a TETRA signal recorded in NFM mode is shown below.

Once you have found some TETRA signals, record their frequencies. Now close SDR#, or whatever software you were using and boot into Linux. In this tutorial we use a 32-bit Ubuntu 14.04 virtual machine running on VMWare Player as our Linux system. Some of the commands may vary if you are using a different system.

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