How to capture GSM traffic

Learn How to capture GSM traffic using GRGSM tool created by Piotr Krysik to capture, transmit and decode GSM packets using SDR.

The gr-gsm project is based on the gsm-receiver written by Piotr Krysik (also the main author of gr-gsm) for the Airprobe project. The aim is to provide set of tools for receiving information transmitted by GSM equipment/devices.

Piotr Krysik

To install grgsm we have two options install it from source or from distro repos. First I will explain how to install it from source

Compile GRGSM from source

One option to install GRGSM is to compile it from source, clone the git repo and create a folder to build the project.

┌──(root💀OffSec)-[~]
└─# git clone https://git.osmocom.org/gr-gsm

┌──(root💀OffSec)-[~]
└─# cd gr-gsm && mkdir build

Enter inside the build folder and execute cmake:

┌──(root💀OffSec)-[~]
└─# cd build
┌──(root💀OffSec)-[~]
└─# cmake ..

Create the settings files for GNURADIO and compile the code:

┌──(root💀OffSec)-[~]
└─# mkdir $HOME/.grc_gnuradio/ $HOME/.gnuradio/

Now its time to compile the code

┌──(root💀OffSec)-[~]
└─# make

Install GRGSM from Repos

┌──(root💀OffSec)-[~]
└─# sudo apt install gr-gsm

GRGSM Tools

grgsm_scanner

-b BAND

How to capture GSM traffic

grgsm_capture

grgsm_livemon

grgsm_trx

grgsm_decode