SOURCEFORGE » RALF

h1. GSM receiver with gr-gsm and Wireshark

In this example, we propose to decode "GSM":http://en.wikipedia.org/wiki/GSM beacons thanks to a module available at https://github.com/ptrkrysik/gr-gsm. As explained in this page, its installation can be performed thanks to PyBombs which should be already installed if you followed our [[UHD and GNURadio installation|installation guide]]. In your PyBombs directory, issue the following instruction:

<pre>

sudo ./pybombs install gr-gsm

sudo ldconfig

</pre>

In order to use this module with USRP hardware, you should use the following GRC flowgraph.

!airprobe_uhd.grc.png!

Once the GRC program is launched and configured on a GSM beacon frequency, decoded data is displayed on standard output as well as on a UDP socket. Wireshark can thus be used to dissect captured frames:

<pre>

sudo wireshark -k -Y '!icmp && gsmtap' -i lo

</pre>