GSM receiver with gr-gsm and Wireshark » History » Version 3

ROQUE, Damien, 02/21/2015 01:25 AM

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h1. GSM receiver with gr-gsm and Wireshark
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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:
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<pre>
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sudo ./pybombs install gr-gsm
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sudo ldconfig
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</pre>
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In order to use this module with USRP hardware, you should use the following GRC flowgraph.
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!airprobe_uhd.grc.png!
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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:
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<pre>
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sudo wireshark -k -Y '!icmp && gsmtap' -i lo
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</pre>